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 reports of missing clamps that are required to provide positive separation between the alternating current (AC) feeder cables and the hydraulic line of the landing gear alternate extension. This AD requires an inspection for missing clamps that are required to provide positive separation between the AC feeder cables and the hydraulic line of the landing gear alternate extension, and related investigative and corrective actions if necessary. We are issuing this AD to detect and correct chafing of the AC feeder cable. A chafed and arcing AC feeder cable could puncture the adjacent hydraulic line, which, in combination with the use of the alternate extension system, could result in an in- flight fire.