AD/B747/170 Amdt 1 - Main Entry Door Girt Bar Support Fitting (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/B747/170 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 747 Series Aeroplanes AD/B747/170 Amdt 1 Main Entry Door Girt Bar Support Fitting 8/2007

Applicability: Model 747-100, -100B, -100B SUD, -200B, -200C, -300, -400, -400D, 747SR, and 747SP series aircraft; line numbers 1 through 868. Requirement: Action in accordance with the technical requirements of FAA AD 2007-12-11 Amdt 39-15089.

Note: Boeing Service Bulletins 747-53A2378 Revision 1 and Revision 3, refer. Compliance: As specified in the Requirement document, with a revised effective date of 2 August 2007. This Amendment becomes effective on 2 August 2007. Background: The FAA received reports of corrosion on the floor structure supports for the escape slides of the main deck entry doors. The corrosion was found during scheduled deployment tests of the main entry door escape slides. Uncontrolled corrosion could result in separation of the escape slide from the lower door sill during deployment, and subsequently prevent proper operation during an emergency.

Amendment 1 is issued in response to a new FAA AD, which results from a report that the square and conical washers may be installed incorrectly in the girt bar support fitting on aircraft on which the support fitting was repaired or replaced, in accordance with the requirements of the original AD.