AD FAA-2012-0589

We are superseding two existing airworthiness directives (ADs) for certain Fokker Services B.V. Model F.28 Mark 0100 airplanes. The first existing AD currently requires removing the actuator from the fuel-balance transfer-valve (FBTV) and installing a locking device on the FBTV. The second existing AD currently requires inspecting to verify that the position indicator of the FBTV is in the closed position and deactivating the fuel-balance transfer-system. This new AD requires installing an FBTV locking device. This AD was prompted by reports that the FBTV was inadvertently reactivated after required de- activation measures were undone. We are issuing this AD to prevent fuel starvation and a consequent double-engine flameout, possibly resulting in a forced landing, damage to the airplane, and injury to occupants.