COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES American Champion (Aeronca, Bellanca) Series Aeroplanes AD/CHA/11 Amdt 3 Undercarriage Attachments 4/79 Applicability: All models 7ECA, 7GCAA, 7KCAB, 7GCBC, 8KCAB and 8GCBC. Requirement: 1. Remove the "U" bolt securing the undercarriage spring leg and inspect using the magnetic particle method for cracks particularly in the area of the threads and the radius of the bends. 2. Remove the AN-7 bolt attaching the inboard end of the under-carriage spring leg and inspect using the magnetic particle method for cracks particularly in the area of the thread and the radius under the bolt head. 3. Retire from service the AN-7 bolt attaching the inboard end of the undercarriage spring leg. 4. Modify the undercarriage attachment by replacing the AN-7 bolt and nut attaching the inboard end of the spring leg with a MS20007-34 bolt, MS20002C7 washer under the bolt head, MS20002-7 washers as required under the nut and an NAS679-A7 nut or equivalent self-locking type. Torque nut to 650 to 700 inch pounds. Note: Bellanca Service Letter No C-135 refers. Compliance: For Para. 1 - Unless already accomplished, within 25 hours time in service after 1 March 1979 and thereafter at intervals not exceeding 300 hours time in service. For Para. 2 - Unless already accomplished, within 25 hours time in service after 1 March 1979 and thereafter at intervals not exceeding 100 hours time in service until modified in accordance with Para. 4. For Para. 3 - Unless already accomplished, within 25 hours time in service after 1 March 1979 for bolts in excess of 300 hours total time in service and before exceeding 300 hours total time in service for AN7 bolts with less than 300 hours. For Para. 4 - At next major inspection after 31 June 1979.