70-21-02 HAWKER SIDDELEY AVIATION, LTD: Amdt. 39-1087. Applies to de Havilland Model DH.104 "Dove" airplanes.
To prevent failure of the flap datum hinge assemblies, unless already accomplished, accomplish the following within the next 3,000 hours' time in service after the effective date of this AD, or by March 31, 1971, whichever occurs first:
(a) Inspect the wall thickness of the bearing housing recess of both the right wing and left wing flap datum hinge links in accordance with Hawker Siddeley Aviation, Limited, Technical News Sheet CT(104) No. 216 Issue 1, June 8, 1970, or later ARB-approved issue or an FAA-approved equivalent. If the wall thickness is found to be less than 0.17 inches, replace the flap datum hinge link with a serviceable link of Modification 982 standard.
(b) Incorporate Modification 982 by replacing the flap datum hinge assemblies P/N 4WF.16A(R.H.) and P/N 4WF.15A(L.H.) with assemblies P/N 14WF.456A(R.H.) and P/N 14WF.455A (L.H.) in accordance with de Havilland Aircraft Company, Limited, Modification No. Dove 982 dated August 20, 1956, or later ARB-approved issue or an FAA-approved equivalent.
This amendment becomes effective November 5, 1970.