2026-07-06: Turbine Section

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2026-07-06 Pratt & Whitney: Amendment 39-23301; Docket No. FAA-2025-0918; Project Identifier AD-2024-00526-E. (a) Effective Date This airworthiness directive (AD) is effective May 29, 2026. (b) Affected ADs None. (c) Applicability This AD applies to Pratt & Whitney (PW) Model F117-PW-100, PW2037, PW2037D, PW2037M, PW2040, and PW2040D engines. (d) Subject Joint Aircraft System Component (JASC) Code 7250, Turbine Section. (e) Unsafe Condition This AD was prompted by an updated analysis of an event involving an International Aero Engines, LLC Model PW1127GA-JM engine, which experienced a high-pressure compressor 7th-stage integrally bladed rotor separation that resulted in an engine shutdown and aborted takeoff. The FAA is issuing this AD to prevent failure of the high-pressure turbine (HPT) 1st-stage disk, and turbine hub. The unsafe condition, if not addressed, could result in uncontained disk failure, release of high-energy debris, damage to the engine, damage to the airplane, and possible loss of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) At the next piece-part exposure after the effective date of this AD and thereafter at every piece-part exposure, do an angled ultrasonic inspection (AUSI) of the HPT 1st-stage disk for any crack indications in accordance with Paragraph 4. of the Accomplishment Instructions of PW Alert Service Bulletin (ASB) PW2000 A72-779, Revision No. 1, dated December 17, 2025, or Paragraph 4. of the Accomplishment Instructions of PW ASB PWF117 A72-434, dated May 1, 2024, as applicable to the engine model. (2) At the next piece-part exposure after the effective date of this AD and thereafter at every piece-part exposure, do an AUSI of the turbine hub for any crack indications in accordance with Paragraph 4. of the Accomplishment Instructions of PW ASB PW2000 A72-780, dated May 2, 2024, or Paragraph 4. of the Accomplishment Instructions of PW ASB PWF117 A72-433, dated May 1, 2024, as applicable to the engine model. (3) If, during any inspection required by paragraph (g)(1) or (2) of this AD, any crack indication is found, remove the affected part from service and replace with a part eligible for installation. (4) For engines with an installed HPT lenticular seal assembly having a part number (P/N) and serial number (S/N) identified in figure 1 to paragraph (g)(4) of this AD: At the next piece-part exposure after the effective date of this AD, remove the HPT lenticular seal assembly from service and replace with a part eligible for installation. Figure 1 to Paragraph ( g )(4)-Affected HPT Lenticular Seal Assemblies P/N S/N 1B8575 DKLBG48210 1B8575 DKLBG48244 1B8575 * DKLBGY5898 1B8575 * DKLBGY5907 1B8575 * DKLBGY5908 1B8575 * DKLBGY5911 1B8575 * DKLBGY5913 1B8575 * DKLBGY5915 1B8575 * DKLBGY5916 1B8575 DKLBGY5919 1B8575 * DKLBGY5921 1B8575 DKLBGY5922 1B8575 * DKLBGY5923 1B8575 * DKLBGY5924 1B8575 * DKLBGY5925 1B8575 * DKLBGY5926 1B8575 * DKLBGY5928 1B8575 * DKLBGY5929 1B8575 * DKLBGY5930 1B8575 * DKLBGY5931 1B8575 * DKLBGY5932 1B8575 * DKLBGY5934 1B8575 * DKLBGY5935 1B8575 DKLBGY5936 1B8575 * DKLBGY5937 1B8575 * DKLBGY5938 1B8575 * DKLBGY5939 1B8575 * DKLBGY5940 1B8575 * DKLBGY5941 1B8575 * DKLBGY5943 1B8575 DKLBGY5944 1B8575 DKLBGY5945 1B8575 DKLBGY5946 1B8575 DKLBGY5948 1B8575 DKLBGY5949 1B8575 DKLBGY5952 1B8575 DKLBGY5953 1B8575 DKLBGY5959 * Serial numbers are PW Model F117-PW-100 engines which are not installed on U.S. registered airplanes. (5) For an HPT lenticular seal assembly having P/N 1B8575 and S/N DKLBG48292: At the next piece-part exposure after the effective date of this AD or before exceeding 2,750 cycles since new, whichever occurs first, remove the HPT lenticular seal assembly from service and replace with a part eligible for installation. (h) Definitions (1) For the purpose of this AD, a "piece-part exposure" is: (i) For paragraph (g)(1) of this AD, when the HPT 1st-stage disk is removed from the engine and all blades, all retaining plates, and all air seals are removed from the HPT 1st-stage disk. (ii) For paragraph (g)(2) of this AD, when the turbine hub is removed from the engine and all blades and all retaining plates are removed from the turbine hub. (iii) For paragraph (g)(4) of this AD, when the HPT lenticular seal assembly is removed from either the HPT 1st-stage disk or the HPT 2nd-stage hub. (2) For