# AD 79-25-04: Models Incorporating Rosemount Servos

- Type: Airworthiness directive
- Status: Current
- Products: M7 Aerospace SA226-AT, SA226-T and SA226-TC
- Effective: December 10, 1979
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-3620
- Registered aircraft: 54 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/031497A918AE81D58625698400723C78.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/79-25-04

## The airworthiness directive

79-25-04 SWEARINGEN : Amendment 39-3620. Applies to Models SA226-T, SA226-AT, and SA226-TC airplanes, certificated in all categories, that incorporate Rosemount SAS Servo P/N 9-50D1001.

Compliance is required within the next 10 hours time in service unless already accomplished. (NOTE: The compliance time given here is, in some instances, different from SB A27-024.)

To prevent the possible jamming of the elevator, accomplish the following:

Remove, disassemble, inspect, modify if necessary, and reidentify servos in accordance with the accomplishment instructions in Swearingen Aviation Corporation Service Bulletin SB A27-024 dated November 13, 1979. All Rosemount P/N 9-50D1001 servos not presently installed must also be disassembled, inspected, modified if necessary, and reidentified prior to installation.

Aircraft may be flown in accordance with FAR 21.197 to a base where this AD can be accomplished.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Swearingen Aviation Corporation, P.O. Box 32486, San Antonio, Texas 76284. These documents may also be examined at Office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas 76101, and at FAA Headquarters, 800 Independence Avenue S.W., Washington, D.C. 20591.

This amendment becomes effective December 10, 1979.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A5SW](https://openairdocs.org/tcds/A5SW): Ontic Engineering and Manufacturing Inc.; names 2 of 7 models: SA226-AT, SA226-T(B)
- [TCDS A8SW](https://openairdocs.org/tcds/A8SW): Ontic Engineering and Manufacturing Inc.; names 1 of 4 models: SA226-TC

## 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: 54 (54 by airframe model, 0 by engine model)
- Makers: Swearingen 48, Fairchild 6

Models with the most aircraft:

- [Swearingen SA-226T](https://openairdocs.org/model/swearingen-sa-226t): 21 aircraft (airframe model)
- [Swearingen SA226-T(B)](https://openairdocs.org/model/swearingen-sa226-t-b): 16 aircraft (airframe model)
- [Swearingen SA226TC](https://openairdocs.org/model/swearingen-sa226tc): 8 aircraft (airframe model)
- [Fairchild SA226-T(B)](https://openairdocs.org/model/fairchild-sa226-t-b): 3 aircraft (airframe model)
- [Swearingen SA-226AT](https://openairdocs.org/model/swearingen-sa-226at): 3 aircraft (airframe model)
- [Fairchild SA226-TC](https://openairdocs.org/model/fairchild-sa226-tc): 1 aircraft (airframe model)
- [Fairchild SA226-T](https://openairdocs.org/model/fairchild-sa226-t): 1 aircraft (airframe model)
- [Fairchild SA226-AT](https://openairdocs.org/model/fairchild-sa226-at): 1 aircraft (airframe model)

All 8 models: https://openairdocs.org/ad/79-25-04/models.md
Every aircraft: https://openairdocs.org/ad/79-25-04/aircraft.md

Its text cites no advisory circulars or STCs.

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