Airworthiness Directives; Bombardier, Inc. Airplanes

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8 airplanes. This AD requires repetitive functional checks of the nose and main landing gear, and corrective actions if necessary. This AD also provides optional terminating action for the repetitive functional checks. This AD was prompted by a report that the emergency downlock indication system (EDIS) had given a false landing gear down-and-locked indication. We are issuing this AD to detect and correct a false down-and-locked landing gear indication, which, on landing, could result in possible collapse of the landing gear.