Vertical take-off and landing aircraft

Abstract

To provide a vertical take-off and landing (VTOL) aircraft that can take-off and land vertically and hover, and has the ability to carry travelers directly to their destination.SOLUTION: A vertical take-off and landing aircraft 100 includes: a fuselage 102; at least one wing 104 connected to the fuselage 102; a plurality of rotors 112a, b, c connected to the at least one wing 104 for providing lift for vertical take-off and landing of the aircraft 100; and a plurality of proprotors 114a, b, c connected to the at least one wing 104, and tiltable between lift configurations for providing lift for vertical take-off and landing of the aircraft and propulsion configurations for providing forward thrust to the aircraft.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Patent Application No. 16 / 878,380, filed May 19, 2020, which is incorporated by reference in its entirety.

[0002] This disclosure relates generally to vertical take-off and landing aircraft, and more particularly, to fixed-wing vertical take-off and landing aircraft. [Background technology]

[0003] A vertical take-off and landing (VTOL) aircraft is an aircraft that can take off and land vertically and hover, providing the ability to transport travelers directly to their destination. Helicopters are VTOL aircraft that generate lift entirely through their rotors. Some VTOL aircraft have wings and a propulsion system that allows the wings to provide the lift required during forward flight. Some winged VTOL aircraft use separate propulsion systems for vertical thrust for use during take-off and landing, and forward thrust for use during cruise. Other winged VTOL aircraft use a tiltable propulsion system that tilts between a vertical thrust position and a forward thrust position. Summary of the Invention

[0004] According to various embodiments, a vertical take-off and landing aircraft includes a fixed wing, multiple rotors for providing lift during vertical take-off and landing, and multiple propeller rotors that can tilt from a lift configuration for providing lift during vertical take-off and landing to a thrust configuration for providing the forward airspeed required for the aircraft to be supported by the fixed wing. By configuring a VTOL aircraft such that a portion of the propulsion system is dedicated to lift and a portion of the propulsion system is used both during lift and forward flight, the aircraft can be lighter and have lower drag than VTOL aircraft with separate lift and propulsion systems, and VTOL aircraft that use all of their propulsion for both lift and forward flight.

[0005] A vertical take-off and landing aircraft includes a fuselage, at least one wing connected to the fuselage, a plurality of rotors connected to the at least one wing for providing lift for vertical take-off and landing of the aircraft, and a plurality of propeller rotors connected to the at least one wing and tiltable between a lift configuration for providing lift for vertical take-off and landing of the aircraft and a thrust configuration for providing forward thrust to the aircraft.

[0006] In any of these embodiments, the rotors may be aft of the at least one wing and the propeller rotors may be forward of the at least one wing. In any of these embodiments, multiple booms may be attached to the at least one wing, each boom attaching one rotor and one propeller rotor to the at least one wing.

[0007] In any of these embodiments, the first prop rotor may be forward of a second prop rotor adjacent to the first prop rotor.

[0008] In any of these embodiments, a first prop rotor may be mounted higher on the aircraft than a second prop rotor adjacent to the first prop rotor.

[0009] In any of these embodiments, each rotor may have only two blades. In any of these embodiments, each rotor may be configured to fix the two blades in place during forward flight. In any of these embodiments, each propeller rotor may have more than two blades.

[0010] In any of these embodiments, a first rotor of the plurality of rotors may be canted relative to a second rotor of the plurality of rotors such that an axis of rotation of the first rotor is non-parallel to an axis of rotation of the second rotor. In any of these embodiments, the cant angle of any rotor or propeller rotor is such that an individual burst disk cannot intersect with any passenger or pilot. In any of these embodiments, the cant angle of any rotor or propeller rotor is such that an individual burst disk cannot intersect with any flight critical component.

[0011] In any of these embodiments, a first prop rotor of the plurality of prop rotors may be inclined relative to a second prop rotor of the plurality of prop rotors such that an axis of rotation of the first prop rotor is non-parallel to an axis of rotation of the second prop rotor.

[0012] In any of these embodiments, the aircraft further includes a control system configured to actively vary the tilt of at least one propeller to generate a yawing moment during hover.

