COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/209 Nacelle Strut Fuse Pins 8/99 Applicability: Model 747-200, and -300 series aircraft equipped with General Electric Model CF6- 80C2 series engines, and Model 747-400 series aircraft; as listed in Boeing Service Bulletin 747-54-2155 Revision 2; except those aircraft on which modification of the strut/wing structure have been accomplished in accordance with either FAA AD 95- 13-05 or AD 95-13-06. Requirement: Action in accordance with the technical requirements of FAA AD 99-10-10 Amdt 39- 11163. Compliance: As specified in the Requirement Document with a revised effective date of 12 August 1999. This Airworthiness Directive becomes effective on 12 August 1999. Background: The FAA received reports of cracked fuse pins in the upper link, midspar fittings, and diagonal brace of the nacelle strut due to fatigue and corrosion. Cracks or corrosion of the fuse pins could result in failure of the fuse pin and strut-to-wing attachment.