# AD 75-12-06: Fin Forward Spar

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-24, PA-24-250, PA-24-260 and PA-24-400
- Effective: June 5, 1975
- Published: June 2, 1975
- Issued: May 22, 1975
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2227
- Registered aircraft: 2,232 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E32713649825EEAD8625699900514744.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/75-12-06

## The airworthiness directive

75-12-06 PIPER: Amendment 39-2227. Applies to Piper Models PA-24, PA-24-250, PA-24-260 and PA-24-400 certificated in all categories.

Compliance required as indicated.

1. Affects the fin forward spar to fuselage attachment assembly where the channel P/N 20749-0 and the straps P/N 20749-5 and -6 are riveted together.

  (a) Within the next 25 hours' time in service, unless already accomplished within the last 75 hours' time in service:

    (i) Inspect the channel P/N 20749-0 and the two straps P/N 20749-5 and -6 in the area of the channel bend relief holes for cracks using a dye penetrant method or an approved equivalent inspection.

    (ii) Polish the rough edges of the bend relief holes.

  (b) Within 100 hours' time in service after the inspection specified in "a" above, visually inspect the channel and straps in the area of the channel relief holes for cracks using a magnifying glass of at least 5 power or an approved equivalent inspection.

  (c) The inspection specified in "b" above shall be repeated at intervals not to exceed 100 hours' time in service from the last inspection.

2. Repair cracked parts with an FAA approved repair or replace parts with an unused part of the same number or an approved equivalent part prior to further flight.

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 inspection interval specified in this AD. Equivalent inspections and parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

This amendment is effective June 5, 1975.

## 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 4 of 4 models: PA-24, PA-24-260, PA-24-250, PA-24-400

## 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: 2,232 (2,232 by airframe model, 0 by engine model)
- Makers: Piper 2,232

Models with the most aircraft:

- [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250): 1,222 aircraft (airframe model)
- [Piper PA-24-260](https://openairdocs.org/model/piper-pa-24-260): 590 aircraft (airframe model)
- [Piper PA-24](https://openairdocs.org/model/piper-pa-24): 345 aircraft (airframe model)
- [Piper PA-24-400](https://openairdocs.org/model/piper-pa-24-400): 75 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/75-12-06/models.md
Every aircraft: https://openairdocs.org/ad/75-12-06/aircraft.md

Its text cites no advisory circulars or STCs.

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