- Effective
- December 26, 1974
- Published
- December 18, 1974
- Issued
- December 11, 1974
- Models
- PA-31, PA-31-300, PA-31-350, PA-31P
- Registered aircraft
- 468 matched by model
- Product
- Aircraft · Small airplane
- Amendment
- 39-2053
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 | 20 KB | 2b494f14…7477985 | FAA DRS (API key needed) |
On this page
The airworthiness directive
74-26-10 PIPER AIRCRAFT: Amendment 39-2053. Applies to Magneto Switch Guard Installation on Piper PA-31 and PA-31-300 S/N 31-2 to 31-7300969 incl; PA-31-350 S/N 31- 5001 to 31-7305091 incl; and PA-31P S/N 31P-1 to 31P-7300161 incl.
To prevent inadvertently or accidentally shutting down an engine, perform the following:
1. Within the next 100 hours time in service, after the effective date of this Airworthiness Directive, install a protective guard over the magneto switches in accordance with Piper Service Letter No. 675, dated September 17, 1973.
2. Equivalent installations must be approved by the Chief, Engineering and Manufacturing Branch, Eastern Region, Jamaica, New York.
3. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time specified in this A.D.
This amendment is effective December 26, 1974.
Affected TCDS · 2
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 468
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1968 | 6 |
|---|---|
| 1969 | 1 |
| 1970 | 6 |
| 1971 | 2 |
| 1972 | 2 |
| 1973 | 24 |
| 1974 | 22 |
| 1975 | 20 |
| 1976 | 24 |
| 1977 | 29 |
| 1978 | 30 |
| 1979 | 44 |
| 1980 | 53 |
| 1981 | 53 |
| 1982 | 16 |
| 1983 | 12 |
| 1984 | 11 |
| 1996 | 1 |
112 with no year recorded