Boeing 737 Classic ENGINEERING CONTINUATION TRAININGcbt.altitudeglobal.aero/Files/A8 Boeing737 Cl 34...

FOR REFERENCE ONLY

Boeing 737 Classic ENGINEERING

CONTINUATION TRAINING

Q3&Q4 2018

FOR REFERENCE ONLY

Contents:

1 INTRODUCTION

2 737 AIRWORTHINESS DIRECTIVES

3 737 UK MAINTENANCE RELATED MOR

4 SPECIAL AIRWORTHINESS INFORMATION BULLETINS

5 PROCEDURES REVIEW

6 ATA 49 APS2000

FOR REFERENCE ONLY

1 Introduction This module covers aspects identified in the period June 2018 to Dec 2018.

2. B737 Classic Airworthiness Directives The following pages lists the Boeing 737 Classic AD’s issued from June 2018 to December 2018. If a full listing is required, they can be found on the EASA website (http://ad.easa.europa.eu) or you can navigate from the Quality Tab on TechCom. Some superseded and superseding ADs have not been included as there is no material change. US AD No.: 2018-17-23 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 53 Fuselage - Number 3 Windshield Assembly Aft

Sill Web - Inspection

Manufacturer/s: The Boeing Company

Applicability This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and - 500 series airplanes, certificated in any category.

Reason: We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by a report indicating that during a fleet survey on a retired Model 737 airplane, cracking was found common to the number 3 windshield assembly, aft sill web. This AD requires, at certain locations, repetitive high frequency eddy current (HFEC) inspections of the number 3 windshield assembly, aft sill web; and applicable on-condition actions. We are issuing this AD to address the unsafe condition on these products.

http://ad.easa.europa.eu/


FOR REFERENCE ONLY

US AD No.: 2018-16-09 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 53 Fuselage - Frame Webs - Inspection Manufacturer/s: The Boeing Company


Reason: We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by report indicating that cracks were found on the fuselage frame webs at stations forward and aft of the overwing emergency exits between stringer-7 (S-7) and S-8. This AD requires repetitive high frequency eddy current (HFEC) inspections for cracking of the fuselage frame webs at certain stations between S-7 and S-8 and applicable on-condition actions. We are issuing this AD to address the unsafe condition on these products.

US AD No.: 2018-18-13 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 57 Wings - Outboard Flap Tracks - Inspection Manufacturer/s: The Boeing Company

Applicability This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and - 500 series airplanes, certificated in any category

Reason: This AD was prompted by reports of cracking in certain flanges, and the adjacent web, of the wing outboard flap track at certain positions, and a determination that new inspections of certain flap track flanges and webs forward of the rear spar attachment are necessary. This AD requires an inspection to determine the part number of the wing outboard flap track assembly; repetitive inspections of each affected wing outboard flap track for discrepancies, and applicable on-condition actions; and repetitive overhaul of each wing outboard flap track. We are issuing this AD to address the unsafe condition on these products.



FOR REFERENCE ONLY

US AD No.: 2018-18-03 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 53 Doors / Fuselage - Floor Beam Lower Chord and

Door Stop Fittings - Inspection Manufacturer/s: The Boeing Company

Applicability This AD applies to The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category, as identified in Boeing Alert Requirements Bulletin 737- 53A1370 RB, dated December 13, 2017.

Reason: This AD was prompted by several reports of cracks in a certain floor beam lower chord at door stop fitting No. 1 of the forward airstair door cutout. This AD requires repetitive inspections for any cracks and applicable on-condition actions. We are issuing this AD to address the unsafe condition on these products

US AD No.: 2018-19-20 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 53 Fuselage - Frames and Stub Beams - Inspection /

Repair Manufacturer/s: The Boeing Company

Applicability This AD applies to The Boeing Company Model 737-200, -300, -400, and -500 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-53A1254, Revision 3, dated November 13, 2017

Reason: AD 2010-25-06 required repetitive inspections for cracking of certain fuselage frames and stub beams, and corrective actions if necessary. AD 2010-25-06 also provided for an optional repair, which terminated the repetitive inspections. For airplanes on which a certain repair was done, AD 2010-25-06 also required repetitive inspections for cracking of certain fuselage frames and stub beams, and corrective actions if necessary. This AD retains the actions required by AD 2010-25-06 and expands the inspection area. This AD was prompted by additional cracking found in areas not covered by the inspections in AD 2010-25-06. We are issuing this AD to address the unsafe condition on these products.



FOR REFERENCE ONLY

US AD No.: 2018-21-08 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 53 Fuselage - Bulkhead Frame Web - Inspection Manufacturer/s: The Boeing Company


Reason: This AD was prompted by the results of a fleet survey that revealed cracking in the bulkhead frame web at a certain body station. This AD requires repetitive inspections of the bulkhead frame web at a certain station, and applicable oncondition actions. We are issuing this AD to address the unsafe condition on these products.

EASA AD No.: 2018-0259 Airworthiness Directives can be viewed at http://ad.easa.europa.eu/ ATA 46 Information Systems – Electronic Flight Bag

Universal Serial Bus Receptacle – Modification Manufacturer/s: Fokker Services B. V.

Applicability Fokker F27 Mark 050, F28 Mark 3000, F28 Mark 0070 and F28 Mark 0100 aeroplanes; Airbus A318, A319, A320, A321, A330 and A340 aeroplanes; Avions de Transport Régional (ATR) ATR42 and ATR72 aeroplanes; Boeing 737, 757, 767 and 777 aeroplanes; and Bombardier (formerly Canadair) CL-600 and (formerly De Havilland Canada) DHC-8 aeroplanes; as identified in Appendix 1 of this AD.

Reason: Several occurrences on various aeroplanes have been reported of smoke and fumes in the cockpit, due to overheating of an Electronic Flight Bag (EFB) USB receptacle, which had been installed by FS Supplemental Type Certificate (STC), SB, or minor modification, either an Engineering Change Request (ECR) or Compliance Record Report (CRR), as applicable. Investigation results revealed that each of these events was caused by a short circuit in the EFB charging cable.



FOR REFERENCE ONLY

3. 737 Classic UK Maintenance Related MOR’s The following are maintenance related MOR from the UK CAA MOR digest. As the information is protected and strictly controlled by the UK CAA, it is respectfully requested that this information is not circulated. “No part of the MOR publication may be reproduced or transmitted outside of the organisation without the express permission in writing of the Civil Aviation Authority Safety Data Office.”

ATA 27 Potential pitch defect concerns expressed by captain before flight but electing to take-off without consulting engineering.

We debriefed the Captain on arrival. The Captain informed me he had concerns on his pre-flight free range of movement check on push back at EMA whilst engines were running. The flight controls in Pitch felt loose in which he did not detect whilst doing his Free range of movement under Electric Driven Pump power. Then on his pre role check again the captain informed us he still felt the controls to be loos in pitch and was considering returning to stand but opted to take off. the feel between the pitch and the role felt by the crew was different and the Captain informed he found co-ordination between the controls to be more difficult. He even mentioned he was concerned the elevators would not react when needed to take off. No ASR was raised, maintrol informed. We had a full de-brief and started troubleshooting the fault. CAA Closure: Investigation Findings and Root Cause: The failure of the feel and centring unit springs has been attributed to premature failure contained in the unit. Remedial Action(s) Taken: A review has been carried out of previous maintenance findings of this nature, with no maintenance findings or Pireps of this nature in the continuing airworthiness database system. The operator has reviewed the issue and has created a task for addition to the C Check package to carry out a remove and replace of the feel and centering unit. The overhaul at workshop will include the replacement of the springs. ATA 24 Smoke in flight deck resulted in Mayday call. Once we arrived on stand at NCE, an Electrical arcing noise emanated from the p6 panel behind the fo. The engines had been shut down with only the APU running. Smoke started to come from around the GCU panel. The passengers were disembarking at this point. I called Ground ATC with a mayday and requested the fire service. I explained we had smoke in the flight deck. I called cabin crew at stations and spoke to the senior. I told her that smoke was coming from a panel in the flight deck and to ensure that passengers disembarked as quickly as possible. I then de-powered the aircraft and the smoke slowly dissipated. Just As the last passengers got off the aircraft the fire service arrived. The smoke had stopped at this point. We had a safety pilot on board who immediately got the fire extinguisher ready as the smoke was seen. The fire bottle was not used. I left the flight deck once the chief fireman arrived and informed the cabin crew that the smoke had stopped but to be prepared to get off the aircraft if necessary. Supplementary 13/07/2018:

FOR REFERENCE ONLY

Smoke in flight deck. Once on stand at NCE smoke and electrical arcing noise emanated from above no2 GCU behind f/o seat. First invest carried out. Found BPU smell + smoke. LRU removed. Waiting b2 Engineer for t/s NCE engineer. Ref item ****** BPP to be replaced BPP replaced and tested. IAW AMM 24-41-21 LMWR - GCU contamination check due to evidence of contamination cited on work orders ***** and ******* on the ENG 2 and APU GCU’s following a smoke event, please investigate source of contamination. LMWR carried out. Flight deck trim panels removed around GCU and bus protection panel. Dust found at panel aperture, dust hoovered, no further contamination found area considered Dry and clean. Panel refitted IAW AMM 25-11-21 Rev 87.

ATA 24 Generator no. 2 disconnected due to oil temperature being high.

Oil temp high on generator drive no2, and increasing, QRH actioned and APU started, Autopilot switched to other side and APU put on Bus 2. With advice of Engineer drive was disconnected. Mel consulted 3 day limit on use of APU as generator The aircraft was at FL350 (limitation) and the flight plan changed to Northerly so we descended to FL340. The Crew followed the correct procedure. The #2 Engine generator CSD is now INOP, APU generator to be used in flight and it has a 3 Day limit. Engineering inspected the aircraft and the #2 CSD filter was found to be contaminated along with the CSD unit. The pipework and Oil Cooler was replaced and a TLP has been attached to this report for work completed..

ATA 49 APU inoperative. Load compressor blades were found to be completely detached from the rotor shaft.

"APU was inoperative the other day. T/Shooting C/O today, on inspection the load compressor blades were found to be completely detached from the rotor shaft. Supplementary 27/07/2018: This appears to be a failure within the APU. To establish the root cause we will need the strip report from the APU repair facility and this will be captured by the *** reliability system. This report has also been filed as an MOR with the CAA."

ATA 21 Electrical connector to the Mix Valve on the Right Hand Pack was found to be disconnected.

The aircraft arrived with an incoming defect - "UNABLE TO CONTROL CABIN TEMPERATURE (AUTO OR MANUAL) FULL COLD" Engineering carried out at the initial General Visual Inspection (GVI) of the Mix Valve and Connector, before carrying out any detailed fault isolation procedures check. It was whilst carrying out the GVI that the electrical connector to the Mix Valve on the Right-Hand Pack was found to be disconnected. The loose connector was covered in masking tape and stowed inside the lightning hole of the Keel Beam.

ATA 73 Hoses connecting fuel filter differential pressure switch to the fuel filter housing were disconnected.

Whilst replacing the fuel filter on engine 2, it was noted that the hoses that connect the fuel filter differential pressure switch to the fuel filter housing were disconnected and the filter housing ports blanked. Please see attached pictures. Powerplant have been informed and are making investigation. Engine 2 fuel filter differential pressure switch hoses found disconnected from fuel filter housing. Connections at fuel Filter housing blanked.

FOR REFERENCE ONLY

ATA 27 Suspect elevator wear and corrosion..

Captain reports suspect elevator/trim tab vibration at airspeeds +270 kts. Reduces slightly as airspeed reduces. Captain also reports stab trim hunting fwd/aft during descent constant airspeed/pitch attitude. Troubleshooting c/o iaw amm 05-51-67/201 and 737-sl-27-154-h. On inspection with hydraulic power applied to the elevators 1.5" travel of wear apparent. Corrosion is also apparent at the elevator torque tube crank assembly fittings.

ATA 05 Crew operated aircraft with three (3) open defects in technical log.

"I met the aircraft on stand from EMA to BFS. I then went to the flight deck to debrief the crew. The Capt. explained he had entered three (3) defects into the tech log and verbally explained what they were. He then said to me that the defects were all deferrable and told me to defer them. I explained that I would have to get access to maintenance docs to see if the defects were within any limits, etc. The Capt. stated that there was no Maint action required, he had checked and that I was not to take the log book off his aircraft. I replied that you (the Operator) like things done by the book, and I am using my licence, therefore I would do the action in the correct manner and consult my AMM documentation. He then said to me, in front of the F/O that ""you are being a complete ****, I don't need your assistance, I can defer these items myself, we no longer require your assistance"" I then left the F/Deck and waited for the aircraft to depart. When I went to the Aircraft the next morning, I had the same entry in again that the ST BY Altimeter was reading minus 450ft. This action was not deferrable and should have grounded the aircraft two sectors earlier. CAA Closure: Root Cause: There was clearly a breakdown in process brought on by a poor working relationship and time pressure to depart the aircraft. The Captain made an error of judgement by electing to monitor the standby altimeter and VNAV defects. This error was partly induced by the engineers misunderstanding of the method for determining the serviceability limits of the standby altimeter and subsequent proposal to return to the line office with the Tech Log. Remedial Action(s) Taken: Flight Operations to issue an FSI to crew on the use of the FCOM to determine standby altimeter serviceability. Part M to issue to contracted Part 145 organisations a procedure on the use of the FCOM to determine standby altimeter serviceability. Flight Operations to review the MEL training syllabus/course to incorporate practical examples of deferring multiple defects, administration process and interaction with engineering. Part M to review procedures for monitoring and recording transient defects."

ATA 78 Pilot reported he found a wrench in the exhaust of the RH eng. In the morning (04/08/2018) at the end of my nightshift the captain of the aircraft reported he saw a wrench in the exhaust of the RH engine. When I arrived at the A/C I found indeed a ¼ open end/ring wrench in the fan exhaust duct inboard side. During the evening shift on 03/04/2018 a HMU replacement was performed on this engine. I was informed the only thing remains to be done was the leak check of this HMU, and that the daily check was almost finished and if I could handle the release to service after a successful leak check of the HMU. The A/C was towed out the hangar and engine run preparation were done iaw the AMM. At this time (around

FOR REFERENCE ONLY

midnight) it was still dark outside (nightshift) and this wrench remained unnoticed. After a successful leak check iaw AMM this wrench apparently wasn’t blown out by the airflow of idle rpm. The daily paperwork was finished and aircraft was towed to it’s departing gate. The captain discovered this wrench upon his walk around, called to maintenance to inform about the wrench and to have an engineer come over. ATA 27 Spanner found near flight control column.

A 1/4" combination spanner fell onto the floor when the R/H upper nose wheel well pressure panel (114AC) was removed during heavy maintenance. The spanner has ***** engraved. on it. ATA 27 Roller bearing found missing from flap sequencing carriage during maintenance.

***** is currently on maintenance at ******, during lubrication of the right hand flap system it was noticed that a roller bearing was missing from the no. 7 sequencing carriage. The split pin, nut and washer that should secure the bearing were also missing. Design Approval Holder to be notified by operator. Split pin, bearing securing nut and washer missing, allowing the bearing to come free. Corrective actions: Non Routine card raised and operator informed for further investigation by operator. Missing parts will be replaced and flap system functionally checked during maintenance input. Report closed from ***** perspective. ATA 27 Aileron cable found damaged during inspection due to incorrect installation. During GVI of w/w on a-******, aileron cable absa-r1 found Damaged. Event reported to b1. During investigation noted cable wrongly installed. Aileron cable absa-r1 replacement required. ATA 52 Girt bar floor fitting installed incorrectly. Whilst carrying out this maintenance on the aircraft, Engineers have found the following fault with regards the L1 Door Aft Girt Bar Floor Attachment Point fitting. It is very apparent that the Aft Girt Bar Floor attachment Point (one of two, the other is forward of door) has been incorrectly installed, it is in fact 180 degrees out of alignment (AMM 25-61-51-402-002 refers). Door L1 Girt Bar floor attachment was found to be incorrectly fitted, the effect of which, if the door was operated in an emergency situation, the emergency Slide could have become detached from the floor fitting when used. ATA29 Engine Driven Pump installation incorrect. During replacement of the #1 engine CSD it was noted that the electrical receptacle on the EDP for that engine was loose and there appeared to be X3 securing screws sheared, (*** pump). A replacement pump was ordered and installed IAW AMM 29-15-11 and on completion of maintenance on that engine an attempt was made to close the fan cowls. It became apparent that there was interference between the EDP depressurisation solenoid electrical plug and the latch fitting of the outboard fan

FOR REFERENCE ONLY

cowl which prevented the cowl from closing. Powerplant were made aware of the situation via tech assist. Further investigation found that the orientation of the QAD adaptor plate was incorrect and required adjustment along with associated hyd plumbing. Initial pump replacement c/o and subsequent investigation/rectification on WO. The damaged pump has been routed to stores and will be held in quarantine until further notice. ATA27 Bolt was protruding from the left outboard flap track fairing drain hole.

