AD/B737/303 Fuel Boost Pump Wiring (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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 Fuel Boost Pump Wiring 7/2007

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 1, dated 19 March 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 the Accomplishment Instructions of ASB 737-28A1263, Revision 1.
Accomplishment of the Requirement 1 initial inspection, together with the Requirement 2 applicable corrective actions and sleeve installation, terminates the requirements for repetitive inspections in accordance with AD/B737/119 Amdt 3, or AD/B737/121 Amdt 2, or AD/B737/138 Amdt 1.
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 the effective date of this Directive in accordance with Boeing Service Bulletin 737-28A1263, dated 19 February 2007, are considered acceptable for compliance with the corresponding actions specified in this Directive.
Later revisions of the above ASB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-11-07, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note:  FAA AD 2007-11-07 Amdt 39-15064 refers.

Compliance:	For Requirement 1 -
a.     Model 737-100, -200, -300, -400 and -500 series aeroplanes - Within 120 days after the effective date of this Directive or within 5,000 hours time in service (TIS) since the last inspection or repair accomplished in accordance with any amendment of AD/B737/119, or AD/B737/121, or AD/B737/138, or equivalent foreign airworthiness directives, whichever occurs later and thereafter at intervals not to exceed 15,000 flight cycles.
b.    Model 737-200C series aeroplanes - Within 120 days after the effective date 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 flight cycles.
For Requirement 2 - Before further flight following the Requirement 1 inspection.
For Requirement 3 -
a.     For any inspection accomplished after the effective date of this Directive - Submit the report within 30 days after the inspection.
b.    For any inspection accomplished before the effective date of this Directive - Submit the report within 30 days after the effective date of this AD.
This Airworthiness Directive becomes effective on 5 July 2007.
Background:	This Directive supersedes AD/B737/119 Amdt 3, AD/B737/121 Amdt 2 and AD/B737/138 Amdt 1 which will be cancelled when the initial compliance period for this Directive has passed.
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 Directive is 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.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

25 May 2007