COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 737 Series Aeroplanes AD/B737/102 Flap Control Cable Failure Detection System 5/97 Applicability: Model 737-300, -400, and -500 series aircraft with line numbers 1001 through 2765. Requirement: Remove the shim, if installed, from behind the proximity switch in the system which detects a loss of tension in the cable controlling the flaps; and trim the switch bracket; in accordance with Boeing Alert Service Bulletin 737-27A1199. Note: FAA AD 97-02-16 Amdt 39-9901 refers. Compliance: Unless already accomplished, within 18 months or 3,200 hours time in service after 24 April 1997, whichever occurs first. This Airworthiness Directive becomes effective on 24 April 1997. Background: The FAA received reports that the affected proximity switch bracket can impair the movement of a pulley arm mechanism, ultimately preventing the detection system from operating. This event could result in movement of the flaps without action by the pilot, and ultimately cause reduced controllability of the aircraft.