FAA Issues AD for Challenger Circuit Breakers

The FAA has issued an Airworthiness Directive for the Bombardier CL-600-2B16 (Challenger 604) prompted by multiple reports of short-circuit events during pre-delivery inspections and test flights. One event resulted in smoke in the cockpit. The AD requires replacing or relocating certain circuit-breaker panel bus bars, inspecting for any loose or improperly crimped lugs and replacement if necessary, and inspecting for foreign object damage in certain areas. It aims to prevent arcing, damage to adjacent structure, smoke in the cockpit or loss of system redundancies.