. On arrival in nce on crew walk round, it was noted that a bolt was protruding from the left outboard flap track fairing drain hole. Engineering inspection performed & it was discovered that the bolt was missing from the flap carriage push rod to fairing support arm interface a further search of the fairing was carried out with no sign of the missing nut & washer. It was also noticed at this time that the nut & washer were also missing from the fairing support arm track bearing. ATA53 Forward pressure bulkhead fasteners found loose. Operator's statement: "On pre departure inspection the engineer noticed most of the forward pressure bulkhead fasteners loose. ( see attached photo) Bolts were all torqued up flight continued no delay incurred. Root Cause: Failure to record correctly the steps taken to rectify a steering issue reported on *****. ***** rectified by cable tension check but no mention of stage sheets or of the panel being removed. 1. No record of the tools used. 2. No record of the new washers used ref AMM 53-14-01-420-801 sect 3 para F (1) (c). 3. No record of the panel being removed. 4. no record of the rig pin used. 5. no record of post fit pressure run or leak check. Corrective Action: the panel fasteners were TQ loaded Preventative Action: This issue has been passed to ****** for investigation" ***** are currently investigating. 4. Special Airworthiness Information Bulletins Information Bulletins can be viewed at http://ad.easa.europa.eu/ No SAIB’s at this time. 5. Procedures Review Due to time to print differences between this publication and current published technical matter, it has been decided to no longer reference changes to individual operators’ technical notices and procedures. This information will of course still be readily available via TechCom or the individual operators’ systems. If you are having difficulty in accessing any of this information, please contact your local supervisor or STN tech library.

These notes are for information and training use ONLY and are NOT subject to amendment or alteration.

Always use the correct and current aircraft maintenance manuals relevant to the

aircraft and operator.

These notes are not intended to be used to carry out maintenance on the aircraft.

Page 1

Altitude Global Limited Training Notes - Issue 3 - 14.08.18

Table of Contents

ATA 49 APU 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APS 2000 INTRODUCTION 2. . . . . . . . . . . . . . . . . . . . . . . . . PANEL DESCRIPTION 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ACCESS DOOR 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APU DRAINS 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AIR INLET DESCRIPTION 10. . . . . . . . . . . . . . . . . . . . . . . . . . APU AIR INLET ADJUSTMENTS 12. . . . . . . . . . . . . . . . . . . . BOROSCOPE INSPECTION 14. . . . . . . . . . . . . . . . . . . . . . . . APU LUBRICATION SYSTEM 16. . . . . . . . . . . . . . . . . . . . . . . OIL TANK DESCRIPTION 18. . . . . . . . . . . . . . . . . . . . . . . . . . COMPONENT DESCRIPTION 20. . . . . . . . . . . . . . . . . . . . . . OIL TANK SERVICING 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . OIL SYSTEM SCHEMATIC DESCRIPTION 24. . . . . . . . . . . APU FUEL SYSTEM 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APU FUEL SHUTOFF VALVE 28. . . . . . . . . . . . . . . . . . . . . . . FUEL HEATER 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ELECTRONIC FUEL CONTROL AND PUMP ASSEMBLY 34START PURGE VALVE 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . FUEL SYSTEM OPERATION 38. . . . . . . . . . . . . . . . . . . . . . . DRY MOTOR THE APU 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . WET MOTOR THE APU 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . LOW PRESSURE BLEED 44. . . . . . . . . . . . . . . . . . . . . . . . . . APU AIR SYSTEM 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APU BLEED BLEED AIR VALVE 48. . . . . . . . . . . . . . . . . . . . . BLEED AIR VALVE OPERATION 50. . . . . . . . . . . . . . . . . . . . APU COOLING AIR SYSTEM 52. . . . . . . . . . . . . . . . . . . . . . . APU COOLING AIR 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . COOLING FAN 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IGNITION AND START SYSTEM 58. . . . . . . . . . . . . . . . . . . . IGNITION COMPONENT DESCRIPTION 60. . . . . . . . . . . . . STARTING COMPONENT DESCRIPTION 62. . . . . . . . . . . . STARTING COMPONENT DESCRIPTION 64. . . . . . . . . . . . APU CONTROLS 66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APU CONTROL UNIT/FADEC DESCRIPTION 68. . . . . . . .

FADEC DESCRIPTION 70. . . . . . . . . . . . . . . . . . . . . . . . . . . . AMBIENT PRESSURE TRANSDUCER 72. . . . . . . . . . . . . . . SPEED SENSOR 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APU START SEQUENCE 76. . . . . . . . . . . . . . . . . . . . . . . . . . . APU SHUT DOWNS 78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. G. T. INDICATING SYSTEM. 80. . . . . . . . . . . . . . . . . . . . . THERMOCOUPLES ( 2 ) 82. . . . . . . . . . . . . . . . . . . . . . . . . . . EGT BALANCING RESISTOR 86. . . . . . . . . . . . . . . . . . . . . . . ID-MODULE 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FADEC BITE CODES AND LIGHTS. 90. . . . . . . . . . . . . . . . . MCDU, APU DATA PAGES. 92. . . . . . . . . . . . . . . . . . . . . . . . . TROUBLE SHOOTING. 94. . . . . . . . . . . . . . . . . . . . . . . . . . . . APU OPERATION LIMITS AND PARAMETERS 97. . . . . . . APU OPERATION TEST 98. . . . . . . . . . . . . . . . . . . . . . . . . . .

Page 2


debbieb

ALT Logo

TABLE OF FIGURESFigure 1 APS 2000 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2 APU Panel 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3 APU Access Door and Shroud. 7. . . . . . . . . . . . . . . . . . . . . . Figure 4 Shroud Drains. 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 5 APU Air Inlet 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6 APU Air Inlet Adjustments 13. . . . . . . . . . . . . . . . . . . . . . . . . . Figure 7 Boroscope Inspection 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 8 Lubrication Schematic 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 9 Lubrication System Components 19. . . . . . . . . . . . . . . . . . . . Figure 10 Lubrication System Components 21. . . . . . . . . . . . . . . . . . . Figure 11 Oil Tank Servicing 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 12 Oil Servicing System Schematic 25. . . . . . . . . . . . . . . . . . . . Figure 13 Fuel System Schematic 27. . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 14 APU Fuel Shutoff Valve and DC Fuel Boost Pump 29. . . . Figure 15 APU Fuel Shutoff Valve Control 30. . . . . . . . . . . . . . . . . . . . Figure 16 DC Fuel Boost Pump Control 31. . . . . . . . . . . . . . . . . . . . . . Figure 17 Fuel Heater and Flow Control Valve 33. . . . . . . . . . . . . . . . Figure 18 Fuel Control and Pump Assembly 35. . . . . . . . . . . . . . . . . . Figure 19 Fuel System Components 37. . . . . . . . . . . . . . . . . . . . . . . . . Figure 20 APU-MAX. EGT CHART 39. . . . . . . . . . . . . . . . . . . . . . . . . . Figure 21 APU Dry Motoring 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 22 APU Wet Motoring 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 23 Low Pressure Bleed 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 24 Bleed Air Schematic 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 25 APU Bleed Air Components 49. . . . . . . . . . . . . . . . . . . . . . . Figure 26 APU Bleed Air Valve Schematic 51. . . . . . . . . . . . . . . . . . . . Figure 27 APU Cooling Air Schematic 53. . . . . . . . . . . . . . . . . . . . . . . . Figure 28 Cooling Air Components 55. . . . . . . . . . . . . . . . . . . . . . . . . . Figure 29 Cooling Air Shutoff Valve 57. . . . . . . . . . . . . . . . . . . . . . . . . . Figure 30 Ignition / Starting Schematic 59. . . . . . . . . . . . . . . . . . . . . . . Figure 31 Ignition Components 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 32 Start Relay Location 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 33 Starter Motor and Shaft Assembly 65. . . . . . . . . . . . . . . . . . Figure 34 APU Control Sytem Schematic 67. . . . . . . . . . . . . . . . . . . . . Figure 35 APU Control Unit and FADEC Component 69. . . . . . . . . . .

Figure 36 FADEC Component 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 37 Amb. Press. Transducer and Amb. Temp. Sensor 73. . . . Figure 38 Speed Sensor 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 39 APU Start Sequence 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 40 Normal/Auto Shut Down 79. . . . . . . . . . . . . . . . . . . . . . . . . . Figure 41 EGT Schematic 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 42 Thermocouples and Event Monitoring Unit. 83. . . . . . . . . . Figure 43 APU E. G. T . System Schematic 85. . . . . . . . . . . . . . . . . . Figure 44 EGT Balancing Resistor and Indicator 87. . . . . . . . . . . . . . Figure 45 ID-Module 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 46 LOP FADEC Bite Code Indication. 91. . . . . . . . . . . . . . . . . . Figure 47 MCDU APU DATA Display 93. . . . . . . . . . . . . . . . . . . . . . . . Figure 48 LOP FADEC BITE Code Shown 95. . . . . . . . . . . . . . . . . . . . Figure 49 LOP FADEC BITE Code Shown 96. . . . . . . . . . . . . . . . . . . .

Page 3


debbieb

ALT Logo

ATA 49 APU FWD

APS 2000

Page 4


APS 2000 INTRODUCTIONThe APS 2000 auxillary power unit (APU) supplies electrical and pneumaticpower to other airplane systems. This permits these airplane systems to oper-ate without the use of ground power sources or the engines. The APU can alsosupply electrical and pneumatic power in the air.

Altitude Operational LimitsThe APU can supply:� 55 KVA electrical power on ground� 45 KVA electrical power up to 37,000 feet (11,277 meters)� Electrical and pneumatic power is available at the same time up to 10,000

feet (3,048 meters).� Pneumatic power alone is available up to 17,000 feet (5,183 meters).� The APU can be started at 37,000 feet or below.

Model Designation:� Manufacturer: Sundstrand Power System, San Diego, USA.

Ratings at SL:� ROTOR SPEED 45,225 RPM steady state� OVERSPEED 105% / 47,486� OUTPUT SPEED 6000 RPM at Generator Drive� BLEED AIR FLOW 193 lbs/min at no electrical load� BLEED AIR PRESSURE 45 PSIG� BLEED AIR TEMP 209�C� FUEL FLOW 200 kg/h during max load at standard day� MAX CONTINUOUS EGT 702 C� Max EGT 730 C

Abreviations and AcronymsAPU Auxilary Power Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . ARINC Aeronautical Radio Inc.. . . . . . . . . . . . . . . . . . . . . . . BATT Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BITE Built in Test Equipment. . . . . . . . . . . . . . . . . . . . . . . . . �C Degrees/Celsius. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CB Circuit Breaker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DC Direct Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DMU Data Managment Unit. . . . . . . . . . . . . . . . . . . . . . . . . EGT Exhaust Gas Temperature. . . . . . . . . . . . . . . . . . . . . . EMU Event Monitoring Unit. . . . . . . . . . . . . . . . . . . . . . . . . . FADEC Full Authority Digital Electronic Controller. . . . . . LBS Pounds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HZ Hertz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KG Kilogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KVA Kilo Volt Ampere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KW Kilowatt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LCD Liquid Crystal Display. . . . . . . . . . . . . . . . . . . . . . . . . . LRU Line Replaceable Unit. . . . . . . . . . . . . . . . . . . . . . . . . . MCDU Multi Purpose Control Display Unit. . . . . . . . . . . . . PPH Pounds Per Hour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PSI Punds Per Square Inch. . . . . . . . . . . . . . . . . . . . . . . . . PSIA Punds Per Square Inch Absolute. . . . . . . . . . . . . . . PSID Punds Per Square Inch Differential. . . . . . . . . . . . . PSIG Punds Per Square Inch Gage. . . . . . . . . . . . . . . . . . RPM Revolutions Per Minute. . . . . . . . . . . . . . . . . . . . . . . . . RTD Resistive Temperature Detector. . . . . . . . . . . . . . . . . SHP Shaft Horsepower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . SW Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V Volts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page 5


Figure 1 APS 2000Page 6


PANEL DESCRIPTIONMAINTENANCE LIGHT ( blue )ON- Identifies an APU Warning. An Electrical fault has occured , or an APU OilServicing is required . See MCDU Multi purpuse Control Display Unit or FADEC Fault Display for Maintenance Light Reason.

LOW OIL PRESSURE LIGHT (amber)� ON- APU oil pressure is low, causing the APU to initiate an automatic shut-

down (after the start cycle is complete).� Light is illuminated during start until APU oil pressure is normal.� Light is armed only when APU switch is not in OFF.

FAULT LIGHT (amber)� ON- Identifies an Automatic Shutdown of the APU. See MCDU Multi pur-

puse Control Display Unit or FADEC Fault Display for Fault Light Rea-son.APU oil temperature is excessive, causing APU to initiate an automaticshutdown.

� Light is armed only when APU switch is not in OFF.

OVERSPEED LIGHT (amber)� ON - APU speed excessive causing APU to initiate an automatic shutdown.

Note: MASTER CAUTION light and the APU annunciator will illuminate togetherwith any of the above described amber caution lights (Exception: Low oilpressure light during APU start)

APU GENERATOR AC AMMETER� Display APU generator load current.

APU MASTER CONTROL SWITCH� OFF- Normal position when APU is not running.� OFF- when APU is running initiates normal shutdown.� ON - Normal position with APU running.� START (Momentary) - When APU switch is moved from OFF to START

and released to ON, causes automatic start sequence to be initiated.

EXHAUST TEMPERATURE INDICATOR� Displays APU exhaust gas temperature.

APU BLEED AIR SWITCH� ON -Opens the APU Bleed Air Valve if the APU is Operating.� OFF- Closes the APU Bleed Air Valve.

Page 7


FORWARD OVERHEAD PANEL, P5

APU MASTER CONTOL SWITCH

APU

START

ON

OFF

BLEED AIRSWITCH

APU

APU EXHAUST GAS TEMPERATURE INDICATOR


WING

RESET

0

OFF

ON1

OFF

HIGH

PACKTRIP OFF

WING-BODYOVERHEAT

OFF

ONAPU

BLEEDTRIP OFF

PACKTRIP OFF

WING-BODY

BLEEDTRIP OFF

ANTIICE

WINGANTIICE

TRIP

PSI

40 60

80

100

RECIRC FAN

OFF

TEST

R PACKISOLATIONOFF

HIGH

VALVECLOSE

AUTO

OPEN

L PACK

OVERHEAT

OVHT

NORMAL

2BLEED

AUTO AUTO

DUCT PRESSUREINDICATOR

MAINTENANCE LIGHT

FAULT LIGHT

OVERSPEED LIGHT

APU GENERATOR AC METER

LOW OIL PRESSURE LIGHT

Figure 2 APU PanelPage 8


ACCESS DOORAccess to the APU is through an access door, completely enclosing the APUcompartment.The access door is hinged on the right side and latched on the left side. It con-sists of skin, ribs and stringers forming the outside contour of the fuselage. Onthe inside are two door open holding rods, two drain cups and cooling air ex-haust. On the outside, is a drain mast connected to the drain cups.The door can be opened for normal APU servicing, or it can be removed byunlatching the hinges on the right side. The drain cups should be inspectedperiodically for cleanliness.The exhaust ducting is cooled by four air inlets around the aft end of the ex-haust fairing.

SHROUDThe APU shroud is a titanium compartment that fully protects the APU powerplant. The APU shroud gives the protection from an APU fire and decrease thenoise from the APU power plant. The APU shroud includes the upper shroudand the lower shroud. The upper shroud attaches to the airplane structure andholds the forward end of the APU exhaust duct. The upper shroud and thelower shroud connect to one another with the shroud latches on the lowershroud.

Upper ShroudThe upper shroud is installed in the APU compartment. When the APU is re-moved from the airplane, the upper shroud will stay in the APU compartment.The upper shroud has openings for the fuel lines, air inlet ducts and bleedair duct. Three mounting brackets for the APU engine attach to the shroudrings.

Lower ShroudThe lower shroud attaches to the upper shroud with ten shroud latches. Thelower shroud has the openings to the filler port for the oil tank and to the over-board exhaust for the APU cooling air. Also, there is an access panel that isremoved to read the elapsed time indicator. When the lower shroud is re-moved, you can get access to do maintenance on the APU.

