70-15-08 HAWKER SIDDELEY: Amdt. 39-1035. Applies to deHavilland Model DH.114 "Heron" airplanes.
Within the next 25 hours' time in service after the effective date of this AD, unless already accomplished, accomplish the following:
(a) Inspect the right wing and left wing flap datum hinge links for drilled holes around the circumference of the bearing housing recess. If one or more drilled holes or attempted drilled holes (for cotter pin installation) are found located outside the limits given in Hawker Siddeley Aviation, Ltd., Technical News Sheet Heron (114) Issue 1, dated June 15, 1970, or later ARB-approved issue or an FAA-approved equivalent, before further flight replace the flap datum hinge link with a serviceable link of either pre-modification 837 or post-modification 837 standards. The complete flap datum hinge assembly must conform to the modification standard of the flap datum hinge link installed.
(b) Install special washers P/N 4WF 465 or an FAA-approved equivalent between the nut on the flap datum hinge bolt and the hinge lever assembly at both the right wing and left wing datum hinge locations. A special washer equivalent to P/N 4WF 465 may be manufactured from 0.028 inch, minimum thickness mild steel sheet material. The special washer must have an outside diameter of at least 0.87 inches, a hole diameter of 0.323 inches, and a flat cut across a sector of the outer circumference producing a straight edge located no closer than 0.35 inches from the center of the hole.
(c) Inspect the flange of the ball race housing on both the right wing and left wing flap datum hinge assemblies to determine that it is secured to the wing flap datum hinge link with a 1/16 inch diameter cotter pin for pre-modification 837 flap datum hinge assemblies or a 1/8 inch diameter cotter pin for post-modification 837 datum hinge assemblies.
This amendment is effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective by the telegram dated June 20, 1970, which contained the amendment.