COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Airtractor AT-300, 400 and 500 Series Aeroplanes AD/AT/15 Amdt 1 Wing Attachment Tube Bushings 10/95 Applicability: Airtractor AT-501 serial numbers up to 510-0128 and Airtractor AT-502 serial numbers up to 502-0128 with unreinforced bushings in the fuselage wing attachment tubes. Requirement: 1. Visually inspect for cracks around the unreinforced bushings in the fuselage wing attachment tubes. Inspect in accordance with Snow Engineering Co. Service Letter No 92. 2. a. Remove the wing gap covers, detachable side skins and wing attachment angles from the wing attachment tubes. Thoroughly clean the area around the unreinforced bushing in the wing attachment tubes, rinse thoroughly with water and air dry. Note: It is advisable not to use paint strippers and volatile cleaning agents in confined areas since they may react with the chemical residue remaining from agricultural operations. 2. b. Remove the paint and perform a fluorescent dye penetrant inspection accordance with CAO 108.10. If no cracks are detected repaint the wing attachment tube. Compliance: 1. Inspect before 5 hours time in service after 22 June 1995. 2. At the next 100 hourly inspection or annual inspection, whichever occurs first. Reinspect at intervals not to exceed 500 hours or each annual inspection, whichever occurs first. This Amendment is effective from the 14 September 1995. Note: Installation of reinforcement gussets P/N 10803-1 (or equivalent) cancels the Requirement of this AD. Background: The manufacturer reports finding cracks in the tubing around an unreinforced bush in the wing attachment tube. This Amendment revises the preparation procedure for inspection, allows a terminating modification and increases the interval for the repeat inspections.