AD 58-08-06

58-08-06 VICKERS: Applies to all Viscount 700 Series Aircraft.

Compliance required as indicated.

As a result of further cracks found in main chassis ram foot fittings, Vickers-Armstrong (Aircraft) Limited has recommended revised inspections which the British Air Registration Board considers mandatory.

When each main chassis ram foot fitting has completed 1,500 landings, it should be inspected as follows:

1. A visual inspection is to be made within every 135 flying hours for the possible presence of cracks in the external surface of each ram foot fitting, particularly in the area of the base and sides of the ram socket for a distance of approximately 2 inches vertically from the base;

2. Inspect within the next 600 flying hours and thereafter within each subsequent 3,000 flying hours as follows: Remove the ram foot from each main undercarriage assembly and inspect for the possible presence of cracks, both inside and outside of the ram socket bore. The examination should be carried out using an approved method of crack detection and particular attention should be given to the radius at the bottom of the ram socket bore joining the bottom flange and the wall of the bore;

3. Any fittings found cracked should be replaced by new parts;

4. After compliance with Vickers-Armstrongs Modification D. 2695, the inspection outlined above may be discontinued. After January 31, 1959, all ram foot fittings exceeding 1,500 landings must incorporate Modification D.2695 or be replaced.

The FAA concurs with this action and considers compliance therewith mandatory.

(Vickers-Armstrongs PTL No. 175, Issue 2, and Modification D.2695, covers this subject.)

This supersedes AD 57-26-01.