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/13 Stall Warning Horn 8/75 Applicability: Models 7EC, 7FC, 7ECA, 7GCAA, 7GCBC and 7KCAB. Requirement: Install an approved stall warning horn system. The following Bellanca-Champion drawings detail approved systems: Dwg. No. 7-1065 for models 7EC and 7FC; OR Dwg. No. 7-1401 for models 7ECA, 7GCAA, 7GCBC and 7KCAB. Compliance: Before 31 January 1976.