COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES CFM International Turbine Engines - CFM56 Series AD/CFM56/13 Accessory Gear Box - Starter Gear Replacement 10/98 DM Applicability: CFM International (CFMI) CFM56-3, -3B and -3C model turbofan engines identified and listed in Table 1 of CFMI Service Bulletin 72-877 Revision 1 and installed on Boeing 737 and other aeroplanes. Requirement: Replace the starter gear (line 5) in the accessory gearbox (AGB) of applicable engines in accordance with CFMI Service Bulletin 72-877 Rev 1. Note: DGAC 98-198(B)R1 dated 01 July 1998 refer. Compliance: 1. For aircraft with two applicable engines fitted, perform above requirement on one engine before 1 October 1998. 2. For aircraft which have only one applicable engine, perform above action before 1 February 1999. This airworthiness directive becomes effective on 29 July 1998. Background: Two in flight shut downs were experienced due to a failure of the starter gear (line5) in the AGB.