AD/B747/16 Amdt 3 - Nacelle Strut Midspar Fuse Pins (Cth)

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

Boeing 747 Series Aeroplanes

AD/B747/16 Amdt 3

Nacelle Strut Midspar Fuse Pins 1/93 TX

Applicability: All Model 747 series aircraft.

Requirement: Action in accordance with the technical requirements of Telex FAA AD T92-24-51.

Note: Boeing Service Bulletins 747-54-2063 and 747-54A2150 refer.

Compliance: As specified in the Requirement Document with a revised effective date of 18 November 1992 for Australian registered aircraft. The compliance of the previous issue of this Directive was:

As specified in the Requirement Document with a revised effective date of 14 October 1992.

This Amendment is effective from 18 November 1992.

Background: The manufacturer has received reports of fatigue failures of the older style fuse pins. Amdt 1 of this Directive referenced R5 of the Service Bulletin (which detailed an improved inspection procedure) and a revision of the FAA AD. Amendment 2 of this Directive is issued to reflect the requirements of the above referenced FAA AD, which supersedes two previous FAA Directives. Since the issuance of the previous Directives, the FAA has received several reports of fatigue cracks initiating at corrosion sites in the new style fuse pins on aircraft equipped with Pratt and Whitney or Rolls Royce series engines. Amendment 3 is issued in response to the latest FAA Directive which is issued as a result of the reports required by the previous Directive (AD 92-21-51 R1). The FAA received numerous reports of corrosion and 13 additional reports of fatigue cracking in the new style fuse pins. As a consequence, this Directive requires the removal of all old style fuse pins from service and revised inspection procedures for the new style fuse pins.