EASA AD CF-2025-05
Landing Gear — Uncommanded Steering
Summary
The Canadian Airworthiness Directive CF-2025-05 addresses uncommanded steering issues in the landing gear of Bombardier Inc. Challenger aircraft models CL-600-1A11, CL-600-2A12, and CL-600-2B16 with specified serial numbers. This directive mandates periodic functional testing of the transfer valve in the nose landing gear steering system to prevent unintended directional changes during landing. The directive applies to multiple variants of the Challenger 600 series aircraft.
What Changed
CF-2025-05 introduces a mandatory periodic operational test of the transfer valve in the nose landing gear steering system to detect and correct undetected failures that can prevent the system from entering free-steering mode. This requirement is added to the maintenance task limits and checks (TLMC) for affected Bombardier Challenger models. Compliance with the specified temporary revisions of the TLMC manuals approved by Transport Canada satisfies this directive.
Why It Matters
This directive is critical for aviation professionals because uncommanded steering during landing poses a safety risk, potentially causing runway excursions or directional control issues. Operators and maintenance organizations must ensure compliance to maintain aircraft airworthiness and prevent incidents related to steering system failures. The directive provides clear maintenance actions to mitigate the risk and ensure continued safe operation of affected Challenger aircraft.
What To Do
Operators of affected Bombardier Challenger CL-600-1A11, CL-600-2A12, and CL-600-2B16 aircraft must perform the transfer valve operational test within the specified thresholds and intervals outlined in the updated TLMC manuals. Compliance must be achieved by the effective date of January 31, 2025, and maintained through adherence to the latest approved TLMC revisions or temporary revisions. Maintenance teams should update their procedures accordingly and ensure all relevant personnel are informed of the new requirements.