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/12
Amdt 1
Wing Ribs 10/79
Applicability: All model 8KCAB with S/Nos. 3-70, 4-71, 5-72, 7-72 to 53-72, 54-73 to 119-73 and 120-74 to 159-74 except those which have incorporated Bellanca Kit No 243.
Requirement: Visually inspect the wing ribs for evidence of cracks and/or buckling of the rib flanges as follows:
(a) Remove the fabric from each of the four doped-on reinforcing rings located on the lower surface of each wing adjacent to the front spar.
(b) Using a flashlight and mirror inspect all ribs from the first rib outboard of fuel tank and continue through aileron area to last outboard full rib.
(c) Examine area approximately 2" aft of front spar (just aft of the rib reinforcement gusset) on the rib top flange for evidence of cracks, distortion and fabric rivet looseness.
If cracks, distortion or loose fabric rivets are found as a result of the inspection, all damaged ribs are to be repaired to a scheme approved by the Secretary before further flight.
Compliance: At intervals not exceeding 50 hours time in service for normal flight and 10 hours time in service for acrobatic flight.