Aire b3 project

B3 SESAR JU PROJECTB3 SESAR JU PROJECTB3 SESAR JU PROJECTB3 SESAR JU PROJECT

–––– Phase 2 Phase 2 Phase 2 Phase 2 ----

Version 4.2 - 15/02/2012- Page i

Phase Two Report



Version 4.2 - 15/02/2012- Page ii

TABLE OF CONTENTSTABLE OF CONTENTSTABLE OF CONTENTSTABLE OF CONTENTS

TABLE OF CONTENTS ................................. ................................................................................. 2

LIST OF FIGURES .......................................................................................................................... 6

LIST OF TABLES .................................... ..................................................................................... 12

EXECUTIVE SUMMARY ............................................................................................................... 13

1. FOREWORD ....................................................................................................................... 1

1.1 ABOUT THE DOCUMENT ................................ .................................................................. 1

1.2 THE AUTHORS ................................................................................................................... 1

1.3 STRUCTURE OF THE DOCUMENT ................................................................................... 1

1.4 GLOSSARY .......................................... .............................................................................. 2

2. INTRODUCTION ................................................................................................................. 3

3. DESCRIPTION OF THE SOLUTION TO LEAD TO THE PROOF-OF -CONCEPT ............... 4

3.1 DESCRIPTION AND PROOF OF CONCEPT ...................................................................... 4 3.1.1 VERTICAL FLIGHT PROFILE – TYPICAL ................................................................................... 4 3.1.2 DESCENT – GENERAL PRINCIPLES ......................................................................................... 6 3.1.3 IMPACT OF NON-ADHERENCE TO THE CALCULATED DESCENT PROFILE ....................... 8 3.1.4 IMPACT ON FUEL-BURN OF A PARTIAL CDO - PROFILE ..................................................... 10 3.1.5 KNOWLEDGE OF DESCENT PATH BY THE ANSP................................................................. 13

3.2 ACHIEVEMENT OF THE PROJECT ........................ ......................................................... 16 3.2.1 THE CDO CHALLENGE ............................................................................................................. 17 3.2.2 EUROCONTROL APPROACH TO CDO ................................................................................... 18 3.2.3 OBJECTIVES OF THE B3 PROJECT ........................................................................................ 18 3.2.4 REFERENCE FOR CDO AT EBBR (BELGOCONTROL & BRUSSELS AIRLINES) ................. 19

3.2.4.1 General ................................................................................................................................ 19 3.2.4.2 Belgocontrol ......................................................................................................................... 21 3.2.4.3 Brussels airlines .................................................................................................................. 22

3.3 THE FLIGHT TRIAL PERIOD ........................... ................................................................. 23 3.3.1 PHASE ONE ............................................................................................................................... 23 3.3.2 PHASE TWO .............................................................................................................................. 23

3.3.2.1 transition into operations ..................................................................................................... 24 3.3.2.2 pace of change .................................................................................................................... 24

4. DATA COLLECTION PROCESS, TOOLS AND ANALYSIS ....... ...................................... 25

4.1 OVERVIEW ....................................................................................................................... 25

4.2 DATA SOURCES ...................................... ........................................................................ 27 4.2.1 NMS (NOISE MONITORING SYSTEM) ..................................................................................... 27 4.2.2 CDO TROUBLE REPORTS ....................................................................................................... 27

4.2.2.1 CDO – trouble reports (Brussels Airlines pilots) .................................................................. 27 4.2.2.2 CDO – trouble reports (ATCOs) .......................................................................................... 27

4.2.3 FLIGHT LISTS WITH INDICATION OF CDO-MARKED FLIGHTS ............................................ 28 4.2.3.1 Marking CDO-approved flights ............................................................................................ 29



Version 4.2 - 15/02/2012- Page iii

4.2.3.2 Extracting Flight data from Eurocat-logfiles for CDO-flights. ............................................... 30 4.2.3.3 Correlate Eurocat-data with REDSTAR-flight data ............................................................. 31 4.2.3.4 Distribute flight lists with indication of CDO-marked flights ................................................. 32

4.2.4 ASTERIX CAT62 RADAR DATA ................................................................................................ 32 4.2.5 FDM-DATA ................................................................................................................................. 33

4.2.5.1 Setting of the Concept ......................................................................................................... 33 4.2.5.2 Technicalities and limiting factors ........................................................................................ 34 4.2.5.3 Extraction of FDM-data – in house development of an algorithm ....................................... 35

4.3 TOOLS .............................................................................................................................. 37 4.3.1 NMS (NOISE MONITORING SYSTEM), SAS AND GIS ............................................................ 37

4.3.1.1 Description of the NMS ........................................................................................................ 37 4.3.1.2 NMS-reports as a reference for airlines and Belgocontrol .................................................. 38 4.3.1.3 NMS-radardata to compare lateral routes for CDO-approved and non-CDO-approved flights using SAS and GIS ................................................................................................... 40

4.3.2 EFICAT ....................................................................................................................................... 40 4.3.2.1 CDO-evaluation by EFICAT ................................................................................................ 40 4.3.2.2 Fuel burn analysis possibilities with EFICAT ....................................................................... 42 4.3.2.3 Radar-data visualization in EFICAT .................................................................................... 43 4.3.2.4 Agreement with Eurocontrol to test the EFICAT tool .......................................................... 45 4.3.2.5 Import of radar data in EFICAT for the B3-project: ............................................................. 45 4.3.2.6 EFICAT Analysis performed for B3-project ......................................................................... 46 4.3.2.7 Export of the EFICAT results to MS Excel for further analysis ............................................ 47

4.3.3 SQL &MS EXCEL FOR THE STATISTICAL ANALYSIS OF CDO-APPROVALS AND OF EFICAT-RESULTS .................................................................................................................................... 48 4.3.4 MS EXCEL FOR DESCENT PROFILE ANALYSIS OF FDM-DATA .......................................... 48

4.3.4.1 Use of FDM-parameters. ..................................................................................................... 48 4.3.4.2 Reference profile construction. ............................................................................................ 49 4.3.4.3 Analysis description. ............................................................................................................ 50

4.3.5 INM (INTEGRATED NOISE MODEL) FOR NOISE CALCULATION ......................................... 55 4.3.5.1 Calculation model ................................................................................................................ 55 4.3.5.2 General calculation method of the INM ............................................................................... 56 4.3.5.3 Method USED to compare the noise impact of CDO and non-CDO approaches ............... 59

4.4 SELECTION OF DATA SAMPLE FOR DETAILED ANALYSIS .... .................................... 63

5. DATA ANALYSIS RESULTS ............................. ............................................................... 65

5.1 SCOPE OF THE TRIALS - 1 JULY 2009 – 31 OCT 2011 ... .............................................. 65 5.1.1 DESCRIPTION ........................................................................................................................... 65 5.1.2 SUMMARY AND CONCLUSION FOR POINT 5.1 ..................................................................... 67

5.2 CDO-MARKED FLIGHTS - 1 JULY 2009 – 31 OCT 2011 .... ............................................. 68 5.2.1 CDO MARKED FLIGHTS PER AIRLINE .................................................................................... 68 5.2.2 EVOLUTION DURING THE TRIAL PERIOD ............................................................................. 70 5.2.3 VARIABILITY FROM DAY TO DAY............................................................................................ 72 5.2.4 VARIABILITY AMONGST THE HOURS OF THE DAY .............................................................. 73 5.2.5 VARIABILITY AMONGST THE WEEKDAYS ............................................................................. 75 5.2.6 COMPARISON FOR RUNWAYS 25R AND 25L ........................................................................ 77 5.2.7 FLIGHT LEVELS AT WHICH CDO IS APPROVED ................................................................... 79 5.2.8 TRACKMILES FROM TOUCHDOWN AFTER CDO APPROVAL ............................................. 81 5.2.9 EFFECT OF THE CHANGE FROM WRITTEN TO CLICKED CDO-MARKS ............................ 83 5.2.10 SUMMARY AND CONCLUSION FOR POINT 5.2 ..................................................................... 85



Version 4.2 - 15/02/2012- Page iv

5.3 CDO-PERFORMANCE (EFICAT-ANALYSIS) – APRIL & MAY 201 1 ............................... 86 5.3.1 CDO-CRITERIA USED ............................................................................................................... 86

5.3.1.1 Parameter Setting ................................................................................................................ 86 5.3.1.2 Classification in four groups of CDO-performance .............................................................. 87 5.3.1.3 Data sample for statistics in section 5.3 .............................................................................. 89

5.3.2 CDO-PERFORMANCE (PROFILES) ......................................................................................... 90 5.3.2.1 All airlines, all runways ........................................................................................................ 90 5.3.2.2 All airlines , runways 25R/L ................................................................................................. 91 5.3.2.3 Marked versus Not Marked for all airlines ........................................................................... 91 5.3.2.4 Marked versus not marked for participating airlines ............................................................ 92 5.3.2.5 Comparison for runway 25 R & 25L .................................................................................... 93

5.3.3 CDO-PERFORMANCE (PROFILES) FOCUS ON BRUSSELS AIRLINES ............................... 94 5.3.4 FUEL AND CO2 ESTIMATIONS WITH EFICAT ........................................................................ 98 5.3.5 FUEL AND CO2 ESTIMATIONS WITH EFICAT COMPARED TO FDM-FUEL DATA ............ 104 5.3.6 SUMMARY AND CONCLUSION FOR POINT 5.3 ................................................................... 106

5.4 RESULTS OF CDO TROUBLE REPORT (ATCOS). ............ ........................................... 108

5.5 RESULTS FROM FDM-ANALYSIS ......................... ........................................................ 109 5.5.1 EXAMPLES. .............................................................................................................................. 109 5.5.2 RECURRENT OBSERVATIONS .............................................................................................. 117 5.5.3 OVERVIEW OF RESULTS. ...................................................................................................... 123

5.6 CALCULATED NOISE IMPACT ........................... ........................................................... 135 5.6.1 NOISE IMPACT CALCULATION – TYPICAL EXAMPLE ........................................................ 135 5.6.2 AREA OF THE LAMAX NOISE CONTOURS .............................................................................. 139

5.6.2.1 Airbus 330-330 analyzed flights ........................................................................................ 139 5.6.2.2 Airbus 319 analyzed flights................................................................................................ 146

5.6.3 LAMAX-NOISE PROFILES .......................................................................................................... 152 5.6.3.1 Airbus 330-330 analyzed flights ........................................................................................ 152 5.6.3.2 Airbus 319 analyzed flights................................................................................................ 157

5.6.4 IMPACT ON LATERAL ROUTES ............................................................................................. 161 5.6.5 CONCLUSION NOISE ANALYSIS ........................................................................................... 164

6. COMMUNICATION PLAN ................................ ............................................................... 165

6.1 IMPLEMENTED COMMUNICATION ACTIONS DURING PHASE 2 .. ............................. 165 6.1.1 BELGOCONTROL .................................................................................................................... 165 6.1.2 BRUSSELS AIRPORT .............................................................................................................. 167 6.1.3 BRUSSELS AIRLINES ............................................................................................................. 167 6.1.4 OTHER ..................................................................................................................................... 168

6.2 PLANNING OF COMMUNICATION ACTIONS AFTER DELIVERY OF PHASE 2 ........... 168

7. THE FUTURE .................................................................................................................. 170

7.1 FROM TRIALS TO IMPLEMENTATION ..................... ..................................................... 170

7.2 PROJECT POINT MERGE BRUSSELS ...................... .................................................... 170 7.2.1 PROJECT OBJECTIVES .......................................................................................................... 170 7.2.2 THE POTENTIAL BENEFITS ................................................................................................... 174

7.2.2.1 For ATC : ........................................................................................................................... 174 7.2.2.2 For the Airlines and Airport Operators : ............................................................................. 174

APPENDICES ............................................................................................................................. 176

APPENDIX 1 - DEFINITION OF FLIGHT PHASES FOR AIRBUS FMS .................................. 177

APPENDIX 2 – DESCENT PROFILE BASICS. .............. ......................................................... 178



Version 4.2 - 15/02/2012- Page v

VERTICAL FLIGHT PROFILE – TYPICAL ............................................................................................. 178 RELATION TO THE SESAR – “BUSINESS TRAJECTORY” ................................................................. 182

The background ................................................................................................................................. 183 Implementing 4D trajectories ............................................................................................................. 183

DESCENT – GENERAL PRINCIPLES ................................................................................................... 184 Mach/CAS descent ............................................................................................................................ 184 Descent speeds – example ............................................................................................................... 186

IMPACT OF NON-ADHERENCE TO THE CALCULATED DESCENT PROFILE .................................. 188 IMPACT ON FUEL-BURN OF A PARTIAL CDO - PROFILE ................................................................. 192 KNOWLEDGE OF DESCENT PATH BY THE ANSP ............................................................................. 195

APPENDIX 3- DESCENT PROFILES FOR AIRBUS A320 AND A3 30 AIRCRAFT ................. 198

APPENDIX 4 – DESCENT SCENARIO – AIRBUS AIRCRAFT. .. ............................................ 199

APPENDIX 5 – AIRBUS A319 - AFM REFERENCE DESCENT PR OFILES. .......................... 203

APPENDIX 6 – AIRBUS A330-300 - AFM REFERENCE DESCEN T PROFILES. ................... 205

APPENDIX 7 -DRAFT CDO PUBLICATION ................. ........................................................... 207 VALIDATION DATE OF PREPARATION ............................................................................................... 207 EBBR AD 2.21 NOISE ABATEMENT PROCEDURES ........................................................................... 207

ARRIVAL PROCEDURES ................................................................................................................. 207 SPEED LIMITATION ......................................................................................................................... 207 EBBR AD 2. 24 CHARTS RELATED TO EBBR ............................................................................... 208



Version 4.2 - 15/02/2012- Page vi

LIST OF FIGURESLIST OF FIGURESLIST OF FIGURESLIST OF FIGURES

Figure 2-1 - Typical vertical profile 4 Figure 2-2 - Simplified descent profile. 7 Figure 2-3 - Location of the "Top-of-Descent" 8 Figure 2-4 - TOD penalties. 9 Figure 2-5 - Airbus A330-300 – M.80/300KT/250KT descent profile and fuel burn. 10 Figure 2-6 - Initiation of a CDO at or below FL150. 11 Figure 2-7 - Example of descent profile and fuel burn below FL150 - Airbus A330-300. 12 Figure 2-8 - Different descent profiles. 13 Figure 2-9 - Descent profiles below FL150 for A330-300. 14 Figure 2-10 - Difference 3 to 4° glide path. 15 Figure 2-11 - Descent optimization. 16 Figure 2-12 - CDO approach. 17 Figure 3-1 - Data Collection scheme legend. 25 Figure 3-2 - Data Collection scheme. 26 Figure 3-3 - CDO Trouble Report. 28 Figure 3-4 - Marked-field on CWP. 29 Figure 3-5 - Marked-field on CWP (2). 30 Figure 3-6 - VPFC. 37 Figure 3-7 - HPFC. 38 Figure 3-8 - Visual detection of a non-CDO (VPFC). 39 Figure 3-9 - Figure 5.9 : Visual detection of a CDO (VPFC). 39 Figure 3-10 - EFICAT Analysis part1. 41 Figure 3-11 - EFICAT Analysis part2 (scrolled to the right). 42 Figure 3-12 - EFICAT – Example of Horizontal Plot. 43 Figure 3-13 - EFICAT - Example of Vertical Plot. 44 Figure 3-14 - EFICAT - Example of Perspective Plot. 45 Figure 3-15 - Reference Descent Profiles. 50 Figure 3-16 - Typical Descent Profile graph. 51 Figure 3-17 - Typical Descent Profile – Time graph. 52 Figure 3-18 - Typical Descent Profile – distance graph. 53 Figure 3-19 - Typical Fuel Burn below FL150 graph. 54 Figure 3-20 - INM 7.0b noise-thrust-distance curves for approach of the Airbus 330-

301 with GE CF6-80 E1A2 engines. 56



Version 4.2 - 15/02/2012- Page vii

Figure 3-21 - Determination of the shortest receiver – ground-track distance during approach. 57

Figure 3-22 - INM 7.0b standard approach profile for the Airbus A330-301 (thrust, speed, altitude). 58

Figure 3-23 - Ground track of an A330 approach on runway 25L at Brussels Airport. 59 Figure 3-24 - Example of a speed profile for an A330 non-CDO approach on Brussels

Airport. 60 Figure 3-25 - Example of an altitude profile for an A330 non-CDO approach on

Brussels Airport. 61 Figure 5-1 - All arrivals at EBBR (1 Jul. 2009 – 31 Oct.2011). 65 Figure 5-2 - All arrivals at EBBR (%) (1 Jul. 2009 31 Oct.2011). 66 Figure 5-3 - Participating airlines, arrivals on RWYs 25R/ (1 Jul. 2009- 31 Oct.2011). 67 Figure 5-4 - Share of CDO-marked flights for the 5 participating airlines (arrivals RWY

25R/L). 68 Figure 5-5 - Share of CDO-marked flights for Brussels Airlines (arrivals RWY 25R/L). 69 Figure 5-6 - Share of CDO-marked flights for Jetairfly (arrivals RWY 25R/L). 69 Figure 5-7 - Share of CDO-marked flights for Thomas Cook (arrivals RWY 25R/L). 69 Figure 5-8 - Share of CDO-marked flights for DHL (arrivals RWY 25R/L). 70 Figure 5-9 - Share of CDO-marked flights for Singapore Airlines Cargo (arrivals

25R/L). 70 Figure 5-10 - Evolution of the number of CDO-marked arrivals. 71 Figure 5-11 - Evolution of the percentage of CDO-marked arrivals. 71 Figure 5-12 - Total amount of arrivals (participating airlines on RWY 25R/L;

Oct.2011). 72 Figure 5-13 - Number of CDO-marked arrivals per day (Oct.2011). 73 Figure 5-14 - Percentage of CDO marked arrivals per day (Oct.2011). 73 Figure 5-15 - Average amount of arrivals per hour (participating airlines on RWY

25R/L; Jan. -> Oct.2011). 74 Figure 5-16 - Average amount of CDO-marked arrivals per hour (Jan. -> Oct.2011). 74 Figure 5-17 - Average % of CDO-marked arrivals per hour (Jan. -> Oct.2011). 75 Figure 5-18 - Average number of arrivals per weekday (participating airlines on RWY

25R/L; first 10 months of 2011). 76 Figure 5-19 - Average number of CDO marked arrivals per weekday (participating

airlines first 10 months of 2011). 76 Figure 5-20 - Percentage of CDO marked arrivals per weekday (participating airlines

first 10 months of 2011). 77 Figure 5-21 - Average number of arrivals for RWYs 25R & 25L (participating airlines;

first 10 months of 2011). 78 Figure 5-22 - Average number of CDO marked arrivals for RWYs 25R & 25L



Version 4.2 - 15/02/2012- Page viii

(participating airlines first 10 months of 2011). 78 Figure 5-23 - Percentages of CDO marked arrivals for RWYs 25R & 25L

(participating airlines first 10 months of 2011). 79 Figure 5-24 - Cumulative distribution of flight levels for CDO-marked arrivals 79 Figure 5-25 - Distribution of flight levels for CDO-marked arrivals (1 Jul.2009 -31

Oct.2011). 80 Figure 5-26 - Evolution of the average FL at the moment arrivals are marked CDO. 81 Figure 5-27 - Cumulative distribution of distance from touchdown after CDO-mark (1

Jul.2009 -31 Oct.2011). 81 Figure 5-28 - Distribution of distance from touchdown after CDO-mark (1 Jul.2009 -

31 Oct.2011). 82 Figure 5-29 - Evolution of the average distance from touchdown after CDO-approval. 82 Figure 5-30 - Effect of switching to marking of flights on the CWP for flight levels . 84 Figure 5-31 - Effect of switching to marking of flights on the CWP for distance from

touchdown. 85 Figure 5-32 - Parameters set in EFICAT to analyse radardata. 87 Figure 5-33 - Examples for “No CDO”. 88 Figure 5-34 - Examples for “CDO FL60”. 88 Figure 5-35 - Example for “CDO FL80”. 89 Figure 5-36 - Examples for “CDO FL100”. 89 Figure 5-37 - CDO estimation by EFICAT, all arrivals, all runways. 90 Figure 5-38 - CDO estimation by EFICAT, all arrivals, only runways 25R/L. 91 Figure 5-39 - Comparison of CDO-performance estimated by EFICAT for marked

flights from participating airlines and not marked flights for all airlines. 92 Figure 5-40 - Comparison of CDO-performance estimated by EFICAT for marked

flights from participating airlines with not marked flights for all airlines. 93 Figure 5-41 - Comparison of CDO-performance estimated by EFICAT for Runways

25R and 25L. 93 Figure 5-42 - EFICAT CDO estimation in absolute values – all runways, all arrivals

with BEL-callsign. 94 Figure 5-43 - Number of marked BEL-arrivals per aircraft type in the April-May 2011

dataset analysed with EFICAT. 95 Figure 5-44 - CDO-performance per aircraft type estimated by EFICAT for Brussels

Airlines arrivals on all runways. 96 Figure 5-45 - CDO-performance per aircraft type estimated by EFICAT for Brussels

Airlines arrivals on runways 25R and 25L. 97 Figure 5-46 - Comparision of CDO-performance estimated by EFICAT for marked and

not marked arrivals - per aircraft type for Brussels Airlines arrivals on runways 25R and 25L. 98



Version 4.2 - 15/02/2012- Page ix

Figure 5-47 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for all participating airlines. 99

Figure 5-48 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for all participating airlines. 100

Figure 5-49 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines. 101

Figure 5-50 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines. 102

Figure 5-51 - Average percentage difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines. 103

Figure 5-52 - Average percentage difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines. 104

Figure 5-53 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 319. 105

Figure 5-54 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 330. 106

Figure 4-13 - Airbus A330-300 – Early descent with several level-off parts. 109 Figure 4-14 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn. 110 Figure 4-15 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn

low altitude. 110 Figure 4-16 - Airbus A330-300 – Descent initiated slightly before the reference profile

TOD. 111 Figure 4-17 - Airbus A330-300 – Descent initiated slightly before the reference profile

TOD - Fuel Burn. 112 Figure 4-18 - Airbus A330-300 – Descent initiated slightly before the reference profile

TOD - Fuel Burn low altitude. 112 Figure 4-19 - Airbus A330-300 – Adherence to reference profile and speed schedule. 113 Figure 4-20 - Airbus A330-300 – Adherence to reference profile and speed schedule-

Fuel Burn. 114 Figure 4-21 - Airbus A330-300 – Descent above the reference profile. 115 Figure 4-22 - Airbus A330-300 – Descent above the reference profile – Fuel Burn. 116 Figure 4-23 - Airbus A330-300 – Descent above the reference profile – Fuel Burn Low

Altitude. 116 Figure 4-24 - Airbus A319 – FCOM Descent Profile. 117 Figure 4-25 - Airbus A319 – FCOM versus FMGS profiles. 118 Figure 4-26 - Airbus A319 – below profile. 120 Figure 4-27 - Airbus 330 – below profile. 120 Figure 4-28 - Airbus 319 – use of speedbrake profile. 121 Figure 4-29 - Airbus 319 – high speed below 10.000ft profile. 122



Version 4.2 - 15/02/2012- Page x

Figure 4-30 - Airbus 319 – high speed below 10.000ft profile (2). 122 Figure 4-31 - Airbus A330-300 arrival ref. A333_22: altitude and true air speed (TAS). 136 Figure 4-32 - Airbus A330-300 arrival ref. A333_22: calculated CNT per engine. 137 Figure 4-33 - Airbus A330-300 arrival ref. A333_22: LAmax noise contours of 60 (red

line), 65 (orange line), 70 (blue line) and 75 (green line) dB(A). 138 Figure 4-34 - Area of the LAmax noise contour of 60 dB(A) for the Airbus A330-300

analyzed flights. 140 Figure 4-35 - Airbus A330-300 analyzed flights: LAmax noise contours of 60, 65, 70

and 75 dB(A). 141 Figure 4-36 - A333_01 (NON MARKED, NO CDO (EFICAT)). 142 Figure 4-37 - A333_06 (NON MARKED, CDO (EFICAT)). 143 Figure 4-38 - A333_08 (NON MARKED, CDO (EFICAT)). 144 Figure 4-39 - A333_22 (MARKED, NON CDO (EFICAT)). 145 Figure 4-40 - Area of the LAmax noise contour of 50 dB(A) for the Airbus A319

analyzed flights. 146 Figure 4-41 - Airbus A319 analyzed flights: LAmax noise contours of 50, 55, 60 and

65 dB(A). 147 Figure 4-42 - A319_15 (MARKED, CDO (EFICAT)). 148 Figure 4-43 - A319_16 (NON MARKED, NON CDO (EFICAT)). 149 Figure 4-44 - A319_19 (MARKED, NON CDO (EFICAT). 150 Figure 4-45 - A319_26 (NOT MARKED, CDO (EFICAT)). 151 Figure 4-46 - Airbus A330-300 analyzed flights: LAmax noise profile under the flight

track. 153 Figure 4-47 - Airbus A330-300 analyzed flights: average LAmax noise difference in

the zone 10 – 25 NM to landing compared to 3° - idl e thrust profile straight under the flight track. 154

Figure 4-48 - Airbus A330-300 analyzed flights: LAmax noise profile 0.5 NM excentrical from the flight track. 155

Figure 4-49 - Airbus A330-300 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idl e thrust profile at 0.5 NM excentrical from the flight track. 156

Figure 4-50 - Airbus A319 analyzed flights: LAmax noise profile under the flight track. 157 Figure 4-51 - Airbus A319 analyzed flights: average LAmax noise difference in the

zone 10 – 25 NM to landing compared to 3° - idle th rust profile straight under the flight track. 158

Figure 4-52 - Airbus A319 analyzed flights: LAmax noise profile 0.5 NM excentrical from the flight track. 160

Figure 4-53 - Airbus A319 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile at 0.5 NM excentrical from the flight track. 161



Version 4.2 - 15/02/2012- Page xi

Figure 4-54 - Visualization of ground tracks on runway 25R. 162 Figure 4-55 - Visualization of ground tracks on runway 25L. 163 Figure 6-1 - Point Merge System for Arrivals RWY25 Left. 173



Version 4.2 - 15/02/2012- Page xii

LIST OF TABLESLIST OF TABLESLIST OF TABLESLIST OF TABLES

Table 3-1 – Example - Main fields for Marked CDO-flights extracted from Eurocat log files. .31

Table 3-2 - Use of recorded data items. ...............................................................................49

Table 4-1 - Airbus A319 – Overview of all flights – Fuel Burn. ............................................ 125

Table 4-2 - Airbus A319 – Overview of all flights with CDO-approval – Fuel Burn. ............. 125

Table 4-3 - Airbus A319 – Overview of all flights without CDO-approval - Fuel Burn. ......... 125

Table 4-4 - Airbus A333 – Overview of all flights - Fuel Burn. ............................................. 126

Table 4-5 - Airbus A333 – Overview of all flights without CDO-approval - Fuel Burn. ......... 127

Table 4-6 - Airbus A333 – Overview of all flights without CDO-approval – Fuel Burn. ........ 127

Table 4-7 - Overview of all analyzed flights - Airbus A319. ................................................. 129

Table 4-8 - Overview of all analyzed flights with CDO-approval - Airbus A319. .................. 130

Table 4-9 - Overview of all analyzed flights without CDO-approval - Airbus A319. ............. 131

Table 4-10 - Overview of all analyzed flights - Airbus A333. ............................................... 132

Table 4-11 - Overview of all analyzed flights with CDO-approval - Airbus A333. ................ 133

Table 4-12 - Overview of all analyzed flights without CDO-approval - Airbus A319. ........... 134

Table 0-1 - Flight Phases - Airbus FMS. ............................................................................. 177

Table 0-2 - Descent profiles - Airbus A320. ........................................................................ 190

Table 0-3 - Descent profiles - Airbus A330. ........................................................................ 190

Table 0-4 - Impact of anti-ice and temperature - Airbus A320. ............................................ 191

Table 0-5 - Impact of anti-ice and temperature - Airbus A330. ............................................ 191



Version 4.2 - 15/02/2012- Page xiii

EXECUTIVE SUMMARYEXECUTIVE SUMMARYEXECUTIVE SUMMARYEXECUTIVE SUMMARY

The B3-projectwas performed by a consortium, consisting of an airline (Brussels Airlines), an air navigation service provider (Belgocontrol) and an airport operator (The Brussels Airport Company). Besides the B3-parners also Jetairfly, Thomas Cook, DHL, Singapore Airlines Cargo participated in the CDO-trials.

This project was conducted within the scope of the AIRE-initiative (Atlantic Interoperability Initiative to Reduce Emissions), managed and financed in Europe by the SESAR Joint Undertaken.

The B3-project aimed to perform and evaluate partial continuous descent flight trials in a complex radar vectoring environment.Main objectives of the trials were to test the operational concept and to quantify the fuel, CO2 and noise benefits, and this in a close cooperation ofthe three B3 partners.

The applied concept is that approach controllers continue to radar-vector the approaching aircraft to the ILS-interception (no change), regularly provide an estimated of the remaining distance to touchdown (lateral guidance); and allow the aircraft to descend continuously when the traffic situation allows for it (vertical liberty).Appropriate consecutive descent levels are given to ensure vertical separation and to keep the aircraft in controlled airspace.

The pilot will then optimize the approachin order to descend via a continuous vertical profile and using minimum engine thrust.The trials were performed for approaches into Brussels Airport, starting below FL150.

The CDO-trials in the context of the B3-project were performed and analysed for a period of 10 months, starting January 1st, 2011and until October 30th, 2011.During this period, for not less than 3.094 flightsCDO was activily facilitated.

The B3-project demonstrated that for Airbus 319 aircraft, an average 50 kg of fuel and 160 kg of CO2 was gained for CDO-facilitated flights below FL150, compared to not-CDO-facilitated flights.For Airbus A330-300 aircraft, the average amount of fuel saved was 100 kg, corresponding to 315 kg of CO2on similar descents. The project was able to demonstrate



Version 4.2 - 15/02/2012- Page xiv

that, even in an operating environment not really suited for the conduct of CDO, substantial gains could be achieved.

In order to study possible noise effects associated with CDO facilitation, noise modeling starting from operational flight data was performed. Significant gains on the noise impact on the ground in the distance range between 10 and 25 nautical miles from touchdown are obtained: in this area (before ILS-capture) the maximum noise level (LAmax) shows an average reduction of 2 dB(A) for Airbus 319 and 3 dB(A) for Airbus 333 between CDO-facilitated and not-CDO-facilitated flights.

The main issues that needed to be solved in the project were the fact that optimum performance not only depends on aircraft type but also on airline policy, actual aircraft weight, temperature and wind and starting position and therefore are only known on board of the aircraft and not by the controlling Air Traffic Controllers.

As known from the start of the project, CDO is only possible in conditions with low traffic, arriving well separated in time and space, this in order to allow the pilot to optimize the vertical approach path while ATC can guaranteethe required separation between individual aircraft.The trial showed that for about 9% of the approaches performed bythe participating airlines, a CDO was facilitated.

The trials proved to be successful and the aim is to firmly implement the trialled operational concept, always taking into account that it will remain only possible when the traffic allows for it.

Although an ICAO CDO-manual is available since 2010, there still remains work to be done for international standardisation of the facilitation of CDO in a radar vectoring environment. Awaiting this standardisation, it is important to be clear and concise in the development and publication of local CDO procedures.



Version 4.2 - 15/02/2012 - Page 1

1.1.1.1. FOREWORDFOREWORDFOREWORDFOREWORD

1.11.11.11.1 ABOUT THE DOCUMENTABOUT THE DOCUMENTABOUT THE DOCUMENTABOUT THE DOCUMENT

This document provides a detailed description of the activities, proceedings and results of the Phase 2 of the B3-project, conducted within the scope of the AIRE-initiative (AtlanticInteroperability Initiative to Reduce Emissions), managed and financed in Europe by the SESAR Joint Undertaken.

The reader is invited to consult the Phase 1 Report of the same project in order to better understand the context, obectives and project organization.

1.21.21.21.2 THE AUTHORSTHE AUTHORSTHE AUTHORSTHE AUTHORS

This document has been developed and compiled as a joint effort by key project representatives of the three involved partners in this project.

1.31.31.31.3 STRUCTURE OF THE DOCSTRUCTURE OF THE DOCSTRUCTURE OF THE DOCSTRUCTURE OF THE DOCUMENTUMENTUMENTUMENT

This document has been structured as follows:

Executive Summary - gives a management overview of the content and main issues of thestrategy.

Foreword - describes the purpose of the document, its authors and its structure.

Introduction – provides an introduction to the project and the report.

Description of the solution - provides the context necessary in order to understand the project, its challenges and its objectives.

Data collection process - describes the process, the used tools and the various analysis activities performed throughout the project.

Data analysis results – lists and discusses the detailed results of the various analysis, and provides the overall results and conclusions.

Annexes - provide additional background information.



