AD/B737/359 Outboard Landing Light Wire Bundles (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/B737/359 Outboard Landing Light Wire Bundles 9/2009

Applicability:	Model 737-100, -200, -200C, -300, -400 and -500 series aeroplanes, as identified in Boeing Service Bulletin (SB) 737-28-1241, Revision 1, dated 31 August 2007.
Requirement:	1.    For Model 737-300, -400 and -500 series aeroplanes identified in Boeing Alert Service Bulletin (ASB) 737-33A1140, dated 22 May 2006 - Accomplish either of the following actions:
a.     Deactivate the outboard landing lights by accomplishing all of the actions specified in Part 1 of the Accomplishment Instructions of ASB 737-33A1140, or
b.    Modify the wiring to the outboard landing lights by accomplishing all of the actions specified in Part 2 of the Accomplishment Instructions of ASB 737-33A1140.
Note 1:  The Master Minimum Equipment List (MMEL) prohibits dispatching an aeroplane for night operations with deactivated outboard landing lights in the event that either of the inboard landing lights fail.  Operators should note that, if the outboard landing lights are deactivated in accordance with Part 1 of ASB 737-33A1140 there is no MMEL relief allowing for this configuration for night operations should any inboard landing light fail.
2.    For all aeroplanes - Accomplish following actions in accordance with 737-28-1241, Revision 1:
a.     Replace the wire bundles for the landing lights and fuel shutoff valves with new, redesigned wire bundles and carry out the related investigative, other specified, together with corrective actions, as applicable.  The related investigative, other specified and corrective actions must be done before further flight after the replacement.
b.    Carry out detailed inspection for any broken, damaged, or missing fairleads, any damaged or missing grommets and any chafed or damaged wires or wire bundles in the four electrical junction boxes of the main wheel well, and do the applicable corrective actions.  The corrective actions must be done before further flight after the inspection.

c.     Replace the electrical connectors and backshell clamps with new, improved electrical connectors and backshell clamps, as applicable.

For Model 737-300, -400 and -500 series aeroplanes identified in ASB 737-33A1140, accomplishing the applicable Requirement 2 actions terminates the Requirement 1 actions.

For aeroplanes identified as Groups 1 and 2 in SB 737-28-1241, Revision 1 - Actions accomplished before the effective date of this Directive in accordance with SB
737-28-1241, dated 7 April 2006, are acceptable for compliance with Requirement 2.

For all aeroplanes - Actions accomplished before the effective date of this Directive in accordance with Part 2 of the Accomplishment Instructions of SB 737-28-1241 are acceptable for compliance with Requirement 2.b.

Later revisions of the above SBs, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2009-14-04 are considered acceptable for compliance with the equivalent Requirements of this Directive.

Note 2:  FAA AD 2009-14-04 Amdt 39-15954 refers.

Compliance:

For Requirement 1 - Within 180 days after the effective date of this Directive.

For Requirement 2 - Within 60 months after the effective date of this Directive.

This Airworthiness Directive becomes effective on 27 August 2009.

Background:

This Directive results from reports of uncommanded engine shutdowns and burned and damaged wire bundles associated with the outboard landing lights and engine fuel shutoff valves.

The Directive is issued to prevent a hot short between the outboard landing light and fuel shutoff valve circuits, which could result in an uncommanded engine shutdown.

James Coyne
Delegate of the Civil Aviation Safety Authority

15 July 2009