2007-12-07: Electronic control units (ECUs)

2007-12-07 General Electric Company: Amendment 39-15085. Docket No. FAA-2006-25738; Directorate Identifier 2006-NE-27-AD. Effective Date (a) This airworthiness directive (AD) becomes effective July 11, 2007. Affected ADs (b) None. Applicability (c) This AD applies to General Electric Company (GE) CF6- 80C2B1F, -80C2B2F, -80C2B4F, -80C2B5F, -80C2B6F, -80C2B6FA, - 80C2B7F, and -80C2B8F turbofan engines with electronic control units (ECUs), installed on Boeing 747 and 767 series airplanes. Unsafe Condition (d) This AD results from reports of engine flameout events during flight, including reports of events where all engines simultaneously experienced a flameout or other adverse operation. We are issuing this AD to provide increased margin to flameout, which will minimize the potential of an all-engine flameout event caused by ice accretion and shedding during flight. Exposure to ice crystals during flight is believed to be associated with these flameout events. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Interim Action (f) These actions are interim actions due to the on-going investigation, and we may take further rulemaking actions in the future based on the results of the investigation and field experience. Engine ECU Software Installation for Boeing 767 Series Airplanes (g) For Boeing 767 series airplanes: (1) All affected engines must have ECU software version 8.2.Q1 installed at next engine shop visit or ECU shop visit, whichever occurs first, but no later than five years after the effective date of this AD. (2) Within 24 months after the effective date of this AD, at least one of the airplane's affected engines must have ECU software version 8.2.Q1 installed. (3) Do the software installations specified in paragraphs (g)(1) and (g)(2) of this AD using paragraphs 3.A. through 3.B.(3)(f)4. of the Accomplishment Instructions of GE Service Bulletin No. CF6-80C2 S/B 73-0339, Revision 1, dated April 24, 2007. Engine ECU Software Installation for Boeing 747 Series Airplanes (h) For Boeing 747 series airplanes: (1) All affected engines must have ECU software version 8.2.Q1 installed at next engine shop visit or ECU shop visit, whichever occurs first, but no later than five years after the effective date of this AD. (2) Do the software installations specified in paragraph (h)(1) of this AD using paragraphs 3.A. through 3.B.(3)(f)4. of the Accomplishment Instructions of GE Service Bulletin No. CF6-80C2 S/B 73-0339, Revision 1, dated April 24, 2007. Reverting to Previous Software Versions of ECU Software (i) After the effective date of this AD: (1) Once software version 8.2.Q1 is installed in an ECU, reverting to previous versions of ECU software in that ECU is prohibited. (2) For a period of 24 months after the effective date of this AD, once an ECU containing software version 8.2.Q1 is installed on an engine, that ECU can be replaced with an ECU containing a previous software version. The calendar time requirements in paragraphs (g) and (h) of this AD are not to be exceeded. (3) After 24 months from the effective date of this AD, once an ECU containing software version 8.2.Q1 is installed on an engine, if the ECU needs to be replaced for any reason, it must only be replaced by another ECU containing version 8.2.Q1 software. Definitions (j) For the purposes of this AD: (1) Next shop visit of the engine ECU is when the ECU is removed from the engine for overhaul or for maintenance. (2) Next shop visit of the engine is when the engine is removed from the airplane for maintenance in which a major engine flange is disassembled after the effective date of this AD. The following engine maintenance actions, either separately or in combination with each other, are not considered a next engineshop visit: (i) Removal of the upper high pressure compressor (HPC) stator case solely for airfoil maintenance. (ii) Module-level inspection of the HPC rotor stages 3-9 spool. (iii) Replacement of stage 5 HPC variable stator vane bushings or lever arms. (iv) Removal of the accessory gearbox. (v) Replacement of the inlet gearbox polytetrafluoroethylene seal. Alternative Methods of Compliance (k) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Special Flight Permits (l) Under 14 CFR part 39.23, special flight permits are prohibited. Material Incorporated by Reference (m) You must use General Electric Company Service Bulletin No. CF6-80C2 S/B 73-0339, Revision 1, dated April 24, 2007, to perform the installation required by this AD. The Director of the Federal Register approved the incorporation by reference of this servicebulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact General Electric Company via Lockheed Martin Technology Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone (513) 672-8400, fax (513) 672-8422 for a copy of this service information. You may review copies at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html .