821 Air Conditioning (ATA 21) service difficulty reports for the Boeing 727 — 1.5% of all reported difficulties.
Most reported components
- CONTROLLER 104
- VALVE 64
- FAN 48
- OUTFLOW VALVE 38
- DUCT 34
- UNKNOWN 29
- GASPER FAN 25
- AIR DISTR 22
- COALESCER BAG 22
- PACK 20
- AIR DISTRIBUTION 20
- ACM 19
- CONTROL VALVE 18
- SHUTOFF VALVE 15
- ODOR 15
Report counts reflect fleet size and reporting activity, not relative safety or reliability. Source: FAA Service Difficulty Reporting System (public domain).