2012-14-09: 3rd and 4th stage vane fractures

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): 2012-14-09 Pratt & Whitney Division: Amendment 39-17123; Docket No. FAA-2012-0060; Directorate Identifier 2012-NE-02-AD. (a) Effective Date This AD is effective November 7, 2012. (b) Affected ADs None. (c) Applicability This AD applies to the following Pratt & Whitney Division turbofan engines: (1) PW4000-94'' engine models PW4050, PW4052, PW4056, PW4152, PW4156, PW4650, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4156A, PW4158, PW4160, PW4460, and PW4462 including models with any dash number suffix. (2) PW4000-100''engine models PW4164, PW4164C, PW4164C/B, PW4168, PW4168A, PW4164-1D, PW4164C-1D, PW4164C/B-1D, PW4168-1D, PW4168A-1D, and PW4170. (d) Unsafe Condition This AD was prompted by reports of 3rd and 4th stage vane fractures in the low-pressure turbine (LPT) of certain PW4000-94'' and PW4000-100'' turbofan engines. These fractures caused an uncontained engine failure and an LPT case puncture, and resulted in multiple in flight shutdowns. We are issuing this AD to prevent 3rd and 4th stage vane fractures in the LPT, damage to the LPT rotor, uncontained engine failure, and damage to the airplane. (e) Compliance Comply with this AD within the compliance times specified, unless already done. (1) At the next LPT overhaul, do the following: (i) Remove LPT 4th stage vanes that have a P/N listed in Table 1 to paragraph (e) of this AD from service if more than one strip and recoat repair has been performed. Table 1 to Paragraph (e)--Affected LPT 4th Stage Vane P/Ns ------------------------------------------------------------------------ ------------------------------------------------------------------------ 50N174 50N674-01 51N174-001 51N374-001 52N574-01 50N474-01 50N774-01 51N174-002 51N674-01 52N674-01 50N474-001 50N774-001 51N174-003 52N274-01 51N774-01 50N574-01 51N174-01 51N374-01 52N474-01 52N774-01 ------------------------------------------------------------------------ (ii) Re-assemble the 3rd stage LPT rotor blades by alternating heavy blades next to light blades and balancing blades of similar weights 180 degrees across the rotor. (iii) Dimensionally examine index 13 through index 34 of the LPT 3rd stage vane cluster assembly. Use Table 2 to paragraph (e) of this AD and Figure 1, Figure 2, and Figure 3 to paragraph (e) of this AD to determine whether the vane is eligible for installation. Table 2 to Paragraph (e)--Determination ofVane Eligibility ---------------------------------------------------------------------------------------------------------------- Inspect: Eligible for installation limits: ---------------------------------------------------------------------------------------------------------------- 13.......................................... 1.820-1.830 inches (46.23-46.48 mm). 14.......................................... 1.920-1.930 inches (48.77-49.02 mm). 15.......................................... 3.200 inches (81.280 mm) Basic. 16.......................................... 0.900 inch (22.860 mm) Basic. 17.......................................... 0.365 inch (9.271 mm) Basic. 18.......................................... 0.350 inch (8.890 mm) Basic. 19.......................................... 0.160 inch (4.064 mm) Basic. 20.......................................... 0.772 inch (19.609 mm) Basic. 21.......................................... 72[deg]Basic. 22.......................................... 22.382 inch (568.503 mm) Radius--Origin on Plane S Basic. 23.......................................... 21.052 inch (534.721 mm) Radius--Origin on Plane S, concentric with Index 8 Basic. 24.......................................... Angle from Plane S to Plane SL 3[deg]4'37'' Basic. 25.......................................... Angle from Plane S to Plane SM 6[deg]9'14'' Basic. 26.......................................... 90[deg] Basic for typical airfoil section. 27: Distance from rear foot outer diameter surface to airfoil section along Planes S, SL, and SM. For Section B-B:.................... 