AD/B747/372 - Engine Core Cowl Flipper Doors (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/B747/372 Engine Core Cowl Flipper Doors 3/2008

Applicability: Model 747-200B, -300, -400, -400D, and -400F series aircraft, equipped with General Electric CF6-80C2 engines. Requirement: Action in accordance with the technical requirements of FAA AD 2007-26-07 Amdt 39-15309.

Note: Boeing Special Attention Service Bulletin 747-71-2310 original issue, and Rohr Service Bulletin TBC/80C2-NAC-71-035 original issue, or later FAA approved revisions, refer. Compliance: As specified in the Requirement document, with a revised effective date of 13 March 2008. This Airworthiness Directive becomes effective on 13 March 2008. Background: The FAA received two reports of missing flipper doors for the engine core cowls. Migrated hinge pins and damaged flipper doors, unless detected and corrected, could allow the flipper door to fall off. This could allow an engine fire to propagate into the flammable leakage zone of the strut and for the amount of fire extinguishing agent reaching the fire to be diluted. The result could be an uncontained fire in the engine compartment.