AD/B767/144 - Warning Electronics Unit (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 39.1 (1) of CAR 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 767 Series Aeroplanes

AD/B767/144 Warning Electronics Unit 8/2001 DM

Applicability: Model 767-200 -300 and -300F series aeroplanes, line numbers 668 through 723 inclusive, equipped with a warning electronics unit (WEU) power supply Part Number (P/N) 285T0035-201.

Requirement: 1. If not previously accomplished in accordance with AD/B767/113 Requirement 1, check the status page of the engine indication and crew alerting system (EICAS) for any WEU failure; and perform Work Instructions in Section 3, Part 1 of Boeing Service Bulletin (SB) 767-31-0106 Revision 1 dated 17 December 1998 or Revision 2 dated 18 November 1999 to detect loss of any visual, aural, or tactile alert.

2. If a WEU failure or loss of any visual, aural, or tactile alert is not detected.

1. Repeat the Requirement 1 EICAS status page check.

b. Repeat the Requirement 1 Work Instructions.

Note 1: The EICAS status page check and performance of the Work Instructions in Section 3, Part 1 of the Service Bulletin are maintenance functions that require an aircraft log book entry and maintenance release prior to flight.