# AD 81-23-07: Engine Mount Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-38-112
- Effective: November 16, 1981
- Published: November 9, 1981
- Issued: October 29, 1981
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-4252
- Registered aircraft: 442 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F4349DBEBF3649A2862569A6005CE1EC.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/81-23-07

## The airworthiness directive

81-23-07 PIPER: Amendment 39-4252. Applies to Model PA-38-112 Serial Nos. 38-78A0001 thru 38-78A0678 certificated in all categories except aircraft incorporating engine mount assembly Piper Part Number 77651-02.

To prevent possible nose-gear failure associated with weakening of the engine-mount, accomplish the following unless previously accomplished:

a. On aircraft modified in accordance with Piper S/B 617 dated October 12, 1978, or equivalent, with less than 950 hours in service since incorporation of the modification, inspect and replace, if required, the engine mount within the next 50 hours in service after the effective date of this AD, in accordance with Piper S/B 617B dated January 13, 1981, Instructions Paragraph 3 or equivalent. Repeat inspection at intervals not to exceed 50 hours until 1000 hours in service from modification or until replacement of the engine mount with engine mount assembly Piper Part Number 77651-02. Replacement engine mount P/N 77651-02must be installed prior to the accumulation of 1000 hours in service on modified engine mount.

b. On aircraft modified in accordance with Piper S/B 617 dated October 12, 1978, or equivalent, with 950 or more hours in service since the modification, within the next 50 hours in service after the effective date of this AD, replace the engine mount with engine mount assembly Piper Part No. 77651-02.

c. On aircraft which have not been modified in accordance with Piper S/B 617, dated October 12, 1978, within the next 50 hours in service after the effective date of this AD, replace the engine mount with engine mount assembly Piper Part No. 77651-02.

d. Alternative inspections and alterations which provide an equivalent level of safety may be used when approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

e. Upon submission of substantiating data through an FAA Maintenance Inspector, the compliance times specified in this AD may be adjusted by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

This amendment supersedes AD 79-01-07.

This amendment is effective November 16, 1981.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A18SO](https://openairdocs.org/tcds/A18SO): Piper Aircraft Inc.; names 1 of 1 models: PA-38-112

## 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: 442 (442 by airframe model, 0 by engine model)
- Makers: Piper 442

Models with the most aircraft:

- [Piper PA-38-112](https://openairdocs.org/model/piper-pa-38-112): 442 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/81-23-07/models.md
Every aircraft: https://openairdocs.org/ad/81-23-07/aircraft.md

Its text cites no advisory circulars or STCs.

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