Airworthiness Directives; Boeing Model 747-400 Series Airplanes Modified by Supplemental Type Certificate SA8843SW

This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 747-400 series airplanes modified by Supplemental Type Certificate (STC) SA8843SW, that requires modifying the passenger entertainment system (PES) installed by that STC and revising the Airplane Flight Manual. This action is necessary to ensure that the flight crew is able to remove electrical power from the PES when necessary and is advised of appropriate procedures for such action. Inability to remove power from the PES during a non-normal or emergency situation could result in inability to control smoke or fumes in the airplane flight deck or cabin. This action is intended to address the identified unsafe condition.