VERTICAL TAKE-OFF AND LANDING (VTOL) AERIAL VEHICLE AND METHOD OF OPERATING SUCH A VTOL AERIAL VEHICLE

1 . A vertical take-off and landing aerial vehicle comprising:

a. a power plant assembly unit with at least one main rotor,

b. a torus-type fuselage in a plane defined by a longitudinal and a transversal axis, said torus-type fuselage having radial inside a duct with a central axis perpendicular to said plane, said duct being between a top and a bottom of said torus-type fuselage and said at least one main rotor having a rotation axis essentially coaxial with the central axis of said duct, said fuselage having a front and rear portion along said longitudinal axis,

c. a pair of lateral wings attached opposed to each other outside the fuselage, and

d. an integrated drive system comprising:

d1. a plurality of support struts between the power plant assembly unit and the fuselage,

d2. at least one engine in the power plant assembly unit for driving said at least one main rotor, and

d3. a mechanical interconnection system between said at least one engine and said at least one main rotor, wherein

d4. at least two propulsion means are provided with respective rotation axis essentially directed parallel to said longitudinal axis, at least one of said propulsion means, including propellers or turbojets, being fitted to each of said wings and the mechanical interconnection system being connected to the propulsion means for driving said propulsion means.

2 . The aerial vehicle according to claim 1 , wherein said power plant assembly unit comprises two turbo engines mounted in a central power plant assembly unit.

3 . The aerial vehicle according to claim 1 , wherein two coaxial, counter rotating main rotors with in between an axial distance of 1 m to 2 m are provided.

4 . The aerial vehicle according to claim 1 , wherein a plurality of support struts are fixed to a radial inner circumference at the bottom of the torus-type fuselage.

5 . The aerial vehicle according to claim 1 , wherein the integrated drive system comprises means of control for an attitude of the aerial vehicle in lift, pitch, roll and yaw in both hover and forward flight, preferably comprising means for applying both collective and cyclic pitch changes to blades of said at least one main rotor(s) depending on forces and moments induced by airflow through and along the torus-type fuselage.

6 . The aerial vehicle according to claim 1 , wherein a hover cushion system is provided at the bottom of the fuselage as landing and starting assistance device and as a diffusion part.

7 . The aerial vehicle according to claim 1 , wherein at least one main rotor is located at level with the top of the fuselage.

8 . The aerial vehicle according to claim 1 , wherein stabilizing and maneuvering control surfaces for pitch are provided at the wings, said control surfaces for pitch being movable relative to a front portion of the wing.

9 . The aerial vehicle according to claim 1 , wherein stabilizing and maneuvering surfaces with at least one fin and a steering control surface as vertical stabilizer are provided at lateral ends of the wings, said at least one steering control surface being movable relative to a front portion of the fin.

10 . The aerial vehicle according to claim 1 , wherein said mechanical interconnection system is provided with collective pitch and cyclic pitch control means of blades of the at least one main rotor and with collective pitch control of propeller blades of said propulsion means.

11 . The aerial vehicle according to claim 2 , wherein the power plant assembly unit is mounted below or within the duct adjacent to the bottom of the fuselage.

12 . The aerial vehicle according to claim 1 , wherein said plurality of support struts are hollow as space for cargo and passenger(s), vehicle flight and control systems including control and service lines, fuel and/or mechanical interconnection systems.

13 . The aerial vehicle according to claim 1 wherein the at least one main rotor has a diameter of 12 m to 25 m or 16 m to 22 m and an air inlet lip established by the torus-type fuselage is always outside of the at least one main rotor with a radius between 13 m and 7 m.

14 . The aerial vehicle according to claim 1 , wherein said plurality of support struts are fabricated of light-weight, composite material or metal.

15 . The aerial vehicle according to claim 1 , wherein said fuselage is shaped as a closed torus.

16 . The aerial vehicle according to claim 1 , wherein a difference in collective pitch of propeller blades of at least one propeller on one side of the fuselage relative to propeller blades of at least one propeller on the opposed side of the fuselage evolves a differential of thrust between both propellers, said differential of thrust being directed against torque generated by one main rotor.

17 . The aerial vehicle according to claim 1 , wherein the wings are in the rear portion of the aerial vehicle and the wings are profiled to provide additional lift forces at forward flight.

18 . The aerial vehicle according to claim 1 , wherein at least a part of the duct is shaped as a diffuser, said diffuser ending at the bottom of the duct with a maximum cross section at least equal to the cross section of the at least one main rotor, said diffuser having a minimum cross section defined by a ratio of 0.7 to 0.8 to 1 for minimum cross section/maximum cross section.

19 . The aerial vehicle according to claim 1 , wherein the torus-type fuselage houses substantially symmetric passenger and/or cargo compartments in its front and its rear portions.

20 . A method of operating an aerial vehicle according to claim 1 , comprising the steps of:

providing lift to the aerial vehicle by means of said at least one main rotor; and

providing horizontal thrust and/or counter torque to the aerial vehicle by said propulsion means being arranged laterally outside said fuselage.

21 . The method according to claim 20 , further comprising the step of:

controlling the lift by adapting the collective pitch of blades of said at least one main rotor as a function of flight conditions to thereby produce lift creating forces on both the main rotor and the fuselage.

22 . The method according to claim 20 , further comprising the step of:

controlling the aerial vehicle by selectively applying longitudinal cyclic pitch to blades of said at least one main rotor as a function of flight conditions to thereby produce pitch forces on both of the at least one main rotor and the fuselage.

23 . The method according to claim 22 , further comprising the step of:

creating inflight mode of aerial vehicle additional pitch forces by means of both pitch control surfaces being movable in the rear portion of the fuselage.

24 . The method according to claim 20 , further comprising the step of:

controlling vehicle roll by selectively applying lateral cyclic pitch to blades of said at least one main rotor as a function of flight conditions to thereby produce roll forces on both the at least one main rotor and the fuselage.

25 . The method according to claim 24 , further comprising the step of:

creating inflight mode of aerial vehicle additional roll forces by one of the pitch control surfaces movable in the rear portion of the fuselage.

26 . The method according to claim 20 , further comprising the step of:

providing yaw control to said aerial vehicle by applying in flight mode a differential of thrust between said at least two propulsion means as a function of flight conditions to thereby produce a required torque differential to effect yaw control.

27 . The method according to claim 20 , further comprising the step of:

creating inflight aerial vehicle yaw forces by movement of both movable steering rudders of the vertical stabilizer in the rear portion of the fuselage.

28 . The method according to claim 20 , further comprising the step of:

abating any nose-up moment created by the torus-type fuselage during forward flight by selectively applying cyclic pitch to said at least one main rotor to selectively vary a pattern of air flowing into said duct to thereby produce a counteracting pitching moment on said torus-type fuselage and to thereby reduce a total nose-up pitching moment created by the fuselage in forward flight until the total nose-up pitching moment is substantially equal to a nose-down pitching moment created by the at least one main rotors.

29 . The method according to claim 20 , further comprising the step of:

performing an anti-torque function by a single propulsion means, including a propeller or by differential thrust between two propulsion means.