AD 66-05-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT3D-1 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, and JT3D-1-MC7 Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC6 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, and JT3D-1-MC7 Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC7 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, and JT3D-1-MC7 Engines |
Unsafe Condition
Failure of the second stage compressor rotor disc, P/N 421602, due to cracks in the inner portion of the web visible through the number one hub bore.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the second stage compressor rotor disc for cracks using a strong light and a glass of at least three power or an FAA-approved equivalent procedure. Replace cracked discs before further flight. Remove P/N 421602 and 571202 discs before accumulating 16,000 hours' time in service. Install rotor discs P/N 405702, 457802, or 571202 as replacements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Compliance required as indicated in the AD, with specific intervals based on cycles and hours' time in service as detailed in sections (a) through (h).
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Affected Aircraft
Pratt & Whitney Models JT3D-1, JT3D-1-MC6, and JT3D-1-MC7 engines with second stage compressor rotor disc P/N 421602 or 571202.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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