Page 9


APU DOOR HINGE( 2 LOCATIONS )

FWD

TO DRAIN MASTEXHAUST DUCTAPU COOLING AIR

(STOWED POSITION)DOOR SUPPORT RODSDRAIN

SEAL PLATES

DRAINHOLES

(3 PLACES)APU DOOR LATCH

LOWER SHROUDFWD

APU SHROUD LATCH( 10 LOCATIONS )

DRAIN FITTING

COOLING AIR EXHAUST

DRAIN LINE

APU ACCESS DOOR

EXHAUST DUCT

UPPERSHROUD

Figure 3 APU Access Door and Shroud.Page 10


APU DRAINSThe APU drains provide means for draining unburned fuel from the engine andfor draining fuel or oil from the shroud in event of leakage inside the shroud.At the aft end of the shroud, a drain cup with stand-pipe picks up unburnedfuel discharged through the turbine exhaust port. Two fuel drain lines are manifolded into a fitting on the engine. This fitting mates with a drain cup in thedrain line. The drain line terminates at a fitting at the forward end of the shroud.Adjacent to the drain line terminal end fitting is another fitting. Through this fit-ting fuel or oil is drained from the shroud. Both fittings at the forward end of theshroud mate with drain cups in the APU compartment access door. The draincups in the access door are connected to a drain mast.

Drain ValveThe drain valve is a spring- loaded ball device. The drain valve permits fuel thatcollects in the combustor to flow to the APU drain mast.The drain valve is located at the lowest point in the combustor plenum. Thispermits complete drainage prior to another attempted start.The drain valve is spring-Ioaded open until the APU reaches approximately 15percent RPM. At 15 % RPM APU combustor pressure closes the drain valve.

Page 11


APU ACCESS DOOR

FWD

DRAIN MAST

DRAIN CUP

APUENGINE

SHROUD DRAIN

EXHAUSTEND DRAIN

APU

LOWER SHROUDDRAIN VALVE

DRAIN CUP

TURBINE

TURBINE EXHAUST END DRAIN

CUP

SHROUD

A09673 91061

CHECK

DRAINRESERVIOR

Figure 4 Shroud Drains.Page 12


AIR INLET DESCRIPTIONThe air supply for the APU engine operation and accessories cooling is througha door installed in the air inlet duct. The air inlet consists of a door with a vortexgenerator and flap, actuator, door position switch and ducting.Access to the actuator and door position switch is through an access door onthe left side of the fuselage, forward of the APU compartment.

OperationWhen the actuator is powered, the pushrods move the door to the open posi-tion. Movement of the door deflects the flap on the vortex generator for impro-vement of air flow into the inlet. When the door is fully open, the door switchoperates. The switch actuation is part of the APU start cycle.

Page 13


DOORAIR INLET

GENERATORVORTEX

AIR DIFFUSERDUCT

COMPRESSORAIR DUCT COOLING

FWD

ACTUATORSWITCH

INLET DOORINLET DOOR

INLET DOOR

POSITION

AIR DIFFUSER DUCT

ACTUATORARM

AIR

AIR

TORQUE BOX

FWD

APU COMPARTMENT STRUCTURE

767245767244

AIR DUCT

Figure 5 APU Air InletPage 14


APU AIR INLET ADJUSTMENTS

Maintenance PracticesThe APU air inlet has three adjustments:

� Air Inlet Door Adjustment .Door alignment. Adjustment is made by varying the length of the two actuatorpush rods.

� Air Inlet Door Position Switch Adjustment.Door open switch, door full open position. Adjustment is made by two nuts onthe switch.

� Vortex Generator Flap Adjustment .Flap deflection with door open. Adjustment is made by varying the length of thecontrol rod and the adjustable flap stop.

Page 15


BEARINGPUSHROD

FWD

AIR INLET DOOR - CLOSED POSITIONNUT NO. 2NUT NO. 1

INBD

AIR INLETDOOR ACTUATOR

VORTEX GENERATOR FLAP

PUSHROD

VORTEX GENERATOR

DOOR

OPEN

CLOSE

DOOR

BARRELFITTING

1 END

3 3

DUCT

NUT

DOOR POSITION SWITCH

AIR DIFFUSER

AIR INLET DOOR

2

(CLOSED POSITION)AIR INLET DOOR

AIR INLET DOOR(OPEN POSITION)

SET SCREW(DOOR OPEN)

FLAP STOP(DOOR CLOSED POSITION) FLAP STOP

(DOOR OPEN POSITION)

Figure 6 APU Air Inlet AdjustmentsPage 16


BOROSCOPE INSPECTIONThe following components of the turbine assembly may be inspected by theuse of a boroscope: Turbine Blade Tips Combustion Chamber Turbine NozzleVanes Turbine Wheel Blades Compressor Wheel Blades Compressor Diffuser

Legend:4. BLADES OF THE COMPRESSOR WHEEL5. LEADlNG EDGE OF THE COMPRESSOR WHEEL6. EXHAUST SECTlON7. BLADES AND VANES OF THE TURBlNE WHEEL8. LEADlNG EDGE OF THE TURBlNE WHEEL (3 LOCATlONS)9. COMBUSTION CHAMBER (4 LOCATlONS)10.HAND-CRANK PROVlSlONS (LOCATED ON THE COOLlNG FAN)

Page 17


FWD

CHAMBERTURBINEWHEELCOMPRESSOR

DIFFUSER

TURBINENOZZLECOMPRESSOR

WHEEL

1

2

3

4

5

6

COMBUSTION

BLADES OF THE COMPRESSOR WHEEL

LEADING EDGE OF THE COMPRESSOR WHEEL

EXHAUST SECTION

BLADES AND VANES OF THE TURBINE WHEEL

LEADING EDGE OF THE TURBINE WHEEL (3 LOCATIONS)

______LEGEND:COVER

COOLINGAIR FANBOLT

COVERBOROSCOPEPLUG

IGNITERPLUG

1 56

2

3

4

FWD

PLATE

COMPRESSORPLENUM

833716945054

COMBUSTION CHAMBER

HAND-CRANKPROVISIONS

MANUAL DRIVE

Figure 7 Boroscope InspectionPage 18


APU LUBRICATION SYSTEMThe APS 2000 is lubricated by a self-contained, wet sump system that is inte-gral with the gearbox. The oil system provides a pressurized supply of oil thatlubricates and cools all the gears and bearings in the gearbox and engine rotorassembly.

OperationBefore the APU is started, the de-prime valve is energized to the open posi-tion. This stops the supply of oil to the oil pump. When the APU accelerates to55% service speed, the de-prime valve is de-energized to the closed position.The oil pump pulls the oil from the oil tank and sends the oil to the oil filter ele-ment. If the oil filter element is clogged, the bypass valve opens to permit theoil fiow to continue. From the oil filter element, the oil goes through the oilcooler. If the oil cooler is clogged, the bypass valve for the oil cooler opens.From the oil cooler, the oil goes to the gearbox assembly and the gears andbearings of the APU engine. In the gears and bearings of the APU engine, anairloil mixture is made. The air/oil mixture is divided when the gearshaft turns.The air is sent to the turbine exhaust port through a gearbox case vent. The oilreturns to the oil tank by gravity.The Iube service panel replenishes the oil tank with the oil. The ADD Iight (am-ber Iight) on the Iube service panei comes on when the oil quantity in the oiltank is 1 .6 U,S quarts (l .5 Iiters). When the ADD Iight is on, a solenoid valveopens to Iet the oil enter the oil tank from the pressure fiII connection. TheFULL Iight (green Iight) comes on when the oil quantity in the oil tank is 2.6 U.Squarts (2.5 Iiters). The solenoid valve wiII close when the FULL Iight is on. Thesolenoid valve closes so the oil tank wiII receive the correct amount of oil.

Gearbox oil distributionOil is drawn from the gearbox sump by the oil pump mounted on the front ofthe gearbox. The oil is filtered prior to leaving the pump and then fiows throughthe oil cooler. The cooled oil is returned to the gearbox oil passages and jets toprovide Iubrication and cooling of the gears, shafts and bearings.During operation of the gear system, an oil/air mist is created inside the gear-box. The oil and air are separated by the action of a mechanical separator thatis part of the generator gear shaft. Oil is returned by gravity to the gearbox oilsump and the air is vented to the APU exhaust through the gearbox vent sys-tem.

Page 19


ÈÈÈÈÈÈÈÈÈÈÈÈÈÈ

ÈÈÈÈÈÈÈÈÈÈÈÈÈ

OIL FILTER

OIL PUMP

PUMP ASSEMBLYOIL FILTER AND

GEARBOX LUBE

AIR/OIL MIST

TURBINE ASSEMBLY

GEARBOX

BYPASS COOLINGOILCOOLER

DE-PRIMEVALVE

ROTORASSEMBLY


LIGHT IS ON

FILLWHEN AMBER

OIL TYPE

APUOIL TANK

FULL

ADD

S

FILL

LUBESERVICING

APUOIL

QTYMODULE

OILTANKSOLENOID VALVE

HIGH OIL

AIR FANVALVE

OIL PRESSURESWITCH

PRESS.CONNECTION

OIL LEVELSENSOR

BYPASSVALVE

OIL FILTER

RELIEFVALVE

OILTANK

DRAIN PLUG

FILLER CAP

SIGHT GLASS

OIL COOLER

S

PANEL833776 830931795131

MAGNETIC

AFTCARGOCPTM

FADEC

TEMP. SW.

ÈÈÈÈ

ÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈ

ÈÈÈÈÈ

ÈÈÈÈÈÈÈÈÈÈÈÈÈÈ

ÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈ

ÈÈ

ÈÈÈÈÈÈÈÈÈÈÈÈÈ

ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ

ÉÉÉ

ÉÉÉ

ÉÉÉÉÉÉÉÉÉÉ

ÉÉÉÉ

ÈÈÈÈ

OIL SUCTION

OIL PRESSURE

OIL PRESS. FILLING

LEGEND

OIL TANK VENT LINETO APU EXHAUST

TO DE-PRIMEVALVE

FROM FADEC

OIL FILTERCLOGGING IND.

< 20 PSI ON> 26 PSI OFF

135� C

40-45 PSID

60 PSI

25-45 PSID

< 55 % OPEN> 55% CLOSE 30-35 PSID

ÂÂ

ÄÄÄÄ OIL TANK VENT LINE

45 PSID

Figure 8 Lubrication SchematicPage 20


OIL TANK DESCRIPTION

Oil TankThe oil tank is part of the gearbox assembly. The oil tank hold the supply of oilfor the APU Iubrication system. The oil is removed from the oil tank by the oilpump. The oil goes through the oil filter element and oil cooler to the gearboxassembly and the APU engine. The oil flows back from the APU engine to theoil tank by gravity. The air in the oil goes out the turbine exhaust port.The oiltank has a filler port with a filIer cap and dipstick. The oil can be added to theoil tank through the filIer port. Also, the oil tank has a sight glass to do a checkon the oil level.

Magnetic Drain PlugThe magnetic drain plug is installed at the bottom of the oil tank. The magneticdrain plug has a magnetic element and a plug. When the oil tank is serviced,the magnetic element is removed to make sure no metal particles are in the oil.If the oil has metal particles, an investigation of damage to the APU engine isnecessary. The magnetic element can be removed without the plug. When theplug and the magnetic element are removed together, the oil will drain from theoil tank.

Oil Level SensorThe oil level sensor transmits a signal through the FADEC to show the APU oilquantity. The FADEC sends the signal to the MAINT Iight on the forward over-head panel and to the lube service panel. The oil level sensor has a tube, floatand microswitch. The microswitch has two circuits that are operated by thefioat. The oil level sensor is installed on the bottom of the APU oil tank.

Page 21


GEARBOX

OILFILLER CAP

DIPSTICK

OIL LEVELSENSOR

OIL LEVELSIGHT GLASS

MAGNETICDRAINPLUG

THE OIL TANKFILLER PORT FOR

(WITH INTEGRATEDOILTANK)

OIL TANKPRESSUREFILL LINE

CHECKVALVE

FWD

FWD

833776803803

Figure 9 Lubrication System ComponentsPage 22


COMPONENT DESCRIPTIONOil CoolerThe oiI cooler is installed on the APU below the APU electrical generator. TheoiI cooler is a rectangular unit made of aiuminum tubes. The oiI cooler receivesthe oil from the oiI pump. In the oil cooler the oil moves through the tubeswhere it is cooled by air from the cooling tan assembly. The oil tIows from theoil cooler to the gearbox assembly and the gears and bearings ot the APU en-gine. The oil cooler has a bypass valve that opens if the oil cooler is clogged.The bypass valve opens when the differentia! pressure across the oii cooler is25 to 35 psig . The bypass valve is tu!Iy open when the differential pressure is45 psig .

Oil Pump and Filter AssemblyThe oil pump and filter assembly is installed on the gearbox assembly. The oilpump and filter assembly has the oil pump, oil filter element, filter bypass valve,differential pressure indicator, oil temperature switch and de-prime valve. Ashaft that connects to the gearbox assembly drives the oil pump and filter as-sembly.The oil pump gets the oil from the oil tank. The oil pump moves the oil underpressure through the oil cooler to the gears and bearings of the APU. The oilfilter assembly has an oil filter element. The oil filter element keeps alI un-wanted material in the oil out of the oil pump. The oil filter element is a 2O mi-cron fiIter that can not be cleaned. The oil filter element must be replaced. Theoil filter element is installed on the oil pump and filter assembly.The filter bypass valve opens at 40-45 psig when the oil filter element isclogged this permits unfiltered oil to enter the oil pump. A filter clogging indica-tor (red ) extends when the differential pressure across the oil filter element is30 to 35 psig .

De-Prime ValveThe de-prime valve is energized open when the APU is started . When theAPU accelerates to 55% service speed, the de-prime valve is de-energized tothe closed position. This will permit the oil pump to produce oil pressure. Whenthe APU is stopped the de-prime valve is energized to the open position tostop the supply of oil to the oil pump. The oil that stays in the APU wiIl drain tothe oil tank. After 5 minutes APU stop the de-prime valve is de-energized tothe close position.The de-prime valve is installed on the oil pump and filter as-sembly. The de-prime valve operates with a solenoid.

Oil Pressure Relief ValveThe pressure relief valve is installed in the lower part of the gearbox housing.The pressure relief valve keeps the oil pump pressure below 40 to 45 psig. Ifthe pressure relief valve opens, the oil wilI flow back to the oil tank.

OiI Pressure SwitchThe oil pressure switch is installed on the gearbox assembly or on the oil coolerThe oil pressure switch stops the APU when the APU oil pressure decreases to20+/-2 psig . The signal from the oil pressure switch is monitored by the FA-DEC and the airplane electronics in the control cabin.

High Oil Temperature SwitchThe oil temperature switch is found on the front of the oil pump and filter as-sembly. The oil temperature switch automatically stops the APU when the APUoil temperature is greater than 135 +/- 5�C The signal from the oil temperatureswitch is monitored by the FADEC and the airplane electronics in the controlcabin.

Page 23


HIGH OILTEMP. SWITCH

FWD

997146803403 830947

FWD

OIL PRESSURE SWITCH

OIL COOLER

CARBON SEALDRAIN

WHITNESSPORT

DO NOT PLUG

GENERATOR

COOLING AIR FAN

FLAME ARRESTORGEARBOX OIL VENTTO APU EXHAUST

AND FILTER ASSEMBLYOIL PUMP

DE-PRIMEVALVE

GEARBOXOIL FILTER

OIL PRESSURERELIEF VALVE

OIL FILTERCLOGGING IND.(RED)

OIL FILTERBYPASS VALVE

Figure 10 Lubrication System ComponentsPage 24


OIL TANK SERVICINGServicing of the oil sump is accomplished by opening the APU access door.The oil level is checked by removing the filIer cap and using the dipstick. If theoil level is below the FULL mark, add oil until the Ievel is at the FULL mark onthe dipstick. To assist in observing the servicing during the addition of oil, a Iineof sight access door is used. The Ievel of oil can be observed through this ac-cess during servicing. A hole drilled through the fiIler tube prevents overfilIingof the sump by allowing excess oil to drain out of the fill tube and into the APUlower shroud.

REMOTE OIL SERVICINGThe external service panel provides a means of replenishing the oil supply forthe APU oil tank.

PowerPower for the system is 28 volts dc from the battery bus,switched hot bat busor APU G.C.U.

Maintenance PracticesThe oil tank is replenished by connecting the oil supply to the pressure fill con-nection and pumping oil into the tank until the green light ilIuminates. Requiredoil supply pressure is 35 psi.

