# AD 2025-18-13: Engine Controls - Type: Airworthiness directive - Status: Current - Products: Airbus Helicopters AS350B3, EC130B4 and EC130T2 - Effective: October 23, 2025 - Published: September 18, 2025, 90 FR 44962–44964 - Issued: September 26, 2025 - Issued as: Final rule - Supersedes: [AD 2020-24-07](https://openairdocs.org/ad/2020-24-07) - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - ATA chapter: 76 · Engine controls - Amendment: 39-23140 - Docket: FAA-2025-1108 (https://www.regulations.gov/docket/FAA-2025-1108) - Project: MCAI-2025-00428-R - Registered aircraft: 954 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/4b/97/4b9777052b8266b59a80bef9c37e184d7014e0adad794223e80f2575755580c1 (from https://www.govinfo.gov/content/pkg/FR-2025-09-18/pdf/2025-18083.pdf) - Federal Register: https://www.federalregister.gov/documents/2025/09/18/2025-18083/airworthiness-directives-airbus-helicopters - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADFRAWD-2025-19079-0000000000.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/2025-18-13 ## Summary The FAA is correcting an airworthiness directive (AD) that published in the Federal Register. That AD applies to certain Airbus Helicopters Model AS350B3, EC130B4, and EC130T2 helicopters. As published, a reference to a measurement in the regulatory text is incorrect. This document corrects that error. In all other respects, the original document remains the same. ## The airworthiness directive 1. The authority citation for part 39 continues to read as follows: 2. The FAA corrects § 39.13 by correcting the following airworthiness directive to read: 2025-18-13 Airbus Helicopters: Amendment 39-23140; Docket No. FAA-2025-1108; Project Identifier MCAI-2025-00428-R. ### (a) Effective Date This airworthiness directive (AD) is effective October 23, 2025. ### (b) Affected ADs This AD replaces AD 2020-24-07, Amendment 39-21337 (85 FR 78954, December 8, 2020) (AD 2020-24-07). ### (c) Applicability This AD applies to Airbus Helicopters Model AS350B3, EC130B4, and EC130T2 helicopters, certificated in any category. ### (d) Subject Joint Aircraft System Component (JASC) Code 7600, Engine Controls. ### (e) Unsafe Condition This AD was prompted by reports of the of the engine remaining in idle when the throttle twist grip was turned from the “IDLE” mode to the “FLIGHT” mode. The FAA is issuing this AD to correct the failure of one of the microswitches, 53Ka, 53Kb, or 65K which can prevent the pilot from switching from “IDLE” mode to “FLIGHT” mode during autorotation training making it impossible to recover from a practice autorotation and compelling the pilot to continue the autorotation to the ground. This condition could result in unintended touchdown to the ground at a flight-idle power setting during a practice autorotation, damage to the helicopter, and injury to occupants. ### (f) Compliance Comply with this AD within the compliance times specified, unless already done. ### (g) Requirements Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency AD 2023-0187R1, dated March 20, 2025 (EASA AD 2023-0187R1). ### (h) Exceptions to EASA AD 2023-0187R1 (1) Where EASA AD 2023-0187R1 refers to the effective dates identified in paragraphs (h)(1)(i) through (iii) of this AD, this AD requires using the effective date of this AD. (i) March 27, 2025 (the effective date of EASA AD 2023-0187R1). (ii) November 10, 2023 (the effective date of EASA AD 2023-0187, dated October 27, 2023). (iii) July 19, 2023 (the effective date of EASA AD 2023-0133, dated July 5, 2023). (2) Where EASA AD 2023-0187R1 refers to April 13, 2017 (the effective date of EASA AD 2017-0059, dated April 6, 2017), this AD requires using January 30, 2019 (the effective date of AD 2018-26-02, Amendment 39-19532 (83 FR 66093, December 26, 2018)). (3) Where EASA AD 2023-0187R1 refers to flight hours (FH), this AD requires using hours time-in-service. (4) This AD does not adopt paragraphs (1) and (2) of EASA AD 2023-0187R1. (5) Instead of complying with the compliance times in Table 1 in paragraph (3) of EASA AD 2023-0187R1, this AD requires the helicopters identified under the Helicopters in Pre-MOD 074699 Configuration column to accomplish the actions required by paragraph (3) of EASA AD 2023-0187R1 before the next practice autorotation, within 100 hours time-in-service, or 6 months after January 12, 2021 (the effective date of AD 2020-24-07), whichever occurs first. (6) Where Table 2 in paragraph (4), Table 3 in paragraph (7), and Table 4 in paragraph (9) of EASA AD 2023-0187R1 state “For helicopters which operate or have operated in salt-laden atmospheric conditions”, this AD requires replacing that text with “For helicopters which operate or have operated in salt-laden atmospheric conditions, or if it cannot be determined if a helicopter has been operated in salt-laden atmospheric conditions”. (7) Where paragraph (6) of EASA AD 2023-0187R1 states “discrepancies are detected”, this AD requires replacing that text with “marks, residue, corrosion, flaky varnish are detected; the values of the insulation test are less than 10 megaOhms; the microswitch closes in the “IDLE” position and does not open as soon as the twist grip is turned to the “FLIGHT” position; or the microswitch is open in the “FLIGHT” position and does not close as soon as the twist grip is turned to the “IDLE” position”. (8) Where paragraph (9) of EASA AD 2023-0187R1 states “any discrepancy,” for purposes of this AD, discrepancy is defined as a nut torque that is outside allowable torque limits, or clearance between the support plate assembly and the washers that is not within 0.1 mm to 0.3 mm. (9) This AD does not adopt the “Remarks” section of EASA AD 2023-0187R1. ### (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, International Validation 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 International Validation Branch, send it to the attention of the person identified in paragraph (j) 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. ### (j) Additional Information For more information about this AD, contact Zain Jamal, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (847) 294-7264; email: zain.jamal@faa.gov. ### (k) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference 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) European Union Aviation Safety Agency (EASA) AD 2023-0187R1, dated March 20, 2025. (ii) [Reserved] (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find this EASA material on the EASA website at ad.easa.europa.eu. (4) You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. 