[0013] In any of these embodiments, the angle of attack of the blades of the propeller may be collectively adjustable in flight.

[0014] In any of these embodiments, propulsion may be provided entirely by the propeller rotor.

[0015] In any of these embodiments, the range of tilt of the prop rotor may be greater than 90 degrees.

[0016] In any of these embodiments, the at least one wing may provide the lift required during cruise.

[0017] In any of these embodiments, the at least one wing may be a high wing attached to an upper side of the fuselage.

[0018] In any of these embodiments, the at least one wing includes a control surface.

[0019] In any of these embodiments, all of the rotors and prop rotors are attached to the at least one wing.

[0020] In any of these embodiments, the aircraft is electric.

[0021] In any of these embodiments, the aircraft is manned. [Brief description of the drawings]

[0022] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0023] [Figure 1] 1 illustrates a VTOL aircraft in a forward flight configuration in accordance with various embodiments.

[0024] [Diagram 2] 1 illustrates a VTOL aircraft in a takeoff and landing configuration in accordance with various embodiments.

[0025] [Diagram 3] FIG. 1 is a perspective view of a VTOL aircraft illustrating rotor and prop rotor positions in lift and forward flight configurations in accordance with various embodiments.

[0026] [Figure 4] FIG. 4 is a top view of the VTOL aircraft of FIG.

[0027] [Diagram 5] FIG. 4 is a front view of the VTOL aircraft of FIG.

[0028] [Figure 6] FIG. 4 is a side view of the VTOL aircraft of FIG.

[0029] [Figure 7] FIG. 2 is a front view of a VTOL aircraft illustrating the size of the aircraft relative to a standing person in accordance with various embodiments. [Figure 8] FIG. 2 is a side view of a VTOL aircraft illustrating the size of the aircraft relative to a standing person in accordance with various embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] According to various embodiments, the VTOL aircraft described herein includes at least one fixed wing, a plurality of rotors fixed to provide lift during takeoff, landing, and hovering, and a plurality of propeller rotors tiltable from a lift configuration to provide lift to a propulsion configuration to provide the forward thrust necessary for the at least one fixed wing to provide lift to the aircraft. By configuring the VTOL aircraft such that a portion of the propulsion system is dedicated to lift and a portion of the propulsion system is used both during lift and forward flight, the aircraft can be lighter and have lower drag than VTOL aircraft with separate lift and propulsion systems, as well as VTOL aircraft that use all of their propulsion for both lift and forward flight. Winged VTOL aircraft with separate propulsion systems for vertical and forward propulsion essentially waste the forward propulsion system during vertical takeoff and landing and during hovering. In contrast, an aircraft according to the principles described herein utilizes a forward propulsion system during vertical takeoff and landing, which can result in a relatively light propulsion system overall. Winged VTOL aircraft with tilting rotors all limit where the rotors can be placed (the rotors must be placed forward and aft of the center of gravity, but these placements are limited by other rotors and the wings), which often results in relatively few and therefore large rotors. In contrast, propulsion systems according to the principles described herein can have relatively small, lightweight, low drag rotors. Thus, aircraft according to various embodiments described herein have an ideal balance between a dedicated lift propulsion system and a tiltable propulsion system.

[0031] According to various embodiments, the prop-rotor is attached to the wing forward of the leading edge and the rotor is attached to the wing aft of the trailing edge. The prop-rotor and rotor may be attached to the wing via booms. In some embodiments, each boom supports a prop-rotor at its forward end and a rotor at its aft end.

[0032] According to various embodiments, the propeller rotors are staggered in the fore-aft direction to prevent a broken blade of one propeller rotor from striking the blade of an adjacent propeller rotor. According to some embodiments, the rotors and / or propeller rotors are positioned and canted so that their blades do not cross each other and to enhance yaw control authority. In some embodiments, the rotors and / or propeller rotors are positioned and canted so that the planes of rotation of their blades do not cross passengers and / or critical system components to minimize potential damage resulting from blade breakage during flight.

[0033] According to some embodiments, the wings are located high on the fuselage to facilitate easy ingress and egress for passengers. The aircraft can be configured so that the bottom of the boom supporting the rotors and propellers is above the head of an average-sized person, also contributing to ease of ingress and egress.