Page 25


GREEN LIGHT

AMBER LIGHT

991803

LIGHT IS ON

FILLWHEN AMBER

OIL TYPE

APUOIL TANK

FULL

ADD

LUBE

ACTUATING MAGNET

PRESSUREFILLCONNECTION

DOOROPENSWITCH

DOOR

SERVICE PANEL

OPEN SWITCH

STABILIZER

ACCESS DOOR

STABILIZER

COMPARTMENT

LUBESERVICE

COMPARTMENT

APU OILQTY MODULEM 925

OILTANKSOLENOIDVALVE

PRESSUREFILL LINETO OIL TANK

BULKHEAD

ACCESSDOOR

FWD

Figure 11 Oil Tank ServicingPage 26


OIL SYSTEM SCHEMATIC DESCRIPTION

OperationWhen the access door to the re-oil system is opened, 28 volts dc is supplied toModule M925.If the oil quantity is more than 2.6 U.S. quarts in the tank, the FULL switch pro-vides a ground for the green (FULL) light, relay R253 and oil tank’ solenoidvalve remains de-energized.If the oil quantity is less than 1.6 U.S. quarts in the tank, the ADD switch pro-vides a ground for the amber (ADD) light, relay R253 and oil tank solenoidvalve are energized. Adding oil to the tank opens the ADD switch and whentank has 2.6 U.S. quarts the FULL switch operates de-energizing R253 andsolenoid valve.

Page 27


LOQ

AFT CARGO CPTM

APU OIL TANK

APU MASTER CONTR. SW. (P5)

MCDU

M280APU CONTROL UNIT( E3-3 )

TOAPUCONT

TOAPUCONT

START

ON

OFF

OIL LEVELSENSOR

FULL

CIRCUIT BREAKERPANEL ( P6 -5 )

APU GENERATORCONTROL UNIT ( P6 )

M 925 APU OIL QTY MODULE

APUCONT

BITE CODE

OIL QTY RELAYR 253

MAINTB

APU PANEL

FADEC

ADD< 5% RPM

LOW OIL QUANTITY

SIGNAL TO FADEC DURING

CLOSE

OPEN

DOOR OPENSWITCH

OIL TANKSOLENOID VALVE

FULL

ADD

G

AADDAPU START AND SHUTDOWN.

WHEN OIL LEVEL”ADD”

HOT BAT BUS

28V DCSWITCHED

HOT BAT BUS

28V DCSWITCHED

Figure 12 Oil Servicing System SchematicPage 28


APU FUEL SYSTEMPurposeThe APU fuel system receives fuel from the airplane wing tanks through ashrouded line. The system then pressurizes, filters, and meters fuel for com-bustion. The primary components are the fuel control and pump assembly. lowand high pressure filters, a start fuel purge solenoid valve, start and main fuelmanifolds, and nozzles. The APU is a constant speed engine. Speed control isaccomplished automatically by the FADEC through torquemotor inputs to thefuel control and pump assembly, resulting in fuel flow regulation.

Fuel Control and Pump AssemblyThis assembly accomplishes all pressurizing, filtering, and metering for theAPU. Electrical connections include the servo valve, the start fuel solenoidvalve, and the main fuel solenoid valve.

SYSTEM OPERATION

StartingPlacing the APU switch to START and ON, opens the APU fuel shutoff valveand the inlet door begins to open. When the inlet door is full open,the FADECactivates the starter and energizes the start fuel solenoid valve to open. Thestart fuel solenoid valve is located on the fuel control and pump assembly.The APU fuel control and pump assembly then receives fuel from the airplanetanks through the APU fuel line. A low pressure centrifugal pump pressurizesthe fuel and delivers it to the high pressure gear pump through the external lowpressure fuel fitter. Unmetered fuel flows through the start fuel solenoid valve,through the start manifold and through the 4 start nozzles into the combustor.The FADEC energizes the ignition exciter one second after the starter is ener-gized. The FADEC energizes the main fuel solenoid valve to open when theAPU reaches 5% RPM with an increase of 28� C EGT. This permits meteredfuel to flow through the in-line filter, through the check valve to the 14 main fuelnozzles. When the APU reaches 55% RPM, the FADEC deenergizes the star-ter and ignition exciter. At 70% RPM the FADEC de-energizes the start fuelsolenoid valve to the close position and energizes the start purge solenoidvalve to the open position for 60 seconds. This removes fuel from the start fuelmanifold and nozzles.The FADEC monitors APU the EGT during starting. The FADEC sends electri-cal control signals to the servo valve to meter the fuel flow.

Running (APU RPM Above 98 Percent)The FADEC receives APU RPM, EGT, inlet temperature and inlet pressure si-gnals from APU sensors. The FADEC sends electrical control signals to theservo valve to meter fuel flow to the main fuel nozzles. This keeps the APU ata constant speed with the APU supplying electrical and/or pneumatic loads orwith the APU unloaded.

ShutdownPlacing the APU switch to off position :The fuel shutoff valve closed.The air inlet door closed.The main fuel solenoid valve de-energized to the close position.The fuel servo valve deenergized.The start purge valve energized to the open position for 30 seconds.Remaining fuel in the APU combustor drains through a drain valve into the lo-wer shroud drain Iine.The de-prime valve energized to the open position.The anti-surge bleed valve energized to the closed position.The hour meter and start counter off.

Page 29


GEARBOXVALVESOLENOIDMAIN FUEL

MAIN FUEL

START FUEL MANIFOLD

START FUELSOLENOIDVALVE

MANIFOLD

VALVE

STARTPURGE

VALVEFLOW CONTROL

FUELHEATER

BYPASS

FILTER

FUEL TANK 1

ÂÂÂÂ

VALVE

STARTPURGE

EGT PROBE (2)

EXH. DRAIN

SPEEDSENSOR

P AMBT AMB

VALVE

VALVE

RELIEF

FUEL SERVO

APU FUELSHUTOFFVALVE

LP-FUELPUMP

FILTER

DIFF.PRESSVALVE

FUELPUMP

M

HP

VALVE

TO DRAIN

FROM

FLAMEARRESTOR

OIL TANKVENT LINE

IGNITOR

(2)

FUEL

APU BLEED AIRCHECK VALVE

NOZZLES

SHROUD

DRAIN

CLOGGINGINDICATOR

FUEL HEATERCHECK VALVE

APU BLEEDAIR

AC BOOST PUMP

APU FUEL DCBOOST PUMP

FUEL

DRAIN CHECKVALVE

SEAL DRAIN

55700 946555

(2)

COMBUSTER

EXHAUST

S

SS

FADEC

M

M

...

FUEL CONTROL / PUMP ASSEMBLY

ÂÂ

ÍÍÍÍ

ÍÍÍÍÍÍÍ

ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ ÍÍÍÍÍÍÍÍÍÍÍÍÍÍ

ÇÇ

Ç ÇÇÇÇ

ÇÇÇÇ

ÇÇÇÇ

ÇÇ

ÇÇ

LEGEND

LOW FUEL PRESSURE

HIGH FUEL PRESSURE

ÂÂÂÂÂ

ÂÂÂÂÂ

ÂÂÂÂÂÂÂÂ

ÇÇÇÇÇ

ÇÇÇÇÇ

APU BLEED AIR

OIL TANK VENT AIR

ÍÍÍÍÍ

ÈÈÈÈÈ

ÈÈÈÈÈ

REGULATED FUEL PRESSURE

MAIN CHECK VALVE

CHECK VALVE

TO DRAIN MAST

TO FADEC

FROMAPU

APU BLEEDAIR DUCT

OPEN: RPM 5% AND EGT RISE >28� C

OPEN: AFTER STARTER CUT IN OR (>2% RPM) CLOSED: RPM >70%

OPEN: RPM >70% FOR 60 SEC. AND APU SHUT DOWN FOR 30 SEC.

FADEC MODULATED POSITION

<18 o C

40PSI

10 PSID

6 PSID

200 PSID640 PSID

600 PSI

FILTER

Figure 13 Fuel System SchematicPage 30


APU FUEL SHUTOFF VALVEThe valve allows fuel supply from the tank to the APU engine.

Physical DescriptionThe valve consists of an actuator assembly and valve body assembly. The ac-tuator is motor operated with a manual override.

PowerThe valve motor utilizes 28 volt dc power.

ControlThe valve operation is controlled by the APU switch on P5 panel and by protec-tion circuits in module M280, APU control unit.The valve is installed on the rear spar of No.1 fuel tank in the Ieft main wheelwelI.

Operation.The valve is opened by placing the APU switch to the ON position. The valvecan be closed by the switch placed to the OFF position or automaticalIy by firedetection or operation of fire handle. The valve can be operated manually wi-thout electrical power by the override handle.

Maintenance PracticesThe valve actuator assembly can be removed separately from the valve body.The removal of the valve body requires No. 1 tank entry.

APU FUEL DC BOOST PUMPThe pump supplies pressurized fuel during starting of the APU.

Physical DescriptionThe pump consists of a motor driven vanes, bypass valve, inlet and outletports. It is held in position by four boats through fianges on pump body.

PowerThe pump utilizes 28 volt dc power.

ControlThe pump operation is controlled by the APU switch and main tank No. 1 boostpump switches on P5 panel.The pump is mounted on the wing bottom skin aft of the rear spar.

OperationThe pump operates only during APU start if:� the APU Master Switch is in ”ON” and� Boost Pump relays from tank #1 are ”OFF” and� APU RPM is below 98%.

When the APU reaches 98% RPM during the start cycle, the APU pump is au-tomatically de-energized.

Page 31


FUEL INLET

OUTLET

BOOST PUMPAPU DC

EDGE PANELINBOARD TRAILINGLEFT LOWER

MANUAL OVERRIDE LEVER

LEFT REAR WING SPAR

FWD INBD

VALVE

APU FUELSHUTOFF

FWDINBD

997665 ATA28.190608

FUEL

Figure 14 APU Fuel Shutoff Valve and DC Fuel Boost PumpPage 32


APU MASTER CONTR. SW. (P5)

START

ON

OFF

CIRCUIT BREAKER PANEL ( P6 -5 )

APU GENERATOR CONTROL UNIT ( P6 )

APUCONT

M M

CLOSE CLOSE

OPENOPEN

NC

NC

DISCH

R

NC

AFT CARGO CPTMFADEC

FULLOPEN

DOORNOTFULLYOPEN

FIREDETECTION

MODULEM 279

APUREMOTECONTROLPANEL

APUFIREHANDLE

APU SHUTDOWN SIGNAL

APU MONITOR

APU STARTCIRCUIT

FIRERELAY

APU FUEL SHUTOFFVALVE

APU AIR INLET DOORACTUATOR

APU AIR INLET DOOR

APU CONTROL UNIT M 280

FADEC M 3056

NORMALSHUTDOWN

POWER SUPPLY

28V DC

28V DC

NORM

FIRE

NORM

FIRE

HOT BAT BUS

28V DCSWITCHED

HOT BAT BUS

28V DCSWITCHED

DOOROPENSWITCH

Figure 15 APU Fuel Shutoff Valve ControlPage 33


APU CONTROL SWITCH

START

ON

OFF

CIRCUIT BREAKER PANEL

( P6 )

MASTER

NC

POWER SUPPLY

AFT CARGO CPTMFADEC M 3056

APU SPEED > 98% RPM

M

28V DC

NC

NC

NC

BAT BUS

APU FUELBOOST PUMP

R 191 BOOST PUMPSHUT-OFF RELAY

R 155 APU FUELBOOST PUMP RELAY

R 18 TANK 1 AFT FUELBOOST PUMP RELAY

R 19 TANK 1 FWD FUELBOOST PUMP RELAY

APU FUEL BOOST PUMP

M280APU CONTROL UNIT ( E3-3 )

APU MONITOR

P 6 LOAD CONTROL CENTER - R

APU GCU

( P6 )

APU CONT

HOT BAT BUS

CIRCUITBREAKERPANEL ( P6 )

SWITCHED28V DC

HOT BAT BUSSWITCHED28V DC

Figure 16 DC Fuel Boost Pump ControlPage 34


FUEL HEATERThe fuel heater is used to prevent ice from blocking the fuel filter.The heater is a tubular fuel / air heat exchanger. The control valve has a bime-tallic element for sensing the fuel temperature and allowing bleed air to passthrough the heater.The fuel heater and control valve with a temperature sensor are attached to theinside surface of the upper shroud.

FIow Control ValveWhen the fuel temperature passing through the valve decreases to 3�C (37 �F), the valve modulates to full open. This allows hot air from the APUbleed duct to pass through the heater and dumps into the shroud. When fueltemperature increases to 18 �C (64�F), the valve closes.

FueI Heater Check ValveA check valve is installed in the fuel Iine upstream of the heater to retain fuel inthe pump. This ensures a positive prime for starting.

FIow Control Check ValveA check valve is instalIed in the air line to prevent fuel entering the bleed airduct.

Page 35


FUEL HOSE

FLOW CONTROL VALVE

BLEED AIRINLET LINE FOR THE

APU BLEED AIR DUCT

FUEL INLET LINE

FUEL HEATER

UPPERSHROUD

OVERBOARDDUMP LINE

BLEED AIRFOR THE

FUEL HEATERCHECK VALVE

PRESSURE LINETO PNEUMATICACTUATOR

FWD

CHECK VALVE

FLOW CONTROL

Figure 17 Fuel Heater and Flow Control ValvePage 36


ELECTRONIC FUEL CONTROL AND PUMP ASSEMBLYThe fuel control and pump assembly supplies high pressure fuel to the startfuel manifold and high pressure, metered fuel to the main fuel manifold. It ismounted to the front face of the accessory gearbox with a quick attach/detachclamp. The fuel control and pump assembly consists of the following compo-nents:� Centrifugal Pump� Gear Pump� High Pressure Relief Valve� Start Fuel Solenoid Valve� Main Fuel Solenoid Valve� Differential Pressure Valve� Fuel Servo Valve

Centrifugal Pump� rise up the Fuel Pressure to 40 PSIG.� Protects the Gear Pump against cavitation.

Gear Pump� rise up the fuel pressure (100% RPM) to 600 PSID with a fuel flow of max

646 kg/h

High Pressure Relief ValveThe high pressure relief valve protects the fuel system against overpressuriza-tion. It has a crack point pressure of 640 psid.

Start Fuel Solenoid ValveThe start fuel solenoid gets a signal from the FADEC to permits unmetered fuelflow through the start fuel nozzles.� opens, after start circuit aktivation. Software Conf.15 or� opens, if RPM > 2% Software Conf.16 ( FF ca 10 kg/h)� closes, if RPM > 70%.

Main Fuel Solenoid ValveThe main fuel solenoid valve permits metered fuel to flow through the main fuelmanifold to the main fuel nozzles.It is energized open during APU start, if� RPM > 5% and� EGT rise >28� C.

It closes during APU shutdown.

Differential Pressure ValveThe differetial pressure valve holds a constant differential pressure of 200 PSIDacross the fuel servo valve. This differential pressure creates a linear relation-ship between fuel flow and torquemotor current.

Fuel Servo ValveThe servo valve controls the fuel flow output from the fuel control and pumpassembly. The servo valve is a torquemotor operated flapper type valve. Thevalve’s position is electrically controlled by the FADEC and has a regulatingrange from 7 to 250 kg/h. The servo valve current is a function of APU speed,inlet temperature and pressure; and is EGT limited.

Page 37


FWD

FUEL CONTROL ANDPUMP ASSEMBLY

MAIN FUEL

VALVESOLENOIDSTART FUEL

FUEL SERVOVALVE

SOLENOID VALVE

FUEL PUMP

GEARBOX

DIFFERENTIALPRESSURE VALVE

FWDFUEL DRAINTUBE

Figure 18 Fuel Control and Pump AssemblyPage 38


START PURGE VALVEThe start fuel purge solenoid va!ve allows APU compressor discharge air toremove remaining fuel in the start fuel manifold and nozzles. This prevents co-king of the start fuel nozzles.The start fuel purge solenoid valve is a normally closed shutoff valve. The FA-DEC energizes the solenoid for 60 seconds to open when the APU reaches70% RPM. This permits compressor discharge air to purge the start manifoldand nozzles of remaining fuel.When the APU Master switch is placed to OFF; the start fuel purge solenoidvalve is energized to the open position for 30 seconds and then deenergized tothe closed position,The start fuel purge solenoid valve is Iocated on the left side of the APU just aftof the ignition exciter. it is located in the high pressure start fuel Iine betweenthe fuel control and pump assembly and the start fuel nozzles.

Start Fuel ManifoldThe start fuel manifold and four start nozzles along with the main fuel manifoldand fourteen fuel nozzles deliver fuel to the combustion chamber for APU ope-ration.

Start Fuel Nozzles ( 4 ) four start nozzles deliver fuel to the combustion chamber for APU operation.

Main Fuel ManifoldThe main fuel manifold attaches to the main fuel nozzles ( 14 ). The main fuelnozzles bolt to the combustor housing. Air in the combustor atomizes the fuelthrough a slot in the fuel nozzles.

Main Fuel Nozzles ( 14 )Fourteen fuel nozzles deliver fuel to the combustion chamber for APU opera-tion.The main fuel nozzles supply fuel to the combustor at 550 pph.Air in thecombustor atomizes the fuel through a slot in the fuel nozzles.besteht aus:Fuel Filter� protects the fuel Gear Stage against contamination.

