AD/B737/237 Amdt 1 - Passenger Cabin Conditioned Air Overhead Ducts (Cth)

AIRWORTHINESS DIRECTIVE On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/237 and issues the following 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/B737/237 Amdt 1 Passenger Cabin Conditioned 10/2007 Air Overhead Ducts

Applicability: Model 737-300, -400, and -500 series aircraft, listed in Boeing Special Attention Service Bulletin 737-21-1131 Revision 3, or later FAA approved revision. Requirement: Action in accordance with the technical requirements of FAA AD 2005-03-02 Amdt 39-13958.

The action (i.e. inspection or modification) defined in Boeing Special Attention Service Bulletin 737-21-1131 Revision 3 may be used as an alternative method of compliance to the requirements of paragraph (b) of FAA AD 2005-03-02. Compliance: As specified in the Requirement document, with a revised effective date of 14 April 2005.

The compliance time remains unchanged by this issue of the Directive. This Amendment becomes effective on 27 September 2007. Background: The manufacturer received a substantial number of reports of leaking air conditioning overhead ducts on Model 737 and Model 757 aircraft from multiple airlines. Two of these reports described overhead duct failures that caused the ceiling panels to fall into the passenger cabin. This Directive requires overhead duct lanyard installations, to prevent a disconnected overhead duct from causing ceiling panels to drop below the minimum height of the evacuation zone for the passenger cabin, which could result in inadequate height for safe exit in the event of an emergency evacuation.