Airworthiness Directive · Amendment 39-23118 · Elevator structure
Viking Air Limited (Type Certificate Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes
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).
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.
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.
(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.
