AD/B737/268 - Floor Beams and Pressure Web Transverse Beams above the Main Wheel Well (Cth)

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 39.001(1) of CASR 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.

Boeing 737 Series Aeroplanes AD/B737/268 Floor Beams and Pressure Web Transverse Beams above the Main Wheel Well 13/2005

Applicability: Model 737-100, -200, and -200C series aircraft, as listed in Boeing Service Bulletin (SB) 737-57-1139 Revision 4, or later FAA approved revision. Requirement: Action in accordance with the technical requirements of FAA AD 2001-17-18 Amdt 39-12409. Compliance: As specified in the Requirement document. This Airworthiness Directive becomes effective on 22 December 2005. Background: The Model 737 Ageing Fleet Structures Working Group has recommended accomplishment of SB 737-57-1139 Revision 4, which requires repetitive inspections of certain floor beams and transverse beams. For certain aircraft, this Directive also provides optional terminating action for the repetitive inspections. The actions specified by this Directive are intended to detect and correct cracking at the aileron control quadrant cut-outs and in the cabin floor beams and pressure web transverse beams above the main wheel well, which could result in rapid loss of cabin pressure and reduced structural integrity of the airframe.