Filter Bypass� Filter Bypass, opens at 10 PSID .

Filter Clogging Indicator� Filter Clogging Indicator ( Red ) , is shown at 6 PSID. Indicates a clogged

fuel filter. is resettable.

Fuel Filter Fitting� protects the 14 Main Fuel Nozzles against contamination.

Main Check Valve� closes when APU is Shutdown.

Drain Check Valve� opens after APU Shutdown, drains the unburned fuel of the Combustion

Chamber, connects the Drain Lines to the Drain Mast .� closes when the Combustion Discharge Presssure ( CDP ) increases (15%

APU RPM )� drains fuel from Start Fuel Nozzles and Start Fuel Manifold during

- APU Start > 70% APU RPM and- during every APU Shutdown when the Start Purge Valve opens,

� drains fuel to the Drain Mast (13 ccm Drain Fuel ).

Page 39


DRAIN CHECK VALVE

MANIFOLDSTART FUEL

FWD

FUEL

( 4 )

IGNITOR

START

( 14 )NOZZLE

FUELSTART

DRAIN LINE TO

COMBUSTIONCHAMBERDRAIN LINE

MAIN FUEL

MAIN FUEL

MANIFOLD

NOZZLESTART PURGE VALVE

MANIFOLD

DRAIN CHECK VALVE

COMBUSTION CHAMBER

803431

997645

MAIN CHECK VALVEFUEL FILTER FITTING MAIN FUEL MANIFOLD

ASSEMBLY

FILTER CLOGGINGINDICATOR

FUEL FILTER

FUEL FILTER

Figure 19 Fuel System ComponentsPage 40


FUEL SYSTEM OPERATIONStartingThe APU start sequence is controlled by the FADEC.� After the start relay is energized (Software version 15) or� After 3% RPM (Software version 16), the fuel solenoid energizes and

opens. (At 2% RPM ignition is activated)Unregulated fuel from the high pressure fuel pump is supplied to the start fuelmanifold. It enters the combustion chamber via 4 start nozzles. After 1 secondignition is activated (Software version 15).� At a speed of 5% RPM and a minor of 28� C EGT rise, the main fuel sole-

noid valve opens. The fuel servo valve starts controlling the fuel flow. Themagnitude of the regulating fuel flow depends upon RPM, EGT, T-amb andP-amb. Control is provided by the temperature control circuit within theFADEC. At this point the fuel flow is approximately 25 kg/h and will conti-nuosly increase. Regulated high-pressure fuel goes into the main fuel man-ifold, from where it leaves through 14 main fuel nozzles for combustion.

� At 55% RPM ignition is deenergized.� At 70% RPM the start fuel solenoid valve closes and the start purge valve

energized open for 60 sec. CDP air enters the 4 start fuel nozzles in orderto blow out the remaining fuel from the start fuel manifold.

� At 80% RPM the temperature control circuit is turned off and the speed con-trol circuit will now control the fuel flow.

Running Speed > 98%2 sec after 98% RPM load can be applied. The fuel servo valve, controlled bythe FADEC, coverns the fuel flow to keep the APU-speed at 100% at all normalloads.The max. load factor is limited by the EGT-set point. The EGT-set point is vari-able and is computed by the FADEC. The set point depends upon T-amb andP-amb (see EGT-Chart).The max. EGT is slightly higher than the EGT-set point. An exceedance ofmax. EGT will cause an APU Auto Shut Down.

ShutdownWhen the APU Master Control Switch is put to OFF following fuel valves willclose:� Main Fuel Solenoid Valve� Fuel Servo Valve and� APU Fuel Shutoff Valve� Start Purge Valve opens for 30 sec. and closes again.

Page 41


EGT Limit - APU Speed more than 98%

MAXIMUM EGT �C

AM

BIE

NT

TEM

PER

ATU

RE

OF

( C

)

710 715 720 725 730 735 740

49

38

27

16

4

-18

-29

-40

-7

Figure 20 APU-MAX. EGT CHARTPage 42


DRY MOTOR THE APUGeneral:You dry motor the APU to operate the APU without fuel to the start fuelnozzles.ProcedureSet the switch and the circuit breaker:� Set the APU master switch on the P5 forward overhead panel to the OFF

position and attach a DO-NOT-OPERATE tag.� Open this circuit breaker and attach a DO-NOT-CLOSE tag:� APU Control Unit, E3-3 Electrical Shelf,� Put the container below the start fuel manifold. � Disconnect the fuel line for the start fuel manifold from the start purge valve.� Connect the fuel hose to the start purge valve.� Put the end of the fuel hose into the container. � Set these circuit breakers and these switches:� Remove the DO-NOT-CLOSE tag and close this circuit breaker:� APU Control Unit, E3-3 Electrical Shelf,� Remove the DO-NOT-OPERATE tag from the APU master switch on

the P5 forward overhead panel.� Set the BAT switch on the P5 forward overhead panel to the ON position.

Make sure this circuit breaker is closed:� DC BOOST PUMP. on the P6-5 Load Control Center Assembly.� Set the APU master switch on the P5 forward overhead panel to the START

position and release it to the ON position.� Permit the APU engine to motor until the APU has an automatic shutdown.

Make sure the FAULT light comes on.NOTE: The FAULT light is on the P5 forward overhead panel.� Make sure the FADEC has a ”LITE” BITE code shown.� Set the APU master switch on the P5 forward overhead panel to the OFF

position and attach a DO-NOT-OPERATE tag.

Page 43


FADEC

FAULT DISPLAYDISPLAY SWITCHFAULT

APU CONTROL UNIT

BREAKERCIRCUIT

P6-5

50 5

TRNO.3

BATBUS

APUFUELBOOSTPUMP

BREAKERCIRCUIT

769273 995421 992794991836

APU MASTER CONTROL SWITCH

P 5 FWDOVERHEADPANEL

ON

OFF

ON

OFF

BAT LITE

E3-3

START

ON



APU CONTROL UNIT

BREAKERCIRCUIT

3


ÅÅÅÅ

FUELFOR STARTMANIFOLD

FUEL LINE

START PURGE VALVE

EXCITERIGNITION

FWD

ÅÅÅÅ ÅÅÅÅÅÅÅÅÅÅ

CONTAINER

ÅÅÅ

ÅÅÅÅÅ FUEL HOSEÅÅÅÅ

Figure 21 APU Dry MotoringPage 44


WET MOTOR THE APUGeneral:You wet motor the APU to operate the APU without ignition.ProcedureSet the switch and the circuit breaker:� Set the APU master switch on the P5 forward overhead panel to the OFF

position and attach a DO-NOT-OPERATE tag.� Open this circuit breaker and attach a DO-NOT-CLOSE tag:� APU Control Unit, E3-3 Electrical Shelf.� Put the container below the combustor drain.

WARNING: DO NOT TOUCH THE IGNITION COMPONENTS UNTIL YOUDO THESE STEPS. THESE STEPS WILL RELEASE THE HIGH VOLTAGEFROM THE IGNITION EXCITER. IF YOU DO NOT OBEY THIS PROCE-DURE, INJURY TO PERSONS CAN OCCUR.Do these steps to release the high voltage from the ignition exiter:� Make sure 5 minutes have gone by since the last APU start.� Disconnect the igniter cables from the igniter plugs.� Ground the igniter cables to the APU.� Disconnect the electrical connector from the ignition exciter.� Set these circuit breakers and these switches:

Remove the DO-NOT-CLOSE tag and close this circuit breaker:� APU Control Unit, E3-3 Electrical Shelf.� Remove the DO-NOT-OPERATE tag from the APU master switch on

the P5 forward overhead panel.� Set the BAT switch on the P5 forward overhead panel to the ON position.

Make sure this circuit breaker is closed:� DC BOOST PUMP, P6-5 Load Control Center Assembly.� Set the APU master switch on the P5 forward overhead panel to the START

position and release it to the ON position. � Permit the APU engine to motor until the APU has an automatic Shut-

down.� Make sure the FAULT light comes on.

NOTE: The FAULT light is on the P5 forward overhead panel.

� Make sure the FADEC has a ” LITE ” BITE code shown.� Set the APU master switch on the P5 forward overhead panel to the OFF


Page 45


FUEL FILTER

ELECTRICALCONNECTOR

IGNITIONEXCITER

995592 991836 992794769273

APU CONTROL UNIT

BREAKERCIRCUIT


ON

OFF

E3-3

FADEC

FAULT DISPLAYDISPLAY SWITCHFAULT


P6-5

TRNO.3

BATBUS

APUFUELBOOSTPUMP

BREAKERCIRCUIT

ON

OFF

BAT LITE

START

ON

APU CONTROL UNIT

BREAKERCIRCUIT


50 53



Figure 22 APU Wet MotoringPage 46


LOW PRESSURE BLEEDThe low pressure bleed makes sure the air is removed from the fuel lineto the fuel control and pump assembly.ProcedureSet the switch and these circuit breakers� Set the APU master switch on the P5 forward overhead panel to the OFF

position and attach a DO-NOT-OPERATE tag . Remove the DO-NOT-CLOSE tag and close this circuit breaker:� DC BOOST PUMP, on the P6-5 Load Control Center Assembly.� Bleed the fuel supply hose to the fuel control and pump assembly.� Put the container below the fuel control and pump assembly.

Remove the DO-NOT-CLOSE tag and close this circuit breaker:� APU Control Unit, E3-3 Electrical Shelf.

Remove the DO-NOT-OPERATE tag from the APU master switch and set theAPU master switch to the ON position.NOTE: The APU master switch is on the P5 forward overhead panel. Do notmove the APU master switch to the START position. It is not necessary tostart the APU.� Loosen the fuel supply hose from the inlet fuel tube for the fuel control and

pump assembly.NOTE: Do not remove the fuel supply hose.� Permit the fuel in the inlet fuel line to drain into the container.� Tighten the fuel supply hose to the inlet fuel tube for the fuel control and

pump assembly.� Set the APU master switch on the P5 forward overhead panel to the OFF


HIGH PRESSURE BLEED

GeneraLThe high pressure bleed makes sure the air is removed from the fuel lineto the start fuel manifold.Do the APU dry motoring to bleed the fuel line to the start fuel manifold(AMM 49-11-00/201).

Page 47


INLET FUEL TUBE

FUEL SUPPLY HOSE


ON

P6-5

TRNO.3

BATBUS

APUFUELBOOSTPUMP

BREAKERCIRCUIT

APU CONTROL UNIT

BREAKERCIRCUIT

ON

OFF

TO THE FUEL CONTROL AND PUMP ASSEMPLY

ON

OFF

BAT

FWD



53 50



Figure 23 Low Pressure BleedPage 48


APU AIR SYSTEMThe bleed air system of the APU supplies compressed air for the air condition-ing system, engine start system and other pneumatic components of the air-plane. It also stops compressor surge during alI APU starts and during the nor-mal operation of the APU.The APU Bleed Air System supply air to the

- Air Condition System,- Engine Start System,- Wing Anti-Ice System,- Water and Hydraulic Tank pressurization.

The bleed air system for the APU has a� bleed air valve� and a bleed servo valve

Page 49


HEATER

COMBUSTORHOUSING

AIR INLETHOUSING

GEARBOX

INLETAIR

OIL COOLER

FANCOOLING

GENERATOR

REG

FADEC


ON

OFF

RPMT AMBP AMBEGT

MAIN ENGINESTART

BLEEDSERVOVALVE

SWITCH28VDC

M278 MISCSWITCHINGMODULE E3-2

M280 APUCONTROL UNIT

FILTER

VALVECHECK

VALVECHECK

TO FUEL

98% RPMAND 2 SEC

ACTUATOR

ACTUATOR

S

APU BLEEDAIR DUCT

E3-2

AFT CARGO CPMT

TO DUALBLEED BLEED LIGHT

OPEN SIGNAL

FILTER

( GRD )

A56082

CLOSED

OPENVENT

APUBLEED

AIR

COOLING AIRSHUTOFF VALVE

APU BLEEDAIR VALVE

LEGEND

BLEED AIR SYSTEM

COOLING AIR SYSTEM

Figure 24 Bleed Air SchematicPage 50


APU BLEED BLEED AIR VALVEThe bleed air valve is used to control the bleed air flow from the APU to theairplane pneumatic system.The valve consists of a butterfly valve, actuator, rate control valve, switchervalve and solenoid. The valve is solenoid controlled, pneumaticalIy operated,shutoff and modulating type.The valve is controlled by the APU bleed valve switch on the P5 panel and thebleed servo valve. The FADEC controls the bleed servo valve. Valve operatingpressure is supplied from pneumatic duct through a differential air pressureregulator.

Differential Air Pressure RegulatorThe differential air pressure regulator provides constant pressure air supply foroperation of the bleed valve.The regulator consists of an air inlet, filter, spring- loaded diaphragm assembly,metering and relief valves. The regulating pressure is set at 19 psig.The APU compressor discharge pressure is supplied to the regulator. The me-tering valve restricts the output to 19 psig independent of ambient conditions.

Bleed Servo ValveThe bleed servo valve changes the control air pressure to the bleed valve. Thispermits the bleed valve to modulate. The FADEC controls the bleed servovalve.The bleed servo valve is Iocated above and inboard of the oil filler neck on theAPU.The bleed servo valve is a pneumatic valve that is electrically controlled.

OperationWhen the APU is operating above 98% RPM and the APU bleed air switch is’ON’, the bleed servo valve changes control pressure to the APU bleed valve.The FADEC controls the bleed servo valve as a function of APU EGT. WhenAPU EGT Iimits are approached, the FADEC signals the bleed servo valve tovent control pressure. This modulates the APU bleed valve closed.

Page 51


BLEED

BLEEDAIR VALVE

PRESSUREREGULATOR

AIR DUCT

FWD

INBD

PLENUMTURBINE

CONTROL AIR LINE TOUPPER

AIR DUCT

SHROUD

FWD

AIR LINECONTROL

AIR FILTER

BLEED AIRVALVE SOLENOID

BLEED SERVO VALVE

POSITION SWITCH

CONTROL PRESSUREAIRTEST PLUG

833545

FWD

ELECTRICALCONNECTOR

BLEEDSERVOVALVE

APU

APU BLEED

Figure 25 APU Bleed Air ComponentsPage 52


BLEED AIR VALVE OPERATIONWhen the solenoid is energized, air upstream of the butterfly valve passesthrough the filter and regulator assembly and switcher valve to chamber C ofthe valve. Chamber D is vented through the switcher valve. As the butterflyvalve opens, upstream pressure decreases, chamber B pressure decreasesfaster than chamber A pressure by virtue of the restrictor. The differential pres-sure acts on the diaphragm and opens the rate control valve. This partiallyvents chamber C, thus decreasing the opening rate of the valve.If high EGT occurs, the bleed servo valve vents chamber C and the valve mod-ulates towards the closed position.When the solenoid is de-energized, control pressure is supplied to chamber D,chamber C is vented and the butterfly closes.Two switches are operated by the bleed valve.� One is for the amber DUAL BLEED light on the P5 panel ( ATA Chapter 36)� and the other goes to the FADEC. The FADEC (Sunstrand) does not use

this signal.

Page 53


(AFT CARGO CPTM)

P5-10 AIR COND.MODULE (P5)

AIR SWITCH

OFF

ENGINE STARTINTERLOCK RELAY

M3056 FADEC

UNIT (E3-3)M280 APU CONTROL

M278 MISC SWITCHINGMODULE (E3-2)

ON

SYSTEMTO PNEUMATIC

NC

MAINENGINESTART

( GRD )

28 V DC

RPM

T AMB

P AMB

EGT

98% RPMAND 2 SEC

OPEN SIGNALTO BLEEDSERVO VALVE

APU BLEED

ENGINESTARTRELAY1

1 AIRPLANES WITH ENGINESTARTER INTERLOCKPROTECTION.

VENT

SERVO VALVE

BLEED AIR VALVE

SOLENOID

REGULATORPRESSURE

CLOSEDOPEN

PNEUMATICACTUATOR

VALVE

SWITCHERVALVE

FILTER

TO DUAL BLEEDLIGHT CIRCUIT

RATEADJUST

POPPET

VALVE

VENTVENT

ÂÂ

COMBUSTORHOUSING

AIR INLETHOUSING

GEARBOX

OIL COOLER

FANCOOLING

GENERATOR

FILTER

INLETAIR

COOLING AIR SHUTOFF VALVE

APUHEATERTO FUEL

A

B

C

D

RATECONTROL

Figure 26 APU Bleed Air Valve SchematicPage 54


APU COOLING AIR SYSTEMThe Cooling Air System consists:� Cooling Air Duct� Cooling Air Pneumatic Actuator� Cooling Air Shutoff Valve� Cooling Air Fan

Cooling Air Inlet DuctThe cooling air duct supplies the stable air to the cooling fan when the airplaneis on the ground. When the airplane is in flight, the cooling air duct supplies theram air to the cooling fan. The cooling air duct is Iocated between the torquebox and the inlet flange of the cooling fan.A cooling fan inlet screen attaches to the cooling fan inlet. An inspection tubeand a cap assembly are attached to the cooling air duct for the inspection ofthe fan inlet screen. The inspection tube goes through a Iightening hole in thehorizontal web above the upper shroud.

