2011-25-08: High- pressure turbine (HPT) case burn-through events

Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: PART 39--AIRWORTHINESS DIRECTIVES 0 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Sec. 39.13 [Amended] 0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): 2011-25-08 International Aero Engines: Amendment 39-16884; Docket No. FAA-2010-0494; Directorate Identifier 2010-NE-20-AD. (a) Effective Date This AD is effective January 17, 2012. (b) Affected ADs None. (c) Applicability This AD applies to International Aero Engines (IAE) V2500-A1, V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528- D5, V2530-A5, and V2533-A5 turbofan engines. (d) Unsafe Condition This AD results from three reports received of high-pressure turbine (HPT) case burn-through events. There have also been numerous shop reports of loss of stage 1 blade outer air seal segments, and HPT case bulging. We are issuing this AD to prevent HPT case burn-through, uncontrolled under-cowl engine fire, and damage to the airplane. (e) Compliance (1) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. (2) For engines that have incorporated IAE Service Bulletin (SB) No. V2500-ENG-72-0483, Revision 3 or earlier, or IAE SB No. V2500- ENG-72-0542, Revision 1 or earlier, no further action is required. (f) Borescope Inspections (1) Perform 360 degree borescope inspections of the HPT stage 1 blade outer air seal segments for evidence of the distress conditions listed in Appendix D of IAE SB No. V2500-ENG-72-0580, Revision 3, dated August 23, 2011. (2) For V2525-D5 and V2528-D5 turbofan engines: (i) Inspect within 1,000 operating hours after the engine meets all criteria as defined in Table 1 of this AD, or within 600 operating hours after the effective date of this AD, whichever is greater. (ii) Thereafter, re-inspect within every 1,000 operating hours or as defined in Appendix D of IAE SB No. V2500-ENG-72-0580, Revision 3, dated August 23, 2011, whichever is less. (iii) Use Accomplishment Instructions paragraphs 3.B.(1) through 3.B.(3), and Appendices A through D of IAE SB No. V2500-ENG-72-0580, Revision 3, dated August 23, 2011, to do these inspections. (3) For V2500-A1, V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-A5, and V2533-A5 turbofan engines: (i) Inspect within 1,200 operating hours after the engine meets all criteria as defined in Table 1 of this AD, or within 600 operating hours after the effective date of this AD, whichever is greater. (ii) Thereafter, re-inspect within every 1,200 operating hours or as defined in Appendix D of IAE SB No. V2500-ENG-72-0580, Revision 3, dated August 23, 2011, whicheveris less. (iii) Use Accomplishment Instructions paragraphs 3.A.(1) through 3.A.(3), and Appendices A through D of IAE SB No. [[Page 77111]] V2500-ENG-72-0580, Revision 3, dated August 23, 2011, to do these inspections. Table 1--Stage 1 Blade Outer Air Seal Segment Inspection Compliance Criteria ---------------------------------------------------------------------------------------------------------------- Stage 1 blade outer air Stage 1 blade outer air Exhaust gas seal segments hours- seal segments cycles- temperature margin Engine model since-new or since-last- since-new or since-last- degrees Celsius (less repair (greater than) repair (greater than) than) ---------------------------------------------------------------------------------------------------------------- A1................................... 6,000 3,800 45 A5................................... 6,000 3,500 45 D5................................... 5,000 3,500 45 ---------------------------------------------------------------------------------------------------------------- (4) Exhaust Gas Temperature Margin is defined as the expected margin during a sea-level takeoff on a 30-degree Celsius Outside Air Temperature Day. Guidance on how to calculate EGT margin can be found in IAE SIL 057. EGT margin smoothed data (data averaged over 6 consecutive flights) is to be compared with the criteria in Table 1. If a gap in EGT data exists due to temporary loss of data, you may use linear interpolation. Calculate operating hours from the point when all criteria exceed the requirements in Table 1. (5) Except as provided below, the inspection of paragraphs (f)(2)(i) through (f)(2)(iii) and (f)(3)(i) through (f)(3)(iii) must be performed after all the criteriain Table 1 are satisfied; regardless of subsequent EGT margin calculations or engine rating changes. Temporary EGT margin excursions below the criteria in Table 1 that are corrected with simple troubleshooting methods (e.g., LRU (line replaceable unit) replacement or correction of a measurement error) do not constitute satisfying the criteria in Table 1. (g) Mandatory Terminating Action (1) As terminating action to the repetitive 360 degree borescope inspections required in paragraphs (f)(2)(ii) and (f)(3)(ii) above, install improved durability stage 1 blade outer air seal segments at the next HPT module subassembly exposure, which is defined as separation of the HPT module mating flanges. (i) For V2500-A1 turbofan engines, use paragraphs 1.B., Concurrent Requirements, and paragraphs 3.(1)(a), 3.(1)(b)(iii), and 3.(2)(a) of the Accomplishment Instructions of IAE SB No. V2500-ENG- 72-0542, Revision 1, dated January 7, 2009, to do the installation. (ii) For V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, and V2533-A5 turbofan engines, use paragraphs 1.B., Concurrent Requirements, and paragraphs 3.(1)(a), 3.(1)(b), 3.(1)(c)(ii), and 3.(2)(a) of the Accomplishment Instructions of IAE SB No. V2500-ENG-72-0483, Revision 3, dated January 7, 2009, to do the installation. (iii) Both IAE SBs No. V2500-ENG-72-0542, Revision 1, and SB No. V2500-ENG-72-0483, Revision 3, require modification of the stage 1 HPT support assembly before installing the new blade outer air seal segments. You must complete the modification using those SBs, as applicable to the appropriate engine model, to properly perform the mandatory terminating action of this AD. (h) Alternative Methods of Compliance The Manager, Engine Certification Office, may approve alternative methods of compliance for this AD. Use the procedures found in 14 CFR 39.19 to make your request. (i) Related Information (1) For more information about this AD,contact Carlos Fernandes, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: (781) 238-7189; fax: (781) 238-7199; email: carlos.fernandes@faa.gov. (2) Contact International Aero Engines AG, 628 Hebron Avenue Suite 400, Glastonbury, CT 06033; phone: (860) 368-3700; fax: (860) 368-4600; email: iaeinfo@iaev2500.com; Web site: https://www.iaeworld.com; for a copy of the service information referenced in this AD. (j) Material Incorporated by Reference (1) You must use the following service information to do the actions required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51 of the following service information on the date specified: (i) International Aero Engines (IAE) SB No. V2500-ENG-72-0580, Revision 3, dated August 23, 2011, approved for IBR January 17, 2012. (ii) IAE SB No. V2500-ENG-72-0542, Revision 1, dated January 7, 2009, approved for IBR January 17, 2012. (iii) IAE SB No. V2500-ENG-72-0483, Revision 3, dated January 7, 2009, approved for IBR January 17, 2012. (2) For service information identified in this AD, contact International Aero Engines AG, 628 Hebron Avenue, Suite 400, Glastonbury, CT 06033; phone: (860) 368-3700; fax: (860) 368-4600; email: iaeinfo@iaev2500.com; Web site: https://www.iaeworld.com. (3) You may review copies of the service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call (781) 238-7125. (4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.