AD 2001-05-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney | PW4000 Series | Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines |
Unsafe Condition
Fatigue cracking of the low pressure turbine (LPT) 4th stage air seal, resulting in seal fracture, uncontained engine failure, and damage to the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the current design LPT 4th stage air seal with a new design seal or a modified seal, as specified in the AD. Refer to Table 2 for acceptable replacement part numbers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the time specified in the AD, unless already completed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney PW4052, PW4056, PW4060, PW4060A, PW4062, PW4152, PW4156, PW4156A, PW4158, PW4164, PW4168, PW4168A, PW4460, and PW4462 turbofan engines with LPT 4th stage air seal part number 50N478 or 50N478-001 installed. These engines are installed on but not limited to Boeing 747, 767, McDonnell Douglas MD-11, Airbus Industrie A300, A310, and A330 series airplanes.
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
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