5.241 inches (133.121 mm). [[Page 60292]] For Section E-E:.................... 3.181 inches (80.797 mm). For Section J-J:.................... 1.935 inches (49.149 mm). 28: Airfoil chord at Section J-J (1.935 1.346 inches (34.188 mm) minimum. inches (49.149 mm) from rear foot outer diametersurface at Planes S, SL, and SM). At Section E-E (3.181 inches (80.797 mm) 1.314 inches (33.376 mm) minimum. from rear foot outer diameter surface at Planes S, SL, and SM). At Section B-B (5.241 inches (133.121 1.188 inches (30.175 mm) minimum. mm) from rear foot outer diameter surface at Planes S, SL, and SM). 29: Airfoil thickness at Section J-J (1.935 0.239 inch (6.071 mm) minimum. inches (49.149 mm) from rear foot outer diameter surface at Planes S, SL, and SM). At Section E-E (3.181 inches (80.797 mm) 0.183 inch (4.648 mm) minimum. from rear foot outer diameter surface at Planes S, SL, and SM). At Section B-B (5.241 inches (133.121 0.139 inch (3.531 mm) minimum. mm) from rear foot outer diameter surface at Planes S, SL, and SM). 30: Distance to trailing edge measurement... 0.062 inch (1.575 mm). 31: Airfoil trailing edge thickness......... 0.030 inch (0.762 mm) minimum. 32: Dimension............................... 0.315-0.324 inch (8.001-8.230 mm) diameter. 33: Dimension............................... 6.785-6.795 inches (172.34-172.59 mm). 34: Dimension............................... 0.692-0.714 inch (17.58-18.14 mm). ---------------------------------------------------------------------------------------------------------------- BILLING CODE 4910-13-P [[Page 60293]] [GRAPHIC] [TIFF OMITTED] TR03OC12.000 [[Page 60294]] [GRAPHIC] [TIFF OMITTED] TR03OC12.001 [[Page 60295]] [GRAPHIC] [TIFF OMITTED] TR03OC12.002 BILLING CODE 4910-13-C (iv) Dimensionally examine index 23 and index 24 of the vane engagement slots on the rear turbine case, where the 3rd stage vane is installed. Use Table 3 to paragraph (e) of this AD and Figure 4 to paragraph (e) of this AD to determine whether the case is eligible for installation. Table 3 to Paragraph (e)--Determination of Case Eligibility ------------------------------------------------------------------------ Inspect: Eligible for installation limits: ------------------------------------------------------------------------ 23............................... 1.875 inch (47.625 mm) minimum. 24............................... 0.097 inch (2.464 mm) minimum. ------------------------------------------------------------------------ [[Page 60296]] [GRAPHIC] [TIFF OMITTED] TR03OC12.003 (v) Inspect the 44 LPT 4th stage vane cluster assemblies P/N 52N774-01 for casting identification ``51N554AT 1447 2S1C1'' and P/N 52N674-01 for casting identification ``51N454AT 655 2S1C1.'' Remove the vane cluster assembly from service if either of these casting identifications is found. (2) At the next high-pressure turbine (HPT) overhaul, re- assemble the 2nd stage HPT rotor blades by alternating heavy blades next to light blades and balancing blades of similar weights 180 degrees across the rotor. (f) Installation Prohibition After the effectivedate of this AD, do not install or reinstall into any engine any LPT 4th stage vanes with a P/N listed in Table 1 to paragraph (e) of this AD that are at piece-part exposure and have had more than one strip and recoat repair. (g) Definitions (1) For the purpose of this AD, an HPT or LPT overhaul occurs when all disks in the rotor are removed from the engine and the blades are removed. (2) For the purpose of this AD, piece-part exposure means that the part is removed from the engine and completely disassembled. (h) Alternative Methods of Compliance (AMOCs) The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request. (i) Related Information For more information about this AD, contact James Gray, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA; phone: 781-238-7742; fax: 781-238-7199; email: james.e.gray@faa.gov. (j) Material Incorporated by Reference None.