FAA Adopts New Airworthiness Directive For Boeing 787 Airplanes

(RTTNews) - The U.S. Federal Aviation Administration said it is adopting a new airworthiness directive or AD for all Boeing Model 787 airplanes, which would require a repetitive maintenance task for electrical power deactivation on Model 787 airplanes.

The decision stems from the determination that a Model 787 airplane that has been powered continuously for 248 days can lose all alternating current electrical power due to the generator control units simultaneously going into failsafe mode.

According to the regulator, this condition is caused by a software counter internal to the generator control units that will overflow after 248 days of continuous power. The AD is being issued to prevent loss of all AC electrical power, which could result in loss of control of the airplane.