277 Hydraulic Power (ATA 29) service difficulty reports for the Boeing 777 (all variants) — 1.1% of all reported difficulties.
Most reported components
- PUMP 51
- LINE 39
- HYDRAULIC LINE 22
- HOSE 21
- HYDRAULIC SYSTEM 13
- SHUTOFF VALVE 10
- CIRCUIT CARD 9
- UNKNOWN 8
- CONNECTOR 7
- CONTROL UNIT 6
- TRANSDUCER 6
- MODULE 5
- B-NUT 5
- O-RING 5
- WARNING SYSTEM 4
Report counts reflect fleet size and reporting activity, not relative safety or reliability. Source: FAA Service Difficulty Reporting System (public domain).