AD/B747/386 EFIS/ECAs Interface Units (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 747 Series Aeroplanes

AD/B747/386 EFIS/ECAS Interface Units 13/2008

Applicability:	Model 747-400, 747-400D and 747- 400F series aeroplanes, as identified in Boeing Service Bulletin (SB) 747-31-2368, Revision 1, dated 24 July 2006.
Requirement:	Replace at least one of the three electronic flight instrument system/engine indicating and crew alerting system (EFIS/EICAS) interface units (EIU), part number (P/N) 622-8589-104, located on the E2-6 shelf of the main equipment centre with a new or modified EIU, P/N 622-8589-105, in accordance with the Accomplishment Instructions of SB 747-31-2368, Revision 1.
Note 1:  SB 747-31-2368, Revision 1, refers to Rockwell Collins Service Bulletin EIU-7000-31-502, dated 21 March 2006, as an additional source of service information for modifying an EIU by adding auto restart circuitry, which converts EIU P/N 622-8589-104 to P/N 622-8589-105.
Actions accomplished before the effective date of this Directive in accordance with Boeing SB 747-31-2368, dated 22 November 2005 (Revision 1 of the service bulletin specifies that the original issue is dated 1 December 2005), are considered acceptable for compliance with the corresponding requirements of this Directive.
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 2008-13-22, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Replacing an EIU with a new or modified EIU in accordance with Requirement 1 of this Directive constitutes terminating action for the EIU replacement (Requirement 3 of AD/B747/308 or paragraph (d)(1) of FAA AD 2004-10-05), provided that the other two EIUs are replaced with EIUs having P/N 622-8589-104 or P/N 622-8589-105.  All other actions required by Requirement 1 of AD/B747/308 or paragraph (d)(1) of AD 2004-10-05 must be complied with.
Note:  FAA AD 2008-13-22 Amdt 39-15585 refers.
Compliance:	Within 24 months after the effective date of this AD.
This Airworthiness Directive becomes effective on 18 December 2008.

Background: This Directive results from two instances where all six integrated display units (IDUs) on the flight deck panels went blank in flight.  The Directive is issued to prevent loss of the IDUs due to failure of all three EFIS/EICAS EIUs, which could result in the inability of the flightcrew to maintain safe flight and landing of the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

6 November 2008