COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Schweizer (Grumman) G-164 (Ag-Cat) Series Aeroplanes AD/G164/8 Amdt 1 Main Landing Gear Leg - Inspection 8/67 Applicability: All models with landing gear legs which have exceeded 5000 landings. Requirement: 1. Inspect the main undercarriage spring legs by magnetic particle method for transverse cracking in the vicinity of the outboard clamp on the upper and lower surfaces. 2. Replace cracked legs before further flight. Compliance: At intervals not exceeding 3000 landings.