EASA AD CF-2025-38
Horizontal Stabilizer (H-Stab) — Anti Yaw Steady Fitting Block — Missing or Loose Bolts
Summary
Canadian Airworthiness Directive CF-2025-38 addresses missing or loose bolts on the horizontal stabilizer (H-Stab) anti-yaw steady fitting block in MHI RJ Aviation ULC aircraft models CL-600-2C10, CL-600-2C11, CL-600-2D15, CL-600-2D24, and CL-600-2E25 within specified serial number ranges. The directive mandates inspections and torque checks of the fitting block bolts to ensure they are secure until replacement hardware with secondary locking features is installed. This AD aims to prevent potential loss of the horizontal stabilizer due to bolt failure under certain loading conditions.
What Changed
CF-2025-38 supersedes AD CF-2024-24 and reduces the initial inspection compliance time for torque checks of the anti-yaw steady fitting block bolts while maintaining the intervals for repetitive inspections and the timeline for hardware replacement. It introduces mandatory torque checks within 800 flight hours or 6 months and repetitive checks every 2200 flight hours until the installation of new bolts with secondary locking features is completed.
Why It Matters
This directive is critical for aviation professionals because loose or missing bolts on the H-Stab anti-yaw steady fitting block can lead to structural failure of the horizontal stabilizer, especially during bird strikes or gust loading. Operators and maintenance organizations must ensure timely inspections and corrective actions to maintain aircraft airworthiness and safety. Compliance with this AD helps prevent in-flight structural issues that could compromise flight safety.
What To Do
Operators of affected MHI RJ Aviation ULC aircraft must perform an initial torque check of the H-Stab anti-yaw steady fitting block bolts within 800 flight hours or 6 months from 19 August 2025, whichever occurs first. Subsequent torque checks are required every 2200 flight hours. Additionally, the replacement of the fitting block hardware with bolts featuring a secondary locking mechanism must be completed within 8800 flight hours or 6 years from 4 July 2024. Completing the hardware replacement terminates the inspection requirements.