AD/B747/21 Amdt 3 - Nacelle Strut Forward Engine Mount Bulkhead (Cth)

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

Boeing 747 Series Aeroplanes

AD/B747/21 Amdt 3

Nacelle Strut Forward Engine Mount Bulkhead 6/98

Applicability: Model 747 series aircraft; as listed in Boeing Alert Service Bulletin 747-54A2069, Revision 9.

Requirement: Action in accordance with the technical requirements of FAA AD 98-02-02 Amdt 39- 10284.

Compliance: As specified in the Requirement document for the repetitive inspection requirements, until terminating modification action is accomplished.

This amendment becomes effective on 21 May 1998.

Background: Service experience with aircraft previously repaired, has shown that the parts provided for the repair were incorrectly heat treated. Amendment 2 provided for on- going repetitive inspection, or, alternatively, accomplishment of a revised repair scheme.

Amendment 3 is issued in response to a new FAA AD prompted by reports that fatigue cracking was found in an area adjacent to the inspection area specified in the existing FAA AD. This amendment adds repetitive inspections for certain aircraft, adds a one-time inspection for other aircraft, and adds an additional optional terminating action for the repetitive inspection requirement.

Amendment 2 to this Airworthiness Directive became effective on 31 December 1982.

Amendment 1 to this Airworthiness Directive became effective on 30 April 1980.

The original issue of this Airworthiness Directive became effective on 29 February 1980.