Pneumatlc ActuatorThe pneumatic actuator controls the shutoff valve. The pneumatic actuator hasa cylinder, piston and rod assembly, spring and cap. The pneumatic actuator isinstalled on the fIange of the cooling air duct. The pneumatic actuator rod ex-tends when the pneumatic pressure from the bleed air duct is greater than thespring force. A filter in the pneumatic Iine seals the pneumatic actuator fromcontaminants. The filter can be one that is used again or one that is discarded.

Cooling Air Shutoff ValveThe shutoff valve stops the airflow through the cooling air duct when the APUis stopped. AIso, the shutoff valve wiII keep aII flames inside the APU shroud ifan APU fire occurs. The shutoff valve has a butterfiy mounted on a shaft. Thebutterfiy is installed in the cooling air duct. The pneumatic actuator controls theshutoff valve.

Page 55


ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ

COMBUSTOR

HOUSING

AIR INLET

HOUSINGGEARBOX

INLETAIR

OIL COOLER

FAN

COOLING

GENERATOR

FILTER VALVECHECK

ACTUATOR

COOLING AIRSHUTOFF VALVE

S

APU BLEED AIR DUCT

COOLING AIRINLET DUCT

ÇÇ ÇÇÇÇ

CONDITION: APU RUNNING.

Figure 27 APU Cooling Air SchematicPage 56


APU COOLING AIR

Page 57


CHECK VALVEHEATER)(TO FUEL

PRESSURE LINE

UPPERSHROUD

FWD BLEED AIR DUCT

PNEUMATIC LINE FILTER

APU

COOLINGAIR INLET

APU BLEED AIR VALVE

AND CHECK VALVE

ACTUATOR

PRESSURE LINETO THE PNEUMATIC

TO THE PNEUMATICACTUATOR

767835

Figure 28 Cooling Air ComponentsPage 58


COOLING FANThe cooling fan supplies a positive, cool airflow through the oil cooler and theAPU electrical generator. The cooling fan is a gear-driven, mixed flow fan. Thecooling fan has a shaft impeller that is installed in a shroud. A housing holdsthe baiI bearing for the impeller shaft. The housing also moves the air to andfrom the shaft impeller. The cooling fan inlet duct and the exhaust scroll for thecooling fan move the air into and out of the cooling fan assembly. The fan inletscreen stops aII unwanted materials before they go into the components of thecooling fan that turn.

Cooling Fan DuctThe airflow from the cooling fan moves through the cooling fan duct to the oilcooler and APU electrical generator.

OperationWhen the APU operates, the cooling fan supplies the cooling air. The gearboxaccessory drive turns the cooling fan. The cooling fan supplies stable air whilethe airplane is on the ground. When the airplane is in flight, the cooling fan sup-plies ram air. The pneumatic actuator receives the pneumatic pressure fromthe bleed air duct to hold the shutoff valve open. The cooling air from the cool-ing fan is supplied to the APU electrical generator and the oil cooler. To get tothe APU shroud, the cooling air moves through the cooling fan duct. In the APUshroud, the cooling air keeps the APU temperature Iow. From the APU shroud,the cooling air goes out through the APU exhaust system. When the APU isstopped, the pneumatic actuator close the shutoff valve. When the shutoffvalve closes, it wiII keep aII f!ames from an APU fire in the APU shroud.

Page 59


SHUTOFF VALVE

PNEUMATICACTUATOR

FWD

COOLING AIR DUCT

UPPERSHROUD

PRESSURE LINE

APUGEARBOXDRIVEN

ACTUATOR EXTENDED

ACTUATOR RETRACTED

OPEN POSITION

CLOSED POSITIONCOOLINGAIRFLOW

COOLING AIRFLOWTO GENERATOR

AND OIL COOLER

COOLING FANINLET SCREEN

COOLING FAN

COOLING FANINLET SCREENINSPECTION TUBE

STABILIZERCOMPARTMENTAREA

COOLING AIR SHUTOFF VALVE TEST

COOLING AIR

PNEUMATICACTUATOR

SHUTOFF VALVECOOLING AIR

767832767831767825

PRESSURE LINEINLET

COVERAND LOCATIONTO MANUALLYTURN THE APU

Figure 29 Cooling Air Shutoff ValvePage 60


IGNITION AND START SYSTEMThe APU ignition and starting system provides the means of rotating the APUengine to starting speed and for igniting the fuel-air mixture in the combustionchamber.

System DescriptionThe system consists of a starter, start relay, ignition exciter, igniter plug, andcontrol circuits.

Component LocationThe starter, ignition exciter, ignition leads and igniter plugs are located on theAPU engine. The start relay is located in the electronic equipment compart-ment right outboard side of the E3 rack.

System InterfacesThe start system interfaces with the full authority digital electronic control (FA-DEC), APU control unit and APU switch.

OperationDuring APU start, the starter is energized and the APU rotates. The ignitionexciter is energized by the action of the FADEC.The starter and ignition circuits are de-energized by the action of the FADECduring APU engine acceleration. During normal engine operation, the exciterremains de-energized.

Page 61


AFT CARGO CPTMFADEC

APU CONTROL SWITCH( P5 )

M280APU CONTROL UNIT ( E3-3 )

START

ON

OFF


APUCONT

FULL OPEN

AIR INLET DOORPOSITION SWITCH

TD 1 SEC

NO FADEC FAULT SIGNAL

= 55 % RPM>

STARTER

IGNITIONEXCITER

IGNITERPLUG

IGNITERPLUG

BATTERY28 V DC

START RELAYR 5

MASTER

APU

NC

POWER SUPPLY

28V DC

APU MONITOR

M 3056


HOT BAT BUS

28V DCSWITCHED

HOT BAT BUS

28V DCSWITCHED

Figure 30 Ignition / Starting SchematicPage 62


IGNITION COMPONENT DESCRIPTION

PurposeThe purpose of the ignition system is to provide the spark necessary to ignitethe fuel and air mixture for APU operation.

Ignition Exiter ( 1 )The ignition exciter supplies the high voltage current necessary to cause theigniter plugs to make the sparks. The ignition exciter has a transformer, in-verter, rectifier, booster coil and capacitors. These components are hermeti-cally sealed in a metal container on the APU. The ignition unit is an LRU.

Igniter Plugs ( 2 )The ignition system has two igniter plugs, left and right. The igniter plugs havean outer casing, center electrode and ceramic insulator. The igniters screw intomounting bosses on the combustor case. The igniters are LRU’S.

WARNING: MAKE SURE YOU REMOVE THE ELECTRICAL POWERFROM THE IGNITION AND START SYSTEM. LET 5 MIN-UTES GO BY BEFORE YOU REMOVE THE IGNITERCABLE. GROUND THE IGNITER CABLE AGAINST THESHELL OF THE IGNITER PLUG BEFORE YOU REMOVETHE IGNITER CABLE. MAKE SURE THAT THE IGNITIONEXITER IS FREE FROM ELECTRICAL POWER BEFOREYOU REMOVE THE IGNITER CABLE. THE ELECTRICALPOWER TO THE IGNITION AND START SYSTEM IS AT AVERY HIGH VOLTAGE. THE ELECTRICAL POWER TO THEIGNITION AND START SYSTEM CAN CAUSE INJURY TOOR KILL PERSONS.

Page 63


IGNITER CABLE

IGNITIONEXCITER

ELECTRICALCONNECTOR

IGNITER FWD

S

COMBUSTIONCHAMBERHOUSING

768571

IGNITERCABLE

PLUG

Figure 31 Ignition ComponentsPage 64


STARTING COMPONENT DESCRIPTION

Start Relay R5Connects the Battery Power 28 V DC to the Starter.energized when:� APU Master Switch „START“,� Air Inlet Door Full Open.� FADEC NO FAULT,

de-energized when :� APU RPM > 55%. or:� FADEC detects FAULT.

Location:� Right Side Electronic Compartment.

Page 65


RELAY R5START

FWD

803778

Figure 32 Start Relay LocationPage 66


STARTING COMPONENT DESCRIPTION

PurposeThe starter provides initial power for rotating the APU engine compressor, tur-bine, and engine-driven accessories to a speed high enough to obtain goodairflow for combustion.

LocationThe starter is mounted on the accessory drive section.

Physical DescriptionThe starter consists of an electric motor, a starter motor shaft assembly with aninternal sprag clutch.

PowerThe power supply to the starter is 28 volt dc from the battery or external dcpower connection.

OperationThe starter is energized by the action of the APU switch. !t wiIl continue todrive the APU until 55% RPM. The power supply to the starter is controlled bythe FADEC. The starter brushwear switch is located inside the starter. Thisswitch is Iocated inside the starter. This switch electrically signals the FADECwhen 75% brushwear occurs.

MonitorThe starter operation is monitored by the dc ammeter on the P5 panel in theflight compartment and the FADEC located in the aft cargo compartment.

Starter Motor Duty CycleAPU Start Mode3 consecutive starts or tries (Maximum) ( NO EGT Increase during the APUstarts or tries ) (30 minutes cooldown time).

Page 67


FWD

FWD

WASHER

GEARBOX

RETAINING RINGSCREW

SHAFT ASSEMBLY

PACKING

V-BAND CLAMP

STARTER MOTOR

( CLUTCH )

SHAFT ASSEMBLY ( CLUTCH ) OPERATION

SPRAG PAWL”ENGAGED”

”DISENGAGED”SPRAG PAWL

STARTER

APU

STARTER

APU

OUTERRACE

INNERRACE

CAUTION: THE SHAFT ASSEMBLY MUST BEPULLED OUT FROM THE GARBOX ASSEM-BLY IN A STRAIGHT DIRECTION. DO NOTTWIST THE SHAFT ASSEMBLY FROM SIDETO SIDE. THE SHAFT ASSEMBLY CAN BE DA-MAGED OR COME APART.

Figure 33 Starter Motor and Shaft AssemblyPage 68


APU CONTROLSThe APU control system consists of manual and automatic controls for� Start Sequence.� Speed Governing.� Load Control.� Shutdown.� Fault Detection and Indication.� Fault History and Memory.

APU control during all phases of operation is primarily the function of the FA-DEC, however, other components are also active in controlling operation.

System DescriptionThe primary APU control system consists of the following:-Full Authority Digital Electronic Control (FADEC)-APU Control Unit ( M28O Module )-Speed Sensors (2)-Ambient Temperature Sensor-Ambient Pressure Sensor

Page 69


( FDAU )

MISCELLANE0USSWITCHINGMODULE

BLEED AIRSTARTING IGNITION PURGE

VALVESOLENOID

VALVE

START MAIN FUELSOLENOID

VALVE

FUEL

VALVESERVO VALVE

SOLENOID

BLEED

VALVESERVO

VALVEDE-PRIME

FADEC

CONTROL UNIT

EGTSENSORNO.1 / 2

RPMSENSOR

AMB.TEMP.SENSOR

AMB.PRESS.SENSOR

LOW OILPRESS.SWITCH

HIGH OILTEMP.SWITCH

OIL LEVELSENSOR

NO.1 / 2

STARTERBRUSH IND

EMU

AIR /GRD

APU

FWD OVERHEADPANEL P5

ON

OFF

APU CONTROL

28V DC SW. HOT BAT BUS

P 5 FWD OVERHEAD PANEL

START FUEL

FLIGHT DATAAQUSITION UNIT

Figure 34 APU Control Sytem SchematicPage 70


APU CONTROL UNIT/FADEC DESCRIPTION

APU Control UnitThe APU Control Unit ( M 280 ) is used in conjunction with the FADEC forStarting, operation, and shutdown of the APU.The Unit contains switches and relays. On the front is a circuit breaker for over-current protection.The Unit contains a 300sec. time delay relay to switch off the APU Indicationafter the APU switch is placed to off.The power supply is 28 v dc batt bus, APU Generator Control Unit and 28 vdcswitched hot batt. bus.The APU Control Unit ( M 280 ) location is in the electronic copartment, E3-3.

FADEC ( Full Authority Digital Electronic Controller ).The Full Authority Digital Electronic Control (FADEC) is a microprocessor-based system.The FADEC controls the following activities::� Start Sequence.� Speed Governing.� Load Control.� Shutdown.� Fault Detection, Protection and Indication.� Fault History.

Recording of engine operating history and provisions for communicating theengine functional status, fault assessment, and operating history to the DigitalFlight Data Acquisition Unit. The DFDAU compiles this information and thensends it to the flight recorder.The power supply is 28 v dc batt bus, and 28 vdc from the switched hot batt.bus.The FADEC location is in the aft cargo compartment .

FIREPROTECTION

START/STOP

BLEED VALVE

INTERFACECOCKPIT

FADECWIRING

INTERFACE

STARTSEQUENCING

SYSTEM

INTERFACE

SPEED

CONTROLSYSTEM

AIRFLOW

CONTROLSYSTEM

SYSTEM

PROTECTIVESHUT DOWN

SELFTEST

APU CONTROL UNIT M280 FADEC M3056

Page 71


ELECTRONIC SHELFE 3

CIRCUIT BREAKER

APU CONTROL UNIT M280

769273

FADEC M3056

AFT CARGO

DOOR

AFT CARGOCOMPARTMENT

Figure 35 APU Control Unit and FADEC ComponentPage 72


FADEC DESCRIPTIONThe FADEC will conduct a self-test and initialization procedure. Following asuccessful self-test, the FADEC wilI enter into a watch state in which it moni-tors APU startup and continuous operation. If a component fails, depending onthe severity of the situation, the FADEC will either shutdown the APU with aFAULT light displayed on the overhead P5 or illuminate a MAlNT light also onthe P5, but continue to operate.

LED DisplayFaults and warnings are displayed on the alpha numeric display on the front ofthe FADEC. Faults/warnings are displayed in the order of occurrence with criti-cal faults taking precedence over warnings. This data is just for the presentAPU cycle. Historical data can be accessed via the Fault Data switch. The faultindication will be cleared once the fault condition has been corrected and a newAPU cycle is initiated. It is not until the FADEC senses the fault again, that itwill display it on the LED.For the situation in which a fault occurs, and power is removed from the air-plane (Bat switch is placed to the OFF position), the FADEC will retain thefault(s).

FADEC BITE Test Procedure� Set the APU Master switch to the OFF position.� Set the BAT switch to the ON position.� Push the FAULT DISPLAY switch on the FADEC.

The fault display on the FADEC will show firstly the APU Identification Number( ENID ). Then the fault display will show the FADEC BITE code (s) of thegiven faults of the last APU auto shutdown or maintenance data ( first historyrecord ) or OK if there were no FADEC BITE code (s) found by the FADEC.Following comes 11 history records (second history records ), a FADEC BITEcode or maintenance data or OK will show for five seconds. After one compledcycle the FADEC BITE code ( first hystory record ) from the last APU autoshutdown or maintenance data or OK will show again for 10-15 seconds. After10-15 seconds the fault display go out of view.

Power Up Self Test.When you move the APU Master switch from OFF to ON, the FAULT DISPLAYwill show the result of the power-up self-test of the FADEC. lf you move theAPU master switch from ON to OFF and you did not move it to START, the re-sult of the power-up self-test for the FADEC will show for 5 minutes then go out

of view. You can then push the FAULT DlSPLAY switch on the FADEC and stillsee the FADEC BITE code for the last auto shutdown.

Start Prepare Test.When you move the APU master switch from ON to START then to ON, thefault display will show the result of the start prepare test. When the APU oper-ates, the fault display will show the condition of the APU system continuously.If the airplane is on the ground and the APU does not start or has an automaticshutdown, do not try a subsequent start until you look at the FADEC. Whenyou move the APU master switch to the OFF position and then to START, theFADEC BITE code from the last auto shutdown will not show. The problemfrom the first start can possibly not occur again on the subsequent start.You must have the APU Master switch in the OFF position to make the FADECBITE code from the last auto shutdown show.

Nonvolatile MemoryFive categories of data will be transmitted to the DFDAU as part of the APUcondition monitoring. These are:

CATEGORY PARAMETERLife Cycle Engine I.D. NumberData Hours of Operation

Number of StartsReal Time EGTOperating SpeedParameters Fuel Flow

Inlet Pressure Inlet Temperature

Real Time 3 Fault CodesFault Data 12 HistoryThe ARlNC 429 transmission take place in the continuous broadcast modeand shall commence when the FADEC is powered up through the APU switchor the display power switch.