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. ## Rule preamble ### Dates This correction is effective October 23, 2025. The effective date of AD 2025-18-13 remains October 23, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 23, 2025 (90 FR 44962, September 18, 2025). ### Addresses AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-1108, or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. Material Incorporated by Reference: • For European Union Aviation Safety Agency (EASA) material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu. • You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at regulations.gov under Docket No. FAA-2025-1108. ### For further information contact Zain Jamal, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (847) 294-7264; email: zain.jamal@faa.gov. ### Background Airworthiness Directive 2025-18-13, Amendment 39-23140 (90 FR 44962, September 18, 2025) (AD 2025-18-13), retains the actions required by AD 2020-24-07 and mandates an additional modification, which would constitute terminating action for the repetitive inspections for certain Airbus Helicopters Model AS350B3, EC130B4, and EC130T2 helicopters. This AD also expands the helicopter applicability, provides additional requirements for certain helicopters, and prohibits installing affected microswitches or an affected twist grip with the affected microswitch. ### Need for the Correction As published, a reference to a measurement specified in the regulatory text of AD 2025-18-13 is incorrect. Paragraph (h)(8) of AD 2025-18-13 defines a discrepancy as a “nut torque that is outside allowable torque limits, or clearance between the support plate assembly and the washers that is not within 01.mm to 0.3 mm”, whereas it should state “nut torque that is outside allowable torque limits, or clearance between the support plate assembly and the washers that is not within 0.1 mm to 0.3 mm”. No other part of the preamble or regulatory information has been changed; for convenience, the entire rule is being republished. The effective date of this AD remains October 23, 2025. ### Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed EASA AD 2023-0187R1, which specifies procedures for modifying the twist grip operational logic on helicopters with MOD 074263 installed. EASA AD 2023-0187R1 also specifies procedures for repetitively inspecting for no marks, residue, or corrosion and testing the “IDLE” and “FLIGHT” controls on the pilot's and copilot's twist grips on helicopters with MOD 074699 installed. Additionally, EASA AD 2023-0187R1 specifies procedures for installing MOD 074782 on helicopters if an affected microswitch is installed, which would constitute terminating action for the repetitive inspections. For those helicopters with MOD 074782 installed, EASA AD 2023-0187R1 specifies accomplishing a one-time inspection of the installation of the microswitch assembly of the engine power control. EASA AD 2023-0187R1 also prohibits installing a microswitch having a part number (P/N) T3933-3 or a twist grip containing a microswitch having P/N T3933-3 on any helicopter. This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. ### Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) by correcting 90 FR 44962, September 18, 2025, beginning at page 44962, column 1 as follows: ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H9EU](https://openairdocs.org/tcds/H9EU): Airbus Helicopters; names 3 of 10 models: AS350B3, EC130B4, EC130T2 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 954 (954 by airframe model, 0 by engine model) - Makers: Airbus Helicopters 473, Eurocopter 343, American Eurocopter 124, Eurocopter France 14 Models with the most aircraft: - [Airbus Helicopters AS350B3](https://openairdocs.org/model/airbus-helicopters-as350b3): 291 aircraft (airframe model) - [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3): 167 aircraft (airframe model) - [Eurocopter EC 130 B4](https://openairdocs.org/model/eurocopter-ec-130-b4): 154 aircraft (airframe model) - [Airbus Helicopters EC 130 T2](https://openairdocs.org/model/airbus-helicopters-ec-130-t2): 124 aircraft (airframe model) - [American Eurocopter AS350B3](https://openairdocs.org/model/american-eurocopter-as350b3): 124 aircraft (airframe model) - [Airbus Helicopters AS 350B3](https://openairdocs.org/model/airbus-helicopters-as-350b3): 56 aircraft (airframe model) - [Eurocopter EC 130 T2](https://openairdocs.org/model/eurocopter-ec-130-t2): 22 aircraft (airframe model) - [Eurocopter France AS 350 B3](https://openairdocs.org/model/eurocopter-france-as-350-b3): 8 aircraft (airframe model) - [Eurocopter France EC 130 B4](https://openairdocs.org/model/eurocopter-france-ec-130-b4): 6 aircraft (airframe model) - [Airbus Helicopters EC 130B4](https://openairdocs.org/model/airbus-helicopters-ec-130b4): 2 aircraft (airframe model) All 11 models: https://openairdocs.org/ad/2025-18-13/models.md Every aircraft: https://openairdocs.org/ad/2025-18-13/aircraft.md ## Related documents - [AD 2020-24-07](https://openairdocs.org/ad/2020-24-07) (historical): Engine Control System Wiring · Airbus Helicopters AS350B3, EC130B4 and EC130T2. Effective Jan 12, 2021. Replaced by this AD - [Proposed rule FAA-2025-1108](https://openairdocs.org/proposed/FAA-2025-1108): Notice of proposed rulemaking (NPRM), published Jun 20, 2025 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.