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 loose bolts that are intended to secure the translating door crank assembly to the outside handle shaft. This AD requires a detailed inspection for loose bolts on the aft translating door crank assembly, and removal and reinstallation of the bolts. We are issuing this AD to prevent loose bolts from falling out. If both bolts become loose or fall out after the door is closed and locked, the door cannot be opened from inside or outside, which could impede evacuation in the event of an emergency.