[0034] In the following description of the disclosure and embodiments, reference is made to the accompanying drawings, in which is shown, by way of illustration, specific embodiments that may be practiced. It will be understood that other embodiments and examples may be practiced and changes may be made without departing from the scope of the disclosure.

[0035] It will further be understood that, as used in the following description, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will also be understood that the term "and / or," as used herein, refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will also be understood that, as used herein, the terms "comprises," "including," "comprising," and / or "comprising" specify the presence of stated features, integers, steps, operations, elements, components, and / or units, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, units, and / or groups thereof.

[0036] As used herein, the term "proprotor" refers to a controllable pitch propeller that can provide thrust for vertical lift and forward propulsion by varying the pitch of the propeller.

[0037] 1 and 2 show a VTOL aircraft 100 in a cruise configuration and a vertical takeoff and landing configuration, respectively, according to various embodiments. The aircraft 100 includes a fuselage 102, wings 104 attached to the fuselage 102, and one or more aft stabilizers 106 attached to the rear of the fuselage 102. A plurality of rotors 112 are attached to the wings 104 and configured to provide lift for vertical takeoff and landing. A plurality of propeller rotors 114 are attached to the wings 104 and are tiltable between a lift configuration, which provides a portion of the lift required for vertical takeoff and landing and hovering, as shown in FIG. 2, and a propulsion configuration, which provides forward thrust to the aircraft 100 for horizontal flight, as shown in FIG. 1. As used herein, a propeller lift configuration refers to the orientation of any propeller rotor in which the propeller thrust is primarily providing lift to the aircraft, and a propeller propulsion configuration refers to the orientation of any propeller rotor in which the propeller thrust is primarily providing forward thrust to the aircraft.

[0038] According to various embodiments, the rotors 112 are configured to provide lift only, with all thrust provided by the propellers. Thus, the rotors 112 may be in a fixed position. During takeoff and landing, the propellers 114 are tilted into a lift configuration in which their thrust is directed downward to provide additional lift.

[0039] For forward flight, the propeller rotors 114 tilt from their lift configuration to their thrust configuration. In other words, the pitch of the propeller rotors 114 changes from a pitch where the propeller thrust is directed downward to provide lift during vertical takeoff and landing and during hovering to a pitch where the propeller thrust is directed backward to provide forward thrust to the aircraft 100. The propeller rotors tilt about an axis 118 that is perpendicular to the forward direction of the aircraft 100. When the aircraft 100 is in full forward flight, lift may be provided entirely by the wings 104 and the rotors 112 may be stopped. The blades 120 of the rotors 112 may be locked in a low drag position for cruise of the aircraft. In some embodiments, the rotors 112 each have two blades 120 locked to cruise in a minimum drag position with one blade directly ahead of the other blade, as shown in FIG. 1. In some embodiments, the rotors 112 have more than two blades. In some embodiments, the propeller rotors 114 include more blades 116 than the rotors 112. 1 and 2, rotors 112 may include two blades each and propeller rotors 114 may include five blades each. According to various embodiments, propeller rotors 114 can have between two and five blades.

[0040] According to various embodiments, the aircraft includes only one wing 104 on each side of the fuselage 102 (or a single wing extending across the entire aircraft), with at least a portion of the rotors 112 located aft of the wing 104 and at least a portion of the propeller rotors 114 located forward of the wing 104. In some embodiments, all of the rotors 112 are located aft of the wing 104 and all of the propeller rotors are located forward of the wing 104. According to some embodiments, all of the rotors 112 and the propeller rotors 114 are wing mounted, i.e., there are no fuselage mounted rotors or propellers. According to various embodiments, all of the rotors 112 are located aft of the wing 104 and all of the propeller rotors 114 are located forward of the wing 104. According to some embodiments, all of the rotors 112 and the propeller rotors 114 are located inboard of the wing tips 109.

