AD 2009-07-12
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | General Electric | Company CF34-1A | Airworthiness Directives; General Electric Company CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 Turbofan Engines |
Unsafe Condition
Interference between the rotating and stationary portions of the 4-step air balance piston seal can develop under certain high-power, high-altitude engine shutdown events, potentially leading to excessive friction and inability to restart the engines after flameout.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove the 4-step air balance piston stationary seals and incorporate an 8-step seal at the next piece-part exposure, which occurs when the 4-step seal is removed from the engine or when the combustion liner is removed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
At the next piece-part exposure (when the 4-step seal is removed or the combustion liner is removed).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
General Electric Company CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines with high-pressure (HP) rotor 4-step air balance piston stationary seals, part numbers 4923T54G01, 6019T90G03, 6037T99G01, 6037T99G02, and 6037T99G03, installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.