AD 72-06-03

72-06-03 HAWKER SIDDELEY: Amdt. 39-1404. Applies to Hawker Siddeley Model DH-114 "Heron" Airplanes.

Compliance is required as indicated.

To prevent hazardous internal corrosion of the tubular structure of engine mounting frames, P/N's 14EM11A and 12A, accomplish the following:

(a) For airplanes with engine mounting frames with serial numbers DHB/1 and subsequent, or with serial numbers prefixed by "DH/...", that do not incorporate Modification No. 1529, within four years after the effective date of this AD, unless already accomplished within the last four years, and thereafter at intervals not to exceed four years from the last inspection, conduct an x-ray inspection of the tubular structure of the engine mounting frame, P/N's 14EM11A and 12A, for internal corrosion in accordance with Hawker Siddeley Aviation Ltd. Technical News Sheet Series: Heron (114) No. E.3, Issue 1, dated August 24, 1964, or Issue 3, dated September 14, 1970, or later ARB-approved issue or FAA-approved equivalent.

(b) For airplanes with engine mounting frames with serial numbers DHB/1 and subsequent, or with serial numbers prefixed by "DH/...", that incorporate Modification No. 1529, within four years after the date of incorporation of the modification, or within one year after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed four years from the last inspection, conduct an x-ray inspection of the tubular structure of the engine mounting frames, P/N's 14EM11A and 12A, for internal corrosion in accordance with Hawker Siddeley Aviation Ltd. Technical Sheet Series: Heron (114) No. E.3, Issue 3, dated September 14, 1970, or later ARB-approved issue or FAA-approved equivalent.

(c) For airplanes with engine mounting frames with serial numbers prefixed by "S4/DHB..." or "BGB/DHB..." (manufactured to the standards of Modification No. 1529), within 10 years from the date of manufacture, and thereafter at intervals not to exceedfour years from the last inspection, conduct an x-ray inspection of the tubular structure of the engine mounting frames, P/N's 14EM11A and 12A, for internal corrosion in accordance with Hawker Siddeley Aviation Ltd. Technical News Sheet Series: Heron (114) No. E.3, Issue 3, dated September 14, 1970, or later ARB-approved issue or FAA-approved equivalent.

NOTE: See Hawker Siddeley Technical News Sheet Series: Heron (114), No. E.3, Issue 3, dated September 14, 1970, for dates of engine mount manufacture.

(d) If internal corrosion is found during an inspection required by paragraph (a), (b), or (c), before further flight replace or repair the engine mounting frame in accordance with Hawker Siddeley factory approved instructions or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region, and continue to inspect in accordance with paragraph (a), (b), or (c) whichever is applicable.

This supersedes Amendment 39-128 (30 F.R. 11030), AD 65-20-03. This amendment becomes effective April 6, 1972.