the purpose of this AD, a "part eligible for installation" is: (i) An HPT 1st-stage disk having P/N 1B7801, 1B3601, or 1B3601-001 that has passed the AUSI required by paragraph (g)(1) of this AD. (ii) An HPT 1st-stage disk having P/N 1B7801, 1B3601, or 1B3601-001, that has a certificate of conformance that shows compliance with Non-Destructive Inspection Procedure (NDIP)-1282. (iii) A new zero-time HPT 1st-stage disk having P/N 1B7801, 1B3601, or 1B3601-001 that has an FAA Form 8130-3 from the original equipment manufacturer for new production dated March 1, 2025, or later. (iv) A turbine hub having P/N 1B4902, 1B6602, or 1B8002 that has passed the AUSI required by paragraph (g)(2) of this AD. (v) A turbine hub having P/N 1B4902, 1B6602, or 1B8002 that has a certificate of conformance that shows compliance with NDIP-1283. (vi) A new zero-time turbine hub having P/N 1B4902, 1B6602, or 1B8002 that has an FAA Form 8130-3 from the original equipment manufacturer for new production dated March 1, 2025, or later. (vii) Any HPT lenticular seal assembly that does not have a part number and serial number identified in figure 1 to paragraph (g)(4) of this AD (i) Optional Terminating Action Revising the airworthiness limitations section (ALS) of the existing engine manual and the operator's existing approved maintenance program or inspection program, as applicable, by incorporating the information in figure 2 to paragraph (i) of this AD, constitutes terminating action for the inspections required by paragraphs (g)(1) through (3) of this AD. Figure 2 to Paragraph ( i )-ALS Additional Inspections Engine manual Chapter/ section HPT enhanced inspection requirements Section Additional inspection PW2000 1A6231 05-10-00 Table 807 Revision Date: 2025-02-01. HPT 1st-stage disk 72-52-02 Immersion Ultrasonic inspect disk. Refer to 72-52-02, Inspection/Check-07 (Task 72-52-02-200-008). Hub-HPT Stage 2 72-52-16 Immersion Ultrasonic inspect hub. Refer to 72-52-16, Inspection/Check-08 (Task 72-52-16-200-009). F117-PW-100 1B2412 05-10-00 Table 802 Revision Date: 2025-02-01. HPT 1st-stage disk 72-52-02 Immersion Ultrasonic inspect disk. Refer to 72-52-02, Inspection/Check-07 (Task 72-52-02-200-007). Hub-HPT Stage 2 72-52-16 Immersion Ultrasonic inspect hub. Refer to 72-52-16, Inspection/Check-08 (Task 72-52-16-200-008). (j) Installation Prohibition (1) As of the effective date of this AD, no person may install on any engine, an HPT 1st-stage disk having P/N 1B7801, 1B3601, or 1B3601-001, unless it is a part eligible for installation as defined in paragraph (h)(2) of this AD. (2) As of the effective date of this AD, no person may install on any engine, a turbine hub having P/N 1B4902, 1B6602, or 1B8002, unless it is a part eligible for installation as defined in paragraph (h)(2) of this AD. (3) As of the effective date of this AD, no person may install on any engine, an HPT lenticular seal assembly having a part number and serial number identified in figure 1 to paragraph (g)(4) of this AD. (k) Alternative Methods of Compliance (AMOCs) (1) The Manager, AIR-520 Continued Operational Safety 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 14 CFR 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 AIR-520 Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (l) of this AD and email to: AMOC@faa.gov. (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. (l) Additional Information For more information about this AD, contact Molly Sturgis, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (562) 627-5373; email: molly.a.sturgis@faa.gov. (m) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) Pratt & Whitney (PW) Alert Service Bulletin (ASB) PW2000 A72-779, Revision No. 1, dated December 17, 2025. (ii) PW ASB PW2000 A72-780, dated May 2, 2024. (iii) PW ASB PWF117 A72-433, dated May 1, 2024. (iv) PW ASB PWF117 A72-434, dated May 1, 2024. (3) For PW material identified in this AD, contact PW, 400 Main Street, East Hartford, CT 06118; phone: (860) 565-0140; email: help24@prattwhitney.com; website: connect.prattwhitney.com. (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110. (5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email fr.inspection@nara.gov. Issued on April 10, 2026. Brian Knaup, Acting Deputy Director, Integrated Certificate Management Division,Aircraft Certification Service. [FR Doc. 2026-08106 Filed 4-23-26; 8:45 am]BILLING CODE 4910-13-P