AD/B737/303 Amdt 2 Fuel 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/B737/303 Amdt 1 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 737 Series Aeroplanes

AD/B737/303 Amdt 2 Fuel Boost Pump Wiring 3/2008

Applicability:	Model 737-100, -200, -200C, -300, -400 and -500 series aeroplanes.
Requirement:	1.    Carry out a detailed inspection for damage of the sleeve and electrical wire of the fuel boost pump in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin (ASB) 737-28A1263 Revision 2 dated 10 August 2007.
2.    Install new, smaller-diameter sleeving on the fuel boost pump wiring, carry out any related investigative and corrective actions, as applicable, in accordance with ASB 737-28A1263, Revision 2.
3.    Submit a report of the findings (both positive and negative) of any Requirement 1 inspection and send any damaged parts to the manufacturer, as described in ASB 737-28A1263, Revision 1.  The report must include the inspection results, a description of any discrepancies found, the aeroplane serial number together with the number of landings and flight hours on the aeroplane.
Actions accomplished before 31 August 2007 (the effective date of Amendment 1 of this Directive) in accordance ASB 737-28A1263, dated 19 February 2007, or actions accomplished before 13 March 2008 (the effective date of this Amendment) in accordance with ASB 737-28A1263 Revision 1, are considered acceptable for compliance with the corresponding actions specified in this Directive.
Later revisions of ASB 737-28A1263, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-24-02, are considered acceptable for compliance with the equivalent Requirements of this Amendment.
Note:  FAA AD 2007-24-02 Amdt 39-15268 refers.

Compliance:	For Requirement 1 -
a.     Model 737-100, -200, -300, -400 and -500 series aeroplanes having line numbers 1 through 3072 inclusive - Within 120 days after the effective date of this Amendment, or within 5,000 hours time in service (TIS) after the last inspection or repair done in accordance with any version of ASB 737-28A1120 listed in Table 1, whichever occurs later and thereafter, at intervals not to exceed 15,000 hours TIS.
b.    Model 737-100, -200, -300, -400 and -500 series aeroplanes having line numbers 3073 and subsequent -
(i)    For aeroplanes on which the inspection or repair specified in any version of ASB 737-28A1120 listed in Table 1, has been done as of the effective date of this Amendment - Within 120 days after the effective date of this Amendment or 5,000 hours TIS after the last inspection done in accordance any of the revisions of ASB 737-28A1120 listed in Table 1, whichever occurs later and thereafter, at intervals not to exceed 15,000 hours TIS.
(ii)   For aeroplanes on which the inspection or repair specified in any version of ASB 737-28A1120 listed in Table 1, has not been done as of the effective date of this Amendment - Before the accumulation of 5,000 total hours TIS, or within 120 days after the effective date of this Amendment, whichever occurs later and thereafter, at intervals not to exceed 15,000 hours TIS.
c.     Model 737-200C series aeroplanes - Within 120 days after the effective date of the original issue of this Directive, or within 5,000 hours TIS since the last inspection or repair done in accordance with any version of Boeing ASB 737-28-1120, whichever occurs later and thereafter at intervals not to exceed 15,000 hours TIS.
Table 1
ASB 737-28A1120 Version	Date	As revised by Notice of Status Change (NSC) as applicable
		Number	Date
Original Issue Revision 1 Revision 2 Revision 3	24 April 1998 28 May 1998 26 November 1998 26 April 2001	NSC 01 NSC 02 NSC 03	7 May 1998 8 May 1998 9 May 1998

For Requirement 2 - Before further flight following the Requirement 1 inspection.
For Requirement 3 - Within 30 days after the Requirement 1 inspection.
This Amendment becomes effective on 13 March 2008.
Background:	The original issue of this Directive superseded AD/B737/119 Amdt 3, AD/B737/121 Amdt 2 and AD/B737/138 Amdt 1 which have been cancelled.
The FAA has advised of a report of a fuel tank explosion on a Model 727-200F aeroplane on the ground together with a report of chafed wires and a damaged power cable sleeve of a fuel boost pump discovered during an inspection on a Model 737-300 aeroplane.  (The fuel boost pump installation on certain Model 737 aeroplanes is almost identical to the installation on Model 727 aeroplanes.)
The original issue of this Directive was issued to detect and correct chafing of the fuel boost pump electrical wiring, prevent leakage of fuel into the conduit and to prevent electrical arcing between the wiring and the surrounding conduit, which could result in arc-through of the conduit together with consequent fire or explosion of the fuel tank.
Amendment 1 resulted from the FAA correcting a typographical error in AD 2007-11-07.  The repetitive inspection interval is now expressed in hours TIS rather than flight cycles and the requirement for retrospective submittal of inspection reports have been deleted as the compliance time has passed.  All other aspects remained unchanged.
This Amendment follows a superseding AD being issued by the FAA.  It reduces the inspection threshold for certain aeroplanes and to avoid confusion, bases the threshold on the completion of service bulletin inspections rather than Airworthiness Directives.
The original issue of this Directive became effective on 5 July 2007.
Amendment 1 of this Directive became effective on 31 August 2007.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

23 January 2008