Version 4.2 - 15/02/2012 - Page 2

1.41.41.41.4 GLOSSARYGLOSSARYGLOSSARYGLOSSARY

APR: Automatic Position Report ATA: Actual Time of Arrival ATCo: Air Traffic Controller CAS: Calibrated Air Speed CCO: Continuous Climb Operations CDO: Continuous Descent Operations CWP: Controller Working Position DGE: Directorate General Equipment EFICAT: Eurocontrol Flight Information Consistency Analysis Tool FDM: Flight Data Monitoring FL: Flight Level FMC: Flight Management Computer FMGS: Flight Management Guidance System GIS: Geographical Information System HPFC: Horizontal Projected Flight Curve IAS: Indicated Air Speed INM: Integrated Noise Model LRC: Long Range Cruise MRC: Maximum Range Cruise ND: Navigation Display NM: Nautical Miles NMS: Noise Monitoring system PFD: Primary Flight Display SAS: Statistical Analysis Software STAR: Standard Arrival Route TAS: True Air Speed VPFC: Vertical Projected Flight Curve



Version 4.2 - 15/02/2012 - Page 3

2.2.2.2. INTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTION

The B3 project aimed to perform and analyse partial continuous descent flight trials in a complex radar vectoring environment.

The B3 consortium was built with an airline (Brussels Airlines), an ANSP (Belgocontrol) and an airport operator (The Brussels Airport Company), all bringing their own expertice, data and tools into the project. Besides the B3-partners other airlines participating in the CDO-trials are Jetairfly, Thomas Cook, DHL, and Singapore Airlines Cargo.

The trials are performed for arrivals to EBBR in one of the most complex airspaces of Europe. Therefore, rather than to trial CDOs from top of descent for a few individual flights, the operational concept of the B3-project aimed to improve the CDO quality for an as large as possible number of flights in the approach part of the descent. In total 3094 CDO trials were performed in a period of 10 months starting from 1/1/2011 until 30/10/2011.

The main objectives of the trials were to test and optimize the operational concept and to quantify the fuel, CO2 and noise benefits.

These objectives were obtained through a constructive and open collaboration between the partners and an extensive deployment of data and tools. Developments were made to generate a database with CDO-approved flights, a beta version of the Eurocontrol EFICAT CDO-analysis tool was tested, FDM-data were extracted and analysed and a method was developed to feed the INM-tool with FDM-data to calculate the noise impact. Also in the course of the project information on marked flights was exchanged continuously among the different partners.

Through this report, the B3-team is happy to share its results with the wider aviation community.



Version 4.2 - 15/02/2012 - Page 4

3.3.3.3. DESCRIPTION OF THE SDESCRIPTION OF THE SDESCRIPTION OF THE SDESCRIPTION OF THE SOLUTION TO LEAD TO TOLUTION TO LEAD TO TOLUTION TO LEAD TO TOLUTION TO LEAD TO THE HE HE HE

PROOFPROOFPROOFPROOF----OFOFOFOF----CONCEPTCONCEPTCONCEPTCONCEPT

3.13.13.13.1 DESCRIPTION AND PROODESCRIPTION AND PROODESCRIPTION AND PROODESCRIPTION AND PROOF OF CONCEPTF OF CONCEPTF OF CONCEPTF OF CONCEPT

In this section we briefly provide the basic principles governing the descent phase of flights performed by modern jet transport aircraft. For a more comprehensive description of descent operations, we invite the reader to consult the Appendixes to this report.

3.1.13.1.13.1.13.1.1 VERTICAL FLIGHT PROFVERTICAL FLIGHT PROFVERTICAL FLIGHT PROFVERTICAL FLIGHT PROFILE ILE ILE ILE –––– TYPICALTYPICALTYPICALTYPICAL

A typical flight profile consists of: 1. A lateral profile 2. A vertical profile

In our B3 concept, we focussed on the vertical profile of thedescent phase of the flight.

Figure 3-1 - Typical vertical profile

The descent phase starts at the top-of-descent (TOD) point, which is typically less than 200NM from destination. Generally, the engine thrust will be set to idle. Initially, the rate-of descent will be adjusted to achieve a descent Mach; below the crossover altitude, in an



Version 4.2 - 15/02/2012 - Page 5

unconstrained situation, the rate-of-descent will be adjusted to adhere to a descent IAS. Airspace constraints may limit the selected speed, typically below a designated altitude and/or at a waypoint. Ideally, no intermediate level-off is desired (implicit Continuous Descent Operation – CDO).

The approach phase starts when the approach deceleration point is passed. The deceleration point is computed backwards from the landing point based on optimized flap/slat configuration changes, altitude/speed constraints and flight path.

For each phase of flight, the aircraft operator may define/calculate an “ideal” speed. Application of all these “ideal” speeds will result in an “ideal” flight profile for the aircraft operator.

The “ideal” profile is intended to achieve an optimization of the direct operating cost for a given flight. It may be observed that an operator may deviate from its own “ideal” profile in order to cope with other specific operating/economic conditions.

Many parameters do influence the calculated speeds. Hence, even for the same aircraft operator on the same type of aircraft, these speeds may be different for each flight (e.g. due to a different mass of the aircraft)!

It should be emphasized that the “ideal” profile will NOT necessarily result in the optimum fuel usage! Generally, a trade-off is made between the fuel-related cost (CF) and the time-related cost (CT).

The ratio between both cost factors is commonly called the Cost Index (CI).

Fuel

TimeI C

CC =

The Cost Index is an airline depending variable introduced in the Flight Management Computer (FMC) to optimize performance calculations including Mach and step climb optimization.

The cost index effectively provides a flexible tool to control fuel burn and trip time.Knowledge of the airline cost structure and operating priorities is essential when aiming to optimize cost by trading increased trip fuel for reduced trip time or vice-versa.

As a result, application of different cost index values will lead to different locations for the top-of-climb and top-of-descent points, and fuel burn in the various phases of flight will differ as well. However, note that an operator will strive towards the most economical solution from gate-to-gate which means that he is not primarily interested in the individual figures for each flight phase.

‘Flight efficiency’ may be seen as the degree to which the actually flown flight profile will adhere to the ‘ideally’ planned profile. Each deviation from this profile (theoretically, at least!) will result in a cost penalty.



Version 4.2 - 15/02/2012 - Page 6

Once a value for the cost index has been determined by the operator for execution of one or moreflights, the resulting profile may be called the “airspace user’s preferred trajectory”. This is the starting point for the “business trajectory” philosophy as used by SESAR.

3.1.23.1.23.1.23.1.2 DESCENT DESCENT DESCENT DESCENT –––– GENERAL PRINCIPLESGENERAL PRINCIPLESGENERAL PRINCIPLESGENERAL PRINCIPLES

Descending a (transport) aircraft from its cruising level down to the landing runway of the destination airport is a matter of “energy sharing”.

For commercial jet operations, a so-called “Mach/CAS Descent” is usually flown.

Mach/CAS descents employ a descent speed profile characterized by a constant Mach segment (above the ‘crossover altitude’ – ca. FL290) followed by a constant calibrated airspeed (CAS)1 segment, performed at idle thrust for maximum fuel efficiency. Mach/CAS descent schedules are typically described in aircraft operating manuals.

The Mach/CAS speeds are adjusted to yield optimum fuel efficiency, time efficiency, or (usually) a combination of the two. Airline policies may recommend selected Mach/CAS schedules to suit their specific operational and economic conditions.

Below FL100, the ‘ideal’ descent profile may be ‘spoiled’ by altitude/speed constraints imposed by the flown STAR2 and/or terminal airspace regulations.

Ideally, no intermediate level off between top-of-descent and capture of the glide path signal is planned: a Continuous Descent Operation (CDO) at a defined

speed , performed in idle thrust conditions is the preferred option.

1 The CAS is the corrected IAS (Indicated Air Speed) as used by the pilot. 2 STAR = Standard Arrival Route.

The “solution” proposed in the B3-project consisted in applying partial CDO’s to the maximum extent possible, allowing the aircraft operator to fly as close as possible to its preferred vertical trajectory during a large part of the descent phaseof flight in a dense and complex radar-vectoring environment. The “data collection process” was aimed at finding out how successful this could be done: how well could the “airspace user’s preferred trajectory” be achieved/approached in the descent phase of flight?



Version 4.2 - 15/02/2012 - Page 7

Figure 3-2 - Simplified descent profile.

Figure 3-2shows a simplified descent profile with various Mach/CAS followed by a standard IAS to final. The location of the Top-Of-Descent (TOD) point is calculated, taking into account:

o The preferred Mach/CAS speed schedule. o The predicted wind profile between cruise altitude and ground level at the destination

airport. o The estimated landing mass of the aircraft. o Deceleration distance to comply with airspace constraints (i.e. max. 250kt IAS below

FL100). o Final approach deceleration distance.

Note that the descent is performed at idle thrust. Adverse weather conditions may impose a higher than normal idle thrust setting, resulting in a more distant TOD location



Version 4.2 - 15/02/2012 - Page 8

3.1.33.1.33.1.33.1.3 IMPACT OF NONIMPACT OF NONIMPACT OF NONIMPACT OF NON----ADHERENCE TO THE ADHERENCE TO THE ADHERENCE TO THE ADHERENCE TO THE CALCULATED DESCENT CALCULATED DESCENT CALCULATED DESCENT CALCULATED DESCENT

PROFILEPROFILEPROFILEPROFILE

The location of the TOD-point is highly dependent (amongst other parameters) of the desired speed at which the descent is expected to be flown. The desired speed most likely will be the result of a cost calculation, using the appropriate cost index value for the aircraft operator and the subject flight.

Figure 3-3 - Location of the "Top-of-Descent"

The ‘optimum’ or ‘ideal’ descent can only be achieved when an unconstrained descent may be flown, starting at the calculated top-of-descent, flying at the preferred speed (indicated as “ECON-speed in Figure 3-3), down to the landing runway. As soon as deviations against this descent path happen, cost penalties will occur:

1. Descents performed ‘below’ the intended descent path will result in a time penalty if flown at idle thrust. If thrust is used in such a descent, either during



Version 4.2 - 15/02/2012 - Page 9

a level-off portion and/or in order to maintain the desired speed, more fuel than anticipated will be burned.

This situation may happen when the flight is requested to descent before having reached the optimum TOD-point.

2. Descents performed ‘above’ the intended descent path will inevitably result in a fuel penalty due to the fuel burned during the extra level segment(s), executed either at cruise altitude, or at any other intermediate altitude.

This situation will occur when the flight is requested to maintain the cruise altitude beyond the optimum TOD-point.

It is important to realize that the incurred penalty is not related to the descent phase of the flight, but to the direct operating cost of the entire flight. Looking at the descent phase of the flight only, may lead to erroneous conclusions!

Figure 3-4 - TOD penalties.

We notice that the higher the cost index:

� the steeper the descent path (the higher the speed); � the shorter the descent distance,the later the top of descent (TOD) point.

As for the climb, descent performance is a function of the cost index; indeed, the higher the cost index, the higher the descent speed. But contrary to the climb, the aircraft gross weight and the TOD flight level appear to have a negligible effect on the descent speedcomputation.



Version 4.2 - 15/02/2012 - Page 10

Values for time, distance, Mach/CAS, fuel consumption do vary much with flight conditions such asTOD flight level temperature and wind, but are less variable with respect to gross weight. Similar to the climb, delta values with regard to time and distance are largely the same whatever the initial flight conditions.

In addition, usually, the wind model accounted for by the FMS in its speed/Mach calculationresults:

� from current position up to 150 NM ahead: actual encountered wind, � further up, a wind evolving linearly towards the wind inserted by the pilot into the FMS

at that flight level. The nominal flight path (i.e. TOD-point) should not be affected if the wind-corrected speed/Mach is applied.

3.1.43.1.43.1.43.1.4 IMPACT ON FUELIMPACT ON FUELIMPACT ON FUELIMPACT ON FUEL----BURN OF A PARTIAL CDBURN OF A PARTIAL CDBURN OF A PARTIAL CDBURN OF A PARTIAL CDO O O O ---- PROFILEPROFILEPROFILEPROFILE

The optimum solution for descent consists in the execution of a continuous descent in idle thrust at the desired speed. Figure 3-5shows a typical (optimum) descent profile and fuel burn figures for the Airbus A330-300.

Any change to this descent profile will result, as seen in the previous section, in a cost and/or fuelpenalty. The fuel burn line represents the optimum achievable for descent.

Figure 3-5 - Airbus A330-300 – M.80/300KT/250KT des cent profile and fuel burn.



Version 4.2 - 15/02/2012 - Page 11

The trial aimed to evaluate the gains obtained by flying part of the descent profile in CDO-mode. TheCDO-part typically began at altitudes between FL60 and FL150. When the CDO-clearance is issued (see Figure 3-6), the subject aircraft was either:

1) Below the intended descent profile:

The aircraft started to descend too early, or descended at higher descent rate than anticipated. Most likely, a level portion of flight was executed below cruise level, resulting in some extra fuel burn. If not, a portion of the descent was flown in idle at a lower speed, resulting in a time penalty.

2) On the intended descent profile:

Either the aircraft performed an ‘ideal’ descent, or found itself on the ideal descent path after a portion of level flight. Therefore, even in this case, a fuel penalty versus the optimum descent path cannot be excluded.

3) Above the intended descent profile:

The aircraft started too late its descent, or found itself above the ideal descent path after a portion of level flight. Clearly, more fuel than anticipated was burned or more time was spent than anticipated.

Clearly, possible gains in fuel burn achieved through the execution of a partial CDO, was biased by extra fuel burn or extra flight time, achieved earlier in the descent phase of flight. Stated differently, the overall fuel burn figure of the flight was dependent of the flown profile before issuance of the CDO clearance.

Figure 3-6 - Initiation of a CDO at or below FL150.

If a continuous descent is initiated at FL150 or below, it is clear that the fuel burn during that phase of flight will be proportional to its duration. The shortest duration will be achieved by



Version 4.2 - 15/02/2012 - Page 12

aircraft, which are at high speed above their ideal descent path when the CDO-clearance is issued, because they will have to descent faster. Hence their fuel burn will seem optimal, when compared to flights on or below the ideal profile

Figure 3-7 - Example of descent profile and fuel bu rn below FL150 - Airbus A330-300.

Figure 3-7shows a typical descent profile flown by an Airbus A330-300 aircraft below FL150. The vertical profile is shown by the dark blue line, while the thin purple line shows the FCOM-suggested profile. The magenta illustrates the throttle activity: virtually ‘idle’ during the whole descent until capture of the glideslope below 3.000 ft. This results in a fuel burn figure (cyan line), which is significantly better than the fuel burn figure given by the FCOM (yellow line). The difference is explained by the fact that the aircraft was flying much faster than normal, resulting in a shorter duration of this phase of flight, and a corresponding fuel “saving” versus the standard. The fact that the aircraft was above its profile at high speed, however, indicated that most likely, extra fuel was burned in the flight phases before passing FL150 in descent.

This simple example clearly demonstrates that monitoring of the fuel burn during the CDO-portion could obviously lead to wrong conclusions in many cases. Therefore, in the B3-project,we monitored the fuel burn from TOD until GS-interception. As a consequence however, it was virtually impossible to establish one (or more) baselines.

In this project, comparisons were made between declared CDO-flights and other flights, based on an initial assessment of the descent profiles, starting at TOD. Assessment of the profiles was done using the Eurocontrol Eficat-tool; detailed analysis of the fuel burn figures and engine throttle ‘activity’ relied on FOQA-data of the subject flights.



Version 4.2 - 15/02/2012 - Page 13

3.1.53.1.53.1.53.1.5 KNOWLEDGE OF DESCENTKNOWLEDGE OF DESCENTKNOWLEDGE OF DESCENTKNOWLEDGE OF DESCENT PATH BY THE ANSPPATH BY THE ANSPPATH BY THE ANSPPATH BY THE ANSP

For the application of CDOs as intended in this program, ATS needed to acquire knowledge about what may be “expected” or is “feasible” for (at least) each aircraft type participating in the CDO-trials.

The next figure shows, for a given aircraft type, a “nominal” descent profile and the extreme cases, taking into consideration possible variations of all parameters which have an impact on the overall descent profile.

Figure 3-8 - Different descent profiles.

The ‘extreme’ cases define the window or “entry gate” in which the aircraft are expected to arrive, when performing its preferred (or ‘ideal’) descent. In the shown example, the “entry gate” at FL100 is situated between 27 and 45 NM before touchdown. The subject aircraft will need to be at FL100 in descent in order to be able to execute the remaining part of the descent at its preferred speed.

Ideally, for the purpose of definition of the “entry gate” at various altitudes, descent profile data (speed, time, fuel, distance to touchdown [or xxx ft] at several altitudes) were to be obtained for (not exhaustive list):



Version 4.2 - 15/02/2012 - Page 14

• “Light” aircraft – Cost index 0.

• “Heavy” aircraft – Cost index 0.

• “Light” aircraft – High cost index.

• “Heavy” aircraft – High cost index.

• Same profiles for high and low temperature?

• Same profiles for 50kt headwind/tailwind.

• ??? Unfortunately, Brussels Airlines did not have the means to calculate the required data for the participating aircraft types. A simplified method was used instead. For each aircraft type participating to the trial, a survey of descent profile data, as published in the Flight Crew Operating Handbook, was made. In addition, the descent profile as provided by the Eurocontrol developed BADA-model, was reviewed as well. Figure 3-9shows the descent profiles below FL150 for the Airbus A330-300 aircraft. The 3 and 4degrees slopes are added as a reference.

Figure 3-9 - Descent profiles below FL150 for A330- 300.

Analysis of all descent profiles revealed that a 4-degree descent path was flyable for all medium weight (M) category aircraft, while a 3-degree descent path was seen as the limit for a heavy-weight (H) category aircraft.



Version 4.2 - 15/02/2012 - Page 15

Figure 3-10 - Difference 3 to 4° glide path.

The 3 and 4-degree rule was used by the Air Traffic Controllers to assess the feasibility and to plan the issuance of a CDO-clearance.

The descending aircraft needed to be located either on/below the 3-degree (H), resp. the 4-degree (M), slope in order to be eligible for a CDO-clearance.

When located above, the Air Traffic Controller inevitably needed to cater for extra track miles in the pattern for allowing a workable descent and approach solution. Obviously, this last scenario needed to be avoided as much as possible.



Version 4.2 - 15/02/2012 - Page 16

3.23.23.23.2 ACHIEVEMENT OF THEACHIEVEMENT OF THEACHIEVEMENT OF THEACHIEVEMENT OF THE PROJECTPROJECTPROJECTPROJECT

In one of the most congested airspace in Europe, the consortium B3 (Belgocontrol, Brussels airport and Brussels Airlines) proposed a challenging integrated approach to optimise the descent within the approach sector. The main objective was and is to reduce CO2 emissions by contributing to the introduction in Europe of a fairly new concept in aviation: Continuous Descent Approaches (CDO). The idea was to validate the proposed project and demonstrate the environmental benefits of the CDO-concept after implementation flight trials performed during 2010-2011. The principle of Continuous Descent Operation (CDO) is an approach procedure that allows descending on an optimum basis. The Continuous Descent Operation (CDO) involves the management of the aircraft configuration (flaps, speed brakes, landing gear, and thrust) by the pilot (known as descent energy management) to use the minimum required thrust on a variable glide angle into an airport. By using the lowest thrust possible and averaging a standard 3-degree glide angle at lower level, aircraft will burn less fuel, emit less CO2 and produce lower levels of noise than aircraft using higher thrust settings as in a “step down” method approach. For stabilization reasons a short level segment before interception of the ILS can be done (as proposed by the FMGS), also in a CDO.

Figure 3-11 - Descent optimization.



Version 4.2 - 15/02/2012 - Page 17

Figure 3-12 - CDO approach.

Figure 3-12is a depiction of the 3-degree and step down approaches.

3.2.13.2.13.2.13.2.1 THE CDO CHALLENGETHE CDO CHALLENGETHE CDO CHALLENGETHE CDO CHALLENGE

For many airports, the opportunity to implement a CDO is limited because of the volume of air traffic on approach and in the vicinity of the airport especially during daytime periods. When approaching traffic is heavy, a pilot may need to adjust thrust, flap settings, and extend landing gear to maintain safe and consistent spacing with other aircraft in the terminal area. Extending flaps, and landing gear makes an aircraft “dirty” (i.e., increases drag), which requires the application of additional thrust to keep the aircraft flying at the same speed.

During a continuous descent approach with engines running at idle power, from cruise altitude or from an intermediate level until the final stage of the approach. With this in mind, cooperation between airlines, airports and ANSPs (B3 Consortium) is focused on the validation of 3-Dimensional (3D) performance-based operations.

The 3D being

• Lateral (X &Y positions, responsibility of the ANSP (Belgocontrol))

• Vertical (Z position, responsibility of the pilot (Brussels Airlines) within the margins allowed by ATC

The B3 project focused on operations that were feasible with current technology with an attention on the last part of the descent, where the flight is under control of the Belgocontrol Approach unit.

Area in which the aircraft adjusts its flight path for the final approach Standard approach

CDO approach

Standard configuration change



Version 4.2 - 15/02/2012 - Page 18

3.2.23.2.23.2.23.2.2 EUROCONTROL APPROACHEUROCONTROL APPROACHEUROCONTROL APPROACHEUROCONTROL APPROACH TO CDOTO CDOTO CDOTO CDO

“Continuous Descent Operation is an aircraft operating technique in which an arriving aircraft descends from an optimal position with minimum thrust and avoids level flight

to the extent permitted by the safe operation of the aircraft and compliance with published procedures and ATC instructions.”

Some basics though must be kept as main goals: 1. A CDO uses descent profiles that reduce noise, fuel burn and CO2 emissions 2. Ideally, a CDO starts from the Top of Descent, but a CDO can also start at a

lower level. 3. The avoidance of level flight (continuously descending) is more important at lower

altitudes where noise becomes more significant. At higher altitudes, level flight at minimum thrust to reduce speed may in some cases help to reduce fuel burn and facilitate better CDO performance at lower altitudes where speed control becomes important for CDO achievement.

4. Low Drag configuration should be maintained to the maximum extent possible.

3.2.33.2.33.2.33.2.3 OBJECTIVES OF THE B3OBJECTIVES OF THE B3OBJECTIVES OF THE B3OBJECTIVES OF THE B3 PROJECTPROJECTPROJECTPROJECT

1. For the trial period, a CDO was only to be expected in lower levels. In the deployment phase, the feasibility to increase the altitude of the entry gates was assessed. All must be well aware that at lower levels, the standard descent in clean configuration and idle thrust will be around a 3° glide (5%) whereas at higher level t he glide angle will be steeper, this is mainly aircraft related. The procedure was based on radar vectoring for an optimum route. As the pilot is unaware of the route that the controller would issue him, he received additional information. During the descent the controller provided the remaining distance to go and thus permit the pilot/aircraft to compute his position in relationship with the ideal CDO profile. The controller explicitly approved a continuous descent. The continuous approach is a team effort from the controller and the pilot.

• The controller was responsible for issuing radar vectors to the aircraft (giving headings and the distance to go) and for all traffic separation

• The pilot was responsible for the descent profile, ensuring he remained as close as possible to his ideal continuous descent profile. When cleared for a CDO, the pilot expected that the controller would anticipate descent clearance to avoid any level off.



Version 4.2 - 15/02/2012 - Page 19

2. As a prerequisite, the CDO trials were performed:

• Without compromising safety,

• Without bringing the capacity below what is needed to accommodate traffic demand.

• Without adverse effect on punctuality

3.2.43.2.43.2.43.2.4 REFERENCE FOR CDO ATREFERENCE FOR CDO ATREFERENCE FOR CDO ATREFERENCE FOR CDO AT EBBR (BELGOCONTROL &EBBR (BELGOCONTROL &EBBR (BELGOCONTROL &EBBR (BELGOCONTROL & BRUSSELS BRUSSELS BRUSSELS BRUSSELS

AIRLINES)AIRLINES)AIRLINES)AIRLINES)

3.2.4.1 GENERAL

For the Trial period the following conditions were applied

• Tailwind component lower than 5 kt (gusts incl)

• no adverse weather conditions that may affect the approach (wind shear, thunderstorms, etc.)

This differed from the current AIP (ref. EBBR, AD2.21) conditions which are more restrictive, namely: 3.4 NOISE ABATEMENT APPROACH AND LANDING PROCEDURES

Noise abatement descent and approach procedures using continuous descent and reduced power / reduced drag techniques should be used when following conditions apply:

� ILS available � runway clear and dry � visibility exceeding 1 900 m � ceiling higher than 500 ft above AD ELEV � cross wind component lower than 15 kt (gusts incl) � tailwind component lower than 5 kt (gusts incl) � no adverse weather conditions that may affect the approach (wind shear,

thunderstorms, etc.) Turbo-jet powered aircraft shall use as final flap setting the minimum certified landing flaps setting published in the Aircraft Flight Manual for the applicable conditions. However, each pilot-in-command may use a different flaps setting approved for the aircraft if he determines that it is necessary in the interest of safety.



Version 4.2 - 15/02/2012 - Page 20

Other AIP-provisions Other AIP-provisions and more specifically AD2.21 Noise Abatement Procedures, point 3. Arrival Procedures and AD2.22 Flight Procedures, point 2. IFR flights (inbound) remain unchanged. Scope of the tests

� The tests was performed on runways 25L & 25R � The zone of the tests was limited to EBBR-TMA + CTA East. � The tests were only open for airlines that formally participate and that confirm that all

the pilots flying under their flag are briefed. � There is no limitation in time of day for the tests. However tests were only to be

expected in low traffic situations and on ATCO’s discretions � The only impacted ATC-unit is CANAC/APP.

Typical phraseology

Circumstances Typical Phraseology

Continuous Descent Approval

[aircraft call sign], [WHEN READY] DESCEND [INITIALLY] TO (level), QNH (number) [units], (distance) FROM

TOUCHDOWN,CONTINUOUS DESCENT APPROVED

Acknowledgment * DESCEND TO (level), QNH (number) [units][aircraft call sign]

Non-acceptance ** *DESCEND TO (LEVEL), QNH (number) [units] NEGATIVE CONTINUOUS DESCENT [aircraft call sign]

Cancellation [aircraft call sign] STOP DESCENT AT (level)

Cancellation Read back

*STOP DESCENT AT (level) [aircraft call sign]

* denotes pilot transmission

** only during test-period



Version 4.2 - 15/02/2012 - Page 21

[ ] Words in square parentheses indicate optional a dditional words or information.

Example for intermediate level

“BEL1721, heading 300, descend INITIALLY to 4000 ft, QNH 1018, 30 NM from touchdown, continuous descent approved”

Next “BEL1721, descend to 3000 ft, cleared ILS 25L” If feasible, followed by an updated distance from touchdown

Example with use of “when ready” e.g.for approaches via Kerky – BUN and level at FL80/FL90.

“BEL1721, WHEN READY descend to 3000 ft QNH 1018, 45 NM from touchdown, continuous descent approved”

3.2.4.2 BELGOCONTROL

Belgocontrol is the Belgian Air Navigation Service provider and is charged with the following tasks of public service:

- Assure the safety of air traffic control in the airspace for which the Belgian state is responsible

- Assure at Brussels Airport the control of the aircraft movements in approach, on landing, on the runways and the taxiways, as well as the guidance of aircraft on the platforms.Belgocontrol assures also the safety of air traffic on the regional public airports and airfields.

- Deliver information on the aircraft, their control, their movements and the noticeable effects of these.

Operational concept for the CDO-trials: APP-controllers did radar-vector aircraft to the ILS-interception, regularly providing distance from touchdown information and explicit approving the aircraft to descend continuously. Intermediate levels were used when needed for traffic separation or for keeping the aircraft in controlled airspace. Controllers identified flights eligible for CDO based on the airline company (callsign).



Version 4.2 - 15/02/2012 - Page 22

3.2.4.3 BRUSSELS AIRLINES

During these lower level transitions the aircraft had to reduce its speed and start its initial configuration. The pilots were challenged to continuously recompute energy level versus distance to land, while adhering to published speeds.

In optimal conditions, each pilot can fly a smooth transition from high cruising speed to final approach speed. This implicates that pilots should, to the max extent possible, keep their aircraft in clean configuration and idle thrust, keeping in mind that aircraft must be stabilized on approach in landing configuration at latest 1.000ft or 500ft depending on company regulations. This technique is mostly referred to as low drag/low noise technique. This reduces the noise level.

Noise abatement descend and approach procedures using continuous descent and reduced power / reduced drag techniques should only be accepted when following conditions apply:

To achieve this in the safest way, some limitations were applied until both pilots and controllers get more familiar with the concept CDO - Low Noise Approaches

• tail wind component lower than 5 kt (gusts included) • no adverse weather conditions that may affect the approach (wind shear,

thunderstorms, etc.) Turbo-jet powered aircraft should use as final flap setting the minimum certified landing flaps setting published in the Aircraft Flight Manual for the applicable conditions or their company SOP configuration. However, each pilot-in-command may use a different flaps setting approved for the aircraft if he determines that it is necessary in the interest of safety.



Version 4.2 - 15/02/2012 - Page 23

3.33.33.33.3 THE FLIGHT TRIAL PERTHE FLIGHT TRIAL PERTHE FLIGHT TRIAL PERTHE FLIGHT TRIAL PERIODIODIODIOD

3.3.13.3.13.3.13.3.1 PHASE ONEPHASE ONEPHASE ONEPHASE ONE

During the phase one (21/09/2010 till 21/01/2010), pilots and controllers were briefed by their appropriate authorities. The initial procedure has already been examined by the BSA (Belgian Security Agency) and has received a formal approval. The procedure being authorized, pilots and controllers had already received initial briefings. In view of this positive evolution, some very limited trial flights have taken place but the data retrieved for proper analysis are very limited.

Final briefings have been produced and forwarded to all participants.

• All ATCO’s have been briefed for the 15th of December • All Brussels Airlines pilots have been briefed for the 1st of December

To be able to assess in an objective way the gain in fuel burn, CO2 emissions reduction and possible noise impact, Brussels Airlines set up a program to track down specific flight data. Belgocontrol developed a means for controllers to simplify the marking of CDO-approved flights (see chapter on data collection process and tools) and Brussels Airport with subcontractor KU Leuven explored INM-possibilities for noise assessment (see chapter on data collection process and tools).Also during phase one the development of an analysis method based on these flight data (trial and non-flight trial data) was started.

Phase one has brought the key players on the same wavelength. Operational live flight tests that are already on-going will continue during Phase two, also ‘the quick performance scan’ will continue.

3.3.23.3.23.3.23.3.2 PHASE TWOPHASE TWOPHASE TWOPHASE TWO

The phase two has run from January 21st till December 21st 2011. During phase two, flights trials and analysis have run together until June1st 2011. In January 2011 until June 2011 the validation exercise was finalized and the final report started to be detailed.

This has required frequent information inside the B3 Consortium: monthly meetings have been held to exchange points of view and to adapt procedures as required.

Flight data was exchanged for flights from October 2010 until October 2011.

During Phase 2, from January 2011 until October 201 1, not less than 3.094 arriving flights were granted a CDO-descent. Detailed analys is was performed on 56 randomly selected Airbus-flights.



Version 4.2 - 15/02/2012 - Page 24

The project didn’t require any change in ground or airborne equipment. Any ATC can implement the project; any airline can fly the CDO. So the validation depended mostly on two factors:

1. Ability to optimise the number of CDOs while maintaining safe separation between flights. Controllers have always assured a safe separation between aircraft.Some factors influencing the possibility to approve a CDO were: the number of flights that are simultaneously approaching, their relative position, direction of the individual aircraft movement, altitudes and speeds.Speed control remained a last resort, as this caused erratic CDOs.

2. Ability for pilots to correctly compute a continuous descent in respect of the applicable local procedures (250kts below 10.000ft, established on ILS latest at 3.000ft at night/ 2.000ft during daytime). Speed reduction was done in a smooth continuous way to avoid level flight although a segment of 2.5 NM level flight is still considered as CDO.

3.3.2.1 TRANSITION INTO OPERATIONS

After the trial period, a formal evaluation has been organized to assess the need for further adaptation or the possibilities for implementation. As previously mentioned, no need for ground or aircraft equipment changes has beenidentified, rendering the implementation dependent on operational elements as well as on the conclusion on the benefits on CDO.

3.3.2.2 PACE OF CHANGE

It is expected that the simplicity of this working method should allow all airlines to jump into the procedure without any internal procedure publication requirement. In case of a general publication into the AIS (Aeronautical information system), the workgroup intends to continue to function during 3 months in order to tackle any undetected problem. Every implementation proposed by B3 has been subject to a formal approval from the BSA (Belgian Supervising Authority).



Version 4.2 - 15/02/2012 - Page 25

4.4.4.4. DATA COLLECTION PROCDATA COLLECTION PROCDATA COLLECTION PROCDATA COLLECTION PROCESS, TOOLS AND ANALYESS, TOOLS AND ANALYESS, TOOLS AND ANALYESS, TOOLS AND ANALYSISSISSISSIS

4.14.14.14.1 OVERVIEWOVERVIEWOVERVIEWOVERVIEW

An overview of the Data Collection Process, Tools and Analysis performed is given in figure on the next page.

