AD 72-08-02

72-08-02 HAWKER SIDDELEY AVIATION: Amdt. 39-1424. Applies to Model DH- 114 "Heron" Series 2 airplanes.

Compliance is required as indicated.

To prevent failures of the main undercarriage main and damper jack attachment bolts, P/N 14-2U.229 and P/N 14-2U.631, accomplish the following:

(a) For airplanes with main undercarriage units that have any P/N 14-2U.229 main and damper jack attachment bolts installed, within the next 150 hours' time in service after the effective date of this AD, unless already accomplished within the last 150 hours' time in service, and thereafter at intervals not to exceed 300 hours' time in service from the last inspection, remove and visually inspect the attachment bolts for cracks.

(b) For airplanes with main undercarriage units that have only P/N 14-2U.631 (Modification 1536) main and damper jack attachment bolts installed, within the next 1,200 hours' time in service after the effective date of this AD, unless already accomplished within the last 1,200 hours' time in service, and thereafter at intervals not to exceed 2,400 hours' time in service from the last inspection, remove and visually inspect the attachment bolts for cracks.

(c) If any bolt is found to be cracked during an inspection required by paragraph (a) or (b), before further flight replace the cracked bolt in accordance with subparagraph (1) or (2):

(1) Replace a cracked bolt, P/N 14-2U.229 with either a serviceable bolt of the same part number or replace with a serviceable bolt, P/N 14-2U.631 (Modification 1536), and continue to inspect in accordance with paragraphs (a) or (b) as applicable.

(2) Replace a cracked bolt, P/N 14-2U-631 (Modification 1536), with a serviceable bolt of the same part number and continue to inspect in accordance with paragraphs (a) or (b) as applicable.

This amendment becomes effective May 1, 1972.