Patent ID: 8337156

Claim:
An extended speed range flight method, using thrust vectoring propellers comprising; providing at least for two counter-rotating propellers with alterable blade setting angle and setting propeller axes along a flight direction; establishing angles of attack on propeller blades by increasing a collective pitch angle γ oIII while moving a propeller in incoming airflow along a propeller axis and by offsetting a propeller axis setting angle relative to the incoming air direction from the incoming airflow direction by an α angle; generating a force perpendicular to the propeller axes and increasing that force together with increasing airspeed and an angle of the propeller axis relative to the direction of the airflow; achieving the speed at which a magnitude of the force approaches the weight of aircraft and ensuring that the propeller axes are sufficiently offset upwardly to create a lifting force needed for flight; upon reaching the airspeed no less than 50 m/s, slowing down the propeller and setting its relative propeller speed V oTH = /U between 1.2 and 3, wherein is a speed of the free flow incoming along propeller axis and U is a speed of a propeller blade; increasing φ oIII with an increase of the relative propeller speed and ensuring that the blades' angles of attack are not leading to a stall, and increasing a force normal to the propellers' axes while decreasing circular speed of the propeller tip, while setting the axes of counter-rotating propellers in one direction relative to the incoming airflow at an angle ranging from 0° to 45°; cyclically varying a pitch angle of the blades to create a maximal blade pitch angle difference between the blades at a first half-turn between 60° and 120° and at a second half-turn between 240° and 300° of each propeller in order to create forces perpendicular to the propellers' axes in a determined direction and control magnitudes of the forces, to vary a difference between maximal and minimal pitch angles during a blade turn of each propeller, and to control a direction and value of the force created by the propellers as well as a lifting force, thrust or a deceleration force during cruising or maneuvering of the flight.