1,927 Auxiliary Power Unit (APU) (ATA 49) service difficulty reports for the Boeing 737 (all variants) — 0.7% of all reported difficulties.
Most reported components
- APU 307
- UNKNOWN 182
- SENSOR 116
- WARNING LIGHT 106
- EXCITER 79
- FILTER 63
- OIL SYSTEM 56
- CONVERTER 55
- WARNING SYSTEM 48
- ECU 47
- STARTER GEN 47
- FUEL CONTROL 43
- FILTER ELEMENT 40
- OIL COOLER 39
- MODULE 37
Report counts reflect fleet size and reporting activity, not relative safety or reliability. Source: FAA Service Difficulty Reporting System (public domain).