AD/B747/375 Main Equipment Centre Dripshield (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 747 Series Aeroplanes

AD/B747/375 Main Equipment Centre Dripshield 6/2008

Applicability:

Model 747-400 series aircraft, as identified in Boeing Alert Service Bulletin 747-25A3526 original issue, or later FAA approved revision.

Model 747-400F aircraft, as identified in Boeing Alert Service Bulletin 747-25A3370 Revision 1, or later FAA approved revision.

Requirement:

Action in accordance with the technical requirements of FAA AD 2008-08-25 Amdt 39-15479. 

Compliance:

As specified in the Requirement document, with a revised effective date of 5 June 2008.

This Airworthiness Directive becomes effective on 5 June 2008.

Background:

The FAA received a report that accumulated water from the drip shield above the M826 Card File in the main equipment centre entered the card file and damaged a circuit card, causing the AFT CARGO FIRE MSG message to be illuminated and resulting in an air turn back.  This Directive requires installation of drains and drain tubes to eliminate water accumulation in the drip shield and possible damage to circuit cards in the card file.

David Villiers
Delegate of the Civil Aviation Safety Authority

23 April 2008