AD 2001-20-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney | PW4000 Series | Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines |
Unsafe Condition
Cracking in the rim area of the 2nd stage high pressure turbine (HPT) air seal assembly, which could lead to seal assembly fracture and result in an uncontained engine failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Recalculate 2nd stage HPT air seal assembly cycles-in-service based on flight hour-to-cycle ratio usage. Perform initial and repetitive on-wing borescope inspections for cracks in the 2nd stage HPT air seal assemblies based on the newly calculated service life. Remove from service any cracked seal assemblies and seal assemblies at or before newly calculated service life limits.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 30 days of the effective date of the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney PW4000 series turbofan engines with 2nd stage HPT air seal assembly part number (P/N) 50L976 or P/N 50L960 installed, including models PW4074, PW4077, PW4077D, PW4084, PW4084D, PW4090, PW4090-3, PW4074D, PW4090D, PW4098.
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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