COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 737 Series Aeroplanes 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/B737/169 Aft Pressure Bulkhead BS 1016 and Vertical Fin Forward Attachment Body Section 48 12/2001 Applicability: Model 737-600, -700, and -800 aircraft, with line numbers 1 through 405, and line numbers 466, 585, 590, and 793. Requirement: Action in accordance with the technical requirements of FAA Emergency AD 2001- 21-51. If any damage is found during the inspection required by this Directive, before further flight, perform a detailed visual inspection of the vertical beam web installation for damage, in accordance with Boeing Telegraphic Service Bulletin 737-53A1238. If damage is found, before further flight, repair all damage per data meeting the type certification basis of the aircraft approved by a Boeing Company Designated Engineering Representative (DER), who has been authorised by the Manager, Seattle Aircraft Certification Office (ACO), to make such findings. Note: Boeing Telegraphic Service Bulletin 737-53A1238, dated 11 October 2001, refers. Compliance: As specified in the Requirement document. This Airworthiness Directive becomes effective on 29 November 2001. Background: The FAA received a report of an operator finding damage to the web of the aft pressure bulkhead at body station (BS) 1016 on a Model 737-700 series aircraft. During replacement of the damaged web sections of the bulkhead, additional damage to the vertical shear beam web and to the skin adjacent to the attachment fittings of the vertical fin at BS 1016 was found. A shimmy event of the main landing gear (MLG) on that aircraft was also reported, and was so severe that it damaged the MLG and resulted in replacement of the right MLG. Subsequent similar reports of damage were received from other operators. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AD/B737/169 (Continued) Such damage at BS 1016, if not found and corrected, could result in structural failure of the aft pressure bulkhead and consequent uncontrolled decompression, or loss of structural integrity of the forward support of the vertical fin, loss of the vertical fin, and consequent loss of control of the aircraft. Neville Probert Delegate of the Civil Aviation Safety Authority 18 October 2001 The above AD is notified in the Commonwealth of Australia Gazette on 7 November 2001.