2026-21-11: Turbine Engine Compressor 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: 2026-21-11 General Electric Company: Amendment 39-23500; Docket No. FAA-2025-3998; Project Identifier AD-2025-00432-E. (a) Effective Date This airworthiness directive (AD) is effective November 27, 2026. (b) Affected ADs None. (c) Applicability This AD applies to the General Electric Company (GE) Model engines identified in paragraphs (c)(1) and (2) of this AD. (1) CF34-8C1, CF34-8C5, CF34-8C5A1, CF34-8C5A2, and CF34-8C5B1 engines with an electronic engine control (EEC) full authority digital electronic control (FADEC) part number (P/N) 4120T00P29, 4120T00P30, 4120T00P37, 4120T00P38, 4120T00P45, 4120T00P46, 4120T00P53, 4120T00P54, 4120T00P57, or 4120T00P58 installed. (2) CF34-8E2, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E5A2HA, CF34-8E6, and CF34-8E6A1 engines with an EEC FADEC P/N 4120T00P42 (VIN 111E9320G43), P/N 4120T00P44 (VIN 111E9320G45), P/N 4120T00P48 (VIN 111E9320G49), P/N 4120T00P50 (VIN 111E9320G51), or P/N 4120T00P60 (VIN 111E9320G61) installed. (d) Subject Joint Aircraft System Component (JASC) Code 7230, Turbine Engine Compressor Section. (e) Unsafe Condition This AD was prompted by an "Engine Degraded" message received in-flight from the engine indicating and crew alerting system, due to corrosion of the variable geometry system actuator. The FAA is issuing this AD to prevent EEC FADEC software from automatically locking the engine at idle until it is restarted. The unsafe condition, if not addressed, could result in failure of one or more engines, loss of engine thrust control, and consequent reduced control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Definitions For the purpose of this AD: (1) "Group 1 engines" are GE Model CF34-8C1, CF34-8C5, CF34-8C5A1, CF34-8C5A2, and CF34-8C5B1 engines. (2) "Group 2 engines" are GE Model CF34-8E2, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E5A2HA, CF34-8E6, and CF34-8E6A1 engines. (3) An "EEC FADEC software version that is eligible for installation" on Group 1 engines is any software version that is V6.60 or later approved version. (4) An "EEC FADEC software version that is eligible for installation" on Group 2 engines is any software version that is V5.70 or later approved version. (h) Required Actions (1) For Group 1 engines, within 12 months after the effective date of this AD, replace any EEC FADEC software version that is V6.50 or earlier with an EEC FADEC software version that is eligible for installation. (2) For Group 2 engines, within 12 months after the effective date of this AD, replace any EEC FADEC software version that is V5.60 or earlier with an EEC FADEC software version that is eligible for installation. (i) 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 AIR-520, Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (j) of this AD and email to: [email protected] . (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. (j) Additional Information For more information about this AD, contact Daiyun Fang, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (206) 910-0063; email: [email protected]. (k) Material Incorporated by Reference None. Issued on October 19, 2026. Brian Knaup, Acting Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service. [FR Doc. 2026-21590 Filed 10-21-26; 8:45 am]BILLING CODE 4910-13-P