What was found
THE BOLT (P/N AN3-34) THAT SERVES AS THE PIVOT FOR THE ALTERNATE AIR DOOR IN THE INDUCTION DUCT ASSEMBLY (P/N 15708-001) IS BEING CHAFFED BY THE INDUCTION DUCT SUPPORT BRACKET (P/N 15671-002). IN ADDITION TO THE CHAFFED BOLT THE INDUCTION DUCT ASSY IS SUSCEPTIBLE TO CRACKING. ALSO INSPECTED 14 OTHER AIRCRAFT WITH COMPARABLE TIME OR LESS AND FOUND SIGNS OF CHAFFING AND/OR INDUCTION DUCT CRACKING REQUIRING REPLACEMENT OF THE INDUCTION DUCT ASSY. THIS CONDITION IS VERY DIFFICULT TO INSPECT WITHOUT REMOVING THE INDUCTION DUCT ASSY.