Data sources are indicated as cylindrical containers

Data analysis steps are shown as rectangles with full lines.Where applicable, he tool used for the analysis is included in the rectangle.

Supporting steps are indicated as dotted rectangles.

The line colour of the containers and rectangles is a reference to the B3-partner that is originator for the data or performs the analysis action.

The fill colour of the containers and rectangles groups related processes.

This is all illustrated in the legend below (Figure 4-1).

Figure 4-1 - Data Collection scheme legend.



Version 4.2 - 15/02/2012 - Page 26

Figure 4-2 - Data Collection scheme.



Version 4.2 - 15/02/2012 - Page 27

4.24.24.24.2 DATA SODATA SODATA SODATA SOURCESURCESURCESURCES

4.2.14.2.14.2.14.2.1 NMSNMSNMSNMS (NOISE MONITORING SY(NOISE MONITORING SY(NOISE MONITORING SY(NOISE MONITORING SYSTEM)STEM)STEM)STEM)

Two sources of radar data are used.

One of the sources is the NMS (Noise Monitoring System) from Brussels Airport in which radar data are stored in a database in conjunction with flight data and measured noise values.This data source is limited in reach to FL90 and a square with sides of 40 NM around EBBR.The advantage of these data is that they are available in a database and that already some reporting tools exist for these data.

4.2.24.2.24.2.24.2.2 CDO TROUBLE REPORTSCDO TROUBLE REPORTSCDO TROUBLE REPORTSCDO TROUBLE REPORTS

4.2.2.1 CDO – TROUBLE REPORTS (BRUSSELS AIRLINES PILOTS)

Pilots from Brussels Airlines were asked to provide feedback on the trials via their central reporting database (SENTINEL).The concept of energy management is briefed and discussed with all pilots during pilot forums and via notifications in the cockpit briefing room.

After each flight the pilot must enter his flight data in our main database for Flight Operations (Blue One). This is a rather complete flight update:

• Actual off-block time, actual take-off time, actual landing time, actual on-block time

• Actual Zero Fuel Weight

• Actual fuel uplift and actual fuel on landing

• Flight Crew Report (FCR) for any specific issue affecting the flight (handling, catering, etc.). This is directly saved in a central database (SENTINEL) It has been asked to the pilots to use this electronic format to enter any CDO concern. All Brussels Airlines members participating to the B3 project have access to this database. It is then possible to make different queries to analyze one flight or a series of flights.

4.2.2.2 CDO – TROUBLE REPORTS (ATCOS)

ATCOs were asked to fill out eventual comments on a trouble report. At the ATCo’s working position a “Trouble report form“ is available, where ATCo’s can give comments on the CDO-trials.The template for the ATCo-trouble report is shown below.



Version 4.2 - 15/02/2012 - Page 28

Figure 4-3 - CDO Trouble Report.

4.2.34.2.34.2.34.2.3 FLIGHT LISTS WITH INFLIGHT LISTS WITH INFLIGHT LISTS WITH INFLIGHT LISTS WITH INDICATION OF CDODICATION OF CDODICATION OF CDODICATION OF CDO----MARKED FLIGHTSMARKED FLIGHTSMARKED FLIGHTSMARKED FLIGHTS

Within Belgocontrol the REDSTAR database contains a list with all flights arriving to Brussels Airport, with indication of the airline, the date and time, the aircraft type and the runway used.

The REDSTAR database however does not contain information on wether an approach is CDO-approved or not.In order to be able to analyse the effect of CDO-approval, for the B3-project the information on CDO-approvals needed to be produced and added to the dataset.

In order to generate the information on the flights marked CDO and to make this data available te following steps are followed:

1. Identification of CDO-flights is done by marking those flights that got a CDO-approval. This marking is done by the ATCO on his/her CWP (Controller Working Position) of the Eurocat system.

2. In order to make this information available the marked files are extracted from the Eurocat log-files. During this process also related data are extracted, such as the altitude of the aircraft at the moment of the “mark”-action.

3. The extracted data for CDO-approved flights are transferred from the operational to the administrative network where they are added to a table CDATEST.The table CDATEST contains data from REDSTAR (reference flight database for EBBR) for all arrivals on the two runways used in the trials: 25R & 25L for the five airlines participating in the trials.For flights that received a CDO-approval, information from



Version 4.2 - 15/02/2012 - Page 29

the Eurocat system (see steps 1 & 2) is added.

4. The resulting data are made available by Belgocontrol to the partners of the B3-project and to the other four airlines participating in the trials.A dedicated software was developed to select the relevant data and to send these to each of the partners external to Belgocontrol. The data from the table CDATEST are also used within Belgocontrol to provide statistics and for analysis in EFICAT.

4.2.3.1 MARKING CDO-APPROVED FLIGHTS

As the tests are performed 24h/24h, but only when traffic permits, only some flights are CDO-approved.In order to allow for a post-analysis of differences between CDO and non-CDO-flights, the ATCOs give a Mark to the flights that received a CDO-approval.For this purpose the Mark-field available on the CWP (Computer Working Position) is used.Marking the flight is much easier for the ATCO compared to note the marked flights on a paper form.The pictures below show an example.

Move over label to open extended label

Left click on call sign to open call sign menu

Figure 4-4 - Marked-field on CWP.



Version 4.2 - 15/02/2012 - Page 30

In the call sign menu

• Left click on “MORE”

• Left click on “MARK”

Figure 4-5 - Marked-field on CWP (2).

4.2.3.2 EXTRACTING FLIGHT DATA FROM EUROCAT-LOGFILES FOR

CDO-FLIGHTS.

The information on flights that are marked is not readily available for use.The information therefore needs to be extracted from the Eurocat-system.

In the Eurocat-system, the marking-action is stored in a general purpose log file.Every day a new log file is started.

In order to extract the data a CDO-dedicated program has been written by the Belgocontrol CANAC²-team.This program runs through the log files of day minus 10 (day -10) and provides a result file per day.

The software program identifies flights that were “marked” CDO and extracts the associated flight plan data .From a separate multi-purpose log file, additionally the altitude at the moment of the mark is extracted, as well as the distance that the aircraft has travelled between the moment the mark-field is checked and the touchdown of the aircraft.

For every day, a separate text file (CDO_YYYYMMDD.csv) is generated. The extracted data for CDO-approved flights are transferred from the operational to the administrative network, where they can be combined with the REDSTAR-flight data.



Version 4.2 - 15/02/2012 - Page 31

4.2.3.3 CORRELATE EUROCAT-DATA WITH REDSTAR-FLIGHT DATA

The extracted data for CDO-approved flights are transferred from the operational to the administrative network where they are added to a table CDATEST.The table CDATEST contains data from REDSTAR (reference flight database for EBBR) for all arrivals on the two runways used in the trials: 25R & 25L for the five airlines participating in the trials.For flights that received a CDO-approval, information extracted from the Eurocatlogfiles (see previous steps) is added.

This part of the process is implemented and automated by the Belgocontrol REDSTAR-team.An Oracle table CDATEST was made.A dedicated software is developed to systematically update the information in the table CDATEST.

Daily, theCDATEST table is updated with data from 2 sources: REDSTAR and the abovementioned CDO_YYYYMMDD.csv-files.

The REDSTAR database can be considered as the reference database with flight date.From REDSTAR, all the arrivals from participating airlines on the runways used in the trials: 25R a 25L are retrieved and stored in CDATEST.More specifically the following selection conditions are applied:

• Movement = arrival • Runway = 25L or 25R • Airline = BCS, BEL, JAF, SQC or TCW • (destination airport = EBBR)

For flights marked by the ATCO’s as CDO-approved, the table CDATEST is complemented with the extra data fields from the CDO_YYYYMMDD.csv-files.

An example of the main data fields in such a result file is shown in the example below (Table 4-1).

Table 4-1 – Example - Main fields for Marked CDO-fl ights extracted from Eurocat log files.

TIME_CDA DURATION GDATE GHOURMIN CLS VLTYPE IMMA RWY ALTITUDE TRACKMILES

04:04:06 00:07:54 02/10/2012 412 BEL245 A333 OOSFM 25L 88 32

10:11:01 00:07:59 02/10/2012 1019 BEL62F A320 OOSNB 25L 81 32

10:40:24 00:07:36 02/10/2012 1048 BEL2038 RJ85 OODJT 25L 131 31

13:20:49 00:08:11 02/10/2012 1329 BEL82K B734 OOVEP 25L 84 28

13:42:59 00:07:01 02/10/2012 1350 BEL33P RJ1H OODWI 25R 87 29

15:12:44 00:08:16 02/10/2012 1521 BEL26W RJ1H OODWH 25L 98 32

22:15:08 00:10:52 02/10/2012 2226 BEL51G RJ1H OODWB 25L 91 31

22:34:04 00:09:56 02/10/2012 2244 BEL32C B733 OOVEH 25R 84 34

23:05:18 00:10:42 02/10/2012 2316 BEL74F B734 OOVEP 25R 112 43

21:20:34 00:10:26 03/10/2012 2131 BEL15X RJ1H OODWA 25R 144 37

21:44:47 00:09:13 03/10/2012 2154 BEL82H A320 OOSNB 25R 66 30

21:53:17 00:09:43 03/10/2012 2203 BEL74F B733 OOVEN 25L 109 41

22:22:28 00:10:32 03/10/2012 2233 BEL51G RJ1H OODWD 25R 105 36



Version 4.2 - 15/02/2012 - Page 32

4.2.3.4 DISTRIBUTE FLIGHT LISTS WITH INDICATION OF CDO-MARKED

FLIGHTS

Besides the use internally in Belgocontrol, the data from CDATEST are also used within the CDO-project by the different B3 and and by the other airlines participating in the CDO-trials.

Brussels Airlines, as well as the other airlines involved in the trials receive information for their own flights.So separate files containing the CDO-approved flights for the individual airline are made to Brussels Airlines, DHL, Jetairfly, Thomas Cook and Singapore Airlines Cargo.Airlines could use these files for information and for further analysis.

Brussels Airport and its’ subcontractor KU Leuven receive the CDO-approved flights for all the participating airlines.For each of the flights in these files, Brussels Airport prints HPFC and VPFC (see further under the description of the NMS-tool).Brussels Airport on its turn then provides these graphical printouts to corresponding airlines and to Belgocontrol as a visual reference for the vertical and horizontal trajectory followed by the flight.

KU Leuven uses the CDATEST-information to distinguish between CDO-approved and non-CDO-approved flights when calculating the noise impact or when assessing the lateral position of arrivals.

Dedicated software development

For the distribution of the data to the partners external to Belgocontrol, Belgocontrol developed dedicated software.This software automates the extraction and e-mailing of the data from the table CDATEST.

From the table CDATEST, each week an extract is sent to each of the participating airlines and to The Brussels Airport Company and its subcontractor KU Leuven.Each of the participating airlines receives information for their own flights.The Brussels Airport Company and its subcontractor KU Leuven receives data for all the flights.

4.2.44.2.44.2.44.2.4 ASTERIX CAT62 RADAR ASTERIX CAT62 RADAR ASTERIX CAT62 RADAR ASTERIX CAT62 RADAR DATADATADATADATA

Besides the radar data available in the NMS (Noise Monitoring System), the second source for radar data that is used are rough radardata in the standard radar format Asterix Cat.62.

The advantage of the Asterix Cat.62radardata is that they cover the whole of Belgium.A disadvantage is the huge file size of about 0.5 GB for one day of data.

Asterix Cat.62 is also the default input format for analysis in the EFICAT CDO/CCO analysis tool.

Prior to the B3-project asterix Cat.62 data were only available in the operational network and for a limited time, with no link to the EFICAT-tool.



Version 4.2 - 15/02/2012 - Page 33

For the B3-project, the Asterix Cat.62 radar data are made available by the Belgocontrol DGE (Directorate General Equipment).

1. Sample data analysis

During phase 1, two samples of Asterix Cat.62 data were received from the Belgocontrol technical department for testing purposes.Both samples were for 9th of November 2010.One sample was for the period 0700-0800 UTC, the second sample was for the period 1700-1800 UTC.The size of these samples was respectively 22 and 20 Mbytes.The size of the basic data thus is quite significant.

In order to import all the data and to keep these available for further analysis (not only for the B3-project); the most adequate way to import data was considered to be one day of data per database.

During phase 2 this was further analysed.Radar data in the Asterix Cat.62 format are standard available per hour.For the B3-project data were combined into files for one day.The first day with these files available is 1st of April 2011.These one-day files, for dates between 1st April 2011 and 13 July 2011, have sizes varying between 380.000 kB and 570.00 kB

2. Making Asterix Cat.62 –data available for the B3-project

The AsterixCat.62-data are originating from the operational network and cannot be accessed by the administrative network.For this reason the Belgocontrol ICT-department provided the necessary space a dedicated folder on the administrative network and developed an automated process to copy the Asterix-files from the operational to the administrative network. From this location the files are retrieved to be imported in the EFICAT CDO/CCO Analysis tool.

4.2.54.2.54.2.54.2.5 FDMFDMFDMFDM----DATADATADATADATA

4.2.5.1 SETTING OF THE CONCEPT

Since 2005 the Flight Safety Department of Brussels Airlines runs a FDM program. Using recorded flight data this Flight Data Monitoring (FDM) program assists an operator to identify, quantify, assess and address operational risks and deviations from Standard Operating Procedures.

Flight data is obtained from the aircraft’s digital systems by a flight data acquisition unit (FDAU) and routed to the crash protected flight data recorder (FDR). In addition to this mandatory flight data recording system, a second output is generated to a non-mandatory recorder.



Version 4.2 - 15/02/2012 - Page 34

This output is, depending on the aircraft type and installed avionics, often more comprehensive than that of the FDR due to the increased capacity and special features of this system. Unlike the FDR, this recording system has a removable recording medium. Because these are easy to gain access to, the non-mandatory recorders are known as quick access recorders (QARs).

At Brussels Airlines, the QAR media are physically replaced every week, and sent to a central point at the Flight Safety Department for input and analysis. The disks are entered and replayed through dedicated computer programs starting with one that converts the raw binary data into engineering units. This is the physical backbone of the FDM program.

This dedicated software is also used to design specific algorithms detecting deviations from accepted norms of flight operations and safety.

Afterwards, such detected deviations help to find subtle trends and tendencies. A population of flights can be statistically analysed, specific flights can be studied thoroughly. As a result this FDM program is a closed loop system that provides a means for the permanent monitoring and improvement of the safety and performance of the flight operations. Recently this tool became part of the Safety Management System within Brussels Airlines.

It has been demonstrated that the FDM program is a valuable proactive tool to improve the day-to-day monitoring of adherence to Standard Operating Procedures and the condition of individual aircraft.

Lastly, this program take places in a de-identified way and is subject to signed agreements and working methods.The flight data utilized in this CDO project had the sole purpose of obtaining factual material to support the CDO analysis in an unbiased manner. It was not used for identification purposes of crews or to apportion blame.

4.2.5.2 TECHNICALITIES AND LIMITING FACTORS

Despite the large fleet, consisting of Avro RJ’s, Airbus A319, Airbus A320, Airbus A330 and Boeing B737, some limits during the B3 project have been noticed.

First of all, not every aircraft recorded the essential parameters that could assist in our study of CDO’s.

Secondly, the Boeing and Avro fleet are equipped with flight data acquisition units that can’t be customized. The required know-how and technical possibilities to update this to more exhaustive standards are considered very costly and outside the scope of any current project.

Finally, differences in the applied decoding software tools and hardware required separate collection methods, algorithms and export features; complicating the process even more.

After consideration and initial testing, only the A319/A320 and A330 fleet were retained for this project. The data integrity and availability of flight data parameters showed many



Version 4.2 - 15/02/2012 - Page 35

advantages. It also proved to be the type of aircraft operating day and night; helping us providing a wider spectrum of data.

The expanding A319/A320 fleet within Brussels Airlines during this B3 project confirmed this choice even more.

At the end twelve aircraft were collecting data for the B3 pro ject . Five different Airbus A319/320 and five Airbus A330-301/A330-322 took part in this part of the project.

4.2.5.3 EXTRACTION OF FDM-DATA – IN HOUSE DEVELOPMENT OF AN

ALGORITHM

In order to handle the large amount of data in a user-friendly way, the flight data analyst opted to design a particular data collection algorithm via his FDM program. This also prevented a negative impact on the main purpose of the FDM program: flight safety.

Every recovered inbound flight triggered this algorithm when crossing a certain flight level. FL100 was agreed upon as the realistic boundary for the situation in Brussels within the B3 project. The segment stopped as soon the aircraft was passing the outer marker, as this moment clearly represents a common end of the approach.

Throughout an approach, several parameters like aircraft registration, landing runway, times, aircraft weight, several sorts of speeds, engine power, air data, descent rates, headings and fuel figures were collected. Additionally, other variables for this segment were derived and averaged in the meantime.Those were parameters like: ambient temperatures, power settings, groundspeeds, gradients and even accurate track miles. Finally, the use of anti-ice systems, flap settings, landing gear and spoilers -when recorded-were registered and timed as well. This in order to find out if conclusions based on this flight data could be matched with CDO marked flights.

The algorithm from the FDM program calculated several additional parameters, which after export, could be used to compare with the results obtained by the EFICAT-CDO-analysis by Belgocontrol. This EFICAT-CDO-analysis tool is based on radar data, whereas FDM data is based on on-board recorded flight data. The aim of this comparison was to compare the fuel/CO2 estimates by the EFICAT-CDO-analysis tool with the fuel calculated from the FDM program.

For this project, Brussels Airlines extracted data from the FDM program in two different ways. Most detail was needed for the calculation of the noise impact (6) and the analysis of individual flights (3). Secondly, a unique algorithm was programmed which was used for a broader analysis. (4) Both types of treated flight data were made available by Brussels Airlines to both Belgocontrol and Brussels Airport.

Brussels Airlines retrieved specific flight data of individual flights. Typically, 50 particular parameters were collected every second as soon as the descent into Brussels was initiated.



Version 4.2 - 15/02/2012 - Page 36

FDM-data for specific flights were made available by Brussels Airlines to both Belgocontrol and Brussels Airport’s subcontractor KU Leuven.These files were handpicked, since they require manual creation.

The analysis of the FDM-data by Belgocontrol aimed for a better understanding and comparison of optimum profiles, related fuel consumption and CO2-production.KU Leuven used the data for acoustic simulations with the software INM.



Version 4.2 - 15/02/2012 - Page 37

4.34.34.34.3 TOOLSTOOLSTOOLSTOOLS

4.3.14.3.14.3.14.3.1 NMS (NOISE MONITORINNMS (NOISE MONITORINNMS (NOISE MONITORINNMS (NOISE MONITORING SYSTEM), SAS AND GG SYSTEM), SAS AND GG SYSTEM), SAS AND GG SYSTEM), SAS AND GISISISIS

4.3.1.1 DESCRIPTION OF THE NMS

The Noise Monitoring System (NMS) operated by The Brussels Airport Company operates, collects, controls and interprets noise data from a network of noise monitoring terminals (NMT’s) on and in the surroundings of Brussels Airport. The NMS also functions as a track keeping system as it correlates noise-, radar-, weather- and flight information.The radar data (smoothed x-, y- and z- radar data) that feeds the NMS daily is provided by CANAC-Belgocontrol. The area for which data is provided is limited within a square of maximum 40 nautical miles and up to an altitude of maximum FL90.

The reporting module within the NMS is a tool to visualize flight trajectories vertically (VPFC) and horizontally (HPFC) in standardized reports.

Figure 4-6 - VPFC.



Version 4.2 - 15/02/2012 - Page 38

Figure 4-7 - HPFC.

4.3.1.2 NMS-REPORTS AS A REFERENCE FOR AIRLINES AND

BELGOCONTROL

For each of the CDO-marked flights, Brussels Airport printed (in pdf) a VPFC (Vertical Projected Flight Curve) and a HPFC (Horizontal Projected Flight Curve) with their NMS (Noise Monitoring System).Brussels Airport provided these reports to the corresponding airlines and to Belgocontrol



Version 4.2 - 15/02/2012 - Page 39

Figure 4-8 - Visual detection of a non-CDO (VPFC).

Figure 4-9 - Figure 5.9 : Visual detection of a CDO (VPFC).



Version 4.2 - 15/02/2012 - Page 40

As the vertical profile (<=FL90) is a perfect tool to spot intermediate level offs, it gives an indication of the precision of the CDO flown.

Within the airlines the visual information was used to evaluate the descent profiles and for personal discussion and briefing on individual flights with the corresponding pilots.

Within Belgocontrol, the HPFC and VPFC printouts were used to obtain a feeling with the diversity of flown profiles in case of CDO-approval and also as reference data during data analysis.

4.3.1.3 NMS-RADARDATA TO COMPARE LATERAL ROUTES FOR CDO-

APPROVED AND NON-CDO-APPROVED FLIGHTS USING SAS AND

GIS

NMS-radardatawere used to investigate if the ground track position of CDO approved approaches and non-CDO approved approaches differ or not.To analyse this, the HPFC’s of CDO and non-CDO flights are compared to each other.In this analysis it was important to take into account that no other parameters influence the HPFC’s of the compared flights.A SAS (Statistical Analysis Software) database is created containing the ground tracks of the different CDO and non-CDO flights, which allow to filter a group of flights.A graphical presentation of these tracks is made in a GIS (Geographical Information System) environment and visually analysed.

4.3.24.3.24.3.24.3.2 EFICATEFICATEFICATEFICAT

4.3.2.1 CDO-EVALUATION BY EFICAT

The CDO/CCO Tool is an off-line tool, which is designed to provide analysis of Continuous Descent Operations, using radar data as inputs.Users can load their own radar data, and extract statistics about CDO/CCO from which reports can be produced.Though the CDO/CCO Tool is designed to analyze Continuous Descent Operations, by analogy the CDO/CCO Tool also has some means to analyze continuous climbs.

The Eficat tool analyses radar data.Most direct parameter calculated is level flight.This allows e.g. identify segments of level flight as a proxy to estimate if a flight is performing a CDO or not.

The print-screens below show an example of an EFICAT analysis. As can be seen in the top part, the EFICAT tool allows a certain but limited filtering of the data.



Version 4.2 - 15/02/2012 - Page 41

Figure 4-10 - EFICAT Analysis part1.



Version 4.2 - 15/02/2012 - Page 42

Figure 4-11 - EFICAT Analysis part2 (scrolled to th e right).

4.3.2.2 FUEL BURN ANALYSIS POSSIBILITIES WITH EFICAT

The fuel burn calculation uses all radar plots within a configured parameter radius of the ADES.The default distance in EFICAT is 150 NM, but can be adapted e.g. to take into account smaller airspaces, or partial continuous descents.The rationale for starting at these static radii is to allow comparison between similar aircraft types at different airports, as well as flights using a particular arrival route at the same airport. In this way, actually the combined effect from the lateral route and the vertical profile is measured.

The calculation of fuel is done using BADA-fuel burn data expressed in Kilograms per Minute (kg/min), based on the radar plot flight levels, time of flight and the phase of flight (cruise, descent, …).Nominal aircraft weights are used.



Version 4.2 - 15/02/2012 - Page 43

3 types of fuel amounts can be calculated in EFICAT:

o The total fuel burn from the configured parameter radius (e.g. 150 NM) until a Minimum plot cutoff altitude (e.g. 1500 ft)

o The fuel burn between the configured parameter radius until (and including) a "above/below altitude cutoff" parameter (e.g. FL100)

o The fuel burn below a "above/below altitude cutoff" parameter (e.g. FL100 and a Minimum plot cutoff altitude (e.g. 1500 ft)

The latter one (bold) is used in the B3-project.

4.3.2.3 RADAR-DATA VISUALIZATION IN EFICAT

Radar-data can be visualized as horizontal plot, as vertical profile or in perspective.Examples are given below.

Figure 4-12 - EFICAT – Example of Horizontal Plot.



Version 4.2 - 15/02/2012 - Page 44

Figure 4-13 - EFICAT - Example of Vertical Plot.



Version 4.2 - 15/02/2012 - Page 45

Figure 4-14 - EFICAT - Example of Perspective Plot.

4.3.2.4 AGREEMENT WITH EUROCONTROL TO TEST THE EFICAT TOOL

Belgocontrol has closed an agreement with Eurocontrol to use the CDO/CCO Tool to assess Continuous Descent Operations (“CDO”) performance, on the condition of providing to Eurocontrol any suggestion for improvement.

4.3.2.5 IMPORT OF RADAR DATA IN EFICAT FOR THE B3-PROJECT:

a) Data in the standard radardata format Asterix Cat.62 were used.Asterix Cat.62 also is one of the standard input formats for the EFICAT CDO/CCO analysis tool.

b) On the 22nd of December 2010, the EFICAT-tool was installed and the import of Asterix 62-data was trained and tested successfully.

Importing the Asterix Cat.62 radar data in EFICAT is a time consuming process. On average it takes about 3 hours to import one day of data.So in the optimum case 3 days can be loaded in one working day.About 90 days of data were imported in EFICAT.All available Asterix data for the months of April, May and June 2011 were loaded, as well as selected days for July 2011.After importing in EFICAT, for each



Version 4.2 - 15/02/2012 - Page 46

imported day a separate database is available.

c) The Asterix Cat.62 data do not contain any information to identify if the arrival was CDO-approved or not.Therefore it was expected that it would not be possible to use the information from marked flights for the global analysis. However a solution for this was found.Output from the EFICAT-tool was combined with 2 other data sources: data from the table CDATEST and data from the reference database REDSTAR.The combination of EFICAT data with these two additional sources was done in MS-Excel.

d) From this combined dataset.A sample of flights was selected for individual analysis.The sample contains some CDO-flights (both marked a not marked) and some non-CDO-flights (both marked and not marked).The conclusion if a flight is considered CDO or not is the result of the analysis with EFICAT.

4.3.2.6 EFICAT ANALYSIS PERFORMED FOR B3-PROJECT

The analysis performed in the B3-project focused on the flight portion below FL100, with intermediate steps at FL80 & FL60.The used low-cut altitude was 1500 ft.This choice was made because the lowest ILS interception altitude at EBBR is 2000 ft and with a CDO no changes are applied for the flight portion where the aircraft is on the ILS.

Within EFICAT Asterix cat.61 data, starting from 1st of April 2011 are imported.

Importing one day of Asterix cat.61 data takes a considerable time.After some measures the time for the import of one day of data could be reduced to +/- 3 hours (depending on the size of the file).

Measures taken are: PC with larger C:-drive, copying the raw Asterix files from the network drive to one of the PC’s hard disks and starting the PC with a minimum of programs running in background,

The import of the AsterixCat.62 data in EFICAT results in one database per day.

For each database/day, 3 analyses are run in EFICAT:

- below FL60 - below FL80 - below FL100

In each of these analyses EFICAT calculates as set of results.For example in the analysis “below FL100” the results are:

- DIST-A: distance flown below FL100 (and above 1500 ft) - DIST-B: distance flown level below FL100 (and above1500ft).When level flight < 2.5

NM, then value is 0. - Time-A: Time flown below FL100 (and above 1500 ft) - Time-B:Time flown level below FL100 (and above 1500 ft).When level flight < 2.5 NM,

then value is 0. - Fuel kg: Fuel burn calculated by EFICAT for time flown between FL100 & 1500ft



Version 4.2 - 15/02/2012 - Page 47

- Angle: average descent angle calculated by EFICAT for time flown between FL100 & 1500ft

- dB40: difference in noise based on altitude difference.Reference = FL40 with 3°, compared to real altitude at this position

- dB80: difference in noise based on altitude difference.Reference = FL80 with 3°, compared to real altitude at this position

- CO2-emission calculated by EFIAT for time flown between FL100 & 1500ft

For the FL60 & FL80 the same parameters are calculated but then for the flight portion between respectively FL60-1500 ft and FL80-1500 ft.

4.3.2.7 EXPORT OF THE EFICAT RESULTS TO MS EXCEL FOR FURTHER

ANALYSIS

During B3-phase I the intention was to analyse the results in EFICAT within the EFICAT-tool only. However in B3-phase II a better solution was found and implemented.This solution was to:

• export the EFICAT-results to MS Excel • offline combine the EFICAT results with additional data sources • make a global analysis in Excel

1. Export to MS Excel:

For each day of data (+/- 90 days), three EFICAT-analyses were run: one for FL60, one for FL80 and one for FL100.For each of these runs an export was made, resulting in about 90 x 3= 270 MS Excel files which were subsequently combined into 3 files (one per month).

2. Offline combination with additional relevant data:

The data from CDATEST, containing information on flights marked by the ATCOs was combined with the exported EFICAT-results.From REDSTAR the following reference data were also added to the EFICAT-results:gdate, cls, rwy, ccls, imma, vltype, mtow, cie, ldate, lday, lday_int, lweek, lhourmin, lhour.The most important being CCLS and RWY.CCLS is the flight code as it is used within Brussels Airlines.The value for CCLS typically slightly differs from the value for CLS, the callsign code used by Belgocontrol.Addition of CCLS to the dataset helped Brussels Airlines to link the EFICAT information to their own data.The runway field was important e.g. as it allows to compare between runways included in the CDO trials and runways not included in the CDO-trials.

3. Make global analysis in MS Excel:

In MS Excel the combined dataset is used to analyse the data



Version 4.2 - 15/02/2012 - Page 48

4.3.34.3.34.3.34.3.3 SQL &SQL &SQL &SQL &MS EXCELMS EXCELMS EXCELMS EXCEL FOR THE STATISTICAL FOR THE STATISTICAL FOR THE STATISTICAL FOR THE STATISTICAL ANALYSIS OANALYSIS OANALYSIS OANALYSIS OF CDOF CDOF CDOF CDO----

APPROVALS AND OF EFIAPPROVALS AND OF EFIAPPROVALS AND OF EFIAPPROVALS AND OF EFICATCATCATCAT----RESULTSRESULTSRESULTSRESULTS

For use within Belgocontrol, the data in the CDATEST-table in REDSTAR can be accessed using SQL and results were exported to MS Excel for further analysis.

MS Excel was also used by Belgocontrol to correlate exported results from the EFICAT tool with data in the CDATEST-table and for subsequent statistical analysis of the resulting dataset e.g. on the percentage of CDO-approvals, on the FL (Flight Level) from which CDOs are approved and the average time between the marking of the CDO-flight and touchdown.

4.3.44.3.44.3.44.3.4 MS EXCELMS EXCELMS EXCELMS EXCEL FOR DESCENT PROFILE FOR DESCENT PROFILE FOR DESCENT PROFILE FOR DESCENT PROFILE ANALYSIS OF FDMANALYSIS OF FDMANALYSIS OF FDMANALYSIS OF FDM----DATADATADATADATA

4.3.4.1 USE OF FDM-PARAMETERS.

For a number of selected flights, the vertical profile of the actually flown descent has been analyzed, using real FDM data, provided by Brussels Airlines. The objectives of this exercise:

1. Detailed determination of the fuel consumption during descent, starting at the Top-Of-Descent (TOD), regardless whether or not a continuous descent has been flown.

2. Evaluation of the impact of a (partial) CDO on the overall descent fuel consumption. 3. Detection of flight practices which lead to fuel consumption inefficiencies.

In this section of the report, the methodology (with its constraints) is outlined.

For each analysis, following parameters, as recorded on board of the aircraft, were used:

Parameter Name Description Use of the data

TIME_R Time Reference of recorded data This reference is used for all time calculations and integrations.

FLIGHT_PHASE Flight Phase Flight phase determination. The TOD is considered to correspond with the transition from CRUISE to DESCENT, unless this transition happens more than 200 NM from the destination airport (ADES).

TAS True Air Speed (kt) TAS is used to calculate the “air distance”. Difference with the “track distance” allows quantify the effect of wind.

IASC Indicated Air Speed (kt) IAS is used to evaluate differences with the reference profiles which are based on specific IAS value(s).

GSC Ground Speed (kt) GS is used to calculate the “track



Version 4.2 - 15/02/2012 - Page 49

distance”.

MACH Mach Number

N11C – N12C N1 - engine 1 and 2 Throttle activity visualisation, and indication that anti-ice could have been activated.

ALT_STDC Altitude (non-baro corrected)

GWC Gross Weight GW at TOD determines the reference descent profiles.

LDGL/R Landing Gear status (Air/ground) The transition from Air to Ground is used to determine the landing point, and to calculate the baro correction.

SPD_BRK Speed brake activation Activation of the speed brake is recorded, but the recording does not show to which extent it has been deployed.

FF1C – FF2C Fuel Flow Engine 1 and 2 (kg/h) Fuel burn is calculated by integration of the instant fuel flow (FF) values of both engines.

FQTY Fuel Quantity (kg) FQTY is used to crosscheck the fuel burn calculation based on fuel flow. The value is known to be less accurate than the FF readings, but allows to detect calculation anomalies.

