# AD 59-12-09: Control Wheel Sprocket Stud

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-24 and PA-24-250
- Effective: June 30, 1959
- Published: June 30, 1959
- Issued: June 24, 1959
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 1,567 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6ECF2C358BB6F1CA8625698B00765684.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/59-12-09

## The airworthiness directive

59-12-09 PIPER: Applies to PA-24 and PA-24 "250" Aircraft Serial Numbers 24-1 Through 24-764, 24-766 Through 24-779, 24-781 Through 24-820, 24-822 Through 24-842, 24- 844 Through 24-849, 24-851 Through 24-856, 24-858, 24-860 Through 24-865, 24-867 Through 24-871, 24-875, 24-878, 24-880, 24-881, and 24-885.

Compliance required not later than July 30, 1959.

Due to a recent inflight incident where control wheel sprocket stud P/N 20913-00 failed, inspect the sprocket stud P/N 20913-00 where the sprocket was attached on all aircraft that have or have had an automatic control system installed and ascertain that the stud is not cracked or twisted and the hole is not elongated. Parts found cracked or damaged are to be replaced before further operation.

(Piper Service Bulletin No. 172 covers this inspection in detail.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1A15](https://openairdocs.org/tcds/1A15): Piper Aircraft Inc.; names 2 of 4 models: PA-24, PA-24-250

## 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: 1,567 (1,567 by airframe model, 0 by engine model)
- Makers: Piper 1,567

Models with the most aircraft:

- [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250): 1,222 aircraft (airframe model)
- [Piper PA-24](https://openairdocs.org/model/piper-pa-24): 345 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/59-12-09/models.md
Every aircraft: https://openairdocs.org/ad/59-12-09/aircraft.md

Its text cites no advisory circulars or STCs.

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