COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/123 Landing Gear Selector Valve Actuator Arm 11/90 Applicability: Model 727 series. Requirement: Unless already accomplished, modify the selector valve actuator arm in accordance with Boeing Service Bulletin 727-32-0372, or Revision 2 of Service Bulletin 727-32-0372. Note: FAA AD 90-02-08 Amdt 39-6470 refers. Compliance: Prior to 31 March 1992. Background: This AD is issued in response to a report of an all wheels-up landing, due to a nut missing from the landing gear control selector valve actuator arm installation.