Table 4-2 - Use of recorded data items.

4.3.4.2 REFERENCE PROFILE CONSTRUCTION.

For each analyzed flight, the flown profile is compared to a known reference profile. Although the detailed operational parameters (i.e. cost index, and chosen descent speed(s)) are not known, this comparison allows to detect inefficiencies linked to the fact that the flown profile deviates from a CDO-one.

The used reference profile is constructed as follows:

1. The baseline profiles are extracted from the AFM of the subject aircraft. See Appendix 4 for the profiles related to the Airbus A319; see Appendix 5 for those related to the Airbus A330-300. These profiles represent, for two typical masses, a nominal descent pattern:

a. A319: descent at M.78 above the crossover altitude; at 300 KIAS3 below the crossover altitude; at 250 KIAS below FL100.

3: KIAS = Knots (kt) Indicated Air Speed



Version 4.2 - 15/02/2012 - Page 50

b. A333: descent at M.80 above the crossover altitude; at 300 KIAS below the crossover altitude; at 250 KIAS below FL100.

2. For each flight the reference profile is linearly interpolated (or extrapolated), taking into consideration the value of the GW of the aircraft at the TOD. The output comprises values for horizontal distance, flight time and fuel consumption.

The resulting reference frames will normally fit within the colored contours shown in Figure 4-15unless the mass of the aircraft at TOD falls outside the given range (exceptions).

The reference profile does not cater for wind, and does not include corrections to take into account particular airframe characteristics of the specific aircraft used for the investigated flight.

Figure 4-15 - Reference Descent Profiles.

4.3.4.3 ANALYSIS DESCRIPTION.

For each analysed flight, four graphs are provided:

Descent profile:

This graph shows the flown vertical profile versus the calculated reference profile. In addition, the selected thrust (Throttle - N1) and speed brake activation are shown. The landing point is shown at the ‘origin’ (0,0) of the graph.

The value for the selected thrust gives an indication about possible selection of engine anti-ice during the descent. Note that “total engine anti-ice” may account for an increase of up to 70% in the nominal fuel consumption for descent!



Version 4.2 - 15/02/2012 - Page 51

A typical example is given inFigure 4-16.

Figure 4-16 - TypicalDescent Profile graph.

In this particular example, the aircraft initiated a reduced descent, well in advance of the reference profile TOD, till reaching this profile just below 25.000 ft altitude. Below 25.000ft, we see the aircraft descending slightly below the reference profile. The speed brake was activated at glideslope interception, in the final stage of the approach.

The right axis is used for the thrust setting, while the left shows the altitude.

Descent profile (time):

This second graph shows again the descent profile, not referenced against track distance, but against time before landing.

Figure 4-17shows the same descent as depicted Figure 4-16. Note that the flight started its descent some 4 minutes before the reference TOD.



Version 4.2 - 15/02/2012 - Page 52

Figure 4-17 - Typical Descent Profile – Time graph.

According to the previously explained rationale, one may expect a time/fuel penalty against the reference profile. This is shown in the third graph:

Fuel burn analysis:

The third graph (see Figure 4-18for an example) shows the descent path again, but now only until 1.500 ft AGL. In addition to the ‘descent profile’ referenced to terrain (ground), also the ‘air-distance’ is shown (Missing for some airframes, due to an observed FDM-anomaly).

In this particular example, we see a significant difference between both profiles above 25.000 ft (tailwind), but no difference below that altitude. This practically means that the reference profile is perfectly valid below 25.000 ft, but should be used with caution above this altitude.

Two fuel burn curves are provided:

1. The red curve displays the real fuel burn up to a given point in cruise.

2. The brown curve shows the theoretical fuel burn, provided the reference profile should have been flown up to the same point.



Version 4.2 - 15/02/2012 - Page 53

Figure 4-18 - TypicalDescent Profile – distance gra ph.

The common reference point is taken at the end-of-descent (EOD) point, defined at 1500 ft above the threshold of the landing runway at the destination airport. The difference between both curves represents the fuel burn penalty (or gain) at the same distance from the EOD. Fuel burn during the cruise portion of the reference fuel burn curve is calculated using the average fuel burn figure at the end of the cruise phase of flight, taking into account the average ground speed of the corresponding cruise leg.

The fuel penalty for the descent shown in Figure 4-18has been calculated to be 67.4 kg, mainly due to the early descent of the aircraft. This is merely an indication rather than a fully exact figure, as no wind has been taken into account for the reference descent path calculation. Especially if the wind is significant, this value should be read with caution!

Indicated air speed throughout the descent is provided as additional information.

In order to assess the continuous descent effects below 15.000 ft, a detailed graph of the final descent profile is given as well: see Figure 4-19.



Version 4.2 - 15/02/2012 - Page 54

Figure 4-19 - Typical Fuel Burn below FL150 graph.

In this particular case we observe a slight fuel burn increase, probably due to the fact that the aircraft remained below the reference profile. Note that the crew initiated the speed reduction down to 250 KIAS well below FL100.

The graphs clearly reveal which flight related events during the descent result in extra fuel burn.

Important Notice:

Operational constraints and instructions from ATC, possibly preventing the flight crew from performing the descent as intended, could NOT be taken into account in this analysis process. As a result, the authors cannot and do not want to attribute any observed ‘event’ to any involved party in this process.



Version 4.2 - 15/02/2012 - Page 55

For each of the analyzed flights, some key values were derived from the FDM data:

Actual fuel burn in descent against the corresponding values of the theoretical reference descent profile between:

a) FL100 and 1500 ft AGL

b) FL80 and 1500 ft AGL

c) FL60 and 1500 ft AGL

Flown track distance in descent between:

a) FL100 and 1500 ft AGL

b) FL80 and 1500 ft AGL

c) FL60 and 1500 ft AGL

4.3.54.3.54.3.54.3.5 INM (INTEGRATED NOISINM (INTEGRATED NOISINM (INTEGRATED NOISINM (INTEGRATED NOISE MODEL) FOR NOISE CE MODEL) FOR NOISE CE MODEL) FOR NOISE CE MODEL) FOR NOISE CALCULATIONALCULATIONALCULATIONALCULATION

KU Leuven, subcontracted by Brussels Airport calculated the noise impact with the INM (Integrated Noise Model).KU Leuven used exported FDM data from Brussels Airlines as an input and Belgocontrol data to distinguish between CDO and non-CDO-approved flights on one hand and on the other hand between flights that are or are not judged CDO by the EFICAT tool.

4.3.5.1 CALCULATION MODEL

For the evaluation of the potential noise benefit of CDO compared to non-CDO approaches the Integrated Noise Model (INM) of the Federal Aviation Administration (FAA) is used.This software tool is worldwide used to calculate the noise in the vicinity of airports due to departing and arriving aircrafts.Also in the Flemish environmental legislation, this model is prescribed to calculate noise contours around the Flemish airports on a yearly basis.Since the middle of the nineties these calculations are executed by the LaboratoriumvoorAkoestiek en ThermischeFysica of the KU Leuven, for the major Flemish airports.In this way a lot of experience exists for the use of this model on Brussels Airport as the airport is located on Flemish territory.

In this project INM 7.0b is used which is the most recent version of the software model and which is compliant with the European Civil Aviation Conference (ECAC) Doc 29 (3rd Edition) “Report on Standard Method of Computing Noise Contours around Civil Airports”.This new version includes among other things the new SAE-AIR-5662 “Method for Predicting Lateral Attenuation of Airplane Noise” and bank angle implementation.



Version 4.2 - 15/02/2012 - Page 56

4.3.5.2 GENERAL CALCULATION METHOD OF THE INM

A database of 139 main aircraft types is connected to the calculation model extended with a database of more than 200 sub aircraft types.The noise performance data of these aircrafts are stored in the database as noise-thrust-distance curves.These curves contain the noise emission (SEL or LAmax) at the position of the receiver in function of the distance between the aircraft and the receiver and the engine thrust of the aircraft (see figure below).During the calculation process these curves are corrected for the meteorological conditions influencing the noise propagation in the air and, for the SEL parameter, also for the actual speed of the aircraft.

Figure 4-20 - INM 7.0b noise-thrust-distance curves for approach of the Airbus 330-301

with GE CF6-80 E1A2 engines.

At each receiver position the aircraft-receiver distance, the engine thrust and the speed of the aircraft are determined at the moment of the shortest receiver – ground-track distance during the flight of the aircraft (see figure below).


Figure 4-21 - Determination of the shortest receiver

In summary, these data is necessary as input in the INM model to predict the noise impact of an aircraft movement:

� Aircraft type

� Ground track of aircraft movement

� 3 different profiles

o Speed profile (speed as a func

o Vertical profile (altitude as a function of the track distance to the airport)

o Engine thrust profile (engine power as a function of the track distance to the airport)

To create these 3 profiles for an individual function of the track distance to the airport) different methods exist in INM.

Firstly, for each aircraft type in the INM database a standard approach profile is available within the software model.The figure the altitude profile this INM standard approach procedure contains a level step at FL30.The peak in the thrust profile after touchdown is caused by the use of reverse thrust to decelerate the aircraft on the runway.



Version 4.2 - 15/02/2012 - Page 57

Determination of the shortest receiver – ground- track distance during approach.

these data is necessary as input in the INM model to predict the noise impact of

Ground track of aircraft movement

Speed profile (speed as a function of the track distance to the airport)

Vertical profile (altitude as a function of the track distance to the airport)

Engine thrust profile (engine power as a function of the track distance to the

To create these 3 profiles for an individual flight (speed, altitude and engine thrust as a function of the track distance to the airport) different methods exist in INM.

Firstly, for each aircraft type in the INM database a standard approach profile is available within the software model.The figure below shows this profile for the A330.As can be seen on the altitude profile this INM standard approach procedure contains a level step at FL30.The peak in the thrust profile after touchdown is caused by the use of reverse thrust to decelerate

track distance during

these data is necessary as input in the INM model to predict the noise impact of

tion of the track distance to the airport)

Vertical profile (altitude as a function of the track distance to the airport)

Engine thrust profile (engine power as a function of the track distance to the

flight (speed, altitude and engine thrust as a function of the track distance to the airport) different methods exist in INM.

Firstly, for each aircraft type in the INM database a standard approach profile is available below shows this profile for the A330.As can be seen on

the altitude profile this INM standard approach procedure contains a level step at FL30.The peak in the thrust profile after touchdown is caused by the use of reverse thrust to decelerate



Version 4.2 - 15/02/2012 - Page 58

Figure 4-22 - INM 7.0b standard approach profile fo r the Airbus A330-301 (thrust,

speed, altitude).

For some aircraft in the INM database these 3 profiles can be created by entering the different steps of the total approach procedure (Level, Level-Decel, Level-Idle, Descend, Descend-Decel, descend-Idle, Land, Decelerate, ...) in the model, the so called procedural profiles.For each step of this procedure some parameters must be known (speed, flap settings ...).Based on this data and the SAE-AIR-1845 equations, the corresponding thrust is calculated within the model.In this case the flap coefficients for the aircraft type must be available.For the airbus aircrafts in the database of INM, these coefficients are available since the 7.0b version.

A third and last method to build the speed, altitude and thrust profiles is to enter these parameters directly into the model if these data (speed, altitude and thrust) are known for the approach under study.These profiles are called the fixed point profiles.



Version 4.2 - 15/02/2012 - Page 59

4.3.5.3 METHOD USED TO COMPARE THE NOISE IMPACT OF CDO AND

NON-CDO APPROACHES

For the evaluation of the noise impact of aircraft approaching Brussels Airport the flights for which FDM data was retrieved from the aircraft were simulated in INM using fixed point profiles.The Belgocontrol data isused to distinguish between CDO and non CDO-approved flights.The text below shows how the necessary INM input data is retrieved for the individual flights.

1. Ground track The Brussels Airlines FOQA data contains the position (latitude / longitude) of the aircraft for each time stamp.However, examples of A330 approaches have shown that an offset might exist between the indicated and the true position of the aircraft (see figure below).This offset can be corrected by the knowledge of the time stamp of touchdown (FDM data) and the runway (NMS) or by the radar data available in the NMS.

Figure 4-23 - Ground track of an A330 approach on r unway 25L at Brussels Airport.

2. Speed Profile

INM requires the true airspeed as a function of the track distance to the runway.The FDM data of Brussels Airlines includes this speed for each time stamp.Combination of this data with the ground track (position and time stamp) allows us create the speed profile.An example for an A330-301 approach is shown in the figure below.

FOQA

FOQA - shifted

Radar (NMS)

FDM

FDM - shifted



Version 4.2 - 15/02/2012 - Page 60

Figure 4-24 - Example of a speed profile for an A33 0 non-CDO approach on Brussels Airport.

3. Altitude profile INM requires the altitude above ground level as a function of the track distance to the runway.The FOQA data contains for each time stamp two fields with an indication of the altitude of the aircraft: the radar altimeter and the altitude derived from the atmospheric pressure.Data from the radio altimeter are very exact, but can only be used below 2500 ft.For the higher levels, the altitudes from the atmospheric pressure (corrected for the altitude of the airport above sea level) will be used.The combination of this data with the ground track (position and time stamp) allows us to build up the altitude profile. An example for an A330-301 approach is shown in the figure below.

0

50

100

150

200

250

300

350

400

-350 -300 -250 -200 -150 -100 -50 0

Tru

e A

irsp

ee

d [

kts

]

distance [1000 ft]



Version 4.2 - 15/02/2012 - Page 61

Figure 4-25 - Example of an altitude profile for an A330 non-CDO approach on Brussels Airport.

4. Thrust profile

INM requires the corrected net thrust (CNT) per engine as a function of the track distance to the runway.Among all necessary data, this profile is the most difficult to create.However the FOQA data contains information about the engines rotation speed and about the engines fuel consumption, no simple and reliable relationship exists between these parameters and the CNT of the engine.

The correct way to calculate the CNT values during approach is to solve the equation of motion of the aircraft where CNT is determined to “balance” the other forces weight, deceleration and drag and lift. In a simplified way (see ECAC Doc.29 3rd Edition - Volume 2 - Appendix B - Eq B-20), this equation can be written as

where the drag and lift forces are expressed in the form of drag-over-lift coefficients (R). In INM 7.0b, these coefficients are available for the airbus aircrafts for different flap settings (Flap Coefficients).

0

2000

4000

6000

8000

10000

12000

14000

16000

-350 -300 -250 -200 -150 -100 -50 0

Alt

itu

de

[ft

]

distance [1000 ft]



Version 4.2 - 15/02/2012 - Page 62

Necessary FDM data fields to solve this equation are: � Time stamp � Position (latitude, longitude) � Altitude � Speed (TAS, GSC) � Weight of the aircraft � Flap setting � Atmospheric pressure and temperature

For the individual CDO and non-CDO flights LAmax noise contours are calculated following the procedure described above.The LAmax parameter represents the maximum value of the A-weighted sound pressure level if an aircraft flies over.Noise contours connect these points on the ground that have the same LAmax value. The noise impact of the CDO and non CDO flights of the same aircraft type approaching the airport are compared in two different ways.

1) Surface of the noise contours 2) LAmax level difference at different track distances to the runway and at

the different lateral positions to the ground track.



Version 4.2 - 15/02/2012 - Page 63

4.44.44.44.4 SELECTION OF DATA SASELECTION OF DATA SASELECTION OF DATA SASELECTION OF DATA SAMPLE FOR DETAILED ANMPLE FOR DETAILED ANMPLE FOR DETAILED ANMPLE FOR DETAILED ANALYSISALYSISALYSISALYSIS

. For detailed analysis of FDM data, both in MS Excel and in INM, a random sample was identified aiming to contain equal numbers of flight for the following combinations, separately for A139 and A333:

• 10 CDO-marked and concluded CDO in EFICAT

• 10 CDO-marked and not concluded CDO in EFICAT

• 10 not-CDO-marked and concluded CDO in EFICAT

• 10 not-CDO-marked an not concluded CDO in EFICAT

This is summarized in the tables below.

A319

Conclusion EFICAT-tool

CDO-approved by ATC CDO No-CDO Totals

Y (marked) 10 10 20

N (not-marked) 10 10 20

Totals 20 20 40

A333



Y (marked) 10 10 20


Totals 20 20 40

Due to the quickly expanding A319/A320 fleet and a few decoding issues with the software, some aircraft were not used for this project (OO-SSQ and OO-SSR). Furthermore, other individual flight data that could not be retrieved due to technical issues (OO-SSP).Therefore these aircraft were removed from the sampling process. The sample was then extended to a total of 46 flights.For 33 from these 46 flights flight data could be retrieved.The resulting sample for A319-arrivals is given in the table below.



Version 4.2 - 15/02/2012 - Page 64

A319



Y (marked) 10 6 16


Totals 18 15 33

For the A333, recorded flight data for 23 out of the 40 selected A333, could be retrieved.The table below gives the distribution for these 23 arrivals with A333.

A333



Y (marked) 7 5 12


Totals 11 12 23


5.5.5.5. DATA ANALYSIS RESULTDATA ANALYSIS RESULTDATA ANALYSIS RESULTDATA ANALYSIS RESULT

5.15.15.15.1 SCOPE OF THE TRIALS SCOPE OF THE TRIALS SCOPE OF THE TRIALS SCOPE OF THE TRIALS

5.1.15.1.15.1.15.1.1 DESCRIPTIONDESCRIPTIONDESCRIPTIONDESCRIPTION

Five airlines participated in the CDODHL and Singapore Airlines Cargo. The trials were performed on the runways 25L & 25R. In the period, starting 1st performed by participating airlines on either the runway 25R or 25L. This is 33 % of all arriving traffic.

Figure 5-1 - All arrivals at EBBR (1 Jul. 2009



Version 4.2 - 15/02/2012 - Page 65

DATA ANALYSIS RESULTDATA ANALYSIS RESULTDATA ANALYSIS RESULTDATA ANALYSIS RESULTSSSS

SCOPE OF THE TRIALS SCOPE OF THE TRIALS SCOPE OF THE TRIALS SCOPE OF THE TRIALS ---- 1 JULY 2009 1 JULY 2009 1 JULY 2009 1 JULY 2009 –––– 33331 OCT 20111 OCT 20111 OCT 20111 OCT 2011

Five airlines participated in the CDO-trials: Brussels Airlines, Jetairfly, Thomas Cook, DHL and Singapore Airlines Cargo. The trials were performed on the runways 25L & 25R.

of July 2009 until 31st of October 2011 89.557 arrivals were performed by participating airlines on either the runway 25R or 25L. This is 33 % of all

All arrivals at EBBR (1 Jul. 2009 – 31 Oct.2011).

1 OCT 20111 OCT 20111 OCT 20111 OCT 2011

trials: Brussels Airlines, Jetairfly, Thomas Cook,

ctober 2011 89.557 arrivals were performed by participating airlines on either the runway 25R or 25L. This is 33 % of all

31 Oct.2011).


Figure 5-2 - All arrivals at EBBR (%) (1 Jul. 2009 31 Oct.2011).

From this 89.557 arrivals by participating airlines on the runways 25R and 25L, the largest amount, 70.283 flights, are arrivals from BrusselsCoos, DHL an Singapore Airlines Cargo respectively performed 8.668, 6.002, 3.888 and 716 arrivals on runways 25R and 25L in the period from 1October 2011.



Version 4.2 - 15/02/2012 - Page 66

All arrivals at EBBR (%) (1 Jul. 2009 31 Oct.2011).

From this 89.557 arrivals by participating airlines on the runways 25R and 25L, the largest amount, 70.283 flights, are arrivals from Brussels Airlines. Jetairfly, Thomas Coos, DHL an Singapore Airlines Cargo respectively performed 8.668, 6.002, 3.888 and 716 arrivals on runways 25R and 25L in the period from 1st of July 2009 until 31

All arrivals at EBBR (%) (1 Jul. 2009 31 Oct.2011).

From this 89.557 arrivals by participating airlines on the runways 25R and 25L, the Airlines. Jetairfly, Thomas

Coos, DHL an Singapore Airlines Cargo respectively performed 8.668, 6.002, 3.888 and of July 2009 until 31st of


Figure 5-3 - Participating airlines, arrivals on RWYs 25R/ (1 Ju l. 2009

5.1.25.1.25.1.25.1.2 SUMMARY AND CONCLUSUMMARY AND CONCLUSUMMARY AND CONCLUSUMMARY AND CONCLU

Participating airlines, arriving on 25R and 25Lrepresent 33% of the traffic at EBBR.This means that the trials are open toof October 2011 this is a total of 89



Version 4.2 - 15/02/2012 - Page 67

Participating airlines, arrivals on RWYs 25R/ (1 Ju l. 2009

SUMMARY AND CONCLUSUMMARY AND CONCLUSUMMARY AND CONCLUSUMMARY AND CONCLUSION FOR POINT 5SION FOR POINT 5SION FOR POINT 5SION FOR POINT 5.1.1.1.1

Participating airlines, arriving on 25R and 25Lrepresent 33% of the traffic at EBBR.This means that the trials are open to one third of the arrivals.From the start of the trials until 31of October 2011 this is a total of 89.557 arrivals.

Participating airlines, arrivals on RWYs 25R/ (1 Ju l. 2009- 31 Oct.2011).

Participating airlines, arriving on 25R and 25Lrepresent 33% of the traffic at EBBR.This one third of the arrivals.From the start of the trials until 31st



Version 4.2 - 15/02/2012 - Page 68

5.25.25.25.2 CDOCDOCDOCDO----MARKED FLIGHTS MARKED FLIGHTS MARKED FLIGHTS MARKED FLIGHTS ---- 1 JULY 2009 1 JULY 2009 1 JULY 2009 1 JULY 2009 –––– 31 OCT 201131 OCT 201131 OCT 201131 OCT 2011

The current section deals only with the data-subset for arrivals by participating airlines on the runways 25R & 25L.

CDO facilitation by ATC is only possible when the traffic situation allows for it. Typically this will be in less busy traffic periods, and also depends on the type of traffic. Therefore only part of the arrivals by participating airlines on the runways 25R/25L will get an ATC approval to perform CDO.

Arrivals facilitated by ATC to perform a CDO are marked by the ATCO. The left hand part of Figure 5-4 shows that between 1st of July 2009 and 31st of October 2011, ATCOs facilitated a total of 5.407 CDOs. The right hand part Figure 5-4 zooms into the current year 2011. In the first 10 months of 2011 already 3094 CDOs were facilitated by ATC. This equals 9% of the total number of arrivals by participating airlines on the runways 25R/L.

Figure 5-4 - Share of CDO-marked flights for the 5 participating airlines (arrivals RWY 25R/L).

5.2.15.2.15.2.15.2.1 CDO MARKED FLIGHTS PCDO MARKED FLIGHTS PCDO MARKED FLIGHTS PCDO MARKED FLIGHTS PER AIRLINEER AIRLINEER AIRLINEER AIRLINE

The figures below provide for each of the five participating airlines the number and percentage of arrivals on runways 25R/L, both for the full period 1 July 2009 – 31 October 2011 and for the current year 2011 (until 31 Oct 2011).

In 2011, for each of the participating airlines the percentage of marked CDOs has improved or at least remained equal compared to the total period from 1 July 2009 until 31 October 2011, showing a positive evolution in the number of marked CDOs. For DHL (BCS) the

marked

5407

6%

not marked

83988

94%

All (BEL, JAF, TCW, BCS, SQC)

Share of CDO-marked

1 Jul. 2009 - 31 Oct.2011

marked

3094

9%

not marked

31426

91%

All (BEL, JAF, TCW, BCS, SQC)

Share of CDO-marked

Jan. -> Oct 2011



Version 4.2 - 15/02/2012 - Page 69

percentage of CDOs marked is significantly larger than for the other airlines. This is because DHL has the highest proportion of night flights and during night the traffic situation more frequently permits to facilitate CDO.

Figure 5-5 - Share of CDO-marked flights for Bruss els Airlines (arrivals RWY 25R/L).

Figure 5-6 - Share of CDO-marked flights for Jetair fly (arrivals RWY 25R/L).

Figure 5-7 - Share of CDO-marked flights for Thomas Cook (arrivals RWY 25R/L).

marked

3796

5%not

marked

66372

95%

BEL

Share of CDO-marked

1 Jul. 2009 - 31 Oct.2011marked

2274

8%

not marked

25132

92%

BEL

Share of CDO-marked

Jan. -> Oct 2011

marked

612

7%not

marked

8036

93%

JAF

Share of CDO-marked

1 Jul. 2009 - 31 Oct.2011marked

272

9%

not marked

2926

91%

JAF

Share of CDO-marked

Jan. -> Oct 2011

marked

440

7%not

marked

5545

93%

TCW

Share of CDO-marked

1 Jul. 2009 - 31 Oct.2011marked

217

10%

not marked

1894

90%

TCW

Share of CDO-marked

Jan. -> Oct 2011



Version 4.2 - 15/02/2012 - Page 70

Figure 5-8 - Share of CDO-marked flights for DHL (a rrivals RWY 25R/L).

Figure 5-9 - Share of CDO-marked flights for Singap ore Airlines Cargo (arrivals 25R/L).

5.2.25.2.25.2.25.2.2 EVOLUTION DURING THEEVOLUTION DURING THEEVOLUTION DURING THEEVOLUTION DURING THE TRIAL PERIODTRIAL PERIODTRIAL PERIODTRIAL PERIOD

Figure 5-10and Figure 5-11 show a relatively high number of CDO-approvals in the months of July and August 2009. From September 2009 onward the number of CDO-approvals falls back, to recover again and to remain relatively stable from December 2010 onward. The drop in number of CDOs can be explained by the transition to a complete new air trafiic control system (CANAC²), asking full attention. Thanks to integration of the trials in the AIRE initiative with the B3-project, the CDO-trials received a new elan. In 2011 (until Oct.2011), there were between 149 and 381 CDO-approvals per month. Percentages are between 6% a month and 11 % a month.

marked

522

13%not

marked

3357

87%

BCS

Share of CDO-marked

1 Jul. 2009 - 31 Oct.2011

marked

318

21%

not marked

1233

79%

BCS

Share of CDO-marked

Jan. -> Oct 2011

marked

37

5%not

marked

678

95%

SQC

Share of CDO-marked

1 Jul. 2009 - 31 Oct.2011marked

13

5%

not marked

241

95%

SQC

Share of CDO-marked

Jan. -> Oct 2011



Version 4.2 - 15/02/2012 - Page 71

Figure 5-10 - Evolution of the number of CDO-marked arrivals.

Figure 5-11 - Evolution of the percentage of CDO-ma rked arrivals.

25

03

33

12

6 15

36

81

2 54 9

5 98

90

58

11

41

01

18

51

30

90 10

62

50 2

95

25

41

49

31

5 34

42

79 3

43 38

13

68

36

6

0

50

100

150

200

250

300

350

400

450

07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10

2009 2010 2011

CDO-marked - evolution

7%

11

%

4% 5%

2%

1% 2

%

4%

3% 4%

2% 3

%

2%

5%

4%

3% 4

%

10

%

10

%

9%

6%

11

%

9%

8% 9

% 10

%

9% 1

0%

0%

2%

4%

6%

8%

10%

12%

14%

07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10

2009 2010 2011

% CDO-marked - evolution



Version 4.2 - 15/02/2012 - Page 72

5.2.35.2.35.2.35.2.3 VARIABILITY FROM DAYVARIABILITY FROM DAYVARIABILITY FROM DAYVARIABILITY FROM DAY TO DAYTO DAYTO DAYTO DAY

For the most recent month of data the variability from day to day is illustrated in Figure 5-12, Figure 5-13 and Figure 5-14. The number of CDO-marked flights varies strongly from day to day. From Figure 5-13 it can be seen that the CDO-peakday in October 2011, counts 39 CDO-marked arrivals, while for 24th of October there were zero CDO-marked arrivals. An important reason is that the CDO trials are only performed on the runways 25R/L. From Figure 5-12 it can be seen that for some days there are no or very little arrivals by participating airlines on the runways 25R/L. Consequently the number of CDO-approvals will be very small or even zero. For example on 24th of October 2011 only 2 flights from participating airlines arrived on runways 25R/L. There were zero CDOs marked for this day. Figure 5-14 gives the percentage of CDO-marked flights. For normal days, the values vary between 0% and 25%. A special case is 13th of October 2011, where only 10 arrivals were performed on the runways 25R/L. 8 from these 10 arrivals received CDO-approval. Deeper investigation revealed that on 13th of October 2011, at 1h35 local time, the arrival runway changed from 25R/L to RWY 02. The 8 CDO-marked arrivals were all performed during the night period.

Figure 5-12 - Total amount of arrivals (participati ng airlines on RWY 25R/L; Oct.2011).

12

01

13

14

6 15

81

47

15

51

62

11

31

14

15

01

53

14

61

04

27

41

37 14

91

47

14

91

56

11

31

03

21

33 14

5 16

21

58

12

21

16

10

8

0

20

40

60

80

100

120

140

160

180

200

01

02

03

04

05

06

07

08

09

10

11

12

13

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

Total - Variability per day (LT)

October 2011



Version 4.2 - 15/02/2012 - Page 73

Figure 5-13 - Number of CDO-marked arrivals per day (Oct.2011).

Figure 5-14 - Percentage of CDO marked arrivals per day (Oct.2011).

5.2.45.2.45.2.45.2.4 VARIABILITY AMONGST VARIABILITY AMONGST VARIABILITY AMONGST VARIABILITY AMONGST THE HOURS OF THE DAYTHE HOURS OF THE DAYTHE HOURS OF THE DAYTHE HOURS OF THE DAY

Analogous to the figures on variability per day, the figures Figure 5-15, Figure 5-16 and Figure 5-17 respectively give: the total average amount of arrivals per hour by, the average number of CDO marked flights per hour and the % of CDO marked flights. Data are for the first 10 months of the current year 2011.

11

15

12

24

10

15

15

11

20

4

16

8

2 3

11

15

3

10

20

17

21

8

13

10

39

18

9

6

0

5

10

15

20

25

30

35

40

01

02

03

04

05

06

07

08

09

10

11

12

13

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

CDO marked - Variability per day (LT)

October 2011

9%

0%

10

%

8%

16

%

6% 9% 1

3%

10

%

13

%

3%

11

%

80

%

5%

4% 8

% 10

%

2% 7

% 13

%

15

% 20

%

0% 6

% 9%

6%

25

%

15

%

8%

6%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

01

02

03

04

05

06

07

08

09

10

11

12

13

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

% CDO marked - Variability per day (LT)

October 2011



Version 4.2 - 15/02/2012 - Page 74

It should be stressed that the figures are a subset from the total set of arrivals at EBBR, containing only the arrivals by participating airlines on the runways 25R/L. The arrival peaks at 08-09h and 18-19h in Figure 5-15 are due to arrival peaks at these moments for Brussels Airlines. Even though Figure 5-15 only contains 33% of the total arrival data for EBBR, the influence of busy landing hours on the amount of CDO marks can be seen in Figure 5-16, with low average numbers of CDOs approved in the hours 08-09h and 18-19h. This effect is even more clearly expressed in Figure 5-17. The hours 08-09h and 18-19h show that on the average only 1%, and 2% arrivals are marked CDO. For other hours the average percentage of marked CDOs is from 6% up to 24%.

Figure 5-15 - Average amount of arrivals per hour ( participating airlines on RWY 25R/L; Jan. -> Oct.2011).

Figure 5-16 - Average amount of CDO-marked arrivals per hour (Jan. -> Oct.2011).

3.82.5

1.1 1.2 1.12.2

1.0

4.1

13.8

4.3 4.7 5.1

7.4 7.5 6.9

4.9 4.95.8

11.9

5.86.9

1.7

6.75.9

0

2

4

6

8

10

12

14

16

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Total - Per hour of the day (LT)

Jan. -> Oct.2011

0.9

0.6

0.2 0.1 0.10.2

0.1

0.30.2 0.3

0.4

0.60.6 0.6

0.50.6

0.4

0.6

0.3

0.4

0.7

0.1

1.2

1.0

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

CDO marked - Per hour of the day (LT)

Jan. -> Oct.2011



Version 4.2 - 15/02/2012 - Page 75

Figure 5-17 - Average % of CDO-marked arrivals per hour (Jan. -> Oct.2011).

5.2.55.2.55.2.55.2.5 VARIABILITY AMONGST VARIABILITY AMONGST VARIABILITY AMONGST VARIABILITY AMONGST THE WEEKDAYSTHE WEEKDAYSTHE WEEKDAYSTHE WEEKDAYS

Bearing in mind that the considered dataset contains only 33% of all arrivals, namely those executed by participating airlines on the runways 25R/L, the distribution of the flights over the weekdays can clearly vary from month to month. This can be seen in Figure 5-18. Averaging over the total period of 10 months in 2011 however shows that Saturday and Sunday have the lowest number of arrivals on runways 25R/L for the participating airlines. This reflects the fact that there is less traffic in the weekend compared to weekdays. The average number of CDOs marked per weekday, as represented in Figure 5-19, is more constant. This means that the average percentage of CDOs approved is the highest in the weekend. This is shown in Figure 5-20.

