EASA AD CF-2025-42
Flight Controls — Horizontal Stabilizer — Autopilot Inability to Trim Horizontal Stabilizer
Summary
Canadian Airworthiness Directive CF-2025-42 addresses an autopilot issue affecting Bombardier Inc. BD-100-1A10 (Challenger 300/350) aircraft. The directive focuses on the inability of the autopilot to trim the horizontal stabilizer, which has led to pitch upset events upon autopilot disconnect. It mandates changes to the Airplane Flight Manual to improve pilot response to related alerts.
What Changed
CF-2025-42 introduces a revision to the Airplane Flight Manual (AFM) for the Bombardier Challenger 300 and 350 models, reclassifying the AP STAB TRIM FAIL (C) alert from a Non-Normal Procedure to an Emergency Procedure. This change requires immediate pilot action upon receiving the alert to prevent pitch upset. The directive is an interim measure pending further regulatory action.
Why It Matters
This directive is critical for flight crews and maintenance teams as it addresses a safety risk involving sudden elevator movements after autopilot disengagement due to improper horizontal stabilizer trim. Operators must ensure pilots are trained on the updated emergency procedures to maintain aircraft control and prevent accidents. Compliance ensures adherence to Canadian Aviation Regulations and enhances flight safety.
What To Do
Operators of Bombardier BD-100-1A10 Challenger 300 and 350 aircraft must revise their AFMs according to the approved Transport Canada revisions within 60 days of the directive's effective date. Flight crews must be informed of these changes and operate the aircraft following the updated emergency procedures. Continued monitoring and readiness for further directives are advised.