COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 737 Series Aeroplanes AD/B737/88 Horizontal Stabiliser Trim Electric Actuator 8/95 Applicability: Model 737-300, -400 and -500 series aircraft identified in Boeing Alert Service Bulletin 737-27A1191 Revision 1 dated 3 November 1994. Requirement: Replace horizontal stabilizer trim electric actuator Part Number (P/N) 10-62033-3 with an actuator that has been modified and re-identified as P/N 10-62033-4, in accordance with Boeing Alert Service Bulletin 737-27A1191 Revision 1 dated 3 November 1994. Note: FAA AD 95-10-05 Amdt 39-9222 refers. Compliance: Prior to 12 June 1996, except that actuators P/N 10-62033-3 may not be installed in an aircraft after 12 December 1995. Note: Actuator P/N 10-62033-3, if installed in an aircraft prior to 12 December 1995, may remain fitted in that aircraft until removed in accordance with Requirement 1. Background: Several operators have reported instances where the stabilizer trim wheel continued to turn when the stabilizer trim switches were operated and released. A binding condition of a clutch disc in the stabilizer trim electric actuator was found to be the cause of the reported incidents. Action specified by this Directive is intended to prevent reduced controllability of the airplane caused by the binding clutch.