24%23%

15%

10%12%11%

9% 8%

1%

6%

9%12%

7% 7% 7%

12%

8%11%

2%

7%9%

6%

17%17%

0%

5%

10%

15%

20%

25%

30%

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

% CDO Marked - Per hour of the day (LT)

Jan. -> Oct.2011



Version 4.2 - 15/02/2012 - Page 76

Figure 5-18 - Average number of arrivals per weekda y (participating airlines on RWY 25R/L; first 10 mont hs of 2011).

Figure 5-19- Average number of CDO marked arrivals per weekday (participating airlines first 10 months of 2011).

124 130 129 131 138

102 98

0

20

40

60

80

100

120

140

160

180

MON TUE WED THU FRI SAT SUN

Nu

mb

er

of

arr

iva

ls (

av

era

ge

pe

r

we

ek

da

y)

Total - variability per weekday

Jan. -> Oct.2011

2011_1

2011_2

2011_3

2011_4

2011_5

2011_6

2011_7

2011_8

2011_9

2011_10

Average 2011

9 10 11 10

13 1211

0

5

10

15

20

25

30


Nu

mb

er

of

CD

O m

ark

ed

arr

iva

ls

(av

era

ge

pe

r w

ee

kd

ay)

CDO Marked - variability per weekday

Jan. -> Oct 2011

2011_1

2011_2

2011_3

2011_4

2011_5

2011_6

2011_7

2011_8

2011_9

2011_10

Average 2011



Version 4.2 - 15/02/2012 - Page 77

Figure 5-20 - Percentage of CDO marked arrivals per weekday (participating airlines first 10 months of 2011).

5.2.65.2.65.2.65.2.6 COMPARISON FOR RUNWACOMPARISON FOR RUNWACOMPARISON FOR RUNWACOMPARISON FOR RUNWAYS 25R AND 25LYS 25R AND 25LYS 25R AND 25LYS 25R AND 25L

Figure 5-21 shows that the number of arrivals on runway 25L is much larger than the number of arrivals on runway 25R, with a monthly average of 2071 arrivals on RWY 25L and a monthly average of 1381 arrivals on RWY 25R. This is because runway 25R is not only used as an arrival runway but also is the most used departure runway, while RWY 25L is almost exclusively used as landing runway. When looking at the number of CDO marked arrivals per runway in Figure 5-22, the differences between the runways are smaller compared to the differences for the total amount of arrivals. This is because runway 25R is used relatively more during the calmer night hours, where also arrivals are more eligible to receive a CDOs approval. This is further demonstrated in Figure 5-23,where the highest numbers, expressed in percentages are for Runway 25R, with 10% of CDO-marked arrivals compared to 8% CDO-marked arrivals on RWY 25L.

7% 8% 8% 8%10%

12%11%

0%

5%

10%

15%

20%

25%


% m

ark

ed

% CDO Marked - Variability per Weekday (LT)

Jan. -> Oct. 2011

2011_1

2011_2

2011_3

2011_4

2011_5

2011_6

2011_7

2011_8

2011_9

2011_10

Average 2011



Version 4.2 - 15/02/2012 - Page 78

Figure 5-21 - Average number of arrivals for RWYs 2 5R & 25L (participating airlines; first 10 months of 2011).

Figure 5-22 - Average number of CDO marked arrivals for RWYs 25R & 25L (participating airlines first 10 months of 2011).

0

500

1000

1500

2000

2500

3000

Total - per runway

Jan. -> Oct. 2011

25L

25R

Averages

- 25L: 2071

- 25R: 1381

0

50

100

150

200

250

CDO marked - per runway

Jan. -> Oct. 2011

25L_marked

25R_marked

Averages

- 25L: 174

- 25R: 135



Version 4.2 - 15/02/2012 - Page 79

Figure 5-23 - Percentages of CDO marked arrivals fo r RWYs 25R & 25L (participating airlines first 10 months of 2011).

5.2.75.2.75.2.75.2.7 FLIGHT LEVELS AT WHIFLIGHT LEVELS AT WHIFLIGHT LEVELS AT WHIFLIGHT LEVELS AT WHICH CDO IS APPROVEDCH CDO IS APPROVEDCH CDO IS APPROVEDCH CDO IS APPROVED

Figure 5-24 shows the cumulative distribution for the flight levels at which the flight is CDO-marked. Most of the flights are marked at flight levels between FL60 andFL150.

Figure 5-24 - Cumulative distribution of flight lev els for CDO-marked arrivals

0%2%4%6%8%

10%12%14%

% CDO marked - per runway

Jan. -> Oct. 2011

% 25L

%25R

Averages

- 25L: 8%

- 25R: 10 %

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

0 50 100 150 200 250

Flight level (FL)

Flight level when marked CDO - Cumulative distribution

1 Jul.2009 -> 31 Oct.2011



Version 4.2 - 15/02/2012 - Page 80

Another presentation of the flight levels at which CDO is approved is given in the histogram of Figure 5-25. For this presentation flight levels are rounded to multiples of ten. The median flight level at which flights are marked CDO is FL100. Again it can be seen that most CDOs are marked for flight levels between FL60 and FL150.

Figure 5-25 - Distribution of flight levels for CDO -marked arrivals (1 Jul.2009 -31 Oct.2011).

Figure 5-26 investigates the evolution over time of the average flight level at which CDOs are approved. There is a relatively high variation from month to month of the average flight level at which CDOs are approved. For the evolution over time however, though the linear regression line shows a small increase, there is no clear indication that the flight level at which CDO is approved changed significantly over time.

0%

0%

0%

0%

0%

3%

4%

11%

16%

19%

16%

11%

8%

5%

3%

2%

1%

0%

0%

0%

0%

0%

0%

0%

0% 5% 10% 15% 20%

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

250

Fli

gh

t Le

ve

l (F

L)

Flight level when Marked CDO - Distribution

1 Jul.2009 -> 31 Oct.2011

Median: FL 100

(Average: FL105)



Version 4.2 - 15/02/2012 - Page 81

Figure 5-26 - Evolution of the average FL at the mo ment arrivals are marked CDO.

5.2.85.2.85.2.85.2.8 TRACKMILES FROM TOUCTRACKMILES FROM TOUCTRACKMILES FROM TOUCTRACKMILES FROM TOUCHDOWN AFTER CDO APPRHDOWN AFTER CDO APPRHDOWN AFTER CDO APPRHDOWN AFTER CDO APPROVALOVALOVALOVAL

The average number of trackmiles from touchdown at the moment of CDO marking is 36 NM. Typical numbers of trackmiles from touchdown range from around 20 NM to around 60 NM. The distribution is given in Figure 5-27 and Figure 5-28.

Figure 5-27 - Cumulative distribution of distance f rom touchdown after CDO-mark (1 Jul.2009 -31 Oct.2011).

85

90

95

100

105

110

115

120

07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10

2009 2010 2011

Av

era

ge

Fli

gh

t Le

ve

l (F

L)

Flight Level when CDO marked - Evolution

Average Flight level at which

CDO is approved = FL 105

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140

Distance from touchdown (NM)

Distance from touchdown after CDO marked - Cumulative

Distribution

1 Jul.2009 > 31 Oct.2011

Average number of trackmiles flown

after CDO marked = 36 NM



Version 4.2 - 15/02/2012 - Page 82

Figure 5-28 - Distribution of distance from touchdo wn after CDO-mark (1 Jul.2009 -31 Oct.2011).

The evolution over time of the average distance from touchdown is given in Figure 5-29. As for the flight levels, there is a relatively high variation from month to month of the average distance from touchdown for CDO-marked flights. For the evolution over time however, a linear regression line shows an increase. Mathematically this is due to the relative low average values in July 2009, October 2009, January 2010 and February 2010, but the reasons behind these low numbers could not be traced.

Figure 5-29 - Evolution of the average distance fro m touchdown after CDO-approval.

0%

10%

20%

30%

40%

50%

10 20 30 40 50 60 70 80 90 100 110 120 140 150

Distance from touchdown (M)

Distance from touchdown after CDO-marked - Distribution

1 Jul.2009 -> 31 Oct.2011

Average number of trackmiles

flown after CDO marked = 36 NM

30

32

34

36

38

40

07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10

2009 2010 2011

Av

era

ge

dis

tan

ce f

rom

Tou

chd

ow

n (

NM

)

Distance from touchdown after CDO marked - EvolutionAverage number of trackmiles flown after CDO marked = 36 NM



Version 4.2 - 15/02/2012 - Page 83

5.2.95.2.95.2.95.2.9 EFFECT OF THE CHANGEEFFECT OF THE CHANGEEFFECT OF THE CHANGEEFFECT OF THE CHANGE FROM WRITTEN TO CFROM WRITTEN TO CFROM WRITTEN TO CFROM WRITTEN TO CLICKED CDOLICKED CDOLICKED CDOLICKED CDO----

MARKSMARKSMARKSMARKS

At the start of the trials in July 2009, distance from touchdown was estimated by the ATCO when approving CDO and written down on paper. Thanks to the B3-project a software development was made that allowed analysis of digital input of the ATCO on his CWP (Controller Working Position). This allowed in the course of November 2010 to replace the written input by digital input on the CWP. Distances are now calculated between the position of the arrival on the moment of digitally marking the flight “CDO-approved” and the moment of touchdown. The most important effect is that digitally marking CDOs is more convenient for the ATCO and thus helps to implement the CDO facilitation. Another advantage is that datacollection into a database is now automated, with a lower workload for post-processing as well as avoidance of human errors when interpreting the written forms. It has to be noted that the meaning of the distance information has slightly changed from the “ATCOs estimated distance from touchdown provided to the pilot by ATC”, to “system calculation of the distance from touchdown”. From the data point of view the effect is that for the written data, ATCOs used merely rounded values. Today, thanks to the digital marking, finer values are obtained. This is illustrated in the Figure 5-30 and Figure 5-31 below, respectively for flight levels at which CDOs are marked and for distances flown after CDO-marking.



Version 4.2 - 15/02/2012 - Page 84

Figure 5-30 - Effect of switching to marking of fli ghts on the CWP for flight levels .

0 10 20 30 40 50 60 70 80 90

80

85

90

95

100

105

110

115

120

Number of CDOs marked

Fli

gh

t le

ve

l (FL

)

Flight Levels at which CDOs are marked

1 Jul.2009 - 31 Oct.2011

2011 (until 31 okt.)

2010

2009 (from 1 Jul.)



Version 4.2 - 15/02/2012 - Page 85

Figure 5-31 - Effect of switching to marking of fli ghts on the CWP for distance from touchdown.

5.2.105.2.105.2.105.2.10 SUMMARY AND COSUMMARY AND COSUMMARY AND COSUMMARY AND CONCLUSION FOR POINT NCLUSION FOR POINT NCLUSION FOR POINT NCLUSION FOR POINT 5555.2.2.2.2

In total for 5.407 arrivals a CDO was facilitated by Brussels APP, from which 3094 considered as B3-trials. After a fallback in 2010, CDO facilitation was actively resumed during Phase II of the B3-project. For the period from 1 January 2011 until 31 October 2011 the total amount of CDOs facilitated was 9% of the a total amount of arrivals by participating airlines on the runways 25R/L. The amounts of CDOs marked vary largely from day to day, from week to week and from hour to hour. Two clear and recurrent reasons for the variability are the amount of traffic and the runways that were in use. The higher the traffic, the lower the percentage of CDOs. The trials were only performed on runways 25R and 25L. Therefore on those times when these runways are not used, there is no potential for trialled flights. Flight levels at which the CDO-facilitation starts are variable. The median value is FL100. More than 90% of the flights is marked at flight levels between FL60 and FL150.

0

20

40

60

80

100

120

140

160

180

200

20 25 30 35 40 45 50 55 60

Nu

mb

er

of

CD

Os

ma

rke

d

Distance from touchdown (NM)

Distance from touchdown after CDO-approval

1 Jul.2009 -> 31 Oct.2011

2009 (from 1 Jul.)

2010

2011 (until 31 okt.)



Version 4.2 - 15/02/2012 - Page 86

5.35.35.35.3 CDOCDOCDOCDO----PERFOPERFOPERFOPERFORMANCE (EFICATRMANCE (EFICATRMANCE (EFICATRMANCE (EFICAT----ANALYSIS) ANALYSIS) ANALYSIS) ANALYSIS) –––– APRIL & MAY 2011APRIL & MAY 2011APRIL & MAY 2011APRIL & MAY 2011

The current section provides the results of the EFICAT analysis. Information on the tool and preparation of the datasets can be found in Chapter 4, more specifically in the points 4.2.4 and 4.3.2.

5.3.15.3.15.3.15.3.1 CDOCDOCDOCDO----CRITERIA USEDCRITERIA USEDCRITERIA USEDCRITERIA USED

5.3.1.1 PARAMETER SETTING

The following criteria were used to identify a CDO in the EFICAT-tool, in which solely radar-information is available: - Maximum 1 segment of level flight below the “Above/ Below Altitude Parameter” .

The Above/Below Atlitude Parameter was consecutively set to FL60, FL80 and FL100. - Level flight max. 2.5 NM

Level flight was defined in the EFICAT tool with the following parameters set:

- Level tolerance = 200 ft/min - Minimum Time for Level Plots = 20 sec , this corresponds to:

o 0.7 NM @ 250 kts o 0.6 NM @ 210 kts

All the results are calculated for radar data from the “Above/Below Altitude Parameter” (FL100, FL80 or FL60)down to 1500 ft. The parameter settings used in EFICAT are shown in the Figure 5-32 below.


Figure 5-32 - Parameters set in EFICAT to analyseradardata.

5.3.1.2 CLASSIFICATION IN FO

After the EFICAT analysis each arrival is cla- No CDO = flights that are not CDO below FL60- CDO from FL60 = flights that are CDO from FL60, but not from FL80- CDO from FL80 = flights that are CDO from FL80, but not from FL100- CDO from FL100

Examples for each of this four categories ar



Version 4.2 - 15/02/2012 - Page 87

Parameters set in EFICAT to analyseradardata.

CLASSIFICATION IN FOUR GROUPS OF CDO-PERFORMANCE

After the EFICAT analysis each arrival is classified either as No CDO = flights that are not CDO below FL60 CDO from FL60 = flights that are CDO from FL60, but not from FL80CDO from FL80 = flights that are CDO from FL80, but not from FL100CDO from FL100

Examples for each of this four categories are shown below.

Parameters set in EFICAT to analyseradardata.

PERFORMANCE

CDO from FL60 = flights that are CDO from FL60, but not from FL80 CDO from FL80 = flights that are CDO from FL80, but not from FL100



Version 4.2 - 15/02/2012 - Page 88

Figure 5-33 - Examples for “No CDO”.

Figure 5-34 - Examples for “CDO FL60”.



Version 4.2 - 15/02/2012 - Page 89

Figure 5-35 - Example for “CDO FL80”.

Figure 5-36 - Examples for “CDO FL100”.

5.3.1.3 DATA SAMPLE FOR STATISTICS IN SECTION 5.3

The EFICAT analysis is performed on data for the months of April and May 2011 . All statistics in section 5.3 refer to this period. The EFICAT analysis is performed for all arrivals at EBBR and therefore includes both participating and non-participating airlines, arrivals on all the EBBR-runways and both marked and not-marked arrivals.



Version 4.2 - 15/02/2012 - Page 90

Remark for EFICAT analysis for June and July 2011: Brussels Airlines provided FDM-data for analysis in the B3-project. Most of these FDM-data are for the months April and May 2011. However some are for June and July 2011. For days in June and July where FDM-data were made available by Brussels Airlines, also the EFICAT analysis was run. The EFICAT-analysis for June and July 2011 however are only used in combination with results of the analysis of the FDM-data and are not included in the statistics in section 6.3.

5.3.25.3.25.3.25.3.2 CDOCDOCDOCDO----PERPERPERPERFORMANCE (PROFILES)FORMANCE (PROFILES)FORMANCE (PROFILES)FORMANCE (PROFILES)

5.3.2.1 ALL AIRLINES, ALL RUNWAYS

As shown in the figure below, a total of 55% of all arrivals follows a continuous descent profile below FL100, another 4% follows a Continuous Descent profile from FL80 and 7% follows a continuous descent profile from FL60. Only 34 % of the arrivals does not follow a continuous descent profile.

Figure 5-37 - CDO estimation by EFICAT, all arrival s, all runways.

CDO FL100

10334

55%

CDO FL 80

697

4%

CDO FL 60

1387

7%

No CDO

6313

34%

CDO estimation by EFICAT

All arrivals - All Rwy's



Version 4.2 - 15/02/2012 - Page 91

5.3.2.2 ALL AIRLINES , RUNWAYS 25R/L

The trials are only performed on runways 25R/L. Therefore the figure below shows the % of continuous descent profiles on runways 25R & 25L only. It can be seen that the continuous descent performance is better on the runways 25R/25L compared to the previous figures for all arrivals. The statistic for 25R/L contains both marked and not marked arrivals.

Figure 5-38 - CDO estimation by EFICAT, all arrival s, only runways 25R/L.

5.3.2.3 MARKED VERSUS NOT MARKED FOR ALL AIRLINES

The figure below compares the profiles for marked flights with profiles for non-marked flights. For the non-marked flights 59% flies a continuous descent profile from FL100. For marked flights this % goes up to 82%. This is an increase with 29 % ((82-59)/82) ! The number of arrivals that does not perform a CDO at all is halved from 30% for non-marked flights to 16 % for marked flights. Also remarkable is that for marked flights almost all arrivals are either CDO from FL100 or no CDO, with almost no arrivals with a CDO starting only at FL60 or FL80. For the non-marked flights respectively 4% peforms a CDO from FL80 and 7% performs a CDO from FL60.

CDO FL100

8882

61%

CDO FL 80

604

4%

CDO FL 60

931

6%

No CDO

4286

29%


All arrivals - RWYs 25L/R



Version 4.2 - 15/02/2012 - Page 92

Figure 5-39 - Comparison of CDO-performance estimat ed by EFICAT

for marked flights from participating airlines and not marked flights for all airlines.

5.3.2.4 MARKED VERSUS NOT MARKED FOR PARTICIPATING AIRLINES

It can be seen from Figure 5-39 and Figure 5-40 that the CDO-performance even for not marked flights is better for airlines participating to the trials compared to the total group of airlines. A potential reason is that pilots from participating airlines give more attention to optimising their descent profile, either because of company policy, either thanks to the increased awareness via the B3-trials. Evidence for the latter is that some controllers reported that pilots seem to perform more CDOs even when not given explicit approval. Other potential explication could be that the four most frequent users of EBBR participate in the trials and thus their pilots might be more familiar with the airport and thus can better optimise their profile. As no historical comparable datasets from before the trials is available, the above potential explications cannot be checked.

Also for the participating airlines, the marked flights show a clearly better CDO-performance than the not marked flights. 82 % of the marked flights has a CDO-profile from FL100 in EFICAT, compared to 65% of the not marked flights. This is an increase with 21% ((82-65)/82).

For participating airlines, the percentage of arrivals that have no CDO profile at all reduces from 26% for non marked flights to 16 % for marked flights. This is a reduction with 38 % ((26-16)/26).

CDO FL100

8356

59%

CDO FL 80

598

4%

CDO FL 60

925

7%

No CDO

4180

30%


All airlines - RWYs 25L/R

Not Marked

CDO FL100

526

82%

CDO FL 80

6

1%

CDO FL 60

6

1%

No CDO

106

16%


Participating airlines - RWYs 25L/R

Marked



Version 4.2 - 15/02/2012 - Page 93

Figure 5-40 - Comparison of CDO-performance estimat ed by EFICAT for marked flights from participating airlines with not marked flights for all airlines.

5.3.2.5 COMPARISON FOR RUNWAY 25 R & 25L

Figure 5-41 shows the comparison between runways 25R and 25L of the CDO-performance for marked flights. The CDO performance is somewhat better for runway 25L compared to runway 25R. This is in the line of expectations because the proportion of downwind arrivals is larger for RWY 25R as for RWY 25L.

Figure 5-41 - Comparison of CDO-performance estimat ed by EFICAT for Runways 25R and 25L.

CDO FL100

3844

65%

CDO FL 80

241

4%

CDO FL 60

274

5%

No CDO

1536

26%


Participating airlines - 25R/L

Not Marked

CDO FL100

526

82%

CDO FL 80

6

1%

CDO FL 60

6

1%

No CDO

106

16%


Participating airlines - 25R/L

Marked

CDO FL100

241

79%

CDO FL 80

6

2%

CDO FL 60

2

1%

No CDO

57

18%


Participating airlines - 25R

Marked

CDO FL100

285

84%

CDO FL 60

4

1%

No CDO

49

15%


Participating airlines - 25L

Marked



Version 4.2 - 15/02/2012 - Page 94

5.3.35.3.35.3.35.3.3 CDOCDOCDOCDO----PERFORMANCE (PROFILEPERFORMANCE (PROFILEPERFORMANCE (PROFILEPERFORMANCE (PROFILES) FOCUS ON BRUSSELSS) FOCUS ON BRUSSELSS) FOCUS ON BRUSSELSS) FOCUS ON BRUSSELS AIRLINESAIRLINESAIRLINESAIRLINES

The figures in this point provide the EFICAT CDO-performance per aircraft type for arrivals with callsign “BEL”.

When interpreting the data it should be born in mind that the number of flights can hugely differ per aircraft type. Figure 5-42 below provides an overview of the number of flights per aircraft type that operated under the BEL-callsign in the dataset for April and May 2011. Figure 5-43 gives the number of marked BEL-flights in the datasampleanalysed with EFICAT. From the latter figure it is clear that average for marked flights are relevant for the Airbusses, the Boeings 733 and 734 and the Avros, but less for DH8D, the Embraers and the other Boeings. These aircraft types are therefore not included in all of the figures that follow.

Figure 5-42 - EFICAT CDO estimation in absolute val ues – all runways, all arrivals with BEL-callsign.

0

500

1000

1500

2000

BEL - CDO estimation by EFICAT

All Arrivals - All RWY's

No CDO

CDO FL 60

CDO FL 80

CDO FL100



Version 4.2 - 15/02/2012 - Page 95

Figure 5-43 - Number of marked BEL-arrivals per air craft type in the April-May 2011 dataset analysed with EFICAT.

Figure 5-44 below gives the overall CDO-performance for BEL-flights. The Avros and the Boeings have the highest overall CDO performance, with more than 60% of CDOs below FL100 and 30% or less with no CDO. The Airbus 333 has, with 39%, the lowest percentage of CDOs-profiles below FL100, as well as with 45% the highest number of non CDO profiles.

89

825

45 44

4 1

114131

0

20

40

60

80

100

120

140

A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85

Nu

mb

er

of

ma

rke

d f

ligh

ts

Marked BEL arrivals - Per Aircraft type

in April- May 2011 dataset analysed with

EFICAT



Version 4.2 - 15/02/2012 - Page 96

Figure 5-44 - CDO-performance per aircraft type est imated by EFICAT for Brussels Airlines arrivals on all runways.

While Figure 5-44 above provides numbers of the total amount of arrivals, the Figure 5-45 focuses on all arrivals on the runways in the trials, 25R and 25L. For 25R/L the CDO performance is clearly better when looking only at runways 25R/L.

48

%

50

%

39

%

63

%

61

%

62

%

51

%

66

%

65

%

2% 1%

2%

5%5% 1%

7%

3% 3%

9% 8%

14%

6%5%

16%

5%

5% 5%

41

%

41

%

45

%

26

%

30

% 21

%

37

% 25

%

27

%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85


All arrivals - All RWY's

No CDO CDO FL 60 CDO FL 80 CDO FL100



Version 4.2 - 15/02/2012 - Page 97

Figure 5-45 - CDO-performance per aircraft type est imated by EFICAT for Brussels Airlines arrivals on runways 25R and 2 5L.

Figure 5-46 compares side by side the CDO-performance for marked an not marked arrivals on the runways 25R/L.

For each of the individual aircraft types, the CDO-performance is clearly better for marked flights compared to non-marked flights.

For Avros, marked flights have respectively 84% and 88% of CDO-profiles compared to 73% and 71% for non marked flight.

For DH8D and E145 100 % of the marked flights have a CDO-profile below FL100. However ref. figure 6.30 there are only 4 marked DH8D and 1 marked E145 in the analysed dataset.

For the Airbus 319 the % of CDO-profiles below FL100 increases from 52% for non marked

53

%

54

%

44

%

66

%

63

% 71

%

50

%

74

%

72

%

2% 1%

2%

6%5%

2%

8%

3% 3%

8% 7%

15%

3%4%

12%

6%

3% 3%

37

%

38

%

39

%

25

%

28

% 15

%

36

%

21

%

22

%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85


All arrivals - RWY's 25R/L




Version 4.2 - 15/02/2012 - Page 98

flights to 63 % for marked flights - an increase with 21% ((63-52)/52). For the Airbus 333 the % of CDO profiles below FL100 increases from 42% for non marked flights to 60% for marked flights - an increase with 43 % ((60-42)/42).

Figure 5-46 - Comparision of CDO-performance estima ted by EFICAT for marked and not marked arrivals - per aircraft type for Brussel s Airlines arrivals on runways 25R

and 25L.

5.3.45.3.45.3.45.3.4 FUEL AND CO2 ESTIMATFUEL AND CO2 ESTIMATFUEL AND CO2 ESTIMATFUEL AND CO2 ESTIMATIONS WITH EFICATIONS WITH EFICATIONS WITH EFICATIONS WITH EFICAT

The EFICAT tool only has available radar data to estimate fuel use and CO2-emissions. Based on the radar data and in combination with BADA (Base of Aircraft Data) reference datasets per aircraft type, the EFICAT-tool makes estimations of the fuel used and CO2 produced.

Fuel data for a limited amount of A319 and A333 is also made available for the B3-project by Brussels Airlines. These data are real fuel measurements and thus are more reliable. These more reliable results are included in section 5.5 and show a fuel difference between marked and not-marked flight of +/- 50 kg for A319 and +/- 100 kg for A333.

Fuel and Co2-estimations made with the EFICAT tool are presented in the Figure 5-47, Figure 5-48and Figure 5-49. Figure 5-47 and Figure 5-48 show the difference in respectively

63

%

88

%

60

%

80

%

82

%

10

0%

10

0%

84

%

88

%

1% 8%

34

%

13

%

32

% 20

%

18

%

15

%

12

%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85


Marked - 25R/L


52

%

49

%

42

%

65

%

61

% 70

%

50

%

73

%

71

%

2%2%

2%

7%

6%

2%

8%

3% 3%

9%8%

16%

3%4%

12%

6%

3% 3%

37

%

41

%

40

%

25

%

29

% 16

%

36

%

22

%

23

%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

A319 A320 A333 B733 B734 DH8D E145 RJ1H RJ85


Not marked - 25R/L




Version 4.2 - 15/02/2012 - Page 99

average fuel and average CO2 for marked and not marked flights for all participating airlines. Except for A30B, the average fuel and CO2 estimates for marked flights are systematically lower compared to not marked flights. The largest difference, an average difference of 125 kg fuel/393 kg CO2 is for B744. As a remark it can be said that the dataset contains 5 marked and 47 not marked B744 with a rather continuous range of fuel values, which provides confidence that no extreme data cause the big difference, but rather the fact that it is the largest aircraft analysed.

Figure 5-47 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for all part icipating airlines.

-5

1522

27

1914

38

17

125

14 16

26

12

-20

0

20

40

60

80

100

120

140

A30B A319 A320 A333 B733 B734 B735 B737 B738 B744 B752 RJ1H RJ85 Grand

TotalFu

el d

iffe

ren

ce (

FL1

00

-1

50

0ft

) b

etw

ee

n n

on

-ma

rke

d

an

d m

ark

ed

arr

s. (

kg

)

EFICAT Fuel estimation (FL100 - 1500 ft)

Participating airlines (min. 5 marked per Aicraft type)

Difference between non-marked and marked



Version 4.2 - 15/02/2012 - Page 100

Figure 5-48 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for all part icipating airlines.

Figure 5-49 and Figure 5-50 below provide the same types of graph, but this time for only the Brussels Airlines flights.

As a global average for Brussels Airlines, EFICAT calculates a difference per flight of 16 kg/ for marked versus not marked flights. For two of these aircraft types: A319 and A333, also real fuel data were received from Brussels airlines. From these FDM-data the difference between marked and non marked flights is clearly larger with +/- 50 kg of difference for A319 and +/- 100 kg difference for A333. So at least for those two aircraft types, the EFICAT estimates of the difference in fuel use is at the lower side.

-15

4768

8660

45

1024

52

393

44 51

82

37

-50

0

50

100

150

200

250

300

350

400

450

A30B A319 A320 A333 B733 B734 B735 B737 B738 B744 B752 RJ1H RJ85 Grand

TotalCO

2d

iffe

ren

ce (

FL1

00

-1

50

0ft

) b

etw

ee

n n

on

-ma

rke

d

an

d m

ark

ed

arr

s. (

kg

)

EFICAT CO2 estimation (FL100 - 1500 ft)

Participating airlines (min. 5 marked per Aicraft type)




Version 4.2 - 15/02/2012 - Page 101

Figure 5-49 - Average absolute difference in EFICAT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines.

15

24

27

19

17 16

26

16

0

10

20

30

A319 A320 A333 B733 B734 RJ1H RJ85 Grand

TotalFu

el d

iffe

ren

ce

(FL1

00

-1

50

0ft

) b

etw

ee

n n

on

-ma

rke

d

an

d m

ark

ed

arr

s. (

kg

)


Brussels Airlines (min. 5 marked per Aircraft type)




Version 4.2 - 15/02/2012 - Page 102

Figure 5-50 - Average absolute difference in EFICAT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines.

Figure 5-51 and Figure 5-52 below also show the percentage differences in respectively fuel and CO2 between marked and not marked flights for Brussels Airlines’ flights. Marked flights compared to not marked flight show, based on EFICAT estimations, differences between 7% and 19% of fuel and CO2 use.

47

75

86

5953 52

82

50

0

10

20

30

40

50

60

70

80

90

100


TotalCO

2d

iffe

ren

ce (

FL1

00

-1

50

0ft

) b

etw

ee

n n

on

-ma

rke

d

an

d m

ark

ed

arr

s. (

kg

)






Version 4.2 - 15/02/2012 - Page 103

Figure 5-51 - Average percentage difference in EFIC AT fuel estimation for marked and not marked flights – per aircraft type for Brussels Airlines.

11%

19%

7%

11%10%

11%

19%

10%

0%

5%

10%

15%

20%


Total

Fu

el d

iffe

ren

ce

(FL1

00

-1

50

0ft

) b

etw

ee

n n

on

-ma

rke

d

an

d m

ark

ed

arr

s. (

kg

)






Version 4.2 - 15/02/2012 - Page 104

Figure 5-52 - Average percentage difference in EFIC AT CO2 estimation for marked and not marked flights – per aircraft type for Brussels Airlines.

5.3.55.3.55.3.55.3.5 FUEL AND CO2 ESTIMATFUEL AND CO2 ESTIMATFUEL AND CO2 ESTIMATFUEL AND CO2 ESTIMATIONS WITH EFICAT COIONS WITH EFICAT COIONS WITH EFICAT COIONS WITH EFICAT COMPARED TO FDMMPARED TO FDMMPARED TO FDMMPARED TO FDM----

FUEL DATAFUEL DATAFUEL DATAFUEL DATA

Figure 5-53 shows for each Airbus 319 flight with FDM-data provided, the difference between the fuel estimation with the EFICAT-tool and the real fuel . Estimations by the EFICAT-tool are relatively good for A319. For CDO flights the differences are equally spread above and below zero. For non CDO flights EFICAT tends to underestimate the fuel use.

11%

19%

7%

11%10%

11%

19%

10%

0%

5%

10%

15%

20%


TotalCO

2d

iffe

ren

ce (

FL1

00

-1

50

0ft

) b

etw

ee

n n

on

-ma

rke

d

an

d m

ark

ed

arr

s. (

kg

)






Version 4.2 - 15/02/2012 - Page 105

Figure 5-53 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 319.

The next figure shows for each Airbus 333 with FDM-data provided, the difference between the fuel estimation with the EFICAT-tool and the real fuel based on FDM-data. It can be seen that for A333, EFICAT overestimates the fuel used. Overestimations are larger for A333 that fly CDO-profiles compared to A333 that fly non CDO profiles.

-60

-40

-20

0

20

40

60

0 4

Difference of EFICAT fuel

estimations with FDM-data

A319

CDO100 CDO60 No_CDO



Version 4.2 - 15/02/2012 - Page 106

Figure 5-54 - Difference of Eficat fuel estimation compared to FDM fuel data for Airbus 330.

5.3.65.3.65.3.65.3.6 SUMMSUMMSUMMSUMMARY AND CONCLUSION FARY AND CONCLUSION FARY AND CONCLUSION FARY AND CONCLUSION FOR POINT 5OR POINT 5OR POINT 5OR POINT 5.3.3.3.3

For the analysis of radartracks with the Eurocontrol EFICAT tool, an arrival was considered CDO if there was only one segment of level flight, with a maximum length of 2.5 NM. The analysis was done from FL60, from FL80 and from FL100, each time until 1500 ft.

