Post on 13-Oct-2020
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Operational Procedures for LAQOperational Procedures for LAQ
John-Paul ClarkeAssociate Professor of Aerospace EngineeringDirector of the Air Transportation LaboratoryGeorgia Institute of Technology
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
OutlineOutline
1. Introduction2. Continuous Descent Arrival3. Surface Movement Optimization4. Conclusions
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
IntroductionIntroduction
Air transportation is: • Enabler of economic growth• Catalyst for economic development
Environmental impact of aviation is:• Significant concern at the global and local levels• Local air quality is a rapidly growing concern
Issue must be addressed in a comprehensive way• Reductions at source• Operational procedures*• Operational charges and restrictions
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
• Sequence and spacing achieved between top-of-descent and metering point(during descent from cruise a.k.a. initial portion of descent)
• No vectoring after passing metering point(during descent to runway a.k.a. latter portion of descent)
• Metering point dependent on traffic conditions
Hei
ght
エ
Monitoring/Intervention
Missed App.
Conventional
FAF
Wake VortexSeparation
4 - 6 nm
エ
Streaming/SequencingStreaming/Sequencing Monitoring/Intervention
Descent from CruiseDescent from Cruise Missed App.
Conventional
FAF
Wake VortexSeparation
4 - 6 nm
SpacingSpacing
Metering Point
Descent to Runway
Top-of-Descent
Continuous Descent Arrival (CDA)Continuous Descent Arrival (CDA)
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
CDA for 2004 SDF Flight TrialsCDA for 2004 SDF Flight Trials
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
LAQ, Noise, and Economic BenefitsLAQ, Noise, and Economic Benefits
Local emissions reduced• CO below 3,000 ft reduced by 12.7% (B-767) and 20.1% (B-757)• HC below 3,000 ft reduced by 11.0% (B-767) and 25.1% (B-757)• NOx below 3,000 ft reduced by 34.3% (B-767) and 34.4% (B-757)
Noise impact reduced• Lower per aircraft noise levels
(3 to 6 dBA; 7 to 15 NM from runway)• Impact concentrated in narrow corridors
Economic costs reduced• Fuel to fly last 180 nm to runway reduced by
364 lbs/flight (B-767) and 118 lbs/flight (B-757)• Time to fly last 180 nm to runway reduced by
147 seconds/flight (B-767) and 118 seconds/flight (B-757)
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Challenge: Getting the “Right” SpacingChallenge: Getting the “Right” Spacing
Spacing (nm)
Prob
abili
ty D
ensi
ty
Target spacing at metering point
Required separation at runway
Range of spacing at runway for a given target spacing at metering point;
Shaded area equal to confidence that descent to runway can be completed without controller intervention;
Shape of distribution depends on target spacing.
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Separation and Throughput
Analysis
Min. FinalSeparation
Max. FinalSeparation
Separation at Metering Point
Intermediate Metering Point Runway Threshold
Time
Along Track Distance
Trailing ACTrailing AC
Leading ACLeading AC
• Shaded area indicatestrajectory variation
• Final separation will be a probability distribution
• Shaded area indicatestrajectory variation
• Final separation will be a probability distribution
Initial Positionof Trailing AC
Initial Positionof Leading AC
Separation at Metering Point
in Time
Min. FinalSeparation
Max. FinalSeparation
Separation at Metering Point
Intermediate Metering Point Runway Threshold
Time
Along Track Distance
Trailing ACTrailing AC
Leading ACLeading AC
• Shaded area indicatestrajectory variation
• Final separation will be a probability distribution
• Shaded area indicatestrajectory variation
• Final separation will be a probability distribution
Initial Positionof Trailing AC
Initial Positionof Leading AC
Separation at Metering Point
in Time
Separation at Metering Point
Prob
abili
ty D
ensi
ty
FeasibleSeparation, p1
AC Type A – Type BFeasible
Separation, p2AC Type B – Type A
A small slice of traffic at separation s
Actual TrafficUnadjusted, pT
Actual TrafficAdjusted, pTa
Target Separation SI
Separation at Metering Point
Prob
abili
ty D
ensi
ty
FeasibleSeparation, p1
AC Type A – Type BFeasible
Separation, p2AC Type B – Type A
A small slice of traffic at separation s
Actual TrafficUnadjusted, pT
Actual TrafficAdjusted, pTa
Target Separation SI
Trajectory
Fast-Time Aircraft
Simulator
