What this system is
ATA 49 covers the airborne auxiliary power unit and its installation, control, starting, fuel, oil, air and electrical interfaces.
AIRCRAFT SYSTEM LEARNING
ATA 49 — Airborne Auxiliary Power
ATA 49 covers the airborne auxiliary power unit and its installation, control, starting, fuel, oil, air and electrical interfaces.
LEARNStart with system fundamentalsUse guided learning paths and beginner-friendly explanations.
SOLVEReview troubleshooting casesFind reported symptoms, findings, causes and verified outcomes.
ASKAsk a technical questionUse the community when indexed knowledge does not answer the problem.
UNDERSTANDLook up technical termsMove from unfamiliar terminology into connected learning.
ATA 49
Airborne Auxiliary Power
APU operation, control, fuel, starting and indication.
78%Developing profileNeeds refresh
START LEARNINGStart with the system purpose and major component groups, then use the linked glossary, resources and videos before moving into aircraft-specific detail.
TROUBLESHOOT THIS SYSTEMDefine the reported symptom, confirm aircraft and configuration applicability, then follow current approved fault-isolation and maintenance data.
Why it exists
Provide auxiliary electrical and pneumatic power, commonly for ground operation and sometimes for selected flight conditions.
What belongs here
- APU engine and gearbox
- Air inlet and exhaust
- Starting system
- Fuel and control system
- Oil system
- Bleed-air load control
- Generator
- Fire detection and extinguishing
- Electronic control unit
What users may see
APU speed, exhaust-gas temperature, oil status, generator load, bleed status, start sequence, fire warning and fault messages may be displayed.
What technicians commonly evaluate
Start sequence, inlet and exhaust condition, oil and fuel leaks, hot-section condition, generator and bleed loading, fire protection, control-unit faults and cooldown requirements are common concerns.
AIRCRAFT APPLICABILITY
General ATA knowledge
General ATA knowledge is separated from aircraft-family and exact-variant information.
Choose an aircraft family to narrow resources, cases, questions and indexed applicability.
Choose aircraftCONNECTED KNOWLEDGE
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Content is filtered by the selected ATA chapter and, where indexed, the aircraft and exact variant.
Technical resources
Browse all →SYSTEM_GUIDEA350 APU Indicating and Crew Interface
Controls, speed/EGT, flap, availability, generator/bleed, oil/fuel and fault messages.
Aircraft familySYSTEM_GUIDEA350 APU Emergency and Protective ShutdownNormal cooldown, ECB protection, cockpit/external stop and automatic ground fire shutdown.
Aircraft familySYSTEM_GUIDEA350 APU Drain System and Leak InterpretationDrain groups, masts, fluid identification, blockage and diagnostic use.
Aircraft familySYSTEM_GUIDEA350 APU Exhaust Muffler and Thermal IsolationBellows, muffler, acoustic liner, supports, clamps, blankets and drain.
Aircraft familySYSTEM_GUIDEA350 APU Fire Seals and Intake Fire BlanketFirewalls, seals, doors and hidden containment degradation.
Aircraft familySYSTEM_GUIDEA350 ATA 49 Maintenance and Troubleshooting WorkshopIntegrated no-start, hot-start, no-output, oil, leak, flap, vibration and shutdown scenarios with evidence-based fault isolation.
Aircraft familySYSTEM_GUIDEA350 APU Operating Sequences and Load ManagementMaster-on preparation, start, acceleration, availability, generator/bleed loading, cooldown, autostart and phase-based diagnosis.
Aircraft familySYSTEM_GUIDEA350 APU Oil System - Supply, Scavenge and CoolingTank, pressure/scavenge pumps, filters, bypasses, bearings, starter-generator, separator, cooler, sensors and debris.
Aircraft familyTraining videos
Browse all →ADVANCED VIDEOATA 49 How to replace Starter on A320 APU
How APU STARTER on A320 works? APU to 55% of the APU's usual speed. You can operate the starting system from the APU panel in the cockpit. The Elect…
Zeto.r · 4:42MIXED VIDEOAirbus, A350, APU start close up. Afterburner?After some request I was finally able to make an A350 APU start up without wind noise. Enjoy. #aviation #aircraft #cockpitview #a350 #a350xwb #air…
Dennis Vijverberg, Brakes Released · 7:10SOURCE & REVIEW BOUNDARY
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