- Effective
- July 25, 1974
- Models
- JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-1A, JT3D-1A-MC6, JT3D-1A-MC7 and 6 more
- Registered aircraft
- 5 matched by model
- Product
- Engine
- Amendment
- 39-1898
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
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|---|---|---|---|
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On this page
The airworthiness directive
74-15-05 PRATT & WHITNEY: Amendment 39-1898. Applies to all Pratt & Whitney Aircraft JT3D turbofan engines containing 14th stage compressor disc, P/N 657814.
Compliance required as indicated.
To ensure adequate life limit margin for 14th stage compressor discs, P/N 657814, the cyclic life limits on these discs have been reduced below the figures currently approved. Unless already accomplished, remove from service 14th stage compressor discs prior to exceeding the revised life limit listed below or within the next 25 cycles in service after the effective date of this airworthiness directive whichever comes later.
Engine Model Previous Life Limit (Cycles) Revised Life Limit (Cycles) JT3D-1 19,000 10,000 JT3D-3B 15,000 8,000 JT3D-7 15,000 8,000
If a disc has been used in more than one engine model, the disc is limited to the lowest cycle life permitted for the engine models in which it has been exposed.
This amendment becomes effective July25, 1974.
Affected TCDS · 2
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 5
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1968 | 2 |
|---|---|
| 1972 | 1 |
| 1974 | 1 |
| 1977 | 1 |