[0041] According to various embodiments, the rotors 112 and the propeller rotors 114 are attached to the wing 104 by a boom 122. The boom 122 may be attached under the wing 104, on top of the wing, and / or integrated into the wing profile. According to various embodiments, one rotor 112 and one propeller rotor 114 are attached to each boom 122. The rotors 112 may be attached to the aft end of the boom 122 and the propeller rotors 114 may be attached to the forward end of the boom 122. In some embodiments, the rotors 112 are attached to a fixed position on the boom 122. In some embodiments, the propeller rotors 114 are attached to the forward end of the boom 122 via a hinge 124. The propeller rotors 114 are attached to the boom 122 such that when in their propulsion configuration, the propeller rotors 114 are aligned with the body of the boom 122, forming a continuous extension of the front end of the boom 122 that minimizes drag for forward flight.

[0042] According to various embodiments, the aircraft 100 may include only one wing on each side of the aircraft 100, or a single wing extending across the aircraft. According to some embodiments, the at least one wing 104 is a high wing attached to the upper side of the fuselage 102. According to some embodiments, the wing includes control surfaces such as flaps and / or ailerons. According to some embodiments, the wing may have curved wing tips 109 to reduce drag during forward flight.

[0043] According to some embodiments, the aft stabilizer 106 includes a control surface, such as one or more rudders, one or more elevators, and / or one or more combined rudder-elevators. The wing may have any suitable design. In some embodiments, the wing has a tapered leading edge 123, for example, as shown in the embodiment of FIG. 1. In some embodiments, the wing has a tapered trailing edge 125, as shown in the embodiment of FIG. 3. In the embodiment of FIG. 3, the wing has a substantially straight leading edge 127 at a midsection of the wing 104.

[0044] The aircraft 100 may include at least one door 110 for passenger ingress and egress. In the illustrated embodiment, the door 110 is located below and forward of the wing 104.

[0045] According to various embodiments, the rotors 112 and propeller rotors 114 are positioned and configured to minimize damage that may occur due to blade breakage (commonly referred to as a rotor burst). Figures 3-6 show the relative positions and orientations of the blades of rotors and propeller rotors in use according to some embodiments. The blade positions through a full rotation are indicated by the disks. The propeller rotors each have two disks, one for the lift configuration and one for the propulsion configuration. The rotor and propeller configurations on the left and right sides of the aircraft are mirror images, and therefore the rotor and propeller configurations on only one side of the aircraft are discussed below.

[0046] As shown in the top view of FIG. 4, the prop rotors 114 may be staggered in the fore-aft direction such that the rotational planes of the prop rotors in their propulsion configuration are non-coplanar. In the illustrated embodiment, the innermost prop rotor 114a is forward of the other prop rotors. In some embodiments, the innermost prop rotor 114a is forward of the passenger compartment or in a position most forward of the passengers in the passenger compartment to ensure that a broken blade cannot enter the passenger compartment and injure the passengers. In some embodiments, at least two prop rotors on the same side of the aircraft are aligned such that their blade rotational planes are coplanar.

[0047] According to some embodiments, the rotors 112 are in a staggered fore-aft position. In some embodiments, the innermost rotor 112a is positioned aft of the other rotors. In some embodiments, at least a portion of the rotors 112 are aligned in the fore-aft direction.