Radardata were analysed for all arrivals at Brussels Airport in the months of April and May 2011, allowing comparisons for CDO-marked and not CDO marked flights. A first observation is the relatively high amount of CDO-profiles: 66% of all arrivals in April and May 2011 had a

-250

-200

-150

-100

-50

0

50

100

150

200

250

0 4

Difference of EFICAT fuel

estimations with FDM-data

A333

CDO100 CDO60 No CDO



Version 4.2 - 15/02/2012 - Page 107

CDO-profile below FL60. 55% even had a CDO-profile below FL100. These numbers are for the total of all airlines, and for all runways.

The amount of CDO-profiles on the runways 25R and 25L for marked flights is 82%. This is a significant increase with regard to not-marked flights for which 59% shows CDO-profiles below FL100.

Exact fuel figures can only origin from airlines. As the B3-project has shown, it asks considerable effort to extract and analyse these data. Also, except in projects like B3, ANSPs and Airports do not have access to the airlines’ fuel data. Therefore the Eurocontrol EFICAT tool provides fuel estimations based on only radar-data.

Fuel estimations with EFICAT show systematically fuel gains for marked flights compared to not marked flights, indicating that fuel can be saved for CDO-facilitated flights. The fuel gains vary widely from aircraft type to aircraft type from around zero to 125 kg for B744.

One of the actions of the B3-project was to compare fuel estimations from the EFICAT tool with real fuel data, for 2 aircraft types. For these two aircraft types the EFICAT-tool seemed to under-estimate the real fuel gains.



Version 4.2 - 15/02/2012 - Page 108

5.45.45.45.4 RESULTS OF CDO TROUBRESULTS OF CDO TROUBRESULTS OF CDO TROUBRESULTS OF CDO TROUBLE REPORT (ATCOS).LE REPORT (ATCOS).LE REPORT (ATCOS).LE REPORT (ATCOS).

Vertical profile.

Traffic routeing via FLORA (CTA East) is overflying Beauvechain TMA and thus is restricted in altitude. This altitude restriction should not be an issue when performing a CDO of +/- 3° descent angle.

At the start of the project CDO Trouble Reports were filed regarding the incorrect execution of CDOs, especially in respect of the vertical profile. This led to an increase of ATCOs interventions to prevent airspace infringements.

By issuing ‘INITIAL’ descend clearances, this problem was solved and no more Trouble Reports regarding this issue were filed.

Speed.

A second issue which was reported in the CDO Trouble Reports was that pilots were not adhering to the published speeds.

It was observed that some pilots maintained a relatively high speed and used a portion of level flight in low altitudes to reduce the speed.

Airlines were asked to brief pilots to adhere to the published speeds.

A third identified issue was regarding the correct speed “phraseology” and the use of it.All ATCOs were briefed on the correct phraseology.

• Avoid the use of “High speed approved”

• The correct phraseology is “No ATC speed restriction”

Remark: this does not apply to situations where speed control is needed for sequencing.



Version 4.2 - 15/02/2012 - Page 109

5.55.55.55.5 RESULTS FROM FDMRESULTS FROM FDMRESULTS FROM FDMRESULTS FROM FDM----ANALYSISANALYSISANALYSISANALYSIS

5.5.15.5.15.5.15.5.1 EXAMPLES.EXAMPLES.EXAMPLES.EXAMPLES.

Airbus A330-300 – Early descent with several level-off parts.

(Ref. A333_01).

Figure 5-55 - Airbus A330-300 – Early descent with several level-off parts.

This flight initiated its descent about 108 NM prior to the TOD corresponding with the reference descent path. Intermediate level-offs were performed at FL340, FL200 and finally at 3000 ft altitude. The aircraft, although coming close to it at FL200, remained below the reference profile during its entire descent.

The flight did not receive a CDO-approval.



Version 4.2 - 15/02/2012 - Page 110

Figure 5-56 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn.

Comparison of the flown profile against the reference descent profile revealed a 460.2 kg fuel penalty and an extra flight time of 3.9 minutes between TOD and a descent fix defined at 1500 ft above runway threshold. Wind below FL200 proved to have no significant impact on the overall profile.

Detailed examination of the descent path below FL100 revealed a level portion of about 10 NM.

Figure 5-57 - Airbus A330-300 – Early descent with several level-off parts - Fuel Burn low altitude.



Version 4.2 - 15/02/2012 - Page 111

This level portion appeared to account for more than 200 kg extra fuel burn in comparison with the fuel burn figure when flying the reference profile. Note the perfect parallelism of both fuel burn figures, which confirms the validity of the reference profile fuel burn.

The level portion at FL200 accounted for another 200 kg extra fuel burn.

Airbus A330-300 – Descent initiated slightly before the reference profile TOD.

(Ref. A333_03).

Figure 5-58 - Airbus A330-300 – Descent initiated s lightly before the reference profile TOD.

A reduced rate of descent was applied until reaching the profiles descent at about FL380. The profile was followed until FL150. Then, the flight crew opted for a descent below the reference profile until a level off portion brought the aircraft back on this profile. Later on, the aircraft again descended below its reference profile.

The flight did not receive a CDO-approval.



Version 4.2 - 15/02/2012 - Page 112

Figure 5-59 - Airbus A330-300 – Descent initiated s lightly before the reference profile TOD - Fuel Burn.

Comparison of the flown profile against the reference descent profile revealed a 137.8 kg fuel penalty and an extra flight time of 0.6 minutes between TOD and a descent fix defined at 1500 ft above runway threshold. A FDM-anomaly on this particular aircraft prevented us from calculating and plotting the ‘air-distance’ in order to evaluate the possible impact of wind.

Figure 5-60 - Airbus A330-300 – Descent initiated s lightly before the reference profile TOD - Fuel Burn low altitude.



Version 4.2 - 15/02/2012 - Page 113

The 8 NM long flat portion of the descent at FL60 accounted for an extra fuel burn of around 100 kg. This level-off was used to reduce speed to 250 KIAS. It is not clear why the flight crew elected to accelerate again, and by doing so, drifted again below the reference profile.

Once more, please note the perfect parallel between both fuel burn figures.

Airbus A330-300 – Adherence to reference profile and speed schedule.

(Ref. A333_06).

Figure 5-61 - Airbus A330-300 – Adherence to refere nce profile and speed schedule.

For this flight, the crew apparently was forced to initiate the descent some 50 NM prior to TOD, and elected to descent at 1000 fpm until reaching (more or less) the reference descent path. From that very moment, and despite the fact that no CDO-approval was delivered, a continuous descent was flown until intercept of the glideslope.



Version 4.2 - 15/02/2012 - Page 114

Figure 5-62 - Airbus A330-300 – Adherence to refere nce profile and speed schedule- Fuel Burn.

This conduct of the descent even resulted in a 3.2 kg fuel burn gain in comparison with the reference profile. The 1.1 minutes time penalty probably results from the descent being flown at 290 KIAS i.s.o 300kt. Note the deceleration to 250 KIAS below FL100.



Version 4.2 - 15/02/2012 - Page 115

Airbus A330-300 – Descent above the reference profile.

(Ref. A333_22).

Figure 5-63 - Airbus A330-300 – Descent above the r eference profile.

In this flight, the descent was initiated well beyond the reference profile TOD, and remained above this reference profile. A level-off at FL220, probably forced, even aggravated this situation. In order to retrieve a ‘normal’ descent profile, extensive use of the spoilers had to be made.

The flight received a CDO-approval at FL124, some 40 NM prior to touchdown. The aircraft was well above the reference profile at that time.



Version 4.2 - 15/02/2012 - Page 116

Figure 5-64 - Airbus A330-300 – Descent above the r eference profile – Fuel Burn.

Late initiation of the descent and the intermediate level-off at FL220 accounted for more than 250 kg extra fuel burn.

Figure 5-65 - Airbus A330-300 – Descent above the r eference profile – Fuel Burn Low Altitude.


The deceleration to 250 KIAS was initiated slightly late, which, combined with a fairly flat descent segment of 8 NM length, may h80-100 kg extra fuel burn.

5.5.25.5.25.5.25.5.2 RECURRENT OBSERVATIORECURRENT OBSERVATIORECURRENT OBSERVATIORECURRENT OBSERVATIO

1. Airplane FMGS As previously mentioned, the FMGS computes the optimum target speed (ECONSPD/MACH) as a function of:� Cost index (CI) � Cruise flight level (CRZ FL)� Gross weight (GW) � Wind and temperature models� Performance factor.

Based on the flight observed and the crew debriefing given, it is obvious that the FMGS module works perfectly as advertise

a. The FCOM, as shown in the paragwithout any level portion allocated for speed reduction.

Figure 5- 66



Version 4.2 - 15/02/2012 - Page 117

The deceleration to 250 KIAS was initiated slightly late, which, combined with a fairly flat descent segment of 8 NM length, may have led to a 3 NM level-off at 2000 ft, resulting in a

RECURRENT OBSERVATIORECURRENT OBSERVATIORECURRENT OBSERVATIORECURRENT OBSERVATIONSNSNSNS

the FMGS computes the optimum target speed (ECONSPD/MACH) as a function of:

el (CRZ FL)

Wind and temperature models

Based on the flight observed and the crew debriefing given, it is obvious that the FMGS module works perfectly as advertised, with restrictions.

as shown in the paragraphs above, will calculate an optimum descent any level portion allocated for speed reduction.

66 - Airbus A319 – FCOM Descent Profile.

The deceleration to 250 KIAS was initiated slightly late, which, combined with a fairly flat off at 2000 ft, resulting in a

Based on the flight observed and the crew debriefing given, it is obvious that the FMGS

will calculate an optimum descent


b. The FMGS will do dynamic planning and speed reduction and initial configuration.portion to variate in length depending on the aircraft speed. The higher the speed, the longer the level portion will be.

Figure 5-67 -

As observed on the above graph (Figure 1.33) the FMGS takes into account three factors:

1) Non obstent what the FCOM (used for planning) gives; the FMGS does not provid

2) In standard conditions the FMGS will provide a deceleration segment between 1.8 to 2nm for deceleration from 250kts to 220kts (initial approach segment for Flap/Slat extension)

3) This level segment is dynamic, the higher thethe segment. This is consistent with high Cost Index to allow safe reduction.

This is of course correct provided the crew has entered descent winds. Otherwise the FMGS will extrapolate between the actual wind during descent and the windin the PERF APPROACH PAGEby the crew. Any incorrect or absence of data could induce invalid profiles causing steeper or shallower approaches.



Version 4.2 - 15/02/2012 - Page 118

The FMGS will do dynamic planning and has a level portion speed reduction and initial configuration. The dynamic planning will allow the level portion to variate in length depending on the aircraft speed. The higher the speed, the longer the level portion will be.

Airbus A319 – FCOM versus FMGS profiles.

s observed on the above graph (Figure 1.33) the FMGS takes into account three

Non obstent what the FCOM (used for planning) gives; the FMGS does not provide a deceleration during descent.In standard conditions the FMGS will provide a deceleration segment between 1.8 to 2nm for deceleration from 250kts to 220kts (initial approach segment for Flap/Slat extension)This level segment is dynamic, the higher thethe segment. This is consistent with high Cost Index to allow safe reduction.

This is of course correct provided the crew has entered descent winds. Otherwise the FMGS will extrapolate between the actual wind during descent and the wind entered in the PERF APPROACH PAGE by the crew. Any incorrect or absence of data could induce invalid profiles causing steeper or shallower approaches.

of flight to allow for The dynamic planning will allow the level

portion to variate in length depending on the aircraft speed. The higher the speed,

FCOM versus FMGS profiles.

s observed on the above graph (Figure 1.33) the FMGS takes into account three

Non obstent what the FCOM (used for planning) gives; the e a deceleration during descent.

In standard conditions the FMGS will provide a deceleration segment between 1.8 to 2nm for deceleration from 250kts to 220kts (initial approach segment for Flap/Slat extension) This level segment is dynamic, the higher the speed the longer the segment. This is consistent with high Cost Index to allow



Version 4.2 - 15/02/2012 - Page 119

2. Pilot Flying Technics

a. Standard approaches using FMGS guidance will show a slightly less than optimum profile. But higher profile could induce late speed reduction with drag devices (speed brakes, landing gear extension, etc.) There for in normal operation the 40kg lost in the level portion have to be considered as the normal fuel consumption during final descent.

b. However, such as described in the manufacturer manuals

� Low Drag Low Noise (Boeing) � Low Power Low Drag (Airbus)

It is possible depending on company regulation and adequate weather, for the pilot to adjust his flight to minimize any configuration change provided he be established on profile in landing configuration with thrust set latest at 1000ft or 500ft Above Ground Level (AGL) (see company regulations)

c. Adding FMGS information and Low Power Low Drag technic can bring the aircraft exactly on the FCOM profile while remaining safe in all aspects of the flight. This requires pilot techniques that are part of the basic flying skills but tend to be less trained over the years.

d. Knowing the importance of the impact of a proper descent to be executed at all times and that the pilot, using all the tools in his possession, can perform as the manufacturer advises in the FCOM, it is the responsibility of each company to brief and train the pilots to the maximum extent possible. Every company is responsible to set the safety standards as high as possible and in the same time train their pilots to achieve CDOs as much as possible. This is where most of the work started within Brussels Airlines: changing the mentalities by making the pilots aware of the savings in fuel (and by such in CO2 emissions) that could be made on a daily basis. Even if all flights cannot perform an optimum descent from TOD, it is possible with partial CDO to make for what was lost on other flights due to external factors (traffic congestion, bad weather, etc.)

e. Examples below will demonstrate various situations where less than optimal resources where used. The causes can by various and cannot be deduced from the graphs below. These deviations can be caused weather, ATC, aircraft restrictions. The aim is not to blame but to learn.



Version 4.2 - 15/02/2012 - Page 120

General tendency to remain below the reference (FMS ) descent profile.

Example: A319_03

Figure 5-68 - Airbus A319 – below profile.

Example: 333_05

Figure 5-69 - Airbus 330 – below profile.



Version 4.2 - 15/02/2012 - Page 121

Inappropriate(?) use of speedbrakes.

Example: A319_10

Figure 5-70 - Airbus 319 – use of speedbrake profil e.



Version 4.2 - 15/02/2012 - Page 122

High speed below FL100.

Example: A319_13

Figure 5-71 - Airbus 319 – high speed below 10.000f t profile.

Example: A319_19

Figure 5-72 - Airbus 319 – high speed below 10.000f t profile (2).



Version 4.2 - 15/02/2012 - Page 123

5.5.35.5.35.5.35.5.3 OVERVIEW OF RESULTS.OVERVIEW OF RESULTS.OVERVIEW OF RESULTS.OVERVIEW OF RESULTS.

The following pages contain the tabulated results of the detailed fuel burn analysis of 56 descents into Brussels Airport.

All descents were flown using either Airbus A319 or Airbus A330-300 (A333) aircraft. A mix of flights with and without explicit CDO-approval were considered:

Aircraft Type Explicit CDO-approval Without CDO-approval

Airbus A319 16 17

Airbus A330-300 12 11

Legend and meaning of the data used in following Ta bles: REF-field: Column 1: Unique reference for each flight. Detailed graphs available for each flight

Column 2: Tail number of the aircraft which performed the descent

CDO approval info: Column 1: Indicates whether or not a CDO-approval was issued. “Marked” means CDO.

Column 2: Time of day of the issuance of the clearance.

Column 3: Duration of the approved CDO-portion of the descent.

Column 4: Altitude (FL – flight level) at which the CDO-approval was issued.

Column 5: Remaining distance (NM) to touchdown at issuance of CDO-approval.

EFICAT-field: Column 1: Indicates whether or not the descent path between FL60 and 1.500 ft AGL

was considered to be a CDO by the Eurocontrol EFICAT-tool. Column 2: Idem for the descent between FL80 and 1.500 ft AGL. Column 3: Idem for the descent between FL100 and 1.500 ft AGL.



Version 4.2 - 15/02/2012 - Page 124

Results based on FDM data: Column 1: Indicates an eastbound (KERKY) or westbound (FLO) approach into either

RWY25L or RWY25R at Brussels Airport.

Column 2: Fuel burn (kg) during the descent from FL60 down to 1500 ft AGL. Column 3: Idem column 2 from FL80 down to 1.500 ft AGL. Column 4: Idem column 2 from FL100 down to 1.500 ft AGL.

Column 5: Descent initiation point versus the reference profile top-of-descent (TOD). E = early descent (before the reference TOD) A = ‘at’ the calculated reference TOD L = late descent (after the reference TOD)

Column 6: Actual descent profile versus reference descent profile between FL300 and FL200. A = above the profile O = on the profile B = below the profile Column 7: Idem column 6 between FL200 and FL100. Column 8: Idem column 6 below FL100.

Column 9-11: Altitude (feet) of intermediate level-off segment(s) if any observed.

Column 12: Speed brake use between FL300 and FL200. Column 13: Idem column 12 between FL200 and FL100. Column 14: Idem column 12 below FL100.

Column 15: Average indicated air speed (KIAS) above FL100. Column 16: Idem column 15 below FL100. Airbus A319.

Ten flights proceed along an eastbound pattern; the remainder (23) follow a westbound pattern into the landing runway(s).

Note that only one descent path is above the reference profile below FL100; three are more or less on the reference profile. The overwhelming majority is clearly below the reference profile.

Although not known to which extent (the FDM-data do not record the details), 9 flights make use of the speed brake below FL100.

For all the analysed descents we recorded/calculated following fuel burn (kg):



Version 4.2 - 15/02/2012 - Page 125

FL60-1500 FL80-1500 FL100-1500

Minimum value 48.1 56.6 66.8

Maximum value 200.0 219.0 243.5

Median value 85.1 103.6 119.4

Average value 90.7 115.0 133.9

Standard deviation 33.8 41.2 44.0

Table 5-1 - Airbus A319 – Overview of all flights – Fuel Burn.

For 6 out of the 16 flights with an explicit CDO-approval delivered, the EFICAT-tool does not consider the flown descent below FL100 to be compatible with a “CDO”. This finding is confirmed by the FDM-data analysis.

For all descents with a CDO-approval, we have following fuel burn (kg):

Altitude Track miles FL60-1500 FL80-1500 FL100-1500

Minimum value 78.0 29.0 48.6 56.6 66.8

Maximum value 143.0 46.0 95.8 115.8 130.5

Median value 109.5 39.5 73.2 93.4 115.7

Average value 110.5 39.2 72.2 89.1 107.2

Standard deviation 13.7 4.2 14.7 16.6 19.1

Table 5-2 - Airbus A319 – Overview of all flights w ith CDO-approval – Fuel Burn.

For 8 out of the 17 flights which did not receive an explicit CDO-approval, the EFICAT tool nevertheless considers the flown profile below FL100 to be compatible with a CDO-profile.

For all descents without a CDO-approval, we have following fuel burn (kg):

FL60-1500 FL80-1500 FL100-1500


Maximum value 200.0 219.0 243.5

Median value 101.5 138.0 163.0

Average value 108.1 139.4 159.0


Table 5-3 - Airbus A319 – Overview of all flights w ithout CDO-approval - Fuel Burn.



Version 4.2 - 15/02/2012 - Page 126

Comparison of the CDO “Marked” against “Not_Marked” flights leads to following results (kg):

FL60-1500 FL80-1500 FL100-1500

Median value -28.3 -44.6 -47.4

Average value -35.9 -50.3 -51.8

Conclusions:

The conduct of a CDO-approach with an Airbus A319 single-aisle aircraft down from FL100 to 1.500 ft AGL in a radar vectoring environment results in a fuel burn gain of approximately 50 kg against a reference which is already influenced by a number of non-declared but CDO-compatible approaches.

Detailed analysis of the descent profiles has clearly revealed that there is a potential for further savings through improved flying techniques.

Airbus A330-300.

Although not fully equal, the overall findings for the Airbus A330-300 flights largely concur with those for the Airbus A319.

Ten flights proceed along an eastbound pattern; the remainder (13) follow a westbound pattern into the landing runway(s).

Note that no single descent path is above the reference profile below FL100; five are more or less on the reference profile. The remainder of the flights are below the reference profile, but somewhat less than the average A319 descent profiles.

Although not known to which extent (the FDM-data do not record the details), 9 flights make use of the speed brake below FL100.

For all the analysed descents we recorded/calculated following fuel burn (kg):

FL60-1500 FL80-1500 FL100-1500


Maximum value 345.2 380.9 528.5

Median value 141.1 191.3 224.6

Average value 170.1 208.8 245.6


Table 5-4 - Airbus A333 – Overview of all flights - Fuel Burn.



Version 4.2 - 15/02/2012 - Page 127

For 5 out of the 12 flights with an explicit CDO-approval delivered, the EFICAT-tool does not consider the flown descent below FL100 to be compatible with a “CDO”. This finding is to a large extent confirmed by the FDM-data analysis.

For all descents with a CDO-approval, we have following fuel burn (kg):

Altitude Track miles FL60-1500 FL80-1500 FL100-1500

Minimum value 89.0 35.0 79.7 99.7 131.3

Maximum value 149.0 58.0 239.6 270.5 287.7

Median value 110.5 41.0 133.0 152.0 197.2

Average value 111.3 43.5 137.2 165.3 196.0

Standard deviation 18.1 6.6 41.1 46.0 44.2

Table 5-5 - Airbus A333 – Overview of all flights w ithout CDO-approval - Fuel Burn.

For 8 out of the 17 flights which did not receive an explicit CDO-approval, the EFICAT tool nevertheless considers the flown profile below FL100 to be compatible with a CDO-profile.

For all descents without a CDO-approval, we have following fuel burn (kg):

FL60-1500 FL80-1500 FL100-1500


Maximum value 345.2 380.9 528.5

Median value 223.7 271.0 296.0

Average value 205.9 256.2 299.7


Table 5-6 - Airbus A333 – Overview of all flights w ithout CDO-approval – Fuel Burn.

Comparison of the CDO “Marked” against “Not_Marked” flights leads to following results (kg):

FL60-1500 FL80-1500 FL100-1500

Median value -90.7 -119.0 -98.8

Average value -68.7 -90.9 -103.6



Version 4.2 - 15/02/2012 - Page 128

Conclusions:

The conduct of a CDO-approach with an Airbus A330-300 widebody aircraft down from FL100 to 1.500 ft AGL in a radar vectoring environment results in a fuel burn gain of approximately 100 kg against a reference which is already influenced by a number of non-declared but CDO-compatible approaches.

Detailed analysis of the descent profiles here as well has revealed that there is a potential for further fuel burn savings.


Table 5-7 - Ov



Version 4.2 - 15/02/2012 - Page 129

Overview of all analyzed flights - Airbus A319

Airbus A319 .


Table 5-8 - Overview of all



Version 4.2 - 15/02/2012 - Page 130

Overview of all analyzed flights with CDO-approval -

Airbus A319.





Version 4.2 - 15/02/2012 - Page 131

Overview of all analyzed flights without CDO- approval

approval - Airbus A319.


Table 5-10 - Overview of all analyzed flights



Version 4.2 - 15/02/2012 - Page 132

Overview of all analyzed flights - Airbus A333

Airbus A333 .





Version 4.2 - 15/02/2012 - Page 133

Overview of all analyzed flights with CDO-approval - Airbus A333.





Version 4.2 - 15/02/2012 - Page 134

Overview of all analyzed flights without CDO- approval approval - Airbus A319.



Version 4.2 - 15/02/2012 - Page 135

5.65.65.65.6 CALCULATED NOISE IMPCALCULATED NOISE IMPCALCULATED NOISE IMPCALCULATED NOISE IMPACTACTACTACT

As previously explained in section4.3.5, the possible noise impact arising from CDO facilitation is simulated (or calculated) rather than monitored. The effects on noise were studied by analyzing the flights from which FDM-data were made available by Brussels Airlines (A333 and A319)..Firstly the applied method is described in detail for one test flight.In the next two paragraphs the calculated noise impact of the different flights is compared in two different ways:

• Based on the area withinthe noise contour(s)

• Based on the LAmax-profiles, as well as straight under the flight track as at a distance of 0.5 NM excentrical from the flight track

The last paragraph of this chapter deals with whether or not the CDO facilitation does have an effect on the position of the ground track of the flight.

5.6.15.6.15.6.15.6.1 NOISE IMNOISE IMNOISE IMNOISE IMPACT CALCULATION PACT CALCULATION PACT CALCULATION PACT CALCULATION –––– TYPICAL EXAMPLETYPICAL EXAMPLETYPICAL EXAMPLETYPICAL EXAMPLE

In this paragraph the working method to calculate the noise impact on the ground based on the FDM data of the flight (see section 4.3.5) is illustrated for the Airbus 330-300 flight with reference A333_22.This method is applied in the same way for all the other analyzed flights.

By analogy with the fuel burn gain and carbon emission calculations, for the calculation of the noise impact on the ground only the last part of the flight from FL100 to touchdown is considered.For flight levels above FL100 it can be assumed that the noise levels on the ground will be more limited due to the geometrical expansion of the sound field and the sound absorption in the air.

As explained in section 4.3.5the INM calculation model requires three parameters in function of the distance to landing to calculate the noise impact on the ground.Two of these parameters can be immediately derived from the provided FDM – data: the altitude of the aircraft and the true air speed.The distance to touchdown is calculated by integration of the groundspeed over time.The result for the altitude (left axis) and the speed (right axis) for the A333-flight of the example is shown in the figure below.It can be seen from this graph that in this example the aircraft was below the 3° referenc e profile.In the level flight segment at an altitude 2.000 ft, just before the ILS-interception, the speed shows an (almost) constant value.



Version 4.2 - 15/02/2012 - Page 136

Figure 5-73 - Airbus A330-300 arrival ref. A333_22: altitude and true air speed (TAS).

Thethird parameter required to calculate the noise impact with INM is the the corrected net thrust (CNT) per engine. As stated in section 4.3.5 there exists no straight forward method to derive the (CNT) per engine from the engine rotation speed available in the FDM database.Instead CNT can be determined by solving the equation of motion of the aircraft.

The resulting CNT for this example is given in the graph below (blue line, left axis).Also on this graph the use of the speed brakes (red line) and the throttle percentages of the engines (brown line, right axis) are showed.

On the graph can be seen that the calculated value of the CNT results innegative values at the moment speed brakes are used. This is a logical result because the drag over lift coefficient which is used to solve the equation of motion is based only on the flap settings of the aircraft.No coefficients are available within INM for configurations of the aircraft with speed brakes on.This results in a drag-over-lift value which is much lower compared to reality and consequently a negative value of CNT.However, when speed brakes are on, it can correctly be assumed that the engines are in idle mode.In this way, idle thrust was assumed as input for INM at the moment speed brakes were switched on (see green line on the graph).

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]

Distance to landing [NM]

Altitude

TAS



Version 4.2 - 15/02/2012 - Page 137

In the zone with a distance between 8 and 27 nautical miles to landing, smaller negative values for CNT are calculated.The explanation for these negative values is that also here the engines are in idle thrust mode.At that moment the engines are not propulsive and instead provide some additional drag resulting from the air going true the fan.Also this drag is not taken into account when solving the equation of motion resulting in the negative calculated value for CNT.Consequently idle thrust can be assumed in this zone for the INM CNT profile (green line on graph).

In the zone with a distance between 0 and 8 nautical miles to landing positive values for CNT are found meaning the engines are used to provide power.Especially in the level flight zone a lot of power is required to remain a constant speed.Also when intercepting the ILS and in the final part of the landing additional power was required.

However CNT cannot be calculated straight forward from the rotational speed of the engines (throttle), the profile of the throttle confirms the shape of the calculated CNT values.Until a distance of 8 nautical miles to the airport the value of the rotational speed of the engines decreases slowly from 34% until 26%, corresponding to idle mode.In the zone with a distance between 0 and 8 nautical miles to landing the shape of the profile of the calculated value of CNT corresponds very well to the shape of the throttle value.

Figure 5-74 - Airbus A330-300 arrival ref. A333_22: calculated CNT per engine.

0

50

100

150

200

250

300

-15000

-10000

-5000

0

5000

10000

15000

20000

0 10 20 30 40 Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]


Corrected Net thrust per engine

Corrected net thrust per engine - INM input

Throttle N1

speed brakes



Version 4.2 - 15/02/2012 - Page 138

The figure below shows the results of the calculated LAmax noise contours of 60 (red), 65 (orange), 70 (blue) and 75 (green) dB(A) with INM 7.0b for this example.For all the simulation it is assumed that the aircraft arrives on a ground track in line with the runway.However this doesn’t correspond to reality, the influence on the calculated noise contour will be minor (execpt for the geographical position of the noise contour). In this way the noise contours of the different flights can easily be compared.The runway is (in each case) located on the left side of the figure.

Figure 5-75 - Airbus A330-300 arrival ref. A333_22: LAmax noise contours of 60 (red line), 65 (orange line), 70 (blue line) and 75 (gre en line) dB(A).

It can be seen from the noise contours that the further away from the airport the more the LAmax-levelgenerally decreases due to the increasing distance between source and receiver (higher altitude of the aircraft).When the engines are in idle mode, the most part of the noise is generated by the aircraft passing true the air (ramp noise).However at locations where the engines are used to provide thrust it can be seen that noise contours become wider. The more power is applied, the more noise is generated by the engines and the wider the resulting noise contours become (surface within the contours increases).

It should be observed that, as explained in section 4.3.5, the noise at the receiver positions is calculated in INM 7.0b based on noise-power-distance curves.For each type of aircraft there is only one set of these curves available.This means that whether speed brakes are switched on or not the same curves are applied resulting in the same noise level.However in reality the use of speed brakes can generate a significant amount of ramp noise due to the extra drag that is generated.Consequently, the calculated noise in the zones where speed brakes are applied is an underestimation of the reality.

Besides the speed brake problem, it can be concluded that with the followed method a realistic simulation of the noise impact of the analyzed flights could be realised taking to account real FDM data of the aircraft.



Version 4.2 - 15/02/2012 - Page 139

5.6.25.6.25.6.25.6.2 AREA OF THE LAREA OF THE LAREA OF THE LAREA OF THE LAMAXAMAXAMAXAMAX NOISE CONTOURSNOISE CONTOURSNOISE CONTOURSNOISE CONTOURS

For the 23 A330-300 and 33 A319 analyzed flightswith FDM-data provided the LAmax-noise contours are calculated with the method described above.The area of noise contours is determined within a GIS environment.In this paragraph a comparison is made between the total area within these noise contours for the different flights.The smaller the surface within the noise contours, the less the noise impact on the ground.

5.6.2.1 AIRBUS 330-330 ANALYZED FLIGHTS

For the A330-300 flights the lowest calculated LAmax noise contour is the noise contour of 60 dB(A).In the figure below the area of this noise contour is compared for the different flights.The marked flights (CDO approved flights) are presented on the left side of the figure while the non marked flights (no explicit CDO approval) are presented on the right side.In addiotion a distinction is made between estimated CDO-profiles below FL100 (green squares) and the ‘No CDO’ - profiles (red squares) according toEFICAT analysis.



Version 4.2 - 15/02/2012 - Page 140

Figure 5-76- Area of the L Amax noise contour of 60 dB(A) for the Airbus A330-300 analyzed flights.

If the marked flights are compared to the non marked flights it is clear that the average area for the marked flights (4.893 ha) is significantly lower than the area for the non-marked flights (6.564 ha), resulting in an average reduction of about 25%.If only the marked flights that flew a CDO under FL100 are taken into account the average area decreases until 4.400 ha.

In the group of the marked flights there is a clear distinction between the CDO -and the non CDO profiles (as estimated by EFICAT analysis) where the area of the noise contour is significantly smaller for the CDO flights. This distinction is less clear in the group of the non marked flights, as previously concluded: a part of the flights, not receiving an explicit CDO-approval, shows a flown profile below FL100 to be compatible with a CDO-profile (EFICAT)

On the graph above four different analyzed flights are indicated with their reference number.

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Are

a [

Ha

]Area within LAmax noise contour of 60 dB(A)

A330-300 test flights

Efficat CDO < FL100

Efficat NO CDO < FL100

Non marked

fligthsMarked

flights

(A333_01)

(A333_08)

(A333_06)

(A333_22)



Version 4.2 - 15/02/2012 - Page 141

In the following section these four flights are analysed in detail based on their speed, altitude and CNT profiles.

The LAmax noise contours of these four flights are compared in the figure below.

Figure 5-77 - Airbus A330-300 analyzed flights: L Amaxnoise contours of 60, 65, 70 and 75 dB(A).



Version 4.2 - 15/02/2012 - Page 142

Ref A333_01 (NON MARKED, NO CDO (EFICAT))

Figure 5-78 - A333_01 (NON MARKED, NO CDO (EFICAT)) .

