- Effective
- October 12, 1971
- Published
- October 19, 1971
- Issued
- September 24, 1971
- Model
- PA-23-250 (Navy UO-1)
- Data sheet
- TCDS1A10
- Registered aircraft
- 899 matched by model
- Product
- Aircraft · Small airplane
- Amendment
- 39-1309
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 November 21, 2025.
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 | 21 KB | 1ea44108…2c5c8b5 | FAA DRS (API key needed) |
On this page
The airworthiness directive
71-21-06 PIPER: Amendment 39-1309. Applies to Turbocharged Type PA 23-250 airplanes Serial Numbers 27-4053, 27-4226 through 27-4563 inclusive, 27-4565 through 27-4579 inclusive, 27-4581 through 27-4617 inclusive, 27-4619 through 27-4627 inclusive, 27-4630 through 27-4636 inclusive.
Compliance required within the next 50 hours' time in service after the effective date of this airworthiness directive unless already accomplished.
To preclude the possibility of fire passing through the engine firewall, in the event of a powerplant fire, replace the existing alternate air flexible duct, P/N 22502-65, with new alternate air duct P/N 48076-02 (fireproof), in accordance with Piper Service Bulletin Number 334 dated 17 March 1971, or later approved revision, or replace with an equivalent alternate air duct approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
Upon request with substantiating data submitted through an FAA maintenance inspector, thecompliance time specified in this AD may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
This amendment is effective October 12, 1971.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 899
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1953 | 1 |
|---|---|
| 1960 | 33 |
| 1961 | 13 |
| 1962 | 21 |
| 1963 | 19 |
| 1964 | 25 |
| 1965 | 44 |
| 1966 | 59 |
| 1967 | 31 |
| 1968 | 39 |
| 1969 | 49 |
| 1970 | 19 |
| 1971 | 24 |
| 1972 | 27 |
| 1973 | 44 |
| 1974 | 49 |
| 1975 | 36 |
| 1976 | 52 |
| 1977 | 35 |
| 1978 | 36 |
| 1979 | 46 |
| 1980 | 11 |
| 1981 | 10 |
| 1995 | 1 |
175 with no year recorded