AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. Pilatus PC-12 Series Aeroplanes AD/PC-12/38 MLG Shock Absorber Attachment Bolts 13/2003 DM Applicability: All Model PC-12 and PC-12/45 aircraft, Manufacturer Serial Numbers 101 through 482. Requirement: 1. Inspect the left and right main landing gear assemblies, part numbers 532.10.12.049 and 532.10.12.050, and determine if the serial numbers start with the letters AM. Pilatus Aircraft Service Bulletin (SB) 32-015 refers. If both main landing gear assembly serial numbers do not start with the letter AM, no further action is required. 2. If the inspection reveals a main landing gear assembly serial number that starts with the letter AM, replace the main landing gear(s) shock absorber attachment bolts with new bolts in accordance with SB 32-015. No spare main landing gear assembly, part number 532.10.12.049 or 532.10.12.050 with a serial number that starts with the letters AM, shall be installed unless attachment bolts part number 532.10.12.110 have been replaced with new bolts in accordance with SB 32-015. Note: FOCA AD HB 2003-522 refers. Compliance: 1. Within 100 hours time in service or 30 days after 19 November 2003, whichever occurs first. 2. Before further flight. This Airworthiness Directive becomes effective on 19 November 2003. Pilatus PC-12 Series Aeroplanes AD/PC-12/38 (continued) Background: It has been determined that the shock absorber attachment bolts installed in some main landing gears have the potential to fail during operation, and result in landing gear collapse. Investigation revealed that some bolts may be affected by hydrogen embrittlement, caused by improper cadmium plating of the high strength steel part. David Villiers Delegate of the Civil Aviation Safety Authority 13 November 2003 The above AD is notified in the Commonwealth of Australia Gazette on 19 November 2003.