65 Auxiliary Power Unit (APU) (ATA 49) service difficulty reports for the Boeing 747 — 0.2% of all reported difficulties.
Most reported components
- APU 20
- STARTER 4
- UNKNOWN 4
- CONTROLLER 3
- LINE 3
- ISOLATION VALVE 2
- O-RING 2
- CHARGER 2
- OIL SYSTEM 2
- WIRE 2
- STIFFENER 2
- FRAME 2
- DUCT 1
- BATTERY 1
- ENGINE 1
Report counts reflect fleet size and reporting activity, not relative safety or reliability. Source: FAA Service Difficulty Reporting System (public domain).