# AD 57-26-02: Flap Idler Sprocket

- Type: Airworthiness directive
- Status: Current
- Products: Vickers-Armstrongs Viscount 744 and Viscount 745D
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A0CCDC0C6C7DA2258625699A00605B2C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/57-26-02

## The airworthiness directive

57-26-02 VICKERS: Applies to All Viscount 700 Series Aircraft.

Compliance required not later than July 1, 1958.

To preclude the possibility of the flap idler sprocket retaining nut, P/N 60903-39 and 60903-1151 from becoming unscrewed, the improved locking means for the sprocket shaft nuts at Nos. 1, 2, and 3 flap units should be incorporated. This consists of the installation of a screwed collar P/N 70103-4227 and a split pin, P/N SP9E10. Vickers PTL No. 174 and Modification Bulletin No. 2439 cover the same subject. Modification No. 2439 has been classified as essential by the British Air Registration Board. The FAA concurs and considers compliance mandatory.

## 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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