EASA AD CF-2025-16
Rotors Flight Control — Stability and Control Augmentation System (SCAS) Actuators Incorrect Lockwire
Summary
Canadian Airworthiness Directive CF-2025-16 addresses an issue with the Stability and Control Augmentation System (SCAS) actuators on Bell Textron Canada Limited model 429 helicopters, specifically those with actuator part numbers 429-001-065-107, -109, and -111. The directive mandates inspection and correction of incorrectly installed lockwire on the actuator jam nuts to prevent actuator rotation and potential control loss. This AD applies to helicopters serial number 57001 and subsequent.
What Changed
CF-2025-16 introduces a mandatory one-time inspection and corrective action for the SCAS actuator jam nut lockwire installation on affected Bell 429 helicopters. It prohibits installation of affected actuators unless the lockwire installation is verified or corrected according to Bell Alert Service Bulletin 429-23-61 Revision A. The AD also recognizes prior compliance with the original ASB dated 27 March 2023 as meeting the requirements.
Why It Matters
This directive is critical for aviation professionals because improper lockwire installation can lead to actuator jam nut loosening, causing the SCAS actuator to rotate and potentially jam flight controls. For operators and maintenance organizations, compliance ensures continued safe helicopter operation and adherence to regulatory requirements. It helps prevent partial or complete loss of helicopter control, thereby reducing safety risks.
What To Do
Operators of Bell 429 helicopters with serial numbers 57001 through 57468 must inspect the SCAS actuators within 100 flight hours or 3 months from 31 March 2025, whichever occurs first, and correct any lockwire installation deficiencies before further flight. Installation of affected actuators on any Bell 429 helicopter serial number 57001 and later is prohibited unless the lockwire installation is confirmed correct or corrected per the applicable Bell ASB. Prior compliance with the original ASB dated 27 March 2023 satisfies this AD.