COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Grob G115 Series Aeroplanes AD/GROB 115/10 Main Landing Gear Axle 7/98 Applicability: Model G115 and G115A, all serial numbers. Requirement: 1. Inspect, using dye penetrant method, the left and right main landing gear axles in accordance with Grob Service Bulletin (SB)1078-12/1. Replace any axle found cracked during inspection. 2. Modify the left and right main landing gear axle assemblies in accordance with the Installation Instructions of Grob SB 1078-12/1. Note: LBA AD 90-185/2 refers. Compliance: For Requirement 1: Unless already accomplished, inspect within 20 hours time in service after 18 June 1998. Thereafter inspect before further flight in the event of a heavy landing, or at intervals not to exceed 500 landings, whichever occurs first, until compliance with Requirement 2 of this Directive. For Requirement 2: Unless already accomplished, modify before further flight if found cracked or before 31 December 1998, whichever occurs later. This airworthiness directive becomes effective on 18 June 1998. Background: Several aircraft have been found with cracks in the main landing gear axle, as a result of inspection in accordance with SB 1078-12/1. This directive requires inspection of the main landing gear axle for cracks, replacement of the axle if cracked and modification of the axle assembly to prevent cracks.