# AD 70-04-05: Automatic Feathering System

- Type: Airworthiness directive
- Status: Current
- Products: Vickers-Armstrongs Viscount 744 and Viscount 745D
- Effective: March 21, 1970
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-942
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/190F1277D7074A63862569A40058F6D5.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/70-04-05

## The airworthiness directive

70-04-05 BRITISH AIRCRAFT CORPORATION: Amendment 39-942. Applies to BAC Viscount Model 744 and 745D airplanes.

Compliance is required within the next 450 hours' time in service after the effective date of this AD, unless already accomplished.

To assure that the automatic feathering system is armed properly during cruise, to protect against turbine overheat and to protect against separation of the propeller from the engine in the event of engine annulus gear failure, replace micro-switch actuating levers and set the "arm" setting of the automatic feathering system throttle micro-switches in accordance with British Aircraft Corporation, Viscount 700 series aircraft, Bulletin for Modification No. D.2207, 4th Issue, dated January 31, 1969, or later ARB-approved issue or an FAA-approved equivalent.

This amendment becomes effective March 21, 1970.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-814](https://openairdocs.org/tcds/A-814): Vickers-Armstrongs (Aircraft Limited); names 2 of 3 models: Viscount 744, Viscount 745D

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

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