AD/B747/171 Amdt 5 Outboard Main Fuel Tank Boost Pump Wiring (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/171 Amdt 4 and issues the following AD under subregulation 39.001(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/B747/171 Amdt 5 Outboard Main Fuel Tank Boost Pump Wiring 6/2006

Applicability:	All Model 747 series aeroplanes.
Requirement:	1.    If not previously accomplished inspect the sleeving and wire bundles of the forward and aft boost pumps of the numbers 1 and 4 main fuel tanks, together with the wire bundles of the auxiliary jettison pumps (if installed), in accordance with Boeing Alert Service Bulletin (ASB) 747-28A2204 dated 19 December 1996 or 747-28A2204 Rev 1 dated 30 October 1997.
2.    If any damaged sleeving is found as a result of the Requirement 1 inspection, replace the sleeving in accordance with ASB 747-28A2204 dated 19 December 1996 or 747-28A2204 Rev 1 dated 30 October 1997.
3.    If any damaged wire is found as a result of the Requirement 1 inspection, repair or replace the wire in accordance with ASB 747-28A2204 dated 19 December 1996 or 747-28A2204 Rev 1 dated 30 October 1997.
4.    If a burned wire is found as a result of the Requirement 1 inspection, perform an inspection to detect damage of the conduit.  If any damage is found, replace the conduit in accordance with ASB 747-28A2204 dated 19 December 1996 or 747-28A2204 Rev 1 dated 30 October 1997.
Later revisions of the above SB(s), approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 97-26-07, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note:  FAA AD 97-26-07 Amdt 39-10250 refers.
Compliance:	For Requirement 1:
a.     For aeroplanes having line numbers 001 through 432 - Remains unchanged as ‘Prior to 20 May 1997 (unchanged from the original issue of this Directive) and thereafter at intervals of 20,000 flight cycles or 60,000 hours time in service since the last inspection, whichever occurs first’.

b.    For aeroplanes having line number 433 and subsequent - Remains unchanged as ‘Prior to the accumulation of 20,000 flight cycles or 60,000 hours time in service (whichever occurs first), or by 30 July 1998 whichever occurs later.  Thereafter at intervals of 20,000 flight cycles or 60,000 hours time in service since the last inspection, whichever occurs first’.
For Requirements 2, 3 and 4:  Before further flight after the Requirement 1 inspection.
This amendment becomes effective on 8 June 2006.
Background:	This Amendment introduced a statement that allows compliance to be accomplished in accordance with later revisions of the service bulletins, if they are approved as AMOCs by the FAA.
Amendment 4 removed the Requirement 5 reporting procedure as this is adequately addressed by the service bulletin.  Amendment 4 also clarified Requirement 1 compliance times.
Amendment 3 introduced reporting of damage and compliance based on aircraft line numbers.
Amendment 2 corrected an editorial error in the required flight cycles from 22,000 hrs to 20,000 hrs and clarified the compliance date.
Amendment 1 expanded the applicability to all B747 aircraft and introduces a repetitive inspection every 22,000 flight cycles or 60,000 hours time in service.
Actions specified by this Directive are designed to detect and correct abrasion of the Teflon sleeving and wires in the bundles of the fuel boost pumps for the numbers 1 and 4 main fuel tanks, together with the wire bundles of the auxiliary jettison pumps (if installed).  Abrasion of Teflon sleeving or wires could result in electrical arcing between the wires and the aluminium conduit and subsequent fire or explosion in the fuel tank.
Amendment 4 of this airworthiness directive became effective on 22 July 1998
Amendment 3 of this airworthiness directive became effective on 3 June 1998.
Amendment 2 of this airworthiness directive became effective on 26 February 1998.

The original issue of this airworthiness directive became effective on 27 February 1997.

James Coyne
Delegate of the Civil Aviation Safety Authority

28 April 2006