# AD 80-26-05: Main Landing Gear Door Hinges

- Type: Airworthiness directive
- Status: Historical
- Products: Piper Aircraft, Inc., The New PA-31, PA-31-300, PA-31-325, PA-31-350, PA-31P, PA-31T and PA-31T1
- Effective: December 19, 1980
- Superseded by: [AD 2000-25-01](https://openairdocs.org/ad/2000-25-01)
- Product type: Aircraft, Small airplane
- Amendment: 39-3994
- Registered aircraft: 756 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3486DE022662075C862569A6005CD96E.0001
- DRS record last changed: August 7, 2025
- Page: https://openairdocs.org/ad/80-26-05

## The airworthiness directive

80-26-05 PIPER: Amendment 39-3994. Applies to Piper Models PA-31, PA-31-300, PA-31-325, Serial Nos. 31-2 thru 31-8012077; PA-31-350, Serial Nos. 31-5001 thru 31- 8052168; PA-31P, Serial Nos. 31P3 thru 31P-7730012; PA-31T1, Serial Nos. 31T-7804001 thru 31T-8004040; and PA-31T, Serial Nos. 31T-7400002 thru 31T-8020076 certificated in all categories.

To prevent hazards associated with failed landing gear door attachments interfering with landing gear operation, accomplish the following:

a. Within the next 100 hours in service from the effective date of this AD and thereafter at intervals not to exceed 100 hours in service from the last inspection, inspect the main landing gear inboard door hinges and hinge attachment angles in accordance with the "Instructions" section of Piper Service Bulletin No. 682 dated July 24, 1980, or equivalent.

b. If cracks are observed, repair in accordance with the "Instructions" section of Piper Service Bulletin No. 682 dated July 24, 1980, or equivalent, prior to further flight, except the aircraft may be flown in accordance with FAR 21.197 to a base where a repair can be made.

c. Upon the incorporation of, or the determination that the door hinges are P/N 47529-32, or are an equivalent part, the repetitive inspection of the hinges may be discontinued. Hinges manufactured by Piper from .250 sheet steel have been found to be equivalent to P/N 47529-32.

d. Upon the incorporation of, or the determination that the hinge attachment angles are P/N 42048-02, -03 or are an equivalent part, the repetitive inspection of the angles may be discontinued. Four inch long angles manufactured by Piper have been found to be equivalent to P/N 42048-02, -03.

e. Equivalent inspections, repairs and parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

f. Upon the 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 the AD.

This amendment is effective December 19, 1980.

## 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 3 of 6 models: PA-31T, PA-31T1, 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: 756 (756 by airframe model, 0 by engine model)
- Makers: Piper 756

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-31T1](https://openairdocs.org/model/piper-pa-31t1): 64 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 7 models: https://openairdocs.org/ad/80-26-05/models.md
Every aircraft: https://openairdocs.org/ad/80-26-05/aircraft.md

## Related documents

- [AD 2000-25-01](https://openairdocs.org/ad/2000-25-01): Main Landing Gear Door Hinges · Piper PA-31, PA-31-300, PA-31-325 and 7 more. Effective Jan 19, 2001. Supersedes this AD

Its text cites no advisory circulars or STCs.

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