OAK engineers proposed an unusual scheme for a vertical take-off and landing (VTOL) aircraft. Course control in it was moved to a separate propulsion system by placing two impellers inside longitudinal beams located along the fuselage.

The main idea of the solution is not to force the main lifting rotors to simultaneously be responsible for vertical flight and turning. In a conventional multi-rotor scheme, course change is achieved by the difference in rotor speeds. This means that part of the available thrust has to be used for control.

In the proposed design, the lifting rotors can maintain the operating mode necessary to keep the aircraft in the air. Two additional impellers, symmetrically installed in the rear parts of the beams, are responsible for turning.

Their thrust is directed in opposite directions, and changing the power of the left and right engines creates a yaw moment.

The impellers are located inside the beams, so they do not protrude into the oncoming flow and should not create additional aerodynamic drag in horizontal flight. This solution also protects the rotors from icing.

Earlier, "Pervy Tekhnichesky" wrote that Russia developed a kit for converting serial aircraft into hybrid aircraft.