disclosed is a remotely controlled aircraft configured to vertically take - off and land . the aircraft includes a pair of propulsion devices that are mounted on an airframe above the level of the center of gravity . a set of control devices are mechanically linked to the propulsion devices for varying the orientation of the propulsion devices during flight . roll right - left fan speeds up , right fan slows down ; roll left - left fan slows down , right fan speeds up ; pitch forward / aft both fans move forward or aft ; yaw - one fan moves forward one fan moves back depending on the direction cw or ccw ; change altitude — both fans speed up or slow down .