[0048] According to some embodiments, at least one of the rotors 112 and / or prop rotors 114 is tilted relative to at least one other rotor 112 and / or prop rotor 114. As used herein, tilt refers to the relative orientation of the rotor / prop rotor's axis of rotation about a line parallel to the longitudinal direction, as well as the roll degree of freedom of the aircraft. The tilt of the rotors and / or prop rotors can help minimize damage from rotor bursts and may provide enhanced yaw control during flight by orienting the plane of rotation of the rotor / prop rotor's disks (blades and rotor portions to which the blades are attached) so that they do not intersect critical parts of the aircraft (areas of the fuselage where personnel may be located, critical flight control systems, batteries, adjacent rotors / prop rotors, etc.) or other rotor disks. In some embodiments, the tilt angle of any rotor or prop rotor is such that an individual burst disk does not intersect with passengers or pilots. In some embodiments, the tilt angle of any rotor or prop rotor is such that an individual burst disk does not intersect with any flight critical components. (As used herein, a critical component is any component that may contribute to or cause a failure condition whose failure would prevent continued controlled flight and landing of the aircraft.) The front view of FIG. 5 best illustrates the tilt of the rotors and prop rotors according to some embodiments. The axis of rotation 130a of the innermost prop rotor 114a in its lift configuration is provided to illustrate the tilt angle of the prop rotor 114a. The tilt of the prop rotors 114 results in the planes of rotation of their blades being oblique to the horizontal, as illustrated, for example, by the disk 132a being non-horizontal. The illustrated tilt angle 136a measured from vertical 138 is approximately 12 degrees and can range from 0 to 30 degrees in either direction.In the illustrated embodiment, the outermost prop rotor 114c is canted in the same direction and by the same amount as the innermost prop rotor 114a, and the intermediate prop rotor 114b is canted in the opposite direction but by the same amount as the innermost and outermost prop rotors 114a, 114c, such that the axis of rotation 130a of the prop rotor 114a is parallel to the axis of rotation 130c of the prop rotor 114c but not parallel to the axis of rotation 130b of the prop rotor 114b. However, this is only one example of the relative cant of the prop rotors, and one skilled in the art will appreciate that any suitable combination of prop rotor cants (including no cant) may be used according to the desired performance characteristics of the aircraft.

[0049] The rotors 112 may also be tilted in any suitable manner and combination. In some embodiments, the rotors 112 are tilted according to the corresponding prop rotors. For example, as can be seen by comparing the innermost rotor blade disk 134a to the innermost prop rotor blade disk 132a, the innermost rotor 112a is tilted the same amount and in the same direction as the innermost prop rotor 114a. Similarly, the rotors 112b and 112c are tilted similarly to the corresponding prop rotors 114b and 114c, respectively. Note that the innermost rotor blade disk 134a is not depicted as a straight line in FIG. 5 because the innermost rotor 112a is oriented with an aft tilt as described further below. Any suitable combination of tilting and / or non-tilting of the rotors relative to each other and to the prop rotors may be used to achieve desired performance characteristics.

[0050] The side view of FIG. 6 shows a relatively small aft tilt of the outermost rotor 112c according to the illustrated embodiment. The axis of rotation 140c of the rotor 112c is tilted aft from vertical 142 by an angle 144c, which may range from 0 to 15 degrees in either direction. The slight aft tilt of the rotor 112c can aid in aircraft stability and yaw control. FIG. 6 also shows the range of tilt of at least the outermost prop rotor 114c according to some embodiments. The outermost prop rotor 114c can be tilted from a straight ahead position indicated by the horizontal axis of rotation 146c of the prop rotor 114c in its propulsion configuration to a position just past (e.g., less than 10 degrees past) vertical 148 as indicated by the axis of rotation 150c of the prop rotor 114c in its lift configuration, such that the prop rotor 114c has a tilt range 151c of approximately 100 degrees. According to various embodiments, each of the prop rotors 114 has a span of greater than 90 degrees.

[0051] 7 and 8 show the location of the wings, rotors, and propellers relative to a person on the ground according to some embodiments. The aircraft 100 may be configured such that the bottom 152a of the innermost propeller 114a is positioned above the head of a person standing on the ground adjacent to the fuselage (e.g., preparing to enter the aircraft) when the aircraft 100 is supported on the ground by its landing gear 154. Locating the wings high on top of the fuselage 102 allows for maximum head clearance for a person to enter and exit the aircraft. Figures 7 and 8 also show a person seated in the passenger compartment of the fuselage to illustrate the relative size of the aircraft according to some embodiments.

[0052] According to some embodiments, the rotors 112 and the prop rotors 114 are all electric. Batteries for powering the rotors 112 and the prop rotors 114 may be located in any suitable location on the aircraft, including the fuselage and / or wings. The number and power of the rotors and the prop rotors may be selected according to desired performance parameters (e.g., target payload, airspeed and altitude). According to some embodiments, the maximum power rating of one or more of the rotors and the prop rotors is 500 kilowatts or less, preferably 200 kilowatts or less, more preferably 150 kilowatts or less. According to some embodiments, the maximum power rating of one or more of the rotors and the prop rotors is at least 10 kilowatts, preferably at least 20 kilowatts, more preferably at least 50 kilowatts. The number of prop rotors may range from as few as two (one on each side of the aircraft) to a maximum of 24 (12 on each side of the aircraft). Preferably, the number of prop rotors is in the range of 4-8. The number of rotors may be in the range of 2-24, preferably in the range of 4-8. An aircraft may have an equal number of rotors and propellers, a greater number of propellers, or a greater number of rotors.

