72-09-04 HAWKER SIDDELEY AVIATION: Amendment 39-1439. Applies to DeHavilland Model DH-114 "Heron" airplanes.
Compliance required as indicated.
(a) Within the next 25 hours' time in service after the effective date of this AD, unless already accomplished within the last 575 hours' time in service, and thereafter at intervals not to exceed 600 hours' time in service from the last inspection, remove the inspection doors just forward and aft of the fuselage rear spar transverse keel frame at fuselage station 43.25 and visually inspect both the front and rear face, including reinforcing sections, if installed, of the fuselage and rear spar transverse keel frame for signs of buckling and cracks.
NOTE: During the inspection required by paragraph (a), particular attention should be directed to the area near the wing rear spar attachment.
(b) If cracks or other damage is found during inspections specified in paragraph (a), before further flight, repair the keel frame inaccordance with ARB approved repair instructions obtained from the Product support Department, Hawker Siddeley Aviation Ltd. Hatfield, Hertfordshire, England or an equivalent approved by the Chief, Engineering and Manufacturing Branch of an FAA Region (or in the case of the Western Region, the Chief, Aircraft Engineering Division).
This amendment is effective April 25, 1972, and was effective upon receipt for all recipients of the telegram dated February 9, 1972, which contained this amendment.