AD/B747/223 - Diagonal Brace Underwing Fitting Bolts (Cth)

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

Boeing 747 Series Aeroplanes

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.

AD/B747/223 Diagonal Brace Underwing Fitting Bolts 5/2000

Applicability: Model 747-100, -200, and 747SP series aircraft, with line numbers 1 through 567, and equipped with aluminium diagonal brace underwing fittings.

Requirement: Inspect in accordance with the technical requirements of FAA AD 2000-03-22 Amdt 39-11582.

Note: Boeing Service Bulletins 747-53A2308 and 747-57-2288 Revision 1 refer.

Compliance: As specified in the Requirement document for the initial and repetitive inspections and eventual bolt replacement, with a revised effective date of 18 May 2000.

This Airworthiness Directive becomes effective on 18 May 2000.

Background: The FAA received reports of damaged, broken, and corroded taperlock bolts of the engine strut diagonal brace underwing fittings on the outboard strut due to stress corrosion cracking. Loss of the underwing fitting load path due to missing, damaged, or broken taperlock bolts, could result in separation of the engine and strut from the aircraft.