# AD 77-18-05: Variable Authority Steering System

- Type: Airworthiness directive
- Status: Current
- Products: M7 Aerospace SA226-AT, SA226-T and SA226-TC
- Effective: September 12, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-3030
- Registered aircraft: 54 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3FA7E86E8D3497F78625698400723B30.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-18-05

## The airworthiness directive

77-18-05 SWEARINGEN : Amendment 39-3030. Applies to all Model SA226T, -AT, and -TC airplanes incorporating a variable authority nose wheel steering system which utilizes a Talley P/N 1399T100-5 or -7 actuator.

Compliance required within the next 25 hours' time in service after the effective date of this AD, unless already accomplished.

To assure the variable authority nose gear steering system will not jeopardize the safe operation of a Model SA226T, -AT, or -TC airplane, it should be disabled in accordance with Swearingen Aviation Corporation Service Bulletin SB 32-012, dated June 20, 1977, or later FAA approved revision, or an equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, Southwest Region, Federal Aviation Administration, Fort Worth, Texas.

The manufacturer's instructions 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 the referenced document from the manufacturer may obtain copies upon request to Swearingen Aviation Corporation, P. O. Box 32486, San Antonio, Texas 78284. The document may also be examined at the Office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD, which includes the incorporated material in full, is maintained by the FAA at its headquarters in Washington, D.C., and at the Southwest Regional Office in Fort Worth, Texas.

This amendment becomes effective September 12, 1977.

## 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/77-18-05/models.md
Every aircraft: https://openairdocs.org/ad/77-18-05/aircraft.md

Its text cites no advisory circulars or STCs.

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