[0053] An aircraft according to the above principles may be configured to carry up to 10 persons, preferably up to 6 persons, more preferably up to 4 persons. According to some embodiments, the aircraft is configured to be piloted and includes a piloting control unit. In some embodiments, the aircraft is configured to operate autonomously without any on-board pilot.

[0054] According to some embodiments, the aircraft is configured to carry up to six people (e.g., a pilot and up to five passengers) up to 75 miles at a cruising speed of up to 150 miles per hour at an altitude of up to 3,000 feet above ground. In some embodiments, the aircraft is configured for five people, such as one pilot and four passengers. According to various embodiments, the maximum range on a single battery charge is 25 miles, 50 miles, 75 miles, 100 miles, or 200 miles.

[0055] According to various embodiments, the rotor 112 and / or propeller 114 are configured to have a relatively low tip speed to reduce the amount of noise generated by the aircraft. In some embodiments, the tip speed of the rotor blades is about 0.4 Mach at hover. According to various embodiments, the diameter of the rotor and / or propeller blades is in the range of 1 to 5 meters, preferably in the range of 1.5 to 2 meters.

[0056] According to various embodiments, the wingspan is in the range of 10 to 20 meters, preferably in the range of 15 to 16 meters. According to various embodiments, the length of the aircraft is in the range of 3 to 20 meters, preferably in the range of 5 to 15 meters, more preferably in the range of 6 to 10 meters.

[0057] According to various embodiments, the aircraft operates during takeoff and landing by placing the prop-rotors in a lift configuration and providing the aircraft with the required lift through the rotors and the combined lift provided by the prop-rotors. According to various embodiments, during vertical takeoff, landing and / or hovering, the prop-rotors may be maintained in a predefined lift configuration, which may be the same across all prop-rotors or may be different for different prop-rotors. According to various embodiments, the tilt of at least some of the prop-rotors may be actively adjusted during takeoff, landing and / or hovering to provide the required stability and / or control. According to some embodiments, the tilt of at least one prop-rotor is actively controlled by a flight controller during takeoff, landing and / or hovering to generate a yawing moment.

[0058] According to various embodiments, each rotor and / or each prop-rotor may be individually controlled by a flight controller according to various degrees of freedom of movement. According to various embodiments, the only degree of freedom of a rotor is the rotational speed of the rotor. In some embodiments, the angle of attack of the blades of the rotor may be adjusted collectively, providing an additional degree of freedom. According to various embodiments, the degrees of freedom of at least some of the prop-rotors include the rotational speed of the prop-rotor, the collective angle of attack of the blades, and the angle of tilt of the prop-rotor. According to various embodiments, any of these degrees of freedom may be actively controlled (autonomously or in response to pilot commands) by a flight controller during takeoff and landing to provide appropriate stability and control.

[0059] Once the aircraft has achieved sufficient altitude to begin forward flight, the propeller rotors begin to tilt forward into their thrust configuration so that their thrust provides a combination of lift and thrust, with the proportion of lift decreasing as the propeller rotors are tilted further into their thrust configuration. The rotors may remain active for at least a portion of the period during which the propeller rotors are tilted forward to continue to provide rotor-based lift. Any time after the forward airspeed is high enough that the wings provide enough lift to maintain the aircraft's altitude, the rotors may be stopped. As described above, the rotor blades may be locked in a low-drag position.

[0060] During cruise, the rotors remain stationary. Control surfaces on the wings and / or rear stabilizer may be used for aircraft steering and stability in a conventional manner. According to some embodiments, the tilt of at least some of the prop rotors may be actively controlled to provide additional stability and / or controllability control. In some embodiments, the tilt of at least some of the prop rotors is actively controlled during takeoff and landing and / or hovering. In some embodiments, the tilt of the prop rotors is fixed (i.e., does not vary) during cruise. According to some embodiments, the tilt of the outermost prop rotor may be actively and independently controlled during vertical takeoff and landing and / or hovering to provide yawing moment as needed.

