AD FAA-2015-3987

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This AD was prompted by a report of wire chafing caused by a left wing spoiler actuator wire not having enough separation from a certain bracket when the spoiler is in the deployed position. This AD requires measuring the separation between a certain electro-mechanical actuator wire of the left wing, spoiler 4, and the support bracket of the flap variable camber trim unit; and related investigative and corrective actions if necessary. We are issuing this AD to detect and correct wire chafing. Such chafing could result in an electrical short and potential fire in a flammable fluid leakage zone and possible loss of several functions essential for safe flight.