2009-18-13: HP Turbine Nozzle Guide Vane (NGV) Convex Surfaces

2009-18-13 Rolls-Royce plc: Amendment 39-16009.; Docket No. FAA- 2009-0771; Directorate Identifier 2009-NE-14-AD. Effective Date (a) This airworthiness directive (AD) becomes effective October 14, 2009. Affected ADs (b) None. Applicability (c) This AD applies to Rolls-Royce plc (RR) model RB211 Trent 970-84, 970B-84, 972-84, 972B-84, 977-84, 977B-84, and 980-84 turbofan engines that do not incorporate RR modification Service Bulletin (SB) RB.211-72-G025. These engines are installed on, but not limited to, Airbus A380 airplanes. Reason (d) Evidence from development testing and flight test Trent 900 engines has identified cracking on some HP Turbine Nozzle Guide Vane (NGV) Convex Surfaces. Analysis of test data and review of the manufacturing process has revealed compounding effects that may contribute to a shortfall in component life and an increased likelihood of premature cracking in this region. Excessive cracking on the Convex Surface may lead tothe release of NGV material or the blockage of Turbine gas flow. This results in a risk of fracture to the HP Turbine Blade. We are issuing this AD to prevent the release of a high-pressure (HP) turbine blade, which could result in an engine power loss or in-flight shut down of one or more engines, resulting in an inability to continue safe flight. Actions and Compliance First Inspection (e) Before accumulating 400 total cycles, inspect the HPT NGV Convex Surfaces, in accordance with the accomplishment instructions in section 3.A of Rolls-Royce RB211-Trent 900 Alert Non Modification Service Bulletin (NMSB) RB.211-72-AF995 Revision 2, dated February 9, 2009. Reinspection (f) If no damage is identified at first inspection: (1) Repeat the inspection at intervals less than 250 Cycles apart. (2) If repeat inspections reveal no damage at 1000 cycles revert to normal inspection maintenance as detailed in the Rolls-Royce RB211-Trent 900 Maintenance Planning Document (MPD), and sign off this AD as complied with; no further inspections are required by this AD. (g) If any damage is identified, refer to the Table 1 and Table 2 in section 3.B. of Rolls-Royce RB211-Trent 900 Alert NMSB RB.211- 72-AF995 Revision 2, dated February 9, 2009, for reinspection intervals and rejection criteria. FAA AD Differences (h) None. Other FAA AD Provisions (i) Alternative Methods of Compliance (AMOCs): The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Related Information (j) Refer to MCAI EASA Airworthiness Directive 2009-0051, dated March 5, 2009. (k) Contact Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park; Burlington, MA 01803; e-mail: [email protected]; telephone (781) 238-7178; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (l) You must use RR Alert Non Mandatory Service Bulletin RB.211- 72-AF995 Revision 2, dated February 9, 2009, to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For service information identified in this AD, contact Rolls-Royce plc, P.O. Box 31, DERBY, DE24 8BJ, UK; telephone 44 (0) 1332 242424; fax 44 (0) 1332 249936. (3) You may review copies at the FAA, New England Region, 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.