- Effective
- February 27, 1981
- Published
- February 26, 1981
- Issued
- February 13, 1981
- Models
- PA-31T, PA-31T1
- Data sheet
- TCDSA8EA
- Registered aircraft
- 151 matched by model
- Product
- Aircraft · Small airplane
- Amendment
- 39-4051
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 | f91c4209…88815b1 | FAA DRS (API key needed) |
On this page
The airworthiness directive
81-01-01 PIPER: Amendment 39-4051. Applies to Piper PA-31T S/N 8120008, 8120009, 8120010, and 8120013, and Piper PA-31T1 airplanes S/N 8104007, 8104008, 8104009, 8104010, 8104011, 8104012, and 8104013. Compliance required as indicated, unless already accomplished.
To prevent loss of the propeller and intake lip deicing functions, comply as follows:
Prior to further flight in known icing conditions, inspect for proper propeller and intake lip deice power relay in accordance with Piper telegraphic form letter #31-28, dated December 22, 1980, or equivalent, approved by Chief, Engineering and Manufacturing Branch. If (P/N 484247) relay is installed, check to insure that correct D.C. relay PRD7DYD (24 VDC) is installed. If the latter relay is not installed, remove and install proper relay prior to further flight in known icing conditions.
This amendment is effective February 27, 1981, and was effective upon receipt by all recipients of the letter dated December 24, 1980.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 151
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1974 | 2 |
|---|---|
| 1975 | 2 |
| 1976 | 6 |
| 1977 | 10 |
| 1978 | 24 |
| 1979 | 23 |
| 1980 | 20 |
| 1981 | 17 |
| 1982 | 4 |
| 1983 | 1 |
| 1984 | 5 |
37 with no year recorded