Page 73


AFT CARGODOOR

FADEC M3056

FAULT

DISPLAY SWITCHFAULT

AFT CARGOCOMPARTMENT

ACCLACFT

AMBTAMBP

ASVLBLDECUEMUEXCTFSRVGDOVHOTLITELOPLOQMFVLOPSWOTMPOVSPPWRFSFVLSPD1SPD2SPVLSRVBSTRTTC1TC2UNSP

FAIL TO ACCEL

AMBIENT PRESSURE SENSING SYSTEMAMBIENT TEMP SENSING SYSTEMANTI SURGE VALVE SYSTEMA/C BLEED VALVE SYSTEMELECTRONIC CONTROL UNIT SYSTEMEVENT MONITOR UNIT SYSTEMIGNITION SYSTEMFUEL SERVO SYSTEMGEARBOX DE-OILING VALVE SYSTEMHIGH OIL TEMPERATUREFAIL TO LITELOW OIL PRESSURELOW OIL QUANTITYMAIN FUEL VALVE SYSTEMOIL PRESSURE SWITCH SYSTEMOVERTEMPOVERSPEEDELECTRICAL POWER SYSTEMSTART FUEL VALVE SYSTEMSPEED SENSING SYSTEM 1 SYSTEMSPEED SENSING SYSTEM 2 SYSTEMSTART PURGE VALVE SYSTEMBLEED SERVO SYSTEMSTARTER SYSTEMEGT SYSTEM 1 SYSTEMEGT SYSTEM 2 SYSTEMUNDERSPEED

FADECIDENTIFICATIONPLATE

FADECDATACONNECTOR

DISPLAY

FADEC BITE CODE DECCODING LABEL

a53173

ENID 1

FAULT DISPLAY

FIRST FADEC BITECODE OF THE FIRSTHISTORY RECORD

FADEC BITE CODE ( S ) OFTHE GIVEN FAULTS ANDMAINTENANCE DATA OF

THE LAST APU SHUTDOWN( FIRST HISTORY RECORD )

HIST

RN 11

2

3

RN 10

RN 09

RN 08

RN 07

RN 06

END

RN 01

RN 02

RN 03

RN 04

RN 05

1

2

3

THE FAULT DISPLAY WILL SHOW THE LAST FOUR NUMBERS OF THE IDENTIFICATION NUMBER ( ENIT )

THE FAULT DISPLAY WILL SHOW ”OK ” WHEN NO FAULTS OR MAINTENANCE DATA ARE IN MEMORY.

THIS IS THE SECOND HISTORY ( RN ) RECORD. UP TO 11 HISTORY RECORDS ARE POSSIBLE. THE FAULTDISPLAY WILL SHOW ”N/A” WHEN NO HISTORY RECORDS ARE IN MEMORY.

FADEC DISPLAY SEQENCE WHEN FAULT DISPLAY SWITCH IS PUSHED.

FIRE/DOOR NOT OPEN/ BATTERY SW OFF

Figure 36 FADEC ComponentPage 74


AMBIENT PRESSURE TRANSDUCERThe ambient pressure sensor senses inlet air pressure to the compressor.The pressure sensor is mounted on the Ieft side of the air inlet muff above thetemperature sensor.The pressure sensor measures inlet air pressure and sends that signal to theFADEC for fuel flow scheduling and operation of the anti-surge bleed valve.

Ambient Temperature SensorThe Ambient Temperature Sensor senses air inlet temperature to the compres-sor.The temperature sensor is mounted on the left side of the air inlet muff belowthe pressure sensor.The temperature sensor measures inlet air temperature and sends the signal tothe FADEC for fuel flow scheduling.

Page 75


FOR THE OIL TANKFILLER PORT

SENSORTEMPERATUREAMBIENT

MOUNTING FLANGE

FWD

MOUNTING FLANGE

AMBIENT PRESSURETRANSDUCER

FWD

833686833587

Figure 37 Amb. Press. Transducer and Amb. Temp. SensorPage 76


SPEED SENSOR

Speed Sensor ( 2 )The two speed sensors deliver analog signals to the FADEC for speed sensing.The FADEC uses this information to operate start sequencing, condition moni-toring and provides overspeed and underspeed control.The speed sensors are located inside of the engine air intake muff and aremounted on the intake-housing.The magnetic probe of each sensor extends through the housing and alignswith the Iobes on the oil impeller. As the turbine/compressor shaft rotates, theIobes on the oil impeller pass by a magnetic probe on each speed sensor. Thisgenerates a sinusoidal output signal which is then sent to the FADEC.The loss of speed sensor will signal the FADEC to give a MAINT light on theP5 panel. The loss of both speed sensors will result in an automatic shutdownand a FAULT light.

Page 77


FWD

BOLT

PACKING

SPEED SENSOR PROBE NO. 1

SPEED SENSOR PROBE NO. 2

833716

SPEED SENSOR PROBE

AIR INLET HOUSING

AIR INLET MUFF

ELECTRICALCONNECTOR

OIL IMPELLER LOBES

APU COMPRESSORAIR INTAKE SCREEN

APU AIR INLET HOUSING

Figure 38 Speed SensorPage 78


APU START SEQUENCE1. BATTERY SWITCH 0N.2. APU MASTER CONTROL SWITCH TO THE START MOMENTARILY AND

TO THE ON POSITION.� APU CONTROL UNIT AND FADEC ELECTRICAL POWERED.� FADEC INITIATES ELECTRICAL POWER FOR SELF TEST INITIALIZA-

TION.� FADEC SELF TEST INITIALIZATION PROCEDURE COMPLETED, WHEN

NO FAULTS, FADEC GOES TO WATCH STATE.� TIME DELAY RELAY ACTIVATES EGT AND FADEC FAULT DISPLAY.� DE-PRIME VALVE OPEN.� DC FUEL PUMP ON.� LOW OIL PRESSURE LIGHT ON.� APU FUEL SHUT OFF VALVE OPENS, WHEN OPEN:� APU AIR INLET DOOR OPENS ( CA 15 SEC, MAX ALLOWABLE 30 SEC)

NOTE: IF APU MASTER CONTROL SWITCH IS PLACED TO THE ONPOSITION : SAME ACTIONS AS ABOVE. THE APU MASTERCONTROL SWITCH THEN SELECTED TO START : APU START SEQUENCE CONTINIUE

3. WHEN APU AIR INLET DOOR FULL OPEN APU ENGINE STARTS:� STARTER RELAY ENERGIZED� START FUEL SOLENOID VALVE OPEN.� + TD1 SEC. IGNITION EXCITER ENERGIZED.

4. APU ENGINE AT 5% SPEED� MAIN FUEL VALVE OPENS WHEN EGT RISE > 28� C.� FUEL SERVO VALVE MODULATES.� FADEC ACTIVATES TEMPERATURE CONTROL CIRCUIT.� HOUR METER ON.� START COUNTER PULSE.

5. APU ENGINE AT 55% SPEED� STARTER RELAY DE-ENERGIZED� IGNITION EXCITER DE-ENERGIZED.� DE-PRIME VALVE CLOSE.

6. APU ENGINE AT 70% SPEED� START FUEL SHUT OFF VALVE DE-ENERGIZED TO CLOSE.� START PURGE VALVE ENERGIZED TO OPEN FOR 60 SEC.� LOW OIL PRESSURE LIGHT OFF, WHEN OIL PRESS. > 26 PSI.

7. APU ENGINE AT 80% SPEED� FADEC: DE- ACTIVATES TEMPERATURE CONTROL CIRCUIT.� FADEC: ACTIVATES SPEED SPEED CONTROL CIRCUIT.

8. APU ENGINE AT 98% SPEED� DC FUEL PUMP OFF.� + TD 2 SEC, READY TO LOAD ( RTL ) SIGNAL, FOR APU BLEED AIR

VALVE,� GEN. BUS OFF LIGHT ILLUMINATES.� LOW OIL PRESS. AUTO SHUTDOWN CIRCUIT ACTIVATED.

9. APU ENGINE AT 100% SPEED� FADEC SPEED CONTOLLED. NORMAL RUNNING SPEED.

Page 79


1 TIME

20%

30%

40%

50%

55%

60%

70%

80%

90%

98%100%

5%

10%

APU

RPM%MOTOR

2 3

4

5

6

7

89

83952

Figure 39 APU Start SequencePage 80


APU SHUT DOWNSAPU NORMAL SHUTDOWN DESCRIPTION1. �APU MASTER CONTROL SWITCH TO OFF POSITION.� REMOVES READY TO LOAD SIGNAL, DISABLE BLEED AIR VALVE,

GEN BUS OFF.� MAIN FUEL SOLENOID VALVE DE-ENERGIZED TO CLOSE� MAIN FUEL SERVO VALVE DE-ENERGIZED� START PURGE VALVE ENERGIZED TO THE OPEN POSITION FOR 30

SEC ,THEN DE-ENERGIZED TO THE CLOSE POSITION.� DE-PRIME VALVE ENERGIZED TO THE OPEN POSITION.� APU FUEL SHUT OFF VALVE CLOSE� APU AIR INLET DOOR CLOSE.� HOUR METER OFF.

APU AUTO SHUTDOWN DESCRIPTION2. �AUTO SHUTDOWN ACTIVATED.� REMOVES READY TO LOAD SIGNAL, DISABLE BLEED AIR VALVE,

GEN BUS OFF.� MAIN FUEL SOLENOID VALVE DE-ENERGIZED TO CLOSE� MAIN FUEL SERVO VALVE DE-ENERGIZED� START PURGE VALVE ENERGIZED TO THE OPEN POSITION FOR 30

SEC ,THEN DE-ENERGIZED TO THE CLOSE POSITION.� DE-PRIME VALVE ENERGIZED TO THE OPEN POSITION.� START FUEL SOLENOID VALVE DE-ENERGIZED( DEPENDS ON RPM )� STARTER RELAY DE-ENERGIZED( DEPENDS ON RPM )� APU FUEL SHUT OFF VALVE CLOSE.( ONLY WHEN : FIRE DETEC-

TION.)� APU AIR INLET DOOR CLOSE. ( ONLY WHEN : FIRE DETECTION ).� HOUR METER OFF

APU MASTER CONTROL SWITCH TO OFF POSITION + 5 MINUTES.� TIME DELAY RELAY SWITCHES OFF EGT INDICATION AND FADEC

FAULT DISPLAY.

Page 81


TIME

20%

30%

40%

50%

55%

60%

70%

80%

90%

98%100%

5%

10%

APU

RPM%MOTOR

MASTER CONTROL SWITCH OFFOR AUTO SHUT DOWN

2

1

83952

Figure 40 Normal/Auto Shut DownPage 82


E. G. T. INDICATING SYSTEM.EGT Indication provides a means of monitoring the efficiency of the APU dur-ing Startup, run (Ioaded or unloaded) and shutdown.The EGT Indicating system consists of:� 2 Thermocouples, located in the exhaust duct.� Event Monitoring Unit, mounted on the cooling air duct.� FADEC, mounted in the aft cargo compartment.� Balancing Resistor, located in the forward right sidewall of the flight deck. .� EGT Indicator, mounted in the P5 panel on the flight deck.

Once the APU switch has been placed to the START position, 28v dc is pro-vided to the FADEC, which will then allow an EGT signal to be sent to the indi-cator on the flight deck. Indication wilI continue during operation and until fiveminutes after shutdown. At this time, the time delay will prevent 28v dc to theFADEC.The thermocouples sense the exhaust gas temperature and convert it to anelectrical signal. This signal is sent to the Event Monitoring Unit (EMU), andthen to the FADEC. The FADEC uses EGT to modify fuel scheduling and mod-ulate the Bleed Air Valve. The signal is also sent through a balancing resistor tothe EGT indicator on the PS panel.

Page 83


FADEC

TO APU START COUNTER

EGT THERMOCOUPLE

EGT THERMOCOUPLE

APUEXHAUST

EVENT MONITORING UNIT

EGTINDICATORCOCKPIT

P5 O/H PANEL

( EMU )

BALANCINGRESISTORCOCKPIT

COCKPIT

AND APU HOUR METER

EGT THERMOCOUPLE SIGNALS 1/2

1

2

Figure 41 EGT SchematicPage 84


THERMOCOUPLES ( 2 )The chromel / alumel thermocouples extend into the exhaust stream to senseAPU exhaust gas temperature. The milli-volt output of the thermocouple istransmitted to the FADEC which analyzes the signal for appropriate schedulingof fuel and control of bleed air.

Event Monitoring Unit ( EMU ).The Event Monitoring Unit (EMU) houses the resistive temperature detectorand also provides indication of APU hours and starts.The EMU is located on the cooling air duct forward of the cooling fan.EGT signals are sent to the EMU before going to the FADEC. The resistivetemperature detector in the EMU provides cold junction compensation for theEGT thermocouples. Displayed on the EMU are the number of APU hours andstarts. Hours are not recorded until 98% RPM is accomplished.

FADECEGT input to the FADEC affects fuel scheduling. The EGT signal is also pro-vided through a balancing resistor to the flight deck.

Page 85


THERMOCOUPLES

FWD

UNITMONITORINGEVENT

FWD

COOLINGAIRDUCT

833726 803964STARTS

1901

HOURS

36880 0

Figure 42 Thermocouples and Event Monitoring Unit.Page 86


THIS PAGE INTENTIONALLY LEFT BLANK

Page 87


EGT RESISTOR

EGT INDICATOR PLUG

EGT INDICATOR

E1

CH

AL

CH

AL

THERMOCOUPLE

THERMOCOUPLE

FADEC

3

21

13

2

2240

21C3

C2D3

2

1 BA

BA

1238

39

D220

18

A9

C1

D1

B9B8

ARMATURE COIL

SPRING

SPRING

6

7

5

4

67

0.05Q0.05Q

0.15Q

SPOOOL0.05Q

0.15Q 0.15Q 0.15Q

CONSTANTAN

COPPER

RESISTORCALIBRATING

EVENTMONITORING

WIRINGAIRPLANE

UNIT

APU ENGINE HARNESS

P5 FORWARD OVERHEAD PANEL

795321

STATION 851

1

2

Figure 43 APU E. G. T . System SchematicPage 88


EGT BALANCING RESISTOR� receive the EGT Signal from the FADEC� is installed between FADEC and EGT Indicator.� allows Adjustment of the EGT Systems with vernier und coarse Coil.� is located in the cockpit right side below the window No #3 .

EGT Indicator� shows the APU Exhaust Gas Temperature in � Celsius� compensates and correct cockpit temperature changes.� is located in the Cockpit P5 Overhead Panel

Page 89


INDICATOR

EGT

RESISTOR

FLIGHT COMPARTMENT

RESISTANCEWIRE SPARE

SPOOL

RESISTANCEWIRE SPOOL

AIRPLANE LEADSVERNIERADJUSTMENTTERMINAL

ADJUSTMENTTERMINAL

COURSE

REMOVED)(WITH THE COVEREGT RESISTOR

VERNIER ADJUSTB3

B2

B1A5

A3

A1INCREASE

COARSE ADJUST

A2A4

INCREASE

.05 /STEPS .15 /STEPS

EGT

BALANCINGEGTAPU

APU

FWD

Figure 44 EGT Balancing Resistor and IndicatorPage 90


ID-MODULEThe Engine Identification Module is installed on the APU and provides a resis-tance value to a microprocessor. The microprocessor interprets this value andenables the FADEC to identify the APU by a number from 0 to 2047.The Engine Identiflcation Module can be physicalIy altered to select a desiredID number. This is accomplished by removing the ID module protective coverexposing a small printed wiring assembly. By cutting one or more copper cladcircuits, resistance is modified, which represents a number and is assigned tothat particular APU.

LocationThe Engine Identification Module is installed on the left side of the APU belowthe ignition exciter.

ExampleThe engine identification number can be represented from 0 to 2047 by physi-cally cutting the appropriate copper clad circuits.The values are as follows:� W1 = 1� W2 = 2� W3 = 4� W4 = 8� W5 =16� W6 =32� W7 =64� W8 =128� W9 =256� W10 =512� W11 =1024

APU SN Nr. 296 is installed� Cut W9 = 256� Cut W6 = 32� Cut W4 = 8

Page 91


CUT ZONE

PRINTED

REMOVABLEPROTECTORCOVER

WIRINGBOARD

ELECTRICALCONNECTOR

ELECTRICALCONNECTOR

PAD

Figure 45 ID-ModulePage 92


FADEC BITE CODES AND LIGHTS.Auto Shut Down with FAULT Light IIlumination.Fadec Bite Code:� ACCL� ACFT� ECU� FSRV� HOT� LITE� MFVL ( ELECTRICAL FAULT )� OPSW� OTMP� OTSP� PWRF� STRT� UNSP

Auto Shut Down with OVERSPEED Light Illumination.

