COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Robinson R22 Series Helicopters AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. AD/R22/49 Main Rotor Drive Shaft Yoke Half Assembly 12/2000 TX Applicability: Model R22 helicopters, with a yoke half assembly part number A203-5 installed. Requirement: 1. Inspect each yoke for evidence of cracking, refer to Figure A. If a yoke is cracked, before further flight, replace the yokes with serviceable yokes, part number A203-7. Both yokes must be replaced with yokes part number A203- 7. 2. Determine the Lot identifier of each yoke, P/N A203-5. If the Lot identifier is from 24 through 43, if it is in letter code, or if it is illegible, replace yokes part number A203-5, with serviceable yokes part number A203-7. Yoke part number A203-7 cannot be installed with yoke part number A203-5. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Note: Emergency FAA AD 2000-20-51 and Robinson R22 Service Bulletin SB-88A refer. Determining that the installed yokes, part number A203-5, are not in the lots affected by this Directive, or replacing yokes, part number A203-5 with yokes part number A203-7, is terminating action for the requirements of this Directive. Compliance: 1. Before further flight after 9 October 2000, and thereafter before the first flight of each day. 2. Before further flight after 1 January 2001. This Directive shall be entered on the Maintenance Release as maintenance required. The Requirement 1 visual inspection may be performed and certified by the Pilot in Command. In which case, a copy of this Directive is to be carried in the aircraft. This Airworthiness Directive becomes effective on 9 October 2000. Background: The FAA received several reports of cracks in the yoke half assembly during pre- flight inspections. The cracked yokes were still in service and functioned for an unknown duration. This condition, if not corrected, could result in separation of the yokes from the main rotor drive shaft and subsequent loss of control of the helicopter. David Alan Villiers Delegate of the Civil Aviation Safety Authority 6 October 2000 The above AD is notified in the Commonwealth of Australia Gazette on 9 October 2000.