AD Amdt-39-10652

Recurring final rule
Data completeness: 70%

Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

AD Number
Amdt-39-10652
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. 97-ANE-04
FR Citation
63 FR 37765

Applicability

TypeManufacturerModelDetails
engine Pratt & Whitney JT9D Series Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

Unsafe Condition

Cracking of cooling air holes or tie bolt holes in first and second stage high pressure turbine (HPT) disks could lead to turbine disk failure and uncontained engine failure.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Revise the AD to clarify affected part numbers (P/N) for second stage HPT hub assemblies, increase the repetitive inspection interval for first stage HPT disks, and follow referenced service bulletin procedures for inspections. Inspections include fluorescent penetrant inspections (FPI) for cracks in cooling air holes and tie bolt holes, with replacement of cracked disks.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Before further flight

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Pratt & Whitney JT9D series turbofan engines with specified second stage HPT hub assemblies by part number and certain first stage HPT disks

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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