2021-14-13: Turbine Section

The Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive: \n\n2021-14-13 Pratt & Whitney: Amendment 39-21640; Docket No. FAA-2020- 0442; Project Identifier AD-2020-00260-E. \n\n(a) Effective Date \n\n\n\tThis airworthiness directive (AD) is effective September 1, 2021. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\tThis AD applies to all Pratt & Whitney (PW) PW2037, PW2037M, PW2040, and F117-PW-100 model turbofan engines. \n\n(d) Subject \n\n\n\tJoint Aircraft System Component (JASC) Code 7250, Turbine Section. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by a report of an uncontained engine failure resulting from cracks originating in the knife edge of the high-pressure turbine (HPT) 2nd-stage air seal assembly. The FAA is issuing this AD to prevent failure of the HPT 2nd-stage air seal assembly. The unsafe condition, if not addressed, could result in uncontained HPT 2nd-stage air seal assembly release, damage to the engine, and damage to the airplane. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Required Actions \n\n(1) Visual Inspection and Fluorescent Penetrant Inspection (FPI) of HPT 2nd-Stage Air Seal Assembly \n\n\n\tAfter the effective date of this AD, at every piece-part opportunity of the HPT 1st-stage disk, HPT 2nd-stage hub, or the HPT 2nd-stage air seal assembly: \n\t(i) Perform a visual inspection of the HPT 2nd-stage air seal assembly, strip the knife edge coating from the HPT 2nd-stage air seal assembly, and then perform an FPI of the HPT 2nd-stage air seal assembly. \n\tNote 1 to paragraph (g)(1)(i): Guidance on striping the knife edge coating from the HPT 2nd-stage air seal assembly required by paragraph (g)(1)(i) of this AD can be found Chapter 72-52-60, Repair-01, of the PW2000 Series Engine Manual. \n\t(ii) If a crack is found in the HPT 2nd-stage air seal assembly during the visual inspection or FPI required by paragraph (g)(1)(i) of this AD, remove the HPT 2nd-stage air seal assembly from service and replace it with a part eligible for installation. \n\n((Page 40305)) \n\n\n\t(iii) During the visual inspection or FPI required by paragraph (g)(1)(i) of this AD, if a crack is found in the shaded regions of the HPT 2nd-stage air seal assembly identified in Figure 1 to paragraph (g)(1)(iii) of this AD (Figure 1), which extends towards the knife-edge region of the HPT 2nd-stage air seal assembly, remove the HPT 2nd-stage air seal assembly, mating HPT 1st-stage disk, and HPT 2nd-stage hub from service, and replace the parts with parts eligible for installation. In order to return the mating HPT 1st- stage disk and HPT 2nd-stage hub to service, the inspections of the HPT 2nd-stage air seal assembly cannot reveal a crack identified in the shaded regions of Figure 1, which extends towards the knife-edge region. (GRAPHIC) (TIFF OMITTED) TR28JY21.013 \n\n(2) Replacement of HPT 2nd-Stage Air Seal Assembly \n\n\n\t(i) For PW PW2037, PW2037M, and PW2040 model turbofan engines, at the next engine shop visit after the effective date of this AD, remove the HPT 2nd-stage air seal assembly, part number (P/N) 1A8209 or 1A8209-001, and replace it with a part eligible for installation. \n\t(ii) For PW F117-PW-100 model turbofan engines, at the next piece part opportunity after the effective date of this AD, remove the HPT 2nd-stage air seal assembly, P/N 1A8209 or 1A8209-001, and replace it with a part eligible for installation. \n\n(h) Definitions \n\n\n\t(1) For the purpose of this AD, an ''engine shop visit'' is the induction of an engine into the shop for maintenance involving the separation of the N or M engine flange. The separation of engine flanges solely for the purposes of transportation of the engine without subsequent engine maintenance does not constitute an engine shop visit. \n\t(2) For the purpose of this AD, a ''piece-part opportunity'' is: \n\t(i) For the HPT 1st-stage disk, when the disk is removed from the engine and all the blades are removed; \n\t(ii) For the HPT 2nd-stage hub, when the hub is removed from the engine and all the blades are removed; or \n\t(iii) For the HPT 2nd-stage air seal assembly, when the assembly is removed from either the HPT 1st-stage disk or the HPT 2nd-stage hub. \n\t(3) For the purpose of this AD, a ''part eligible for installation'' is an HPT 2nd-stage air seal assembly with a P/N other than 1A8209 or 1A8209-001. \n\n(i) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, ECO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in Related Information. You may email your request to: ANE-AD-AMOC@faa.gov. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. \n\n((Page 40306)) \n\n(j) Related Information \n\n\n\tFor more information about this AD, contact Carol Nguyen, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781) 238-7655; fax: (781) 238-7199; email: carol.nguyen@faa.gov. \n\n(k) Material Incorporated by Reference \n\n\n\tNone. \n\n\n\tIssued on June 30, 2021. Ross Landes, Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service. (FR Doc. 2021-15947 Filed 7-27-21; 8:45 am) BILLING CODE 4910-13-P