AD/B737/251 - Smiths Industries Aerospace Flight Management Computers (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/B737/251 Smiths Industries Aerospace Flight Management Computers 12/2005

Applicability: Model 737-300, -400, -500, -600, -700, -700C, -800 and -900 series aeroplanes, equipped with two Smiths Industries Aerospace Flight Management Computers (FMC) having part number 171497-05-01 or 176200-01-01; installed with operational program software (OPS) version U10.3, U10.4, U10.4A or U10.5. Requirement: 1. Carry out the following in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin (ASB) 737-34A1801, dated 15 July 2004 (for Model 737- 600, -700, -700C, -800 and -900 series aeroplanes) or Boeing ASB 737-34A1821, dated 15 July 2004 (for Model 737- 300, -400 and -500 series aeroplanes); as applicable. a. Install the updated version of the OPS, the compatible model/engine database (MEDB) software if applicable, the current version of the navigational database (NDB) software, and the software options database (OPC) in the left and right FMCs. b. Do configuration checks of the left and right FMCs to ensure that the updated version of the OPS, compatible version of the MEDB software if applicable, and OPC software is correctly installed. 2. If the incorrect software version of the OPS, MEDB software if applicable, or OPC software is found installed on any FMC during any configuration check required by Requirement 1, reinstall the applicable software in accordance with the Accomplishment Instructions ASB 737-34A1801 or ASB 737-34A1821, as applicable. Optional installation of software in accordance with the Accomplishment Instructions of Boeing Service Bulletin (SB) 737-34-1768, dated 11 August 2005 (for Model 737-600, -700, -700C, -800 and -900 series aeroplanes); or Boeing SB 737-34-1879, dated 11 August 2005 (for Model 737-300, -400 and -500 series aeroplanes), as applicable, is acceptable for compliance with the corresponding requirements of Requirements 1 and 2 providing the following sub-paragraphs are followed: