COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes AD/CESSNA 170/34 Amdt 1 Engine Mounting Bracket Bolts 9/80 Applicability: All Cessna Model 172N fitted with Lycoming 0-320-H2AD series engines with S/Nos L-101-76 to L-5707-76 or any engine remanufactured prior to 4 January 1979. Requirement: To prevent loss of integrity of the engine to aircraft mounting due to loosening of the engine mounting bracket attaching bolts, accomplish the following: 1. Inspect the eight P/N LW 38-2.75 mounting bolts for tightness. Mounting bolts found to have less than 200 inch-pounds of torque when measured in the tightening direction must be replaced and the new bolts torqued to 360 inch-pounds. 2. Those bolts found with less than 360 inch-pounds torque but more than 200 inch- pounds must be re-torqued to 360 inch-pounds. Note: Lycoming SI No 1380 and FAA AD 79-10-03 R2 Amendment 39-3628 refers. Compliance: Unless already accomplished, within 10 hours time in service after 1 August 1980 and thereafter at intervals not exceeding 100 hours time in service. Background: The engine mounting bracket bolts may lose torque during service. This amendment references affected engines by serial number and adds certain remanufactured engines.