# AD 76-04-11: Loose Bolts

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-31, PA-31-300, PA-31-325, PA-31-350, PA-31P and PA-31T
- Effective: March 5, 1976
- Published: March 4, 1976
- Issued: February 20, 1976
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2532
- Registered aircraft: 692 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FE71A60A15ACDC858625699E004A8C28.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/76-04-11

## The airworthiness directive

76-04-11 PIPER: Amendment 39-2532. Applies to Models PA-31, PA-31-300, and PA- 31-325, Serial Numbers 31-2 through 31-7612009; Model PA-31-350, Serial Numbers 31-5001 through 31-7612018; Model PA-31P, Serial Numbers 31P-1 through 31P-7630001 and 31P-7630003; Model PA-31T, Serial Numbers 31T-7400002 through 31T-7620002, 31T-7620004, 31T-7620005 and 31T-7620007, certificated in all categories.

To prevent possible hazards in flight associated with loose bolts which attach the control shaft collar to the control shaft tube, accomplish the following within the next fifty hours in service from the effective date of this AD unless previously accomplished.

  (a) Alter the attachment of the control shaft collar to the control shaft tube in accordance with Piper Service Letter No. 643 and the directions contained in paragraphs one through eight of the "Instructions" section of Piper Service Bulletin No. 487 or approved equivalent alteration.

Equivalent alterations must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

This amendment is effective March 5, 1976.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A20SO](https://openairdocs.org/tcds/A20SO): Piper Aircraft Inc.; names 4 of 4 models: PA-31, PA-31-325, PA-31-300, PA-31-350
- [TCDS A8EA](https://openairdocs.org/tcds/A8EA): Piper Aircraft Inc.; names 2 of 6 models: PA-31T, 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: 692 (692 by airframe model, 0 by engine model)
- Makers: Piper 692

Models with the most aircraft:

- [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350): 399 aircraft (airframe model)
- [Piper PA-31-325](https://openairdocs.org/model/piper-pa-31-325): 137 aircraft (airframe model)
- [Piper PA-31T](https://openairdocs.org/model/piper-pa-31t): 87 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-31-300](https://openairdocs.org/model/piper-pa-31-300): 3 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/76-04-11/models.md
Every aircraft: https://openairdocs.org/ad/76-04-11/aircraft.md

Its text cites no advisory circulars or STCs.

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