A vertical/short take-off and landing aircraft with a single proprotor assembly that has a pair of inline counter-rotating rotors. Two inline counter-rotating engines are directly connected to the rotors. One engine is shut down in horizontal flight to improve efficiency. Gimbal mounting the proprotor assembly permits thrust to be directed forward to back and left to right to control pitch and roll when hovering. Varying the relative engine speeds controls yaw. The aircraft is adaptable as an unmanned vehicle.