# AD 77-09-10: Electric Trim Switch

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-23-250, PA-23-250 (Navy UO-1), PA-24-260, PA-30, PA-31, PA-31-300, PA-31-350, PA-31P and PA-39
- Effective: May 12, 1977
- Published: May 9, 1977
- Issued: April 28, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2892
- Registered aircraft: 2,917 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/153E79A105E72BB88625699E004A9BD6.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/77-09-10

## The airworthiness directive

77-09-10 PIPER AIRCRAFT CORP: Amendment 39-2892. Applies to models:

PA-23-250 (6 place) S/Nos. 27-3837, 27-3944 to 27-4796 inclusive PA-24-260 S/Nos. 24-4783, 24-4804 to 24-5047 inclusive PA-30 S/Nos. 30-1717, 30-1745 to 30-2000 inclusive PA-31 and 31-300 S/Nos. 31-2 to 31-797 inclusive PA-31-350 S/Nos. 31-5001 to 31-5004 inclusive PA-31P S/Nos. 31P-1 to 31P-109 inclusive PA-39 S/Nos. 39-1 to 39-155 inclusive

Compliance required within the next 100 hours in service after the effective date of this AD, unless already accomplished.

  (a) Modify the electric trim switch in accordance with instruction paragraph of Piper Service Bulletin No. 527, dated November 5, 1976, or equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

  (b) Upon request with substantiating data submitted through an FAA Maintenance Inspector, the compliance time specified in this AD may be adjusted by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

This amendment becomes effective May 12, 1977.

## Affected data sheets (5) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A20SO](https://openairdocs.org/tcds/A20SO): Piper Aircraft Inc.; names 3 of 4 models: PA-31, PA-31-300, PA-31-350
- [TCDS A1EA](https://openairdocs.org/tcds/A1EA): Piper Aircraft Inc.; names 2 of 3 models: PA-30, PA-39
- [TCDS 1A10](https://openairdocs.org/tcds/1A10): Piper Aircraft Inc.; names 1 of 6 models: PA-23-250 (Navy UO-1)
- [TCDS 1A15](https://openairdocs.org/tcds/1A15): Piper Aircraft Inc.; names 1 of 4 models: PA-24-260
- [TCDS A8EA](https://openairdocs.org/tcds/A8EA): Piper Aircraft Inc.; names 1 of 6 models: PA-31P

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 2,917 (2,917 by airframe model, 0 by engine model)
- Makers: Piper 2,917

Models with the most aircraft:

- [Piper PA-23-250](https://openairdocs.org/model/piper-pa-23-250): 894 aircraft (airframe model)
- [Piper PA-30](https://openairdocs.org/model/piper-pa-30): 878 aircraft (airframe model)
- [Piper PA-24-260](https://openairdocs.org/model/piper-pa-24-260): 590 aircraft (airframe model)
- [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350): 399 aircraft (airframe model)
- [Piper PA-39](https://openairdocs.org/model/piper-pa-39): 82 aircraft (airframe model)
- [Piper PA-31P](https://openairdocs.org/model/piper-pa-31p): 40 aircraft (airframe model)
- [Piper PA-31](https://openairdocs.org/model/piper-pa-31): 26 aircraft (airframe model)
- [Piper PA-23-250 (6PCLM)](https://openairdocs.org/model/piper-pa-23-250-6pclm): 5 aircraft (airframe model)
- [Piper PA-31-300](https://openairdocs.org/model/piper-pa-31-300): 3 aircraft (airframe model)

All 9 models: https://openairdocs.org/ad/77-09-10/models.md
Every aircraft: https://openairdocs.org/ad/77-09-10/aircraft.md

Its text cites no advisory circulars or STCs.

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