Fadec Bite Code:� ECU ( = FADEC )� OVSP

Auto Shut Down with LOW OIL PRESSURE LIght Illumination.

Fadec Bite Code:� LOP

No Auto Shut Down. Illumination of the MAINT Light.

Fadec Bite Code:� ECU ( FADEC SPEED CHANNEL 1 OR 2 FAULT )� LOQ� MFVL ( MECHANICAL FAULT )� SPD 1� SPD 2� TC 1� TC2

No Auto Shut Down, No Light Illumination .

Fadec Bite Code:� AMBP� AMPT� ASVL� BLD� EMU� EXCT� GDOV� SFVL� SPVL� SRVB� STRT

Page 93


FADEC

FAULT DISPLAY

FADECBITE

CODE

RELATED APUINDICATING

LIGHT

CORRECTIVEACTION

MCDU DISPLAY

ACCL FAULTFAIL TO ACCELERATEACFT

AMBTAMBP

ASVLBLD

ECU

EMUEXCTFSRVGDOVHOTLITE

LOP

LOQMFVLOPSWOTMP

OVSPPWRFSFVLSPD1SPD2SPVLSRVB

STRT

FAULT

TC1TC2UNSP

FAULT

FAULT orOVERSPEED

FAULTFAULT

LOW OILPRESSURE

FAULT orFAULTFAULT

OVERSPEEDFAULT

MAINT

FAULT

MAINT

MAINT*(1)MAINT*(1)

MAINT*(2)MAINT*(2)

See Fig. 101See Fig. 102See Fig. 103See Fig. 104See Fig. 105See Fig. 106

See Fig. 107See Fig. 108See Fig. 109See Fig. 110See Fig. 111See Fig. 112See Fig. 113

See Fig. 114See Fig. 115See Fig. 116See Fig. 117

See Fig. 118See Fig. 119See Fig. 120See Fig. 121See Fig. 122See Fig. 123See Fig. 124

See Fig. 125

See Fig. 126See Fig. 127See Fig. 128

REPLACE THE FADEC

< RETURN

APU DATA 2 / 5APU ACTUAL BITE

DATE FLIGHTMODE UTC13MAY96 01 094656

PRINT >

LOP

A/C FAULTP1 SENSOR FAILT1 SENSOR FAIL

ANTI SURGE VALVE FAILA/C BLEED FAIL

FADEC FAILURE

EMU FAILEXCITER FAILUREFUEL SERVO VALVE

GBX DE-OILING VALVE FAILHIGH OIL TEMPERATURE

FAIL TO LIGHTLOW OIL PRESSURE

LOW OIL QUANTITYMAIN FUEL VALVE FAILURE

OVER TEMPERATURE

OVERSPEED

OIL PRESSURE SWITCH FAIL

ELECTRICAL POWER FAULTSTART FUEL SOV FAIL

N SENSOR 1 FAILN SENSOR 2 FAIL

BLEED SERVO VALVE FAILSTARTER WARNING ORFAIL TO START

START PURGE SOV FAIL

EGT PROBE 1 FAILEGT PROBE 2 FAILUNDERSPEED

MCDU DISPLAY

INDICATING LIGHTRELATED APU

*(1) IF BOTH SPD1 AND SPD2 ARE SET,THE FAULT LIGHT WILL SHOW. MCDU DISPLAY: BOTH N SENSORS FAIL

*(2) IF BOTH TC1 AND TC2 ARE SET,THE FAULT LIGHT WILL SHOW. MCDU DISPLAY: BOTH TC FAIL.

FADECBITE

DECODINGLABEL

TROUBLE SHOOTING FAULT INDEX AMM 49-00-00 PAGE 108 TABLE 101

Ref MM 49-61-12/401

MAINT

OTST FAULT See Fig. 117 AOVER TEMPERATURE AT START

*(3) IF ECU SHOWS AFTER REPLACE-MENT OF THE FADEC, DO THESEPROCEDURE ”SPD 1”( FIG 121) AND”SPD 2” ( FIG 122 ).

LOW OIL PRESSURE

*(3)

Figure 46 LOP FADEC Bite Code Indication.Page 94


MCDU, APU DATA PAGES.APU DATA Pages.are monitored and stored by the FADEC . This data are displayed by theMCDU.� These are the DATA pages:

- APU DATA- ACTUAL APU BITE- APU BITE HISTORY

All DATA can be displayed and print.

APU DATA Page� for indication push the following keys:

- MENU- LINE SELECT KEY 3: ACMS- LINE SELECT KEY 1: APU DATA

� With the APU Master Control Switch in ON, the display shows actual APUData. These are the data:- EGT � C- INLET � C- INLET PRESS. PSIA- SPEED %- GEN LOAD. KVA.

A Current Transformer measures the Gen. Load. The wires are routedvia a solid state circuit (installed in the Misc. Switching Unit) to theMCDU.

ACTUAL APU BITE� 7 aktuell APU BITE Codes can be displayed. With the APU Master Switch

in ON and a given AUTO SHUTDOWN the MCDU shows the reason.� When you move the APU Master Switch to OFF the “FAULT“ changes to

the „APU BITE HISTORY“� < shows a HELP Page for additional information.

APU BITE HISTORY� 12 APU BITE HISTORY Codes can be displayed.

NEXT PAGE KEY

INIT REF KEY

INITREF

PREVPAGE

DEPARR

RTE

W

PROG

1

PAGENEXT

HOLD

FIX

LEGS EXEC

DESCRZ

W

A

BRT

CLB

Z

MSG

FAIL

DSPY

U V W

P Q R S

X

T

Y

F

K

G

L

H

M

I

N

J

O

A B C D E

DEL / CLR

2 3

4 5 6

7 8 9

. 0 +/-

N1LIMIT

1L2L

4L5L6L

1R2R3R4R5R6R

3L

DATA SCREEN

LINESELECTKEYSRIGHT

LINESELECTKEYSLEFT

Multi purpose Control Display Unit ( MCDU )

MENU

Page 95


LINE SELECT KEYSLEFT

2L

4L

5L

6L

1R

2R

3R

4R

5R

6R

< FMC

< ACARS

< ACMS3L

MENU

MENU

1L

2L

4L

5L

6L

1R

2R

3R

4R

5R

6R

< APU DATA

< ACMS MENU

3L

ACMS

1L 1L

2L

4L

5L

6L

1R

2R

3R

4R

5R

6R

EGT321 DEG CN1- APU

-------------------------

3L

< RETURN

1L

2L

4L

5L

6L

1R

2R

3R

4R

5R

6R-------------------------

3L

< RETURN

APU DATA 1 / 5

PAGENEXT

100 %GEN LOAD0.37 KVA

ACTUAL APU BITE HELP

INLET TEMP020 DEG C

INLET PRES13 PSIA

FUEL FLOW156 KG/H

APU DATA 2 / 5

PRINT >

APU BITE HISTORY

DATE FLIGHTMODE UTC03JUN96 01 120429

FAIL TO ACCELERATE

DATE FLIGHTMODE UTC01JUN96 01 094656

PRINT >

< ACT >

< FREE REPORTA / C FAULT

LOW OIL QUANTITYDATE FLIGHTMODE UTC

01JUN96 01 164546

< LOW OIL PRESSURE

Figure 47 MCDU APU DATA DisplayPage 96


TROUBLE SHOOTING.� A This section gives the troubleshooting tips and the procedures to correct

problems of the APU.� B. The troubleshooting tips give the data that can help to identify and to

isolate a problem. The troubleshooting tips also has the cautions and the warnings that must be obeyed during the troubleshooting procedures.

� C. The fault index gives the APU operation problems and the corrective action for the problems.

(1) The fault index has six groups of APU problems: (a) APU indication problems before the start (b) APU start problems (c) APU automatic shutdown (d) APU indication problems during APU operation (e) APU bleed air problems (f) Other APU problems. (2) The fault index can refer you to a figure or a table in this section to correct the problem. ( a) The FADEC BITE codes are on Table 101. Table 101 gives the corrective action or the figure number for each FADEC BITE code. ( b) Each figure has a troubleshooting procedure.The troubleshooting procedure has three sections:1) Description. a) The description has the data about the problem. For the FADEC BITE codes, the description tells what makes the code show.2) Possible Causes. a) The list of possible causes can be used if there is not much time. The possible causes are given in a sequence with the most possible and easiest causes at the top. The least possible and most difficult causes are at the bottom.

3) Fault Isolation a) The fault isolation is a diagram which gives the procedure to find the problem.

Page 97


Figure 113 (Sheet 1)

NO

NO

SEE SHEET 2(BLOCK 4)

NO

YES

YES

YES

”LOP” FADEC BITECODE SHOWN

PREREQUISITES

MAKE SURE THIS SYSTEM WILL OPERATE: APU (AMM 49-11-00/201)

20-22 PSIG.

THE OPEN POSITION?

CLOGGED OIL PRESSURE RELIEF VALVE (AMM 49-91-21/401)

_______________POSSIBLE CAUSES:

THE CIRCUIT FOR THE LOW OIL PRESSURE WAS OPEN (THE SWITCH FOR THE LOW OIL PRESSURE OPENED) WHEN THE APU

___________DESCRIPTION:

SPEED WAS MORE THAN 98% FOR 10 SECONDS. THIS USUALLY OCCURS WHEN THE OIL PRESSURE DECREASES TO LESS THAN

ARE METAL PARTICLES FOUND

1 EXAMINE THE MAGNETIC DRAIN

GLASS ON THE LOWER, FRONT SIDEOF THE GEARBOX HOUSING.IS THE OIL LEVEL BELOW THE

THAT ARE NOT PERMITTED?

”ADD” MARK?

_______________FAULT ISOLATION:

2 LOOK AT THE OIL SIGHT

3 EXAMINE THE OIL PRESSURERELIEF VALVE. IS IT CLOGGED OR STUCK IN

2.3.4.5.6.

1. LOW OIL QUANTITY (AMM 12-13-31/301)

PLUG (AMM 49-91-81/601).

RELIEF VALVE

(AMM 49-11-00/401).51 REPLACE THE APU

(AMM 12-13-31/301).52 SERVICE THE APU OIL TANK

(AMM 49-91-21/401).

53 REPLACE THE OIL PRESSURE

OIL PRESSURE SWITCH PROBLEM (AMM 49-94-22/401)OIL FILTER AND PUMP ASSEMBLY PROBLEM (AMM 49-91-11/401)DE-PRIME VALVE PROBLEM (AMM 49-91-91/401)FADEC, M3056, PROBLEM (AMM 49-61-12/401).

Figure 48 LOP FADEC BITE Code ShownPage 98


Figure 113 (Sheet 2)

NO

YES

YES

NO

NO

YES

NO

(BLOCK 3)FROM SHEET 1

YESNO

INCREASE TO ABOVE 26 PSI(179 KPA)?

58 REPLACE THE FADEC, M3056(AMM 49-61-12/401).

57 REPAIR THE PROBLEMS THATYOU FIND.

START THE APU(AMM 49-11-00/201).

21 REPLACE THE DE-PRIME VALVE(AMM 49-91-91/401).

DOES THE PROBLEM CONTINUE?

55 THE SYSTEM IS OK.

(WDM 49-61-11).NECTOR P14, PINS 1,2OIL PRESSURE SWITCH, S2, CON-D10432A, PINS C10,B11, TO THE

22 EXAMINE THE CIRCUITS FROMTHE FADEC, M3056, CONNECTOR

CLOSE WITH AN INCREASE IN OILPRESSURE. DID THE OIL PRESSURE

5 DID THE OIL PRESSURESWITCH CLOSE AT APPROXIMATELY26 PSI (179 KPA)?

IS THERE AN OPEN CIRCUIT?

56 REPLACE THE OIL PRESSURESWITCH (AMM 49-94-22/401).

THE OIL PRESSURE SWITCH TO(AMM 49-11-00/201). LOOK FOR

START THE APU

4 REMOVE THE OIL PRESSUREPUMP ASSEMBLY (AMM 49-91-11/

SURE SWITCH. INSTALL THE OILGEARBOX PORT FOR THE OIL PRES-

PRESSURE SWITCH AND A 0-50 PSI

INSTALL A T-FITTING IN THEFROM THE DE-PRIME VALVE.DISCONNECT THE CONNECTOR P5SWITCH (AMM 49-94-22/401).

401).

54 REPLACE THE OIL FILTER AND

THE OIL PRESSURE SWITCH.OHMMETER TO PINS 1 AND 2 OFTHE T-FITTING. CONNECT AN(0-300 KPA) PRESSURE GAGE ON

Figure 49 LOP FADEC BITE Code ShownPage 99


APU OPERATION LIMITS AND PARAMETERS(1) The APU operation limits and parameters are used when you operate or motor the APU. If the APU does not operate in the specified limits, damage tothe APU can occur.(2) The APU operation limits and parameters are shown in the table that fol-lows:

Condition Operation Mode LimitOil Temperature Overtemperature Shutdown 135 � C max.Maximum EGTExhaust Gas Temperature APU Speed -Up to 60% 1100� C max.(-108 FADEC and Amb. APU Speed - 60% to 98% 899� C max.Temp: > -18 � C.) APU Speed More than 98%

See Fig.201, MM49-11-00/204Fuel Temperature Any Operation Mode -40� C to 57� C.Oil Consumption: 10.0 cc each hour.Oil Pressure: Maximum at Gearbox 40-45 psig.

Low Oil Pressure Shutdown 20-22 psig.Fuel Quantity: APU Start Mode (Minimum) 159 kg.(No. 1 Fuel Tank) Cont. Operation (Minimum) 159 kg./ h.Fuel Pressure Any Operation Mode 10-55 psig Engine Speed: (Cont. Ops.) ECS and MES and Idle 100 0.25%

Maximum Allowable 105 0.25%(Overspeed Shutdown)Minimum Allowable 97%(Automatic Shutdown)

Condition Operation Mode Limit

AC Frequency Meter: Continuous Operation 395-405 Hzwith No Load ConditionAC Frequency Meter: Continuous Operation 375-417 Hz

with Fully Loaded Condition(Maximum Fluctuation) 2-4 Hz

Bleed Duct Pressure: APU Bleed Valve CLOSED 0 psig(No Load Condition) APU Bleed Valve OPEN 46 5 psig (Minimum) 30 psig(Fully Loaded Condition) APU Bleed Valve OPEN 21-5 psig

See Fig.201, MM49-11-00/204NOTE: A Fully Loaded Condition for the APU has the two airconditioning packs on HIGH and an electrical load of 100 amps.Battery: APU Start Mode(Without AC Power) 22-28 VDC(With AC Power) 26-28 VDCStarter Motor: APU Start Mode 3 consecutiveDuty Cycle starts or tries

(Maximum)( 30 minutes cool-down time )

Page 100


APU OPERATION TESTProcedure(1) Start the APU (AMM 49-11-00/201).(2) Look at the FREQ meter. NOTE: With no load applied to the APU, the FREQ meter should become stable at 400 15 CPS.(3) Apply the load to the APU:

- a) Put an electrical load of 100 amps on the APU electrical generator.- (b) Set these switches on the P5 forward overhead panel:

1) Set the ISOLATION VALVE switch to the OPEN position.2) Make sure the engines 1 and /or 2 BLEED switches on the P5 forward overhead panel are in the OFF position.3) Set the APU BLEED switch to the ON position.4) Set the switches for the cabin temperature controls to the AUTO position.

- (c) Set the L PACK and R PACK switches to AUTO.- (d) Let the EGT become stable in 1 to 2 minutes.- (e) Set the L PACK and R PACK switches to HIGH.- (f) Let the EGT become stable in 1 to 2 minutes.

(4) Look at the FREQ meter:NOTE: With the APU fully loaded, the FREQ meter must become stable bet ween 397-417 CPS.(5) Remove the load from the APU:

- a) Set the L PACK and R PACK switches to OFF.- (b) Set these switches on the P5 forward overhead panel:

1) Set the switches for the cabin temperature controls to the OFF position.2) Set the APU BLEED switch to the OFF position.3) Set the ISOLATION VALVE switch to the CLOSE position.4) Remove the electrical load from the APU electrical generator.

- (c) Let the APU operate in the no load condition for a minimum of1 minute.

(6) Make sure the MAINT light for the APU did not come on.(7) Do the APU usual shutdown (AMM 49-11-00/201).

Page 101


Boeing 737 Classic ENGINEERING CONTINUATION TRAININGcbt.altitudeglobal.aero/Files/A8 Boeing737 Cl 34...

Documents

Transcript of Boeing 737 Classic ENGINEERING CONTINUATION TRAININGcbt.altitudeglobal.aero/Files/A8 Boeing737 Cl 34...