AD 2000-25-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney | PW4000 Series | Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines. |
Unsafe Condition
Cracks in the low pressure turbine (LPT) 4th stage air seals due to excessive axial loads, leading to 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, part number 50N478 or 50N478-001, with a new design seal, part number 51N038, or modify the current seal to increase service life. Compliance must be completed before exceeding specified cycles-since-new (CSN) or cycles-in-service (CIS) limits based on engine model.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before exceeding the cycles-since-new (CSN) or cycles-in-service (CIS) limits specified in Table 1 of the AD.
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 low pressure turbine (LPT) 4th stage air seal, part number 50N478 or 50N478-001 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
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