81-16-04 BELLANCA AIRCRAFT CORPORATION: Amendment 39-4172. Applies to Models 8KCAB, 7ECA, 7GCAA, 7GCBC and 7KCAB airplanes certificated in Acrobatic category. \n\n\tTo insure that the competition harness (also referred to as the ACRO harness) is installed properly, accomplish the following before further flight: \n\n\t1.\tUnless previously accomplished, insert figure I of this AD into all applicable aircraft having approved flight manuals. \n\n\t2.\tAttach figure I of this AD to all "Operating Limitation Instructions" (yellow card) for those applicable aircraft where a flight manual is not required (Model 7 Series airplanes). \n\n\t3.\tInspect all competition harness installations to insure that the shoulder straps are installed in accordance with figure I of this AD. Insure that the shoulder straps of the added harness pass on the forward side of the seat back. \n\n\tThis amendment becomes effective July 28, 1981.