- Effective
- December 29, 1970
- Models
- JT8D-1, JT8D-11, JT8D-15, JT8D-15A, JT8D-17, JT8D-17A and 15 more
- Registered aircraft
- 150 matched by model
- Product
- Engine
- Amendment
- 39-1131
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.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 20 KB | 4f5a408b…da41ece | FAA DRS (API key needed) |
On this page
The airworthiness directive
70-26-05 PRATT & WHITNEY AIRCRAFT: Amdt. 39-1131. Applies to all model JT8D series turbofan engines.
Compliance required as indicated.
To prevent failure of the first stage compressor rotor blades as the result of improperly machined blade roots, accomplish the following:
(a) Within the next 900 hours in service after the effective date of this AD, unless already accomplished, visually inspect all P/N 487801, 511901 change letter L or earlier, 594601 and 616601 change letter B or earlier first stage compressor rotor blades, for tool marks within the radius of the Z plane platform on both sides of the blade root area. If tool marks are observed, replace the blade.
(b) Upon submission of substantiating data through an FAA Maintenance Inspector by an owner or operator to the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, compliance time may be adjusted.
(Pratt & Whitney letter PSE:HHB:0-4-6-1-33 dated April 6, 1970, pertains to this subject.)
This amendment is effective December 29, 1970.
Affected TCDS · 2
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 150
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1963 | 1 |
|---|---|
| 1966 | 1 |
| 1967 | 4 |
| 1969 | 3 |
| 1970 | 1 |
| 1972 | 1 |
| 1974 | 1 |
| 1975 | 3 |
| 1976 | 3 |
| 1977 | 1 |
| 1978 | 2 |
| 1979 | 3 |
| 1981 | 4 |
| 1982 | 3 |
| 1983 | 1 |
| 1984 | 3 |
| 1986 | 2 |
| 1987 | 5 |
| 1988 | 5 |
| 1989 | 4 |
| 1990 | 6 |
| 1991 | 31 |
| 1992 | 7 |
| 1993 | 2 |
| 1994 | 1 |
| 1996 | 3 |
| 1997 | 7 |
| 1998 | 6 |
| 1999 | 16 |
20 with no year recorded