Pentacopter is an augmented battery powered quadcopter by attaching an engine powered propeller at the centre. The central propeller gives 60-75% lift so that the quad propellers need to generate only the remaining thrust, inaddition to the thrust needed for manuvering. Central propeller unsually runs at constant RPM, and the adverse yaw motion it generates is conpensated by two small horizontal-axis thrusters symetrically mounted on eother side of one cross-arm.