EASA SIB CASA-2025-03
Flight Controls — Unannunciated Loss of Ground Lift Dump Spoilers due to Faulty Throttle Quadrant Assembly
Summary
Transport Canada Civil Aviation Safety Alert CASA 2025-03 addresses failures in the ground lift dump spoiler system on Bombardier Inc. BD-100-1A10 (Challenger 300/350) aircraft caused by faulty throttle quadrant assemblies (TQA). The alert highlights that silicon contamination in the TQA switches can prevent ground spoilers from deploying on landing without any warning to the flight crew. This issue affects all BD-100-1A10 aircraft with serial numbers post 20806.
What Changed
CASA 2025-03 introduces inspection, removal, and replacement procedures for affected TQAs as detailed in Bombardier Service Bulletins 100-76-04 and 350-76-004. It mandates endurance testing and return-to-service checks to ensure the TQA switches function correctly and prevent undetected failures of the ground spoiler system. This alert builds on previous service bulletins from 2019 that inadvertently made single idle switch failures undetectable.
Why It Matters
This alert is critical for operators, maintenance organizations, and compliance teams because failure of the ground spoilers to deploy on landing can lead to longer landing distances, increasing safety risks. The unannunciated nature of the failure means flight crews may be unaware of the malfunction, making timely maintenance actions essential. Addressing this issue helps maintain aircraft safety and regulatory compliance.
What To Do
Operators of Bombardier BD-100-1A10 aircraft should incorporate Service Bulletins 100-76-04 and 350-76-004 at the next maintenance opportunity. This includes inspecting the installed TQA, replacing any affected units, and performing return-to-service testing as per the Aircraft Maintenance Manual. For further information, stakeholders can contact Transport Canada Continuing Airworthiness.