COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 737 Series Aeroplanes AD/B737/77 Amdt 1 Pilot and Co-Pilot Seats 13/97 Applicability: Model 737 series aircraft equipped with IPECO Model 093 pilot and copilot seats, with seat serial numbers up to and including 21121. Requirement: Action in accordance with the technical requirements of FAA AD 97-19-03 Amdt 39- 10123. Note: IPECO Service Bulletins A001-25-74 Issue 2 and A001-25-92 Issue 1 refer. Compliance: Before 4 March 1998. This airworthiness directive becomes effective on 4 December 1997. Background: The FAA received reports of pilot seats that failed to lock horizontally due to the tracklock pin detaching from its housing and wedging in the mechanism. This condition could lead to the inability of the pilot to control the aircraft. Amendment 1 is issued in response to a new FAA AD which requires a re-inspection of the seats due to reports of a failure of the horizontal locking and other defects of aircraft seats previously inspected.