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2025-17-08: Elevator Structure

FAA order 2025-17-08 is an airworthiness directive in force since September 29, 2025. The FAA's subject line: Elevator Structure. System: flight controls.

What it applies to as the FAA lists it

Kind of product: Aircraft
Makes: Viking Air Limited
Models: DHC-3

Dates and paperwork

In force since: September 29, 2025
Published: August 25, 2025 (signed August 20, 2025)
Docket: FAA-2025-1107
Replaces: 2022-23-08
Status: Current
The FAA's document: Read the order on the FAA's site

The FAA's summary their words, unchanged

The FAA is superseding Airworthiness Directive (AD) 2022-23- 08, which applied to all Viking Air Limited (Viking) Model DHC-3 airplanes. AD 2022-23-08 required a visual inspection of the stabilizer actuator to confirm that the stabilizer actuator lock ring is present, correctly seated in the groove in the upper housing, and engaged in the clamp nut, applicable corrective actions, application of a torque seal, and sending the inspection results to the FAA. Since the FAA issued AD 2022-23-08, Transport Canada, which is the aviation authority for Canada, issued mandatory continuing airworthiness information (MCAI) to address the unsafe condition identified as a missing stabilizer actuator lock ring. This AD requires repetitively inspecting the stabilizer actuator to confirm that the stabilizer actuator lock ring is present, correctly seated in the groove in the upper housing, and engaged in the clamp nut; taking applicable corrective actions; applying a witness mark (torque seal); and installing a secondary retention feature as terminating action for the repetitive inspections. This AD also prohibits installing any stabilizer actuator unless it is a serviceable part. The FAA is issuing this AD to address the unsafe condition on these products.

The order itself the regulatory text, as published

Show the full text (5,189 characters)

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: a. Removing Airworthiness Directive 2022-23-08, Amendment 39-22235 (87 FR 66084, November 2, 2022); and b. Adding the following new airworthiness directive: 2025-17-08 Viking Air Limited (type certificate previously held by Bombardier Inc. and de Havilland, Inc.): Amendment 39-23118; Docket No. FAA-2025-1107; Project Identifier MCAI-2024-00784-A. (a) Effective Date This airworthiness directive (AD) is effective September 29, 2025. (b) Affected ADs This AD replaces AD 2022-23-08, Amendment 39-22235 (87 FR 66084, November 2, 2022). (c) Applicability This AD applies to Viking Air Limited (Viking) (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) Model DHC-3 airplanes, certificated in any category, as identified in Transport Canada AD CF-2024-46, dated December 23, 2024 (Transport Canada AD CF-2024-46). (d) Subject Joint Aircraft System Component (JASC) Code 5520, Elevator Structure. (e) Unsafe Condition This AD was prompted by an investigation of a Viking Model DHC-3 airplane where the lock ring of the stabilizer actuator was found to be missing. The FAA is issuing this AD to ensure that the stabilizer actuator clamp nut does not separate from the stabilizer barrel by unthreading and to ensure that the lock ring securing the clamp nut to the stabilizer barrel does not separate. This condition, if not detected and corrected, could result in a reduction or loss of pitch control during flight with consequent loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, Transport Canada AD CF-2024-46. (h) Exceptions to Transport Canada AD CF-2024-46 (1) Where Transport Canada AD CF-2024-46 refers to its effective date, this AD requires using the effective date of this AD. (2) Where Transport Canada AD CF-2024-46 requires compliance in terms of hours air time, this AD requires using hours time-in-service (TIS). (3) Where Part V of Transport Canada AD CF-2024-46 specifies installing a new clamp nut and safety wire on the horizontal stabilizer as an optional terminating action using FAA Supplemental Type Certificate SA02761SE, this AD requires installing a secondary retention feature using a method approved by the FAA within 330 hours time-in-service after the effective date of this AD. (4) Where Transport Canada AD CF-2024-46 requires reporting any movement of the lock ring or witness mark to the Transport Canada Web Service Difficulty Reporting System (WSDRS), this AD does not require that action. (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, mail it to the address 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 Brenda Buitrago, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (516) 228-7368; email: [email protected] . (k) 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) Transport Canada AD CF-2024-46, dated December 23, 2024. (ii) [Reserved] (3) For Transport Canada material identified in this AD, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, Canada; phone: (888) 663-3639; email: [email protected] ; website: tc.canada.ca/en/aviation . (4) You may view this material at FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. 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 [email protected] . Issued on August 20, 2025. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2025-16190 Filed 8-22-25; 8:45 am]BILLING CODE 4910-13-P

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/2025-17-08.json · aircraft systems.