Patent ID: 7364115

Claim:
An aircraft including a ducted fan and an engine for driving the ducted fan, comprising: a plurality of vanes movably mounted to the aircraft at a substantially rectangular exhaust end of the aircraft, wherein each of the plurality of vanes is substantially rectangular, and wherein the plurality of vanes are configured to alter an exit area of the exhaust end; a sensor circuit configured to detect a RPM of the engine and to output a RPM signal; a control circuit coupled to the sensor circuit and the plurality of vanes, wherein the control circuit is configured to actuate the plurality of vanes to alter the exit area of the exhaust end to vary a pressure load on the ducted fan to control the RPM of the engine in response to the RPM signal; and a first servo mechanism configured to balance pressure loads on the plurality of vanes, wherein the first servo mechanism comprises a high force, low speed servo; a second servo mechanism configured to actuate the plurality of vanes, wherein the second servo mechanism comprises a low force, high speed servo; and a linkage configured to couple the first and second servo mechanisms to the plurality of vanes.