AD/B737/341 Cracking of Cutout in Web of Body Station Frame (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/B737/341 Cracking of Cutout in Web of Body
Station Frame 11/2008 DM

Applicability:

All Boeing 737-100, -200, -200C, -300, -400, -500 models as identified in Boeing Service Bulletins 737-53A1197 dated 25 August 2006, and 737-53A1188 revision 2 dated 9 May 2007, or later FAA approved revisions, as appropriate.

Requirement:

Action in accordance with FAA AD 2008-17-03.

Note:  Boeing Alert Service Bulletins 737-53A1188 Revision 2 and 737-53A1197 or later FAA approved revisions.

Compliance:

Action in accordance with the requirement document.

This Airworthiness Directive becomes effective on 23 September 2008.

Background:

This directive is issued due to reports of cracks found at the cut out in the web of body station frame 303.9 inboard of stringer 16L.  Failure to detect and correct such cracking could prevent the left forward entry door from sealing correctly, and could cause in-flight decompression of the aircraft.  Repetitive inspections are required to detect cracking of the body station 303.9 frame, and corrective action taken if necessary.  This directive also provides for optional terminating action for the repetitive inspections.

David Villiers
Delegate of the Civil Aviation Safety Authority

22 August 2008