AD/B747/256 - Body Station 1480 Bulkhead (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

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 39.1 (1) of CAR 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/B747/256 Body Station 1480 Bulkhead 10/2001

Applicability: Model 747 series aircraft, line numbers 1 through 1254.

Requirement: Action in accordance with the technical requirements of FAA AD 2001-11-06 Amdt 39-12248.

Note: Boeing Service Bulletins 747-53A2390 and 747-53A2390 Revision 1 refer.

Compliance: As specified in the Requirement document with a revised effective date of 4 October 2001.

This Airworthiness Directive becomes effective on 4 October 2001.

Background: The FAA received reports that fatigue cracking has been found in the outer chord of the BS 1480 bulkhead at the overwing longeron splice on aircraft not subject to previously issued AD 98-20-25, which was only applicable to Model 747-100 aircraft. Fatigue cracking of the skin, splice fittings, bulkhead web, and outer chord of the BS1480 upper and lower bulkhead and longeron splice fitting, unless detected and corrected, could result in reduced structural integrity of the fuselage and the inability to carry limit load.