# AD 77-21-06: Fuselage Steel Tubing Cluster

- Type: Airworthiness directive
- Status: Current
- Products: Lavia Argentina PA-25, PA-25-235 and PA-25-260
- Effective: October 19, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-3058
- Registered aircraft: 454 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7F290B9EA94C80388625699D004F63FB.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-21-06

## The airworthiness directive

77-21-06 PIPER: Amendment 39-3058. Applies to Models PA-25, PA-25-235 and PA-25-260, Serial Nos. 25-1 and up, certificated in all categories.

To prevent weakening of the fuselage steel tubing cluster in the area of the rear wing spar attachment due to corrosion of the fuselage tubing, accomplish the following:

  (a) Within the next 30 days in service after the effective date of this AD or upon the attainment of a total of 1 year in service, whichever occurs later, unless previously accomplished within the last year and at intervals not to exceed 1 year from the last inspection, inspect the fuselage steel tubing cluster in the area of the rear wing spar attachment and repair if necessary, in accordance with the "Instructions" section of Piper Service Bulletin No. 551 dated April 22, 1977, or equivalent. The aircraft may be flown in accordance with FAR 21.197 to a base where inspection and repair can be made.

  (b) Equivalent inspections and repairs must be approved bythe Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

  (c) 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 intervals specified in this AD.

This amendment is effective October 19, 1977.

## 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: 454 (454 by airframe model, 0 by engine model)
- Makers: Piper 453, Lavia Argentina 1

Models with the most aircraft:

- [Piper PA-25-235](https://openairdocs.org/model/piper-pa-25-235): 347 aircraft (airframe model)
- [Piper PA-25](https://openairdocs.org/model/piper-pa-25): 59 aircraft (airframe model)
- [Piper PA-25-260](https://openairdocs.org/model/piper-pa-25-260): 47 aircraft (airframe model)
- [Lavia Argentina PA-25-260](https://openairdocs.org/model/lavia-argentina-pa-25-260): 1 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/77-21-06/models.md
Every aircraft: https://openairdocs.org/ad/77-21-06/aircraft.md

Its text cites no advisory circulars or STCs.

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