AD/B747/304 - Wing Rear Spar Upper Chord and Splice Fitting Structure (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety 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 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/B747/304 Wing Rear Spar Upper Chord and Splice Fitting Structure

4/2004

Applicability: All Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP series aircraft.

Requirement: Action in accordance with the technical requirements of FAA AD 2004-03-09 Amdt 39-13453.

Note: Boeing Alert Service Bulletin 747-57A2314 Revision 1 refers.

Compliance: As specified in the Requirement document, with a revised effective date of 15 April 2004.

This Airworthiness Directive becomes effective on 15 April 2004.

Background: The manufacturer received reports of forty-three cracks found on eleven aircraft since 1989. This Directive requires repetitive inspections for discrepancies of the structure near and common to the upper chord and splice fittings of the rear spar of the wing. An optional modification is provided which terminates the repetitive inspection requirement. Unless detected and corrected, cracking could result in loss of structural integrity of the aircraft and fuel leakage into the wheel well cavity.