The area of the LAmaxnoise contour of 60 dB(A) of this flight is 8.840 ha, which is the largest value of all the A330-300 analyzed flights.The main reason is that the flight profile is for the shown section contantly below the reference profile. At a distance of about 20 NM from touchdown the flight already levels off at 3.000 ft altitude to intercept the ILS at about 9.5 NM from touchdown.In some parts during this extended level off phase a considerable amount of engine thrust shows to be required to maintain the speed at a constant level. This results in an significant increase of the noise contours.

0

50

100

150

200

250

300

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 143

Ref A333_06 (NON MARKED, CDO (EFICAT))

Figure 5-79 - A333_06 (NON MARKED, CDO (EFICAT)).

The area of the LAmaxnoise contour of 60 dB(A) of this flight is 3.623 ha, the smallest of all A330-300 analyzed flights.However this flight follows a very successful CDO-profile (close to the reference profile of 3°) it was not marked. Mor eover, during the descent from FL100 until the interception of the ILS the engines were almost always in idle mode. The only drawback of this flight is the use of the speed brakes in the zone with distance from 14 NM until 8 NM to landing.As remarked before, it was not possible to take this into account in the noise contour calculation with INM 7.0b.

0

50

100

150

200

250

300

0

2000

4000

6000

8000

10000

12000

14000

0 5 10 15 20 25 30 35 40

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 5 10 15 20 25 30 35 40

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 144

Ref A333_08 (NON MARKED, CDO (EFICAT))

Figure 5-80 - A333_08 (NON MARKED, CDO (EFICAT)).

The area within the LAmaxnoise contour of 60 dB(A) of this flight is 7.272 ha.However this flight is considered a CDO below FL100 based on the EFICAT analysis the resulting noise contour is rather large.The reason here is that also this flight is below the reference profile.Especially in the zone from 33 to 25 NM distance to landing the flight makes a steep descent from approximately FL80 to FL40.Speed brakes are not used in this zone resulting in an increase of the speed during this descent.After the sharp descent the aircraft slowly descends further continuously until the interception of the ILS at 2.000 ft.Also speed is reduced slowly during this flights phase.Except for the zone around 14 NM distance to landing,engines were in idle mode resulting in a positive noise impact. Speed brakes were not used descending from FL100 until touchdown.

0

50

100

150

200

250

300

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

0 10 20 30 40 50

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 145

Ref A333_22 (MARKED, NON CDO (EFICAT))

Figure 5-81 - A333_22 (MARKED, NON CDO (EFICAT)).

The area of the LAmaxnoise contour of 60 dB(A) of this flight is 6.-207 ha, the highest value for the CDO approved flight test with A330-300. Also for this flights the main reason is that the flight is below reference profile.Even more there is a level off segment of about 3 NM to touchdown at 2.000 ft before the interception.Because also the speed is constant in this part of the flight a lot of engine thrust was necessary generating an extra noise impact on the ground (at this low height).

0

50

100

150

200

250

300

0

2000

4000

6000

8000

10000

12000

14000

16000

0 5 10 15 20 25 30 35 40

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 5 10 15 20 25 30 35 40

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 146

5.6.2.2 AIRBUS 319 ANALYZED FLIGHTS

The A319 is a smaller aircraft compared to the A333 aircraft resulting in smaller noise contours.For most approaches the LAmax-noise contour of 60 dB(A) is limited to the zone where the flight is on the ILS.As the B3 CDO concept aims at improving (CO2, fuel, noise) the stage before aircrafts intercept the ILS, it was decided to use the area of the LAmax noise contour of 50 dB(A) to compare the different A319 test flight (see graph below).

Figure 5-82 - Area of the L Amax noise contour of 50 dB(A) for the Airbus A319 anal yzed flights.

Concerning the surface of the LAmax noise contour for the A319 analyzed flights similar results are found as for the A330-300 flights:

0

2000

4000

6000

8000

10000

12000

Are

a [

Ha

]

Area within LAmax noise contour of 50 dB(A)

A319 test flights

Efficat CDO < FL100


Non marked

fligthsMarked

flights

Non marked

fligthsMarked

flights

(A319_15)

(A319_19)

(A319_26)

(A319_16)



Version 4.2 - 15/02/2012 - Page 147

• The average surface of the CDO approved flights (5.517 ha) is lower as for the non CDO approved flights (6.620 ha) meaning a decrease of about 17%.

• In the group of the CDO approved flights it is clear that those flight that were considered CDO (under FL100 by EFICAT), have the smallest noise contour area.The averages area of the LAmax noise contour of 50 dB(A) for these flights is 4.780 ha, 28% lower than for the non CDO approved flights.

• This distinction between EFICAT-CDO flights and EFICAT-non CDO flights is less clear for the non CDO marked flights, however the flights with the lowest noise contour area are also mostly CDO flights.

On the graph above four different analyzed flights are indicated with their reference number. In the following section these four flights are analysed in detail based on their speed, altitude and CNT profiles. The LAmax noise contours of these four flights are compared in the figure below.

Figure 5-83 - Airbus A319 analyzed flights: L Amaxnoise contours of 50, 55, 60 and 65 dB(A).



Version 4.2 - 15/02/2012 - Page 148

Ref A319_15 (MARKED, CDO (EFICAT))

Figure 5-84 - A319_15 (MARKED, CDO (EFICAT)).

The area of the LAmaxnoise contour of 50 dB(A) of this flight measures 3.638 ha, the smallest of all A319 analyzed flights. The flight was CDO approved by the ATC.

This flight is an example of a well executed CDO.The altitude profile corresponds very close to a 3° reference profile and during most time of t he descent the engines were in idle mode.However the use of the speed brakes could not be avoided in zone with a distance from 12 to 6 NM to landing to avoid the aircraft accelerating during the descent.

0

50

100

150

200

250

300

0

1000

2000

3000

4000

5000

6000

7000

8000

0 5 10 15 20 25 30 35

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 5 10 15 20 25 30 35

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 149

Ref A319_16 (NON MARKED, NON CDO (EFICAT))

Figure 5-85 - A319_16 (NON MARKED, NON CDO (EFICAT) ).

The area of the LAmaxnoise contour of 50 dB(A) of this non CDO approved flight is 11.022 ha which is the highest value of all A319 analyzed flights. This effect is caused by an altitude profile that is far below the reference profile.Moreover the speed is contained at constant level during this approach from 40 NM to 8 NM from touchdown which leads up to a considerably constant high engine power (and noise!) required to execute the flight.

0

50

100

150

200

250

300

0

1000

2000

3000

4000

5000

6000

0 10 20 30 40 50 60

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50 60

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 150

Ref A319_19 (MARKED, NON CDO (EFICAT)

Figure 5-86 - A319_19 (MARKED, NON CDO (EFICAT).

The area of the LAmaxnoise contour of 50 dB(A) of this CDO approved flight is 7.665 ha, more than double of the flights with the smallest noise contour area.

However the flight is close to the 3° line at FL100 , it descends steep resulting in a level off at 2.000 ft over a distance of about 10 NM.Given the high speed below FL100, as previously reported, the aircraft had to loose speed during the level-off step so that except for a small part the engines were in idle thrust mode.

0

50

100

150

200

250

300

0

1000

2000

3000

4000

5000

6000

0 5 10 15 20 25 30 35

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

400

0

2000

4000

6000

8000

10000

12000

14000

16000

0 5 10 15 20 25 30 35

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 151

Ref A319_26 (NOT MARKED, CDO (EFICAT))

Figure 5-87 - A319_26 (NOT MARKED, CDO (EFICAT)).

The area of the LAmaxnoise contour of 50 dB(A) of this non CDO approved flight is 3.826 ha.

As can be seen on the altitude profile this flight is at FL100 about 3.000 ft above the reference line of 3°.As discussed before this leads to a higher fuel consumption (and carbon emissions).

This position of the aircraft requires a very steep descent to intercept the ILS at 2.000 ft.As can be seen on the graph even the use of the speed brakes can’t avoid the accelaterion of the aircraft during this descent.However we were not able to take the effect of the speed

0

50

100

150

200

250

300

0

1000

2000

3000

4000

5000

6000

7000

0 10 20 30 40 50

Th

rott

le N

1 [

%]

Co

rre

cte

d n

et

thru

st p

er

en

gin

e [

lbs]



Throttle N1

speed brakes

0

50

100

150

200

250

300

350

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50

Tru

e A

ir S

pe

ed

[kt

]

Alt

itu

de

[ft

]


Altitude

TAS



Version 4.2 - 15/02/2012 - Page 152

brakes into account for the noise impact calculation, it can be assumed that the gain in noise level due to the higher position of the aircraft will be counteracted by the use of the speed brakes.

This flight had also a constant speed after the ILS interception.This required a lot of engine thrust resulting in a very noisy last part of the landing (after ILS interception).In this zone the noise contours are wider as for most other flights studied.

5.6.35.6.35.6.35.6.3 LLLLAMAXAMAXAMAXAMAX----NOISE PROFILESNOISE PROFILESNOISE PROFILESNOISE PROFILES

5.6.3.1 AIRBUS 330-330 ANALYZED FLIGHTS

The figure below shows the LAmax noise profile for the different A330-300 analyzed flights in function of the distance to landing straight under the flight path.The green lines present the profiles of the flights that were CDO approved by ATC (marked) while the brown lines present the profiles for the non CDO approved flights (non marked).

As a reference the red line presents the LAmax profile of a flight that follows perfectly a 3° slope descent to the airport and has the engines in IDLE mode.This line is only presented in zone starting from 10 NM to landing. Closer to the airport the interception of the ILS influences the thrust profile.

As can be seen on the graph the LAmax value generally decreases in function of the distance to landing due to the increasing distance between source and observer.However in zones where engines power is applied this decrease is interrupted and higher noise levels occur.



Version 4.2 - 15/02/2012 - Page 153

Figure 5-88 - Airbus A330-300 analyzed flights: L Amaxnoise profile under the flight track.

To compare the different flights the average difference between the LAmax profile of the flight and the 3° - idle thrust reference profile is deter mined for each flight in the zone with a distance between 10 and 25 NM to landing.As explained before this is the zone where noise benefits of CDO approaches can be expected.The result of this analysis is presented in the figure below.This graph is created in the same way as for the comparison of the area of the noise contours in the previous paragraph: a distinction is made between marked and non marked flights and the color indicates whether the flight is analysed as a CDO below FL100 by EFICAT or not.The references of the flights discussed in detail in the previous section are also indicated on the graph.

30

35

40

45

50

55

60

65

70

75

80

5 10 15 20 25

L Am

ax[d

B(A

)]


LAmax noise profile for A333 under the flight track

Marked flights (CDO approved)

Non marked flights (NO CDO approval)

3° - IDLE thrust reference



Version 4.2 - 15/02/2012 - Page 154

Figure 5-89 - Airbus A330-300 analyzed flights: ave rage L Amaxnoise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile straight under the flight

track.

The average LAmax noise difference is clearly smaller for the marked flights (3.1 dB(A)) compared to the non marked flights (5.8 dB(A)).If only the marked flights which are considered CDO below FL100 (EFICAT) are taken into account the average difference is 2.3 dB(A).

The same analysis is made for a position of the receiver on the ground at 0.5 NM excentrical from the flight track.The resulting LAmax-profiles and the average difference compared to a 3° idle thrust profile (in the zone 10-25 NM to lan ding) are presented in the figures below.

Generally the same conclusions are valid for this excentrical position of the receiver (compared to the position under the flight track) however the noise differences between the

0

1

2

3

4

5

6

7

8

9

10

L Am

axd

iffe

ren

ce [

dB

(A)]

Average LAmax noise difference in the zone 10 - 25

NM to landing compared to 3° - idle thrust profile

Under flight track


Efficat CDO < FL100


Non marked

fligthsMarked

flights

(A333_06)

(A333_01)

(A333_08)

(A333_22)



Version 4.2 - 15/02/2012 - Page 155

different flights are smaller.This is caused by the fact that the lateral attenuation of the aircraft noise is higher for smaller values of the viewing angle of the aircraft from the observer (i.e. when the aircraft is lower).This effect partially counteracts the noise benefit of a higher position of the aircraft.

Figure 5-90 - Airbus A330-300 analyzed flights: L Amaxnoise profile 0.5 NM excentrical from the flight track.

30

35

40

45

50

55

60

65

70

75

80

5 10 15 20 25

L Am

ax[d

B(A

)]


LAmax noise profile for A333 under 0.5 NM excentrical from the

flight track

Marked flights (CDO approved)

Non marked flights (NO CDO approval)




Version 4.2 - 15/02/2012 - Page 156

Figure 5-91 - Airbus A330-300 analyzed flights: ave rage L Amaxnoise difference in the zone 10 – 25 NM to landing compared to 3° - idle th rust profile at 0.5 NM excentrical

from the flight track.

0

1

2

3

4

5

6

7

8

9

10

L Am

axd

iffe

ren

ce [

dB

(A)]



0.5 NM excentrical from flight track


Efficat CDO < FL100


Non marked

fligthsMarked

flights

(A333_01)

(A333_08)

(A333_22)

(A333_06)



Version 4.2 - 15/02/2012 - Page 157

5.6.3.2 AIRBUS 319 ANALYZED FLIGHTS

The figure below shows the LAmax noise profile for the different A319 analyzed flights in function of the distance to landing straight under the flight path.The green lines present the profiles of the flights that were CDO approved by ATC while the brown lines present the profile for the non CDO approved flights.

As a reference the red line presents the LAmax profile of a flight that follows perfectly a 3° slope descent to the airport and has the engines in IDLE mode.This line is only presented in zone starting from 10 NM to landing.Closer to the airport the interception of the ILS influences the thrust profile.

If the profiles of the A319 are compared to the profiles of the Airbus 330-300 a shift of about 10 dB(A) towards lower values can be noticed.However the spread of the values for the different flights is of the same magnitude.

Figure 5-92 - Airbus A319 analyzed flights: L Amaxnoise profile under the flight track.

20

25

30

35

40

45

50

55

60

65

70

75

80

5 10 15 20 25

L Am

ax[d

B(A

)]


LAmax noise profile for A319 under the flight track

Non Marked flights (NO CDO approval)

Marked flights (CDO approval)




Version 4.2 - 15/02/2012 - Page 158

To compare the different flights the average difference between the LAmax profile of the flight and the 3° - idle thrust reference profile is deter mined for each flight in the zone with a distance between 10 and 25 NM to landing.The result of this analysis is presented in the figure below.This graph is created in the same way as for the comparison of the area of the noise contours in the previous paragraph: a distinction is made between marked and non marked flights and the color indicates whether the flight is analysed as a CDO below FL100 by EFICAT or not.The references of the flights discussed in detail in the previous section are also indicated on the graph.

Figure 5-93 - Airbus A319 analyzed flights: average LAmax noise difference in the zone 10 – 25 NM to landing compared to 3° - idle thrust profile straight under the flight

track.

-4

-2

0

2

4

6

8

10

L Am

axd

iffe

ren

ce [

dB

(A)]



under the flight track

A319 test flights

Efficat CDO < FL100


Non marked

fligthsMarked

flights

Non marked

fligthsMarked

flights

Non marked

fligthsMarked

flights

Non marked

fligthsMarked

flights

(A319_16)

(*) (A319_26)

(A319_15)

(A319_18)



Version 4.2 - 15/02/2012 - Page 159

(*) Remark A319_26 : for this flight an average LAmax difference is found of about -3 dB(A).As discussed in the previous section this flight was high above its reference profile. However speed brakes had to be applied to realise a steep descent to intercept the ILS.As explained, this effect could not be modeled by the INM but will result in higher noise levels.Also in the zone after the ILS interception this flight was very noisy due to the necessary engine thrust to maintain a constant speed.Because of this reason the the total area of the LAmax noise contour of 50 dB(A) was not the smallest of all flights studied.

The average LAmaxnoise difference is smaller for the marked flights (2.7 dB(A)) compared to the non marked flights (4.2 dB(A)).

Also here there is a clear distinction in the group of the marked flights between the flights that are considered a CDO below FL100 (EFICAT) and the flights that are not.The CDO have an average difference of 1.4 dB(A) while the non CDO flights have an average difference of 5.1 dB(A).

The same analysis is made for a position of the receiver on the ground at 0.5 NM excentrical from the flight track.The resulting LAmax-profiles and the average difference compared to a 3° idle thrust profile (in the zone 10-25 NM to landing) are presented in the figures below.

Generally the same conclusions are valid for this excentrical position of the receiver however the noise differences between the different flights are smaller.This is caused by the fact that the lateral attenuation of the aircraft noise is higher for smaller values of the viewing angle of the aircraft from the observer (i.e. when the aircraft is lower).This effect counteracts partially the noise benefit of a higher position of the aircraft.



Version 4.2 - 15/02/2012 - Page 160

Figure 5-94 - Airbus A319 analyzed flights: L Amaxnoise profile 0.5 NM excentrical from the flight track.

30

35

40

45

50

55

60

65

70

5 10 15 20 25

L Am

ax[d

B(A

)]


LAmax noise profile for A319 0.5 NM excentrical from flight track

Non Marked flights (NO CDO approval)

Marked flights (CDO approval)




Version 4.2 - 15/02/2012 - Page 161

Figure 5-95 - Airbus A319 analyzed flights: average LAmaxnoise difference in the zone 10 – 25 NM to landing compared to 3° - idle thrust profile at 0.5 NM excentrical from

the flight track.

5.6.45.6.45.6.45.6.4 IMPACT ON LATERAL ROIMPACT ON LATERAL ROIMPACT ON LATERAL ROIMPACT ON LATERAL ROUTESUTESUTESUTES

To study the possible difference between the ground track of CDO approved flights and CDO non approved flights the ground tracks of the flights arrived at Brussels Airport in the months April and May 2011 on runways 25L and 25R were analysed.To avoid as much as possible the impact of other parameters influencing the position of the ground tracks only the flights during the most calm period of the day were selected (from midnight until 0.5 am).Radar data available in the NMS of Brussels Airport was used and linked to the Belgocontrol list of CDO approvals for these months.

-4

-2

0

2

4

6

8

10

L Am

axd

iffe

ren

ce [

dB

(A)]



0.5 NM excentrical from flight track

A319 test flights

Efficat CDO < FL100


Non marked

fligthsMarked

flights

Non marked

fligthsMarked

flights

(A319_16)

(A319_26)

(A319_15)

(A319_19)



Version 4.2 - 15/02/2012 - Page 162

In the figures below the red lines show the ground track of the CDO approved fligts while the green lines show the ground tracks of the flights without CDO approval.The upper graph is for the arrivals on runway 25R while the lower shows the arriavsl in runway 25L.

The main conclusion that can be drawn from this graph is that no new zones are overflown by the CDO approved flights approaching Brussels Airport that were not overflown by the non CDO approved flights.

If other small visually noticeable shifts (e.g. the average route of the landings on runway 25R coming from the east is lying a bit more to the south) are representivecan not be concluded from these graphs.

Figure 5-96 - Visualization of ground tracks on run way 25R.



Version 4.2 - 15/02/2012 - Page 163

Figure 5-97 - Visualization of ground tracks on run way 25L.



Version 4.2 - 15/02/2012 - Page 164

5.6.55.6.55.6.55.6.5 CONCLUSION NOISE ANACONCLUSION NOISE ANACONCLUSION NOISE ANACONCLUSION NOISE ANALYSISLYSISLYSISLYSIS

Next to reducing fuel burn and emissions, an objective of the B3-project was to study the potential aircraft noise reductionbenefits associated with continuous descent approaches in the vicinity of Brussels Airport.

In order to study these benefits associated with CDO facilitation noise modeling was preferred rather than noise monitoring because of the relatively low individual aircraft noise levels in the areas where CDO is deployed (i.e. typically at more than 10 nm from the threshold) and given the potential for significant variations in factors that can influence measurements

Operational flight data (FDM) provided by Brussels Airlines were used to simulate more dan 50 approaches in detail.

The analysis of the noise simulations shows significant gains can be realised on the noise impact on the ground in the area between FL100 and interception of ILS. Below this area, which occurs typically at 2,000ft or 3,000ft, no differences with a conventional arrival are significant. At altitudes more 10,000ft CDO noise benefits are negligible.

Intermediate level-off segments, other than for stabilization reasons, during descent have to be avoided. During these phases a higher noise impact can be expected not only due to a smaller source – receiver distance but also because in most cases additional engine thrust is required. Unnecessary speed brake activation should be avoided during descent phase because of the extra noise generation due to a higher drag value of the aircraft passing true the air.

Finally, it should be kept in mind that the largest noise impact occurs in the zone closer to the airport, below the altitude at which the ILS is intercepted. In this zone no effects assigned to a CDO-approach can be expected in comparison to a coventional “step down” approach.



Version 4.2 - 15/02/2012 - Page 165

6.6.6.6. COMMUNICATION PLANCOMMUNICATION PLANCOMMUNICATION PLANCOMMUNICATION PLAN

Several communication actions have been organised during phase 2 of the B3-project.These actions focus on internal communication as well as external communications. After the delivery of the final report, we will continue to communicate on the project. A communication action plan has been developed (see infra).

6.16.16.16.1 IMPLEMENTED COMMUNICIMPLEMENTED COMMUNICIMPLEMENTED COMMUNICIMPLEMENTED COMMUNICATION ACTIONS DURINGATION ACTIONS DURINGATION ACTIONS DURINGATION ACTIONS DURING PHASE PHASE PHASE PHASE 2222

6.1.16.1.16.1.16.1.1 BELGOCONTROLBELGOCONTROLBELGOCONTROLBELGOCONTROL

Hereunder you will find a list of communication actions which Belgocontrol realised in 2011.

Media Type of Media Target Group Date Subject Hubnews - Personnel

Magazine Whole staff No. 14 – 03/

2011 (page 5) B: phase 1 - Congratulations of SESAR JU

No. 15 – 07/2011 (page 4)

Brussels Airport Environment Award

Monthly emailing to ATCOs

- Email with attachment

APP ATCOs Monthly 2011 Overview of marked CDOs

Face to face - Refresher courses

APP ATCO’s 02/2011 Briefing on B3 project

ATC Global Amsterdam

- Participation to FABEC booth with information on B3

- Distribution of flyer on FABEC projects participating in AIRE

Internal : FABEC partners. External : all stakeholders

March 2011 Summary of the project



Version 4.2 - 15/02/2012 - Page 166

FABEC Newsletter

- Digital No 11 Article on B3 project

Overleg-forum

- Presentation Local residents representatives

30/09/2011 Presentation of the CDO-project

FABEC Standing Committee Environ-ment

- Presentation Members of the FABEC Standing Committee Environment

07/10/2011

How the measurement of CDO is addressed in the B3-project

Eurocontrol CDA workshop

- Presentation ANSPs, Airlines, Airport operators

11&12/10/2011 Experience with the Eurocontrol EFICAT tool

Belgocontrol portal and website

- Continuous update of information on project – dedicated pages on CDO (and B3) on portal and website

Internal and external stakeholders

Continuously in 2011

-

Belgocontrol Annual Report 2010

- From page 30 to 34, published June 2011

- Dedicated chapter on sustainable performance with extensive information on the B3 project and CDOs.



Version 4.2 - 15/02/2012 - Page 167

6.1.26.1.26.1.26.1.2 BRUSSELS AIRPORTBRUSSELS AIRPORTBRUSSELS AIRPORTBRUSSELS AIRPORT

The Brussels Airport Company published several articles in its internal media and organised face-to-face communication. The Brussels Airport Company published several articles in its internal and external media and organised (existing) meetings with the surrounding communities

Media Type of Media Target Group Date Subject Brussels Airport Intranet

Intranet Bulletin Whole staff October 2010 Presentation of the project and of the partners involved

Brussels Airport News

Newsletter Airport Community

No. 41 – October 2010

Short article on the B3Sesar project

Consultative Bodies

Project Presentation

Airport Surrounding Communities

September 2010

Presentation of the project – Q&A

6.1.36.1.36.1.36.1.3 BRUSSELS AIRLINESBRUSSELS AIRLINESBRUSSELS AIRLINESBRUSSELS AIRLINES

Just like Belgocontrol and The Brussels Airport, Brussels Airlines focus was during phase 1 on creating staff awareness. This target was reached via several internal communication actions. B3 was included as from the start of phase one in the company wide 'b.green' project that covers and steers all environmental actions of the airline. Internal Communication messages reached all internal stakeholders via various channels:

- Presentation to the Executive Management - Presentation of B3 in internal newsletters, TV info screens and communication

messages - Intranet 'b.green' - Specific communication actions towards the pilot community and the staff of the

airline’s operations centre - Face to face communication by the project leader

The pilot community will be further made aware during phase during the Pilot/ATCO exchange meetings described above.

On Hangar Flying, an article “(Still) going strong: Brussels Airlines and the 737 classic” covering amongs others the continuous descent trials was published 19/5/2011



Version 4.2 - 15/02/2012 - Page 168

6.1.46.1.46.1.46.1.4 OTHEROTHEROTHEROTHER

An article “Continuous Descent Operations” was published on 14th of January 2011 in “Hangar flying” Hangar Flying is a Belgian bilingual monthly aviation luchtvaart-eNews, published the 15th of each month and publicly available on www.hangarflying.be.A small article was also written in the journal “Le Soir” in the beginning of 2011.

6.26.26.26.2 PLANNING OF COMMUNICPLANNING OF COMMUNICPLANNING OF COMMUNICPLANNING OF COMMUNICATION ACTIONS ATION ACTIONS ATION ACTIONS ATION ACTIONS AFTER DELIVERY AFTER DELIVERY AFTER DELIVERY AFTER DELIVERY

OFOFOFOFPHASE 2PHASE 2PHASE 2PHASE 2

As the final report will be delivered end of December 2011, press activities have been planned for the beginning of 2012: press release, press conference, meetings with local press.

Several articles are also planned in the above-mentioned means : publications of Belgocontrol, FABEC, ....

To motivate the ATCOs of Belgocontrol to continue the development of CDOs at Brussels Airport, a mousepad with following message will be distributed to APP/ACC ATCOs:

Think green, act CDOs.

Furthermore, when the pilot/ATCO exchange program (pilots visiting the control centre of Belgocontrol and ATCOs accompanying pilots during Brussels Airlines flights) is approved, the B3-project will be one of the main topics. The pilots and ATCOs will have the possibility to exchange their views and experiences in order to create a better understanding of each other’s work.



Version 4.2 - 15/02/2012 - Page 169

List of external communication actions being prepar ed and planned by the three B3-partners:

Media Type of media Target group Date Subject

Press Press release

Meetings with local press

External stakeholders

January 2011 Information on the project and on importance of environmental benefits

Press Press communiqué (national, general information press &trade press)

External stakeholders

June 2011 Progress of project and first results

Website Dedicated web pages on the websites of the 3 parties involved

External Stakeholders

January 2011 Information on project and progress

Annual reports 2010

Report on activities of 2010

External (and internal) stakeholders

April 2011 Information on ‘environmental’ performances



Version 4.2 - 15/02/2012 - Page 170

7.7.7.7. THE THE THE THE FUTUREFUTUREFUTUREFUTURE

7.17.17.17.1 FROM TRIALS TO IMPLEFROM TRIALS TO IMPLEFROM TRIALS TO IMPLEFROM TRIALS TO IMPLEMENTATIONMENTATIONMENTATIONMENTATION

The aim is to bring the CDO-facilitation from trials into implementation.This means that the facilitation shall be open to all airlines and shall not only be available on runways 25R and 25L but also on the runways 20 and 02.A draft for publication in the AIP is added in appendix 11.

7.27.27.27.2 PROJECT POINT MERGE PROJECT POINT MERGE PROJECT POINT MERGE PROJECT POINT MERGE BRUSSELSBRUSSELSBRUSSELSBRUSSELS

Aside from the CDO-trials in the B3 project, Belgocontrol also studies other options for optimizing vertical profiles, mostly in relation to broader projects. End 2011, Belgocontrol finished a feasibility study on the use of a point merge system for Brussels airport.

7.2.17.2.17.2.17.2.1 PPPPROJECT ROJECT ROJECT ROJECT OBJECTIVESOBJECTIVESOBJECTIVESOBJECTIVES

The Point Merge project for Brussels mainly aims at handling the arrival traffic more efficiently by means of a series of new P-RNAV routes, with the following main project objectives:

� Enhanced safety, through efficient systemisation of traffic � Efficient use of capacity by presenting traffic in more optimised and

organised sequences

� Improved Flight Efficiency and Predictability (minimise the number of track miles flown in EBBU FIR/UIR), by allowing the use of aircraft FMS and associated flight trajectories to the maximum extent

� Provide P-RNAV route with realistic turns � More efficient fuel management by keeping aircraft at higher altitudes in

the TMA until their optimum point for descent to the airport



Version 4.2 - 15/02/2012 - Page 171

� Enabling Continuous Descent Approaches, thereby giving economic and

environmental advantages (reduced noise nuisance and emissions) � Reduction of workload for flight crew and air traffic controllers (especially

important in the critical arrival phase of flight) � Enhanced situational awareness for flight crews and better anticipation of

ATC clearances The progressive merging of arrival flows into a runway sequence is often performed in current day operation through the use of open-loop vectoring, air traffic controllers typically issuing a large number of heading, speed and level instructions. This method is highly flexible; however it results in high workload both for flight crews and controllers, and in an intensive use of the R/T. Indeed, it generally requires numerous actions to deviate aircraft from their most direct route for path stretching - and later put them back towards a waypoint or the runway axis for integration. Additionally, it is less efficient for the flight crew or the operation of the aircraft, due to the fact that with open-loop vectors, some parameters are not known, and thus situation awareness is less.. Replacing open-loop vectors by standard flight trajectories increases the efficiency in the ground system: ground-based tools involving trajectory prediction (e.g. conflict detection tools, AMAN, etc.) can be updated more accurately.

Finally, implementing a 3D-structure will limit the use of intermediate level offs, because compared to open-loop vectoring the implementation and the fine tuning of the sequence will be easier and more efficient. Under the proposed new “point merge” procedure for integrating arrival flows, the following principles will apply:

� There will be no change with respect to the ATC goals, which are to enable a

safe, expeditious and orderly flow of air traffic. It is expected that there will not be any regulatory issues, in particular regarding ICAO PANS-ATM (Doc 4444). Separation minima - and spacing - will still be based on distance.



Version 4.2 - 15/02/2012 - Page 172

� The objective is to effectively integrate the arrival flows, while keeping aircraft on lateral navigation, even at high traffic loads. In this context, open-loop radar vectors should only be used to recover from unexpected situations.

� Delaying or expediting aircraft (through path stretching/shortening) will be

performed in a more flexible manner than with current P-RNAV applications in TMA (which are based on a set of pre-defined routes).

� A key principle is to keep things simple. The new procedure will provide the

controllers with a structured and intuitive way of building and maintaining the sequence.

� The new procedure seeks to decrease the level of ATC intervention, and

relies on simple clearances/instructions. In addition to reducing workload, this should diminish the risk of errors and misunderstandings, even in high density TMAs.

� The procedure should also fit in with well-established air and ground practices

and related constraints. In particular, from a cockpit perspective, ‘heads-down’ time should be minimised, especially when aircraft are in the TMA and below FL100.

Based on these principles, the proposed new procedure associates a dedicated route structure with a systemised operating method to integrate arrival flows with extensive use of RNAV. It builds on the following key aspects:

� Integration of arrival flows is achieved on a common point using ‘Direct To’

instructions.

� Path stretching is performed without the use of open-loop radar vectors. A “point merge system” is a portion of a route structure, enabling the integration of two or more inbound flows into one sequence, and characterised by the features described below.

Traffic integration is performed by merging inbound flows to a single point. After this merge point, aircraft are established on a fixed common route until the exit of the point merge system.



Version 4.2 - 15/02/2012 - Page 173

Before the merge point, a ‘sequencing leg’ is dedicated to path stretching/shortening for each inbound flow. While along a sequencing leg, aircraft can be instructed to fly ‘Direct To’ the merge point at any appropriate time (i.e. be kept for a certain amount of time on the leg for path stretching, or inversely sent early direct to the merge point for path shortening). Sequencing legs have a pre-defined length.

In order for the controller to easily and intuitively determine the appropriate moment to issue the ‘Direct-To’ instructions for each aircraft, based on its spacing with the preceding aircraft in the sequence, and without requiring the support of any new ground tool, the geometry of the point merge system shall ensure that:

� Aircraft left flying on a sequencing leg are kept (approximately) at the same

distance (‘iso-distance’) from the merge point all along this leg;

� Distinct sequencing legs are (approximately) located at the same distance from the merge point.

Figure 7-1 - Point Merge System for Arrivals RWY25 Left.

