9,136 Lights (ATA 33) service difficulty reports for the Boeing 747 — 33.8% of all reported difficulties.
Most reported components
- LIGHT 3,455
- LAMP 1,767
- CONNECTOR 926
- BATTERY PACK 635
- BATTERY 406
- WIRE 393
- POWER SUPPLY 360
- FEEDER CABLE 249
- FUSE 210
- BULB 98
- CHARGER 81
- CABLE 75
- SIGN 56
- LENS 43
- WIRE HARNESS 41
Report counts reflect fleet size and reporting activity, not relative safety or reliability. Source: FAA Service Difficulty Reporting System (public domain).