76-02-04 BRITTEN NORMAN LTD: Amendment 39-2499. Applies to BN-2A and BN-2A Mark III airplanes, all series, certificated in all categories, equipped with engine mounting frames P/N's NB-20-D-5209, NB-20-G-1901, NB-20-G-5231, or NB-51-H-1021.
Compliance is required as indicated.
To prevent failure of the engine mounting frame and possible physical separation of the engine, accomplish the following:
(a) Within the next 10 hours' time in service after the effective date of this AD, unless already accomplished, visually inspect the welds on the engine mounting frame around the periphery of the mounting pads for cracks and the mounting pads for conformance to the dimensions set forth in the first paragraph of the section entitled "Inspection" of Britten Norman Service Bulletin No. BN-2/SB.72, dated March 27, 1974, or an FAA-approved equivalent.
(b) As a result of the inspection required by paragraph (a) of this AD, if two or more of the engine mounting pads are foundnot to conform to all of the dimensions specified in Britten Norman Service Bulletin No. BN-2/SB.72, dated March 27, 1974, prior to further flight, replace the engine mounting frame in accordance with paragraph (e) of this AD.
(c) As a result of the inspection required by paragraph (a) of this AD, if one of the engine mounting pads is found not to conform to all of the dimensions specified in Service Bulletin No. BN-2/SB.72, visually inspect the welds around the periphery of the mounting pads prior to the first flight of each day, until the engine mounting frame is replaced in accordance with paragraph (e) of this AD.
(d) If a crack is found as a result of an inspection required by paragraphs (a) or (c) of this AD, before further flight, replace the engine mounting frame in accordance with paragraph (e) of this AD.
(e) Where required or authorized by paragraph (b), (c), or (d) of this AD, replace the engine mounting frame with a serviceable engine mounting frame of the same part number that has been inspected and found to have no cracks in the welds around the periphery of the mounting pads and found to conform to all of the dimensions specified in the "Inspection" paragraph of Britten Norman Service Bulletin No. BN-2/SB.72 dated March 27, 1974, or an FAA-approved equivalent.
This amendment becomes effective January 30, 1976.