[0061] The foregoing description has been described with reference to specific embodiments for purposes of illustration. However, the illustrative discussion above is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments have been chosen and described in order to best explain the principles of the technology and their practical application, thereby enabling those skilled in the art to best utilize the technology and various embodiments with various modifications as suited to the particular use contemplated.

[0062] Although the present disclosure and embodiments have been fully described with reference to the accompanying drawings, it should be noted that various changes and improvements will become apparent to those skilled in the art. Such changes and improvements should be understood to be included within the scope of the present disclosure and embodiments as defined by the claims. Finally, the entire disclosures of the patents and publications mentioned in this application are incorporated herein by reference.

Claims

1. 1. A vertical take-off and landing aircraft, comprising: The torso and at least one wing connected to the fuselage; a plurality of rotors connected to the at least one wing for providing lift for vertical takeoff and landing of the aircraft; a plurality of propellers connected to the at least one wing and tiltable between a lift configuration to provide lift for vertical takeoff and landing of the aircraft and a thrust configuration to provide forward thrust to the aircraft.

2. 2. The aircraft of claim 1, wherein the plurality of rotors are aft of the at least one wing and the plurality of prop rotors are forward of the at least one wing.

3. 3. The aircraft of claim 2, further comprising a plurality of booms attached to the at least one wing, each boom mounting one rotor and one propeller rotor to the at least one wing.

4. 4. An aircraft according to any one of claims 1 to 3, wherein a first prop rotor is forward of a second prop rotor adjacent to the first prop rotor.

5. 5. An aircraft according to claim 1, wherein a first prop rotor is mounted higher on the aircraft than a second prop rotor adjacent to the first prop rotor.

6. 6. An aircraft as claimed in any preceding claim, wherein each rotor has only two blades.

7. 7. The aircraft of claim 6, wherein each rotor is configured to lock the two blades in position during forward flight.

8. 8. An aircraft as claimed in claim 6 or 7, wherein each propeller rotor has more than two blades.

9. 9. The aircraft of claim 1, wherein a first rotor of the plurality of rotors is inclined relative to a second rotor of the plurality of rotors such that an axis of rotation of the first rotor is non-parallel to an axis of rotation of the second rotor.

10. 10. The aircraft of claim 9, wherein the tilt angle of any rotor or propeller is such that an individual burst disk cannot intersect any passenger or pilot.

11. 11. An aircraft as claimed in claim 9 or 10, wherein the tilt angle of any rotor or propeller is such that an individual burst disk cannot intersect any flight critical component.

12. 12. The aircraft of claim 1, wherein a first prop rotor of the plurality of prop rotors is inclined relative to a second prop rotor of the plurality of prop rotors such that an axis of rotation of the first prop rotor is non-parallel to an axis of rotation of the second prop rotor.

13. 13. The aircraft of any one of claims 1 to 12, further comprising a control system configured to actively vary the tilt of at least one propeller to generate a yawing moment during hover.

14. 14. An aircraft according to any one of claims 1 to 13, wherein the angle of attack of the blades of the propeller rotor is collectively adjustable in flight.

15. 15. An aircraft as claimed in any preceding claim, wherein propulsion is provided entirely by the propeller rotor.

16. 16. An aircraft as claimed in any preceding claim, wherein the range of tilt of the propeller is greater than 90 degrees.

17. 17. An aircraft as claimed in any preceding claim, wherein the at least one wing provides lift required during cruise.

18. 18. An aircraft as claimed in any preceding claim, wherein the at least one wing is a high wing mounted above the fuselage.

19. 19. An aircraft as claimed in any preceding claim, wherein the at least one wing comprises a control surface.

20. 20. An aircraft as claimed in any preceding claim, wherein all of the rotors and propellers are mounted on the at least one wing.

21. 21. An aircraft according to any one of claims 1 to 20, wherein the aircraft is electrically powered.

22. 22. An aircraft as claimed in any preceding claim, wherein the aircraft is manned.

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