Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires inspecting the electrical connectors of the fire extinguisher bottles for the forward and aft baggage compartments and for the auxiliary power unit and engine nacelles to determine if they are connected correctly; and doing related investigative and corrective actions, if necessary. This AD is prompted by reports of the electrical connectors for the fire bottles in the forward and aft baggage compartments being cross connected. We are issuing this AD to detect and correct cross connection of the fire extinguisher bottles, which could result in failure of the fire bottles to discharge and consequent inability to extinguish a fire in the affected areas.