AD 66-17-02

66-17-02 de HAVILLAND: Amdt. 39-259, Part 39, Federal Register July 12, 1966. Applies to Model DHC-2 Series (Mk 1, 2, and 3) Airplanes.

Compliance required within the next 100 hours' time in service after the effective date of this AD, unless already accomplished within the last 400 hours' time in service, and thereafter at intervals not to exceed 500 hours' time in service from the last inspection until the incorporation of Modification 2/1497, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

To detect cracks in the wing ribs, accomplish the following:

(a) Inspect by radiographic technique or by incorporating a special inspection panel in the wing bottom skin and inspecting visually or with dye penetrant or an equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, the wing ribs at Stations 15.50, 29.00 and 42.50 for cracks in the rib web in the upper and lower rib flanges between the front and rear spars in accordance with de Havilland Engineering Bulletin, Series "B", No. 35, Modification 2/1497, dated March 18, 1966, for Mk 1 and 2 airplanes; de Havilland Engineering Bulletin Series "T.B.", No. 3, Modification 2/1497, dated March 18, 1966, for Mk 3 airplanes; or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

(b) Repair cracks before further flight in accordance with the applicable Engineering Bulletin specified in (a) or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

This directive effective July 22, 1966.