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 170/30 Wing Flap Actuator Ball Nut Assemblies 1/77 Applicability: Model 172 and R172 with S/Nos. as detailed in Cessna Service Letter SE76-25. Requirement: 1. Inspect P/N C301002-0101 wing flap actuator for date stamp code as detailed in Cessna SL SE76-25. 2. If the date stamp code on the actuator is OH, HH, WH or ZH, install a placard near the flap control which reads: "FLAP EXTENSION PROHIBITED". Note: This placard may be removed when the Paragraph 3 requirement is satisfied. 3. Replace affected wing flap actuator ball nut assemblies in accordance with Cessna SL SE76-25. Compliance: Paragraphs 1 and 2 - Before further flight after 28 January 1977. Paragraph 3 - Within 100 hours time in service after 28 January 1977. Federal Register of Legislative Instruments F2006B04962