Fast-Time Aircraft
Simulator
Con
volu
tion
Monte Carlo Tool
Procedure DefinitionAircraft / Flap Schedule
Weight Distribution
Pilot Response
Local Wind Variation
Wind Forecast
45/270, 4000030/256, 2000021/252, 900010/249, 450
Tool for the Analysis of Separation and Throughput (TASAT)Tool for the Analysis of Separation and Throughput (TASAT)
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
R&D Activities in AtlantaR&D Activities in Atlanta
Flight test of time-based arrival fix metering*• Demonstrate ability to set initial spacing based on aircraft type, weight, and wind,
and deliver aircraft on final approach with very high accuracy in terms of both time and spacing
• Began on 16 April 2007Time-based metering of arrivals from NE and NW destined to 8L/26R*
• Build upon results of 2007 flight test• Starting in 2008 or 2009
Metroplex design for 2015 and 2025• JPDO project to develop a concept of operations for 2015 and 2025 at ATL
* Partnership between Delta, Georgia Tech, FAA (HQ, ZTL, ZTL-A80)
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
CDA for 2007 ATL Flight TrialsCDA for 2007 ATL Flight Trials
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Reduced Low Altitude VectoringReduced Low Altitude Vectoring
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Surface Movement OptimizationSurface Movement Optimization
What’s wrong with this picture?
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Growth Rates versus Phase of FlightGrowth Rates versus Phase of Flight
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Airport & Terminal Area Traffic FlowAirport & Terminal Area Traffic Flow
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Airport & Terminal Area QueuesAirport & Terminal Area Queues
Taxiway RampGatesDeparture
Runway (22R)Arrival Runways
27/22L
Arrival routes
Departure routes
Local Controller
Local Controller Ground Controller
Ground Controller
Gate ControllerControl actions
Resource utilization
FixesLanding queues
Exit fix queues
Takeoff queues
Departure runway crossing
queues
Arrival runway crossing queues
Departure taxi queues
Arrival taxi queues
Departure ramp queues
Ally blocked or gate occupied queues
Turnaround
Pushback queues
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
“ N Control”“ N Control”
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0 5 10 15 20 25 30
No. of Aircraft Taxiing Out
Take
off R
ate
(per
min
ute)
• Saturation point beyond which there is no significant gain in takeoff rate
• Gate release control may be used to provide the desired number of aircraft
• Meets objectives of• Maximizing throughput • Reducing engine-run times• Reducing fuel burn• Reducing emissions
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
Two-Stage Optimization AlgorithmTwo-Stage Optimization Algorithm
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
37.44
34.73
39.9238.74
20
25
30
35
40
45
50
Unrestricted Restricted
Traffic Scenario
Dep
artu
res
/ Hou
r
WITHOUT Planning
WITH Planning
40.98
48.89
55.351.4
15
25
35
45
55
65
75
85
Unrestricted RestrictedTraffic Scenario
Del
ay (M
in)
WITHOUT Planning
WITH Planning
decreased delayincreased throughput
Operational Benefits of OptimizationOperational Benefits of Optimization
FCFS with EWR & JFK
Miles In Trailactive
Runway Idle Time
EWR:35 MIT
JFK:30 MIT
Availability Seq.@ Rwy
(also FCFS withNO Active
Restrictions)
Time
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
LAQ Benefits of OptimizationLAQ Benefits of Optimization
ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007
ConclusionsConclusions
Operational procedures can provide (and are providing) much needed LAQ benefits:
• Well designed CDA’s significantly reduce (in many cases eliminate) low altitude vectoring and reduce the time in the mixing layer
• Surface movement optimization significantly reduces taxi time and thus the emissions from surface operations (fastest growing emissions segment)
Development of operational procedures will also provide solutions to some fundamental air traffic control questions:
• How does terminal area trajectory prediction accuracy vary as a function of uncertainties in wind, aircraft weight, pilot performance?
• 4-D trajectory management limits• Under what conditions can precise aircraft sequencing and spacing be achieved
in the terminal area and one the surface with “strategic control?”• Requirements for avionics, air traffic control decision support and wind prediction tools