2005-18-01: Turbine aft cooling plate boltholes

2005-18-01 General Electric Company: Amendment 39-14241. Docket No. FAA-2005-20944; Directorate Identifier. 2003-NE-64-AD. Effective Date (a) This airworthiness directive (AD) becomes effective October 24, 2005. Affected ADs (b) None. Applicability (c) This AD applies to General Electric Company (GE) CT7-5A2, - 5A3, -7A, -7A1, -9B, -9B1, and -9B2 turboprop engines, with stage 2 turbine aft cooling plate, part number (P/N) 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01 installed. These engines are installed on, but not limited to, Construcciones Aeronauticas, SA CN-235 series and SAAB Aircraft AB SF340 series airplanes. Unsafe Condition (d) This AD results from reports of six stage 2 turbine aft cooling plates found cracked during inspection. The actions specified in this AD are intended to prevent stage 2 aft cooling plate separation, resulting in uncontained engine failure and damage to the airplane. Compliance (e) You are responsiblefor having the actions required by this AD performed at the next engine or hot section module shop visit, but before accumulating an additional 6,000 cycles-in-service after the effective date of the AD, unless already done. Onetime Eddy Current Inspection (ECI) (f) Perform a onetime ECI of the stage 2 turbine aft cooling plate boltholes, using paragraph 3.B. of GE Alert Service Bulletin (ASB) No. CT7-TP S/B 72-A0464, Revision 2, dated May 9, 2003. (g) Remove from service any stage 2 turbine aft cooling plate that does not pass the return to service criteria specified in paragraph 3.B.(2) of GE Alert Service Bulletin (ASB) No. CT7-TP S/B 72-A0464, Revision 2, dated May 9, 2003. Previous Credit (h) Previous credit is allowed for onetime ECIs of the stage 2 turbine aft cooling plate boltholes that were done using GE ASB No. CT7-TP S/B 72-A0464, dated February 25, 2003, or GE ASB No. CT7-TP S/B 72-A0464, Revision 1, dated March 12, 2003, before the effective date ofthis AD. Definition of Engine or Hot Section Module Shop Visit (i) For the purposes of this AD, an engine or hot section module shop visit is defined as the introduction of the engine or hot section module into a shop that includes separation of CT7 turboprop engine major case flanges. Alternative Methods of Compliance (j) 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. Related Information (k) None. Material Incorporated by Reference (l) You must use GE Alert Service Bulletin (ASB) No. CT7-TP S/B72-A0464, Revision 2, dated May 9, 2003, to perform the inspection required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact General Electric Aircraft Engines CT7 Series Turboprop Engines, 1000 Western Ave., Lynn, MA 01910; telephone (781) 594-3140, fax (781) 594-4805, for a copy of this service information. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001, on the Internet at http://dms.dot.gov, 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 .