Airworthiness Directives; Bombardier, Inc., Airplanes

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model DHC-8-400 series airplanes. This AD was prompted by a report of uncommanded deployment of the ground spoilers when the power levers were advanced for takeoff, which was caused by faulty switches in the power lever module. This AD requires revising the maintenance or inspection program, as applicable. We are issuing this AD to address the unsafe condition on these products.