TS 150910

WOODY

MOT01

MOT02

MOT03

MOT04

MOT05

MOTTO FL90-

WOD01 FL100+

WOD02

WOD03

WOD04

KERKY

HUL

BUB

SPI

AFI

CIV

EBBR POINT MERGE

PS2 – RWY 25L

WESTYNIK

ANT

10 5 100

NOTE:

SLP 230kts IAS

@

WOODY, MOTTO, TERRY and LEGGY

LEGGY

TERRY FL90-

LEG01 FL100+

LEG02

LEG03

LEG04

LEG05

TER01

TER02

TER03

TER04

TER05

BUN

FLO

LGE

LNO

EASTO

BRAVO A4000+

YANKI A3000-

CHRLY

ZULUU



Version 4.2 - 15/02/2012 - Page 174

Controller feedback on PMS operations highlighted the following benefits: � The noticeable reduction in R/T usage was a significant factor.

� The systemised nature of PMS approach operations facilitated easy and smooth procedures.

� The embedded CDA facility in PMS was a bonus.

� Predictability was improved leading to enhanced situational awareness for controllers and pilots.

� It was easy to revert to radar vectoring to solve problems.

7.2.27.2.27.2.27.2.2 THE POTENTIAL BENEFITHE POTENTIAL BENEFITHE POTENTIAL BENEFITHE POTENTIAL BENEFITSTSTSTS

7.2.2.17.2.2.17.2.2.17.2.2.1 FOR ATC :

� Ability to handle future traffic projections with current staffing levels.

� More intuitive controller system with increased trajectory predictability enabling better anticipation of traffic evolution.

� Better task allocation and workload distribution between TMA controllers.

� Enhanced safety, through efficient systemisation of traffic.

� Ground system upgrades not required.

� Standardisation of controller’s performances, thus implying a standard high quality of the traffic management, less conditioned by personal skills.

� General reduction of controller’s workload in all TMA sectors, since the standardised way of managing the arrival traffic simplifies the work and reduces the need for problem solving, continuous monitoring and R/T communication.

7.2.2.27.2.2.27.2.2.27.2.2.2 FOR THE AIRLINES AND AIRPORT OPERATORS :

� Improved flight efficiency and predictability through optimised Flight Management System (FMS) usage.

� Potential for reduced fuel usage/emissions by enabling Continuous Descent Operations.



Version 4.2 - 15/02/2012 - Page 175

� Enhanced situational awareness for flight crews.

� No avionics system upgrades required.

� Better Collaborative Decision Making (CDM).



Version 4.2 - 15/02/2012 - Page 176

APPENDICAPPENDICAPPENDICAPPENDICESESESES



Version 4.2 - 15/02/2012 - Page 177

APPENDIX APPENDIX APPENDIX APPENDIX 1 1 1 1 ---- DEFINITION OF FLIGHTDEFINITION OF FLIGHTDEFINITION OF FLIGHTDEFINITION OF FLIGHT PHASES FOR AIRBUS FMPHASES FOR AIRBUS FMPHASES FOR AIRBUS FMPHASES FOR AIRBUS FMSSSS

Table 0-1 - Flight Phases - Airbus FMS.



Version 4.2 - 15/02/2012 - Page 178

APPENDIX 2 APPENDIX 2 APPENDIX 2 APPENDIX 2 –––– DESCENT PROFILE BASIDESCENT PROFILE BASIDESCENT PROFILE BASIDESCENT PROFILE BASICS.CS.CS.CS.

VERTICAL FLIGHT PROFVERTICAL FLIGHT PROFVERTICAL FLIGHT PROFVERTICAL FLIGHT PROFILE ILE ILE ILE –––– TYPICALTYPICALTYPICALTYPICAL

A typical flight profile consists of: 1. A lateral profile 2. A vertical profile

In our B3 concept, focus is on management of the vertical profile.

Typical vertical profile.

Within this profile, following flight phases may be distinguished:

1. Takeoff phase . The takeoff phase extends to the acceleration altitude, e.g. 3.000 ft Above Ground Level. Initially, takeoff thrust (or reduced TO thrust) is set; at the thrust reduction altitude, a climb thrust setting is applied.

2. Climb phase . The climb phase extends from the acceleration altitude to the top-of-climb (TOC) cruise flight level. In an unconstrained situation, using climb thrust, the aircraft will climb at a selected climb IAS until reaching the crossover altitude, from which point a climb Mach will be adhered to. Airspace constraints



Version 4.2 - 15/02/2012 - Page 179

may limit the climb speed until passing a designated altitude and/or waypoint. Giving the possibility to the aircraft to climb at its optimal speed and with no step climb till cruising level is an efficient way to save fuel but this should be part of another subject : Continuous Climb Operations (CCO)

3. Cruise phase . The cruise phase extends from the top-of-climb point to the top-of-descent (TOD). The cruise phase can include intermediate climbs as well as en-route descents. These altitude changes are usually performed at cruise speed/Mach. Thrust will be set in order to achieve the selected cruise speed/Mach.

4. Descent phase . The descent phase starts at the top-of-descent (TOD) point, which is typically less than 200NM from destination. Generally, the engine thrust will be set to idle. Initially, the rate-of descent will be adjusted to achieve a descent Mach; below the crossover altitude, in an unconstrained situation, the rate-of-descent will be adjusted to adhere to a descent IAS. Airspace constraints may limit the selected speed, typically below a designated altitude and/or at a waypoint. Ideally, no intermediate level-off is desired (implicit Continuous Descent Operation – CDO).

5. Approach phase . The approach phase starts when the approach deceleration point is passed. The deceleration point is computed backwards from the landing point based on optimized flap/slat configuration changes, altitude/speed constraints and flight path.

For each phase of flight, the aircraft operator may define/calculate an “ideal” speed. Application of all these “ideal” speeds will result in an “ideal” flight profile for the aircraft operator. These speeds are often referred as “economical” (or ECON) speeds.

Trip Cost versus Speed.



Version 4.2 - 15/02/2012 - Page 180

The “ideal” profile is intended to achieve an optimization of the direct operating cost for a given flight. It may be observed that an operator may deviate from its own “ideal” profile in order to cope with other specific operating/economic conditions. Many parameters do influence the calculated speeds. Hence, even for the same aircraft operator on the same type of aircraft, these speeds may be different for each flight (e.g. due to a different mass of the aircraft)! It should be emphasized that the “ideal” profile will NOT necessarily result in the optimum fuel usage! Generally, a trade-off is made between the fuel-related cost (CF) and the time-related cost (CT). The ratio between both cost factors is commonly called the Cost Index (CI).

Fuel

TimeI C

CC =

The Cost Index is an airline depending variable introduced in the Flight Management Computer (FMC) to optimize performance calculations including Mach and step climb optimization. The cost index effectively provides a flexible tool to control fuel burn and trip time between these two extremes. Knowledge of the airline cost structure and operating priorities is essential when aiming to optimize cost by trading increased trip fuel for reduced trip time or vice-versa.

Cost Index values.



Version 4.2 - 15/02/2012 - Page 181

Extreme cases: a) CI=0: (when CT=small and CF=large)

MINIMUM FUEL STRATEGIC MODE This is the case of highest influence of fuel cost in the operating bill: ECON speeds to minimize consumption in all flight phases:

- climb at or about max rate of climb speed - cruise at or about LRC (long range cruise) - descent at speeds close to minimum drag speed

b) CI=max: (when CT=large and CF=small) MINIMUM TIME STRATEGIC MODE

This is the case when a premium exists on time (arrival); corresponding speeds are then maximal in all flight phases, the FMC defining its own particular VMO/MMOlimits. (VMO = max operating speed / MMO = max operating Mach number)

Obviously, the overall shape of the vertical profile will be influenced by the selected speeds for each flight phase. The next figure gives a simplified overall picture. As a result, application of different cost index values will lead to different locations for the top-of-climb and top-of-descent points, and fuel burn in the various phases of flight will differ as well. However, note that an operator will strive towards the most economical solution from gate-to-gate which means that he is not primarily interested in the individual figures for each flight phase.

Once a value for the cost index has been determined by the operator for execution of one or more flights, the resulting profile may be called the “airspace user’s preferred trajectory”. This is the starting point for the “business trajectory” philosophy as used by SESAR.

‘Flight e fficiency’ may be seen as the degree to which the actually flown flight profile will adhere to the ‘ideally’ planned profile. Each deviation from this profile (theoretically, at least!) will result in a cost penalty.



Version 4.2 - 15/02/2012 - Page 182

Impact of the cost index on flight profiles.

RELATION TO THE SESARELATION TO THE SESARELATION TO THE SESARELATION TO THE SESAR R R R –––– “BUSINESS TRAJECTORY“BUSINESS TRAJECTORY“BUSINESS TRAJECTORY“BUSINESS TRAJECTORY””””

The four-dimensional (4D) trajectory or ‘business trajectory’ is key to the concept of the future Air Traffic Management (ATM) system being developed by the Single European Sky ATM Research (SESAR) program. Airspace users will agree with Air Navigation Service Providers (ANSPs) and airport operators, from early planning to the day of operations the airspace user’s preferred trajectory for the flight in four dimensions (three spatial dimensions, plus time), where the various constraints of airspace and airport capacity have been fully taken into account. This ‘4D’ trajectory is called the ‘Business trajectory’ in the case of civil aviation and the ‘Mission trajectory’ for military flights, and once agreed it becomes the reference which the airspace user agrees to fly and all the service providers agree to facilitate with their



Version 4.2 - 15/02/2012 - Page 183

respective services. From then on, all stakeholders will share information on this 4D Business/Mission trajectory in real time throughout the flight: from preparation through operations to post-disembarking.

THE BACKGROUND

Currently, aircraft operators plan each flight in detail and then submit a less detailed flight plan in overview to the relevant air traffic control providers and central flow management unit. The respective air traffic control units then compute these flight plans down to a detailed level in their respective flight data processing systems. These then form the baseline for the voice communication controllers and pilots throughout the flight.

IMPLEMENTING 4D TRAJECTORIES

The 4D trajectory concept requires that airspace users be able to agree upon the detailed 4D Business/Mission trajectory directly with the service providers involved in facilitating the flight in the specific airspaces concerned. Detailed positional information for the aircraft throughout the flight will be exchanged with all service providers on the route, as well as ascent and descent paths, and times will be agreed with departure and arrival airports in advance. ATM operations will be automated to a greater extent than currently, with data exchanged directly between the airborne and ground systems. Greater certainty about the positions of every airspace user in the sky at any given moment will improve safety as well as flight predictability. The more efficient resource planning will in turn enable a greater carrying capacity for both airports and the European sky in general.

The “airspace user’s preferred trajectory” is part of the baseline used by the aircraft operator in its negotiations with ANSPs and airport operators in order to obtain a “business trajectory” for a given flight.



Version 4.2 - 15/02/2012 - Page 184

4D-trajectory.

DESCENT DESCENT DESCENT DESCENT –––– GENERAL PRINCIPLESGENERAL PRINCIPLESGENERAL PRINCIPLESGENERAL PRINCIPLES

Descending a (transport) aircraft from its cruising level down to the landing runway of the destination airport is a matter of “energy sharing”.

For commercial jet operations, a so-called “Mach/CAS Descent” is usually flown.

Ideally, no intermediate level off between top-of-descent and capture of the glide path signal is planned: a Continuous Descent Operation (CDO) at a defined

speed , performed in idle thrust conditions is the preferred option.

MACH/CAS DESCENT

Mach/CAS descents employ a descent speed profile characterized by a constant Mach segment (above the ‘crossover altitude’ – ca. FL290) followed by a constant calibrated



Version 4.2 - 15/02/2012 - Page 185

airspeed (CAS)4 segment, performed at idle thrust for maximum fuel efficiency. Mach/CAS descent schedules are typically described in aircraft operating manuals.

The Mach/CAS speeds are adjusted to yield optimum fuel efficiency, time efficiency, or (usually) a combination of the two. Airline policies may recommend selected Mach/CAS schedules to suit their specific operational and economic conditions.

Below FL100, the ‘ideal’ descent profile may be ‘spoiled’ by altitude/speed constraints imposed by the flown STAR5 and/or terminal airspace regulations.

Simplified descent profile.

Figure 3-2 - Simplified descent profile..4 shows a simplified descent profile with various Mach/CAS followed by a standard IAS to final. The location of the Top-Of-Descent (TOD) point is calculated, taking into account:

o The preferred Mach/CAS speed schedule. o The predicted wind profile between cruise altitude and ground level at the destination

4 The CAS is the corrected IAS (Indicated Air Speed) as used by the pilot. 5 STAR = Standard Arrival Route.



Version 4.2 - 15/02/2012 - Page 186

airport. o The estimated landing mass of the aircraft. o Deceleration distance to comply with airspace constraints (i.e. max. 250kt IAS below

FL100). o Final approach deceleration distance.

Note that the descent is performed at idle thrust. Adverse weather conditions may impose a higher than normal idle thrust setting, resulting in a more distant TOD location

DESCENT SPEEDS – EXAMPLE

The simulated speed-control process for a representative Mach/CAS schedule of 0.65/280 is illustrated in the following figure. The aircraft, cruising at Mach 0.82 and 35,000 ft, decelerates at cruise altitude to Mach 0.65, with the speed change (Segment 1) complete at a range of about 10 nm. The aircraft maintains this cruise speed until the TOD, at about 34 nm (Segment 2). The aircraft then begins its descent at constant Mach 0.65 to a range of about 61 nm (Segment 3). During the constant-Mach portion of the descent, the CAS gradually increases from 215 kt to 280 kt. At about 23,500 ft, Mach 0.65 is equivalent to 280 kt CAS, and the aircraft switches to descend at constant CAS (Segment 4). At 95 nm, the aircraft has reached 10,000 ft, where it levels-off and decelerates to 250 kt CAS.



Version 4.2 - 15/02/2012 - Page 187

Descent profile.

Impact on TAS (True Air Speed) and GS (Ground speed) are not discussed in this section.



Version 4.2 - 15/02/2012 - Page 188

IMPACT OF NONIMPACT OF NONIMPACT OF NONIMPACT OF NON----ADHERENCE TO THE CALADHERENCE TO THE CALADHERENCE TO THE CALADHERENCE TO THE CALCULATED DESCENT PROFCULATED DESCENT PROFCULATED DESCENT PROFCULATED DESCENT PROFILEILEILEILE

As seen before, the location of the TOD-point is highly dependent (amongst other parameters) of the desired speed at which the descent is expected to be flown. The desired speed most likely will be the result of a cost calculation, using the appropriate cost index value for the aircraft operator and the subject flight.

Location of the "Top-of-Descent".

The ‘optimum’ or ‘ideal’ descent can only be achieved when an unconstrained descent may be flown, starting at the calculated top-of-descent, down to the landing runway. As soon as deviations against this descent path happen, cost penalties will occur:

3. Descents performed ‘below’ the intended descent path will result in a time penalty if flown at idle thrust. If thrust is used in such a descent, either during a level-off portion and/or in order to maintain the desired speed, more fuel than anticipated will be burned. This situation may happen when the flight is requested to descent before having reached the optimum TOD-point.



Version 4.2 - 15/02/2012 - Page 189

4. Descents performed ‘above’ the intended descent path will inevitably result in a fuel penalty due to the fuel burned during the extra level segment(s), executed either at cruise altitude, or at any other intermediate altitude. This situation will occur when the flight is requested to maintain the cruise altitude beyond the optimum TOD-point.

It is important to realize that the incurred penalty is not related to the descent phase of the flight, but to the direct operating cost of the entire flight. Looking at the descent phase of the flight only, may lead to erroneous conclusions!

TOD penalties.

We notice that the higher the cost index:

� the steeper the descent path (the higher the speed), � the shorter the descent distance,the later the top of descent (TOD) point.

As for the climb, descent performance is a function of the cost index; indeed, the higher the cost index, the higher the descent speed. But contrary to the climb, the aircraft gross weight and the TOD flight level appear to have a negligible effect on the descent speed computation. Values for time, distance, Mach/CAS, fuel consumption do vary much with flight conditions such as TOD flight level temperature and wind but are less variable with respect to gross weight. Similar to the climb, delta values with regard to time and distance are largely the same whatever the initial flight conditions.



Version 4.2 - 15/02/2012 - Page 190

For a typical medium-weight airliner (Airbus A320), we have following values (average takeoff weight):

Table 0-2 - Descent profiles - Airbus A320.

These values apply for a descent from FL 370 (ISA conditions, no wind), with a speed restriction of 250kt below FL100. The same values for a heavy-weight airliner (Airbus A330):

Table 0-3 - Descent profiles - Airbus A330.

Activation of anti-icing devices has a significant impact on the descent parameters (time/distance profile and fuel consumption) as shown in the following tables (ref. Airbus FCOM).



Version 4.2 - 15/02/2012 - Page 191

Airbus A320:

Table 0-4 - Impact of anti-ice and temperature - Ai rbus A320.

Table 0-5 - Impact of anti-ice and temperature - Ai rbus A330.

Note the impact of temperature deviations. All the above figures do not take WIND into consideration. The FMS integrates ground speed (i.e. wind) when computing ECON speed/Mach corresponding to a given cost index:

� headwinds command higher ECON speeds (less exposure time to higher winds) � tailwinds command lower ECON speeds (let winds work).

Indeed, in the case of headwind, the fuel increment (due to higher speeds) is compensated for by the reduced trip time in terms of cost and vice versa. For all Airbus models, the speed/Mach change is of the order of:

• Mach + 0.005 MN for 50kt headwind • Mach - 0.005 MN for 50kt tailwind.

In addition, usually, the wind model accounted for by the FMS in its ECON speed/Mach calculation results:



Version 4.2 - 15/02/2012 - Page 192

� from current position up to 150 NM ahead: actual encountered wind, � further up, a wind evolving linearly towards the wind inserted by the pilot into the FMS

at that flight level. The nominal flight path (i.e. TOD-point) should not be affected if the wind-corrected ECON speed/Mach is applied.

IMPACT ON FUELIMPACT ON FUELIMPACT ON FUELIMPACT ON FUEL----BURN OF A PARTIAL CDBURN OF A PARTIAL CDBURN OF A PARTIAL CDBURN OF A PARTIAL CDO O O O ---- PROFILEPROFILEPROFILEPROFILE

The optimum solution for descent consists in the execution of a continuous descent in idle thrust at the desired speed. Figure 1.12 shows a typical (optimum) descent profile and fuel burn figures for the Airbus A330-300. Any change to this descent profile will result, as seen in the previous section, in a cost and/or fuel penalty. The fuel burn line represents the optimum achievable for descent.

Airbus A330-300 – M.80/300KT/250KT descent profile and fuel burn.

The trial aimed to evaluate the gains obtained by flying part of the descent profile in CDO-mode. The CDO-part typically began at altitudes between FL60 and FL150. When the CDO-clearance is issued (see next Figure), the subject aircraft was either:



Version 4.2 - 15/02/2012 - Page 193

4) Below the intended descent profile:

The aircraft started to descend too early, or descended at higher descent rate than anticipated. Most likely, a level portion of flight was executed below cruise level, resulting in some extra fuel burn. If not, a portion of the descent was flown in idle at a lower speed, resulting in a time penalty.

5) On the intended descent profile:

Either the aircraft performed an ‘ideal’ descent, or found itself on the ideal descent path after a portion of level flight. Therefore, even in this case, a fuel penalty versus the optimum descent path cannot be excluded.

6) Above the intended descent profile:

The aircraft started too late its descent, or found itself above the ideal descent path after a portion of level flight. Clearly, more fuel than anticipated was burned or more time was spent than anticipated.

Clearly, possible gains in fuel burn achieved through the execution of a partial CDO, was biased by extra fuel burn or extra flight time, earlier in the descent phase of flight. Stated differently, the overall fuel burn figure of the flight would dependent of the flown profile before issuance of the CDO clearance.

Initiation of a CDO at or below FL150.



Version 4.2 - 15/02/2012 - Page 194

If a continuous descent is initiated at FL150 or below, it is clear that the fuel burn during that phase of flight will be proportional to its duration. The shortest duration will be achieved by aircraft, which are at high speed above their ideal descent path when the CDO-clearance is issued, because they will have to descent faster. Hence their fuel burn will seem optimal, when compared to flights on or below the ideal profile

Example of descent profile and fuel burn below FL15 0 - Airbus A330-300.

Above figure shows a typical descent profile flown by an Airbus A330-300 aircraft below FL150. The vertical profile is shown by the dark blue line, while the thin purple line shows the FCOM-suggested profile. The magenta illustrates the throttle activity: virtually ‘idle’ during the whole descent until capture of the glideslope below 3000 ft. This results in a fuel burn figure (cyan line), which is significantly better than the fuel burn figure given by the FCOM (yellow line). The difference is explained by the fact that the aircraft was flying much faster than normal, resulting in a shorter duration of this phase of flight, and a corresponding fuel “saving” versus the standard. The fact that the aircraft was above its profile at high speed, however, indicated that most likely, extra fuel was burned in the flight phases before passing FL150 in descent. This simple example clearly demonstrates that monitoring of the fuel burn during the CDO-portion could obviously lead to wrong conclusions in many cases. Therefore we monitored the fuel burn from TOD until GS-interception. As a consequence however, it was virtually impossible to establish one (or more) baselines. In this project, comparisons were made between declared CDO-flights and other flights, based on an initial assessment of the descent profiles, starting at TOD. Assessment of the



Version 4.2 - 15/02/2012 - Page 195

profiles was done using the Eurocontrol Eficat-tool; detailed analysis of the fuel burn figures and engine throttle ‘activity’ relied on FOQA-data of the subject flights.

KNOWLEDGE OF DESCENTKNOWLEDGE OF DESCENTKNOWLEDGE OF DESCENTKNOWLEDGE OF DESCENT PATH BY THE ANSPPATH BY THE ANSPPATH BY THE ANSPPATH BY THE ANSP

For the application of CDOs as intended in this program, ATS needed to acquire knowledge about what may be “expected” or is “feasible” for (at least) each aircraft type participating in the CDO-trials.

The next figure shows, for a given aircraft type, a “nominal” descent profile and the extreme cases, taking into consideration possible variations of all parameters which have an impact on the overall descent profile.

Different descent profiles.

The ‘extreme’ cases define the window or “entry gate” in which the aircraft are expected to arrive, when performing its preferred (or ‘ideal’) descent. In the shown example, the “entry gate” at FL100 is situated between 27 and 45 NM before touchdown. The subject aircraft will need to be at FL100 in descent in order to be able to execute the remaining part of the descent at its preferred speed. Ideally, for the purpose of definition of the “entry gate” at various altitudes, descent profile data (speed, time, fuel, distance to touchdown [or xxx ft] at several altitudes) were to be obtained for (not exhaustive list):



Version 4.2 - 15/02/2012 - Page 196

• “Light” aircraft – Cost index 0.

• “Heavy” aircraft – Cost index 0.

• “Light” aircraft – High cost index.

• “Heavy” aircraft – High cost index.

• Same profiles for high and low temperature?

• Same profiles for 50kt headwind/tailwind.

• ???

Unfortunately, Brussels Airlines does not have the means to calculate the required data the participating airline. A simplified method was used instead. For each aircraft type participating to the trial, a survey of descent profile data, as published in the Flight Crew Operating Handbook, was made. In addition, the descent profile as provided by the Eurocontrol developed BADA-model, was reviewed as well. This figure shows the descent profiles below FL150 for the Airbus A330-300 aircraft. The 3 and 4 degrees slopes are added as a reference.

Descent profiles below FL150 for A330-300.



Version 4.2 - 15/02/2012 - Page 197

Analysis of all descent profiles revealed that a 4-degree descent path was flyable for all medium weight (M) category aircraft, while a 3-degree descent path was seen as the limit for a heavy-weight (H) category aircraft.

Difference 3 to 4° glide path.

The 3 and 4-degree rule was used by the Air Traffic Controllers to assess the feasibility and to plan the issuance of a CDO-clearance. The descending aircraft needed to be located either on/below the 3-degree (H), resp. the 4-degree (M), slope in order to be eligible for a CDO-clearance. When located above, the Air Traffic Controller inevitably needed to cater for extra track miles in the pattern for allowing a workable descent and approach solution. Obviously, this last scenario needs to be avoided as much as possible.



Version 4.2 - 15/02/2012 - Page 198

APPENDAPPENDAPPENDAPPENDIX 3IX 3IX 3IX 3---- DESCENT PRDESCENT PRDESCENT PRDESCENT PROOOOFILES FOR AIRBUS A32FILES FOR AIRBUS A32FILES FOR AIRBUS A32FILES FOR AIRBUS A320 AND A330 AIRCRAFT0 AND A330 AIRCRAFT0 AND A330 AIRCRAFT0 AND A330 AIRCRAFT



Version 4.2 - 15/02/2012 - Page 199

APPENDIX APPENDIX APPENDIX APPENDIX 4444 –––– DESCENT SCENARIO DESCENT SCENARIO DESCENT SCENARIO DESCENT SCENARIO –––– AIRBUS AIRCRAFT.AIRBUS AIRCRAFT.AIRBUS AIRCRAFT.AIRBUS AIRCRAFT.

1. CRUISE DESCENT

A cruise descent to a new altitude is initiated by lowering the FCU altitude below the existing cruise altitude when the aircraft is more than 200 NM from the destination, or if a pre-planned step exists (and if the lowered FCU altitude is above FL200 and the highest descent constraint altitude). A managed cruise descent to a new lower cruise altitude results in using an ECON speed profile based on gross weight, cost index, and winds. Once the aircraft is at the new cruise altitude, the cruise flight level is re-established and a newly computed ECON cruise speed/Mach is flown. This results in a smooth transition to the new cruise altitude and speeds.

2. DESCENT TO DESTINATION

A descent to the destination (transition to DESCENT flight phase) is initiated by lowering the FCU altitude below the cruise altitude when the aircraft is within 200 NM of the destination and no pre-planned step exists in front of the aircraft. To enter the DESCENT flight phase when the aircraft is more than 200 NM from the destination and above 20,000 ft, momentarily set the FCU altitude to below 20,000 ft, push or pull the ALT select knob on the FCU, and then set and select the desired altitude on the FCU. If the ALT knob is pushed, the aircraft descends at 1000 fpm in vertical speed mode. If the ALT knob is pulled, an open descent is initiated.

NOTE: The above technique can also be used to transition from cruise descent to the DESCENT flight phase.

To return to the CRUISE flight phase when in DESCENT, enter a new cruise altitude on the PROG page that is lower than the aircraft altitude, with the FCU altitude set above 20,000 ft and the highest descent constraint altitude. To return to the CLIMB phase when in DESCENT, enter a new cruise altitude on the PROG page that is higher than the aircraft altitude, with the FCU altitude set above 20,000 ft and the highest descent constraint altitude. A descent to the destination can be either an early descent or late descent, depending on where it is initiated relative to the top-of-descent point.



Version 4.2 - 15/02/2012 - Page 200

a) Early Descent/Below Path

An early descent (also known as an immediate descent) occurs when a descent to the destination is initiated before the top-of-descent point is sequenced. In early descent (managed flight), the aircraft begins a 1000 fpm vertical speed descent while targeting the descent speed profile (managed mode if the FCU ALT knob is pushed). If speed is managed, managed Mach is flown above the crossover altitude and managed CAS is flown below the crossover altitude. The point where the immediate descent vertical speed path intercepts the FMS-constructed optimum descent path is indicated by a blue lightning bolt on the ND6. If the descent speed limit (or deceleration to the descent speed limit) is encountered while below path in the 1000 fpm descent, the vertical speed is reduced to 500 fpm. The vertical speed descent rate remains at 500 fpm for the duration of the descent as long as this mode is active. The speed targeted is unaffected by the change in the descent rate. If the immediate descent vertical speed path reaches an AT or AT OR ABOVE altitude constraint prior to intercepting the FMS-constructed descent path, the aircraft levels off, proceeds to the constraint in level flight, and resumes the descent upon sequencing the constraint. (This may result in the aircraft recapturing the descent profile, or resuming another vertical speed descent if still below the optimized descent profile.)

b) Late Descent/Above Path

A late descent occurs when a descent to the destination is initiated after the top-at-descent point is sequenced while in the CLIMB or CRUISE flight phase. The pilot is alerted at the aircraft total energy status by the DECELERATE message on the EFIS and in the MCDU scratch pad if in automatic speed management.

NOTE: The top-at-descent point is displayed only, it engaged in lateral auto control. It is not displayed it engaged in lateral manual control.

In a late descent (managed flight), the aircraft begins an idle thrust descent. If speed is managed, managed Mach is flown above the crossover altitude and managed CAS is flown below the crossover-altitude. When above path, the aircraft accelerates to the descent speed (ECON or pre-selected descent auto speed) plus 20 knots (limited by VMO-3 or MMO-0.0067) to let induced drag and higherspeed facilitate intercepting the vertical profile from above. If a descent speed limit (i.e., 250 knots/10,000 ft) or a speed constraint is encountered, the aircraft is limited to the constraint speed plus 5 knots to re-intercept the path.

6 ND = Navigation Display. 7VMO = maximum operating speed – MMO = maximum operating Mach number.



Version 4.2 - 15/02/2012 - Page 201

When either of these speeds is insufficient to return to the vertical profile two miles before reaching the next AT or AT OR BELOW altitude constraint, the message EXTEND SPD BRK is displayed on the MCDU and the PFD8. In trying to re intercept an FMS profile, a descent to a speed limit or speed constraint can also trigger the EXTEND SPD BRK message. This message always assumesthat the pilot will use at least 1/2 air brakes to meet the constraint.

NOTE: The FMS predictions (especially vertical and performance) require an accurate wind model. Altitude constraints are considered made when the aircraft is within 250 ft.

Descent Path Speed Targets The descent path speed targets are displayed in the following graph:

8PFD = Primary Flight Display.




Version 4.2 - 15/02/2012 - Page 202



Version 4.2 - 15/02/2012 - Page 203

APPENDIX APPENDIX APPENDIX APPENDIX 5555 –––– AIRBUS A319 AIRBUS A319 AIRBUS A319 AIRBUS A319 ---- AFM REFERENCE DESCENAFM REFERENCE DESCENAFM REFERENCE DESCENAFM REFERENCE DESCENT PROFILES.T PROFILES.T PROFILES.T PROFILES.

Airbus A319 – Normal Descent.



Version 4.2 - 15/02/2012 - Page 204



Version 4.2 - 15/02/2012 - Page 205

APPENDIX APPENDIX APPENDIX APPENDIX 6666 –––– AIRBUS A330AIRBUS A330AIRBUS A330AIRBUS A330----300 300 300 300 ---- AFM REFERENCE DESCENAFM REFERENCE DESCENAFM REFERENCE DESCENAFM REFERENCE DESCENT PROT PROT PROT PROFILES.FILES.FILES.FILES.

Airbus A330-300 – Normal Descent.



Version 4.2 - 15/02/2012 - Page 206



Version 4.2 - 15/02/2012 - Page 207

AAAAPPENDIX 7PPENDIX 7PPENDIX 7PPENDIX 7 ----DRAFTDRAFTDRAFTDRAFT CDO PUBLICATIONCDO PUBLICATIONCDO PUBLICATIONCDO PUBLICATION

VALIDATION DATE OF PVALIDATION DATE OF PVALIDATION DATE OF PVALIDATION DATE OF PREPARATIONREPARATIONREPARATIONREPARATION

v.1.0 dd. 17 Dec 2011

EBBR AD 2.21 NOISE AEBBR AD 2.21 NOISE AEBBR AD 2.21 NOISE AEBBR AD 2.21 NOISE ABATEMENT PROCEDURESBATEMENT PROCEDURESBATEMENT PROCEDURESBATEMENT PROCEDURES

ARRIVAL PROCEDURES

Between 2300 and 0459 CDO-facilitation is at ATC discretion or at pilot’s request. Brussels ARR ATIS will broadcast “CDO facilitation on Approach frequency”. Between 0500 and 2259 CDO-facilitation is at ATC discretion only. As soon as practicable after first call on the Approach frequency, ATC shall provide distance-to-go to the runway threshold and an approval to descend at pilot’s discretion. Phraseology “when ready, descend” or “descend at pilot’s discretion”. CDO’s will NOT be facilitated when following conditions apply:

• adverse weather conditions that may affect the approach (wind shear, thunderstorms, etc)

• landing runway in use is 07L or 07R.

Subject to ATC instructions, inbound aircraft shall adopt a continuous descent profile – to the greatest possible extent – compatible with safe operation of the aircraft – by employing minimum engine thrust, ideally in a low drag configuration, prior to the FAF/FAP. Note: all noise abatement procedures for arrivals as well as the speed limitations from EBBR AD 2.22FLIGHT PROCEDURES 2.1.3 remain applicable when performing a CDO.

SPEED LIMITATION

Aircraft inside the Radar Vectoring Area, depicted on chart AD 2.EBBR Star.01, shall reduce speed



Version 4.2 - 15/02/2012 - Page 208

to 250 KIAS when below FL100.

EBBR AD 2. 24 CHARTS RELATED TO EBBR

- Information box to be added to chart EBBR STAR.01:

Continuous Descent Operations (CDO)

(see EBBR AD 2.21, § 3.4)

- SLP on AD 2 EBBR-STAR.01 to be removed.

Below the current map AD 2 EBBR STAR.01



Version 4.2 - 15/02/2012 - Page 209

Aire b3 project

Documents

Transcript of Aire b3 project