AD 2001-17-30
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney | JT9D-7R4 Series | Airworthiness Directives; Pratt & Whitney JT9D-7R4 Series Turbofan Engines |
Unsafe Condition
Reports of cracks in HPT 1st stage disk firtrees and failure of firtree lugs, which could result in 1st stage HPT disk firtree fracture, leading to an uncontained engine failure and damage to the airplane.
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Required Actions
Inspect the HPT 1st stage disk aft lug fillet radius for cracks using fluorescent penetrant inspection (FPI). Replace the HPT 1st stage disk and HPT 1st stage airseals if cracks are found. For engines with HPT 1st stage disk assembly P/N 787521, replace HPT 1st stage airseals with P/N 820121 at the next disk piece-part opportunity.
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Compliance Time
Within 500 flight hours after the effective date of this AD for initial inspection, and within 4,000 cycles since last inspection (CSLI) for repetitive inspections.
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Affected Aircraft
Pratt & Whitney JT9D-7R4 series turbofan engines installed on, but not limited to, Boeing 747 and 767 series and Airbus A300 and A310 series airplanes.
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Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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