IL308002A - Aerial vehicle - Google Patents

Description

0296841816- AERIAL VEHICLE TECHNOLOGICAL FIELD The presently disclosed subject matter relates to systems and methods for in-flight releasing and/or in-flight capturing a fixed-wing aircraft using an aerial vehicle with VTOL capabilities.

BACKGROUND There are known systems for releasing and/or capturing a fixed-wing aircraft using an aerial vehicle with VTOL capabilities while in flight.

By way of non-limiting example, US 2021/107652 discloses techniques that involve releasing and/or capturing a fixed-wing aircraft using an aerial vehicle with VTOL capabilities while the fixed-wing aircraft is in flight. For example, the VTOL aerial vehicle may take off vertically while carrying the fixed-wing aircraft and then fly horizontally before releasing the fixed-wing aircraft. Upon release, the fixed-wing aircraft flies independently to perform a mission (e.g., surveillance, payload delivery, combinations thereof, etc.). After the fixed-wing aircraft has completed its mission, the VTOL aerial vehicle may capture the fixed-wing aircraft while both are in flight, and then land together vertically.

Also way of non-limiting example, WO 2017/106324 discloses a helicopter-mediated system and method for launching and retrieving an aircraft capable of long-distance efficient cruising flight from a small space without the use of a long runway.

Also way of non-limiting example, WO 2018/107278 discloses a capture-and-release aircraft for capturing and releasing fixed-wing aircraft. The capture-and-release aircraft comprises a frame to which is secured a set of rotor units. Each rotor unit has a rotor with a rotation axis, the rotation axes of the rotors being generally parallel. A set of 0296841816- aircraft engagement members is also secured to the frame that can align with a set of anchors of a fixed-wing aircraft to releasably couple with the anchors.

Also way of non-limiting example, US 2017/036762 discloses a system that includes an unmanned, multirotor helicopter and a fixed-wing aircraft. The multirotor helicopter may couple to the fixed-wing aircraft to support and hold the fixed-wing aircraft. The multirotor helicopter may then elevate the fixed-wing aircraft from a launch site to a release altitude. The multirotor helicopter may also accelerate the fixed-wing aircraft to a release speed and upon reaching the release speed, release the fixed-wing aircraft. The unmanned, multirotor helicopter may then return to the launch site.

Also way of non-limiting example, US 9,630,712 discloses systems and processes using multirotor lifter to deploy and/or engage fixed wing aircraft. For example, one or more unmanned multirotor lifters may engage an unmanned fixed wing aircraft, aerially navigate the fixed wing aircraft vertically to a desired altitude, and then release the fixed wing aircraft so that the fixed wing aircraft can initiate a flight plan. In some implementations, multirotor lifter may also be configured to engage fixed wing aircraft while both the multirotor lifters and the fixed wing aircraft are in flight.

Also way of non-limiting example, US 2017/274997 discloses various embodiments of a rotorcraft-assisted launch and retrieval system including a rotorcraft having a fixed-wing aircraft capture assembly configured to capture a fixed-wing aircraft.

Also way of non-limiting example, US 2020/361606 discloses a vehicle system and method for VTOL. The vehicle system includes: a carrier vehicle and a cruise vehicle. The carrier vehicle includes one or more fuselages, one or more wings, one or more attach units coupled to the one or more fuselages or to the one or more wings, and propulsion systems operable to provide, at least, substantially vertical thrust and substantially horizontal thrust. The cruise vehicle includes one or more fuselages for carrying passengers or cargo and one or more wings. The one or more attach units of the carrier vehicle are adapted to couple to the cruise vehicle to detachably engage.

Also way of non-limiting example, WO 2021/074480 discloses a method of approach and coupling between VTOL and HTOL platforms, self-contained approach and coupling system, and associated VTOL platform. This consists of a vertical take-off 0296841816- and landing (VTOL) assistance system for platforms lacking said capability, such as HTOL platforms, enabling the combined operation of two flight platforms, a VTOL and a HTOL. To this end, it presents a dual dynamic, controlled coupling and uncoupling system between the two platforms during the take-off and landing maneuvers.

Also way of non-limiting example, DE 102016014309 discloses a throw and catch device as an aid for taking off and landing unmanned air vehicle, wherein the device comprises an electrically driven multicopter having a plurality of rotors in the direction of the vertical axis, and at least one rotor with an electrically driven propulsion thrust vector in the direction of the longitudinal axis of the multicopter.

Also way of non-limiting example, US 2016/327945 discloses methods and apparatus to deploy and recover a fixed wing unmanned aerial vehicle via a non-fixed wing aircraft are described herein. An example method includes tracking a location of a non-fixed wing aircraft in flight, tracking a location of a fixed wing aircraft in flight, positioning the non-fixed wing aircraft relative to the fixed wing aircraft based on the locations of the non-fixed wing aircraft and the fixed wing aircraft and coupling, via a gripper, the fixed wing aircraft to the non-fixed wing aircraft in mid-flight at a recovery location.

Also way of non-limiting example, CN 106882386 discloses a taking-off and landing method of an aircraft and a device thereof. The taking-off and landing device comprises a fixed wing aircraft, a multi-rotor type aircraft and a multi-rotor type aircraft parking platform; the fixed wing aircraft is provided with a GPS navigation device, an inertia sensor, an infrared illuminator, a communication module and an adsorption plane; the multi-rotor type aircraft comprises a flight control computer, a multi-rotor inertia sensor, an infrared thermal imager, a multi-rotor GPS navigation device, a multi-rotor communication module, a vacuum generator, a sucking disc, a connecting rod and a connecting rod vertical device. The multi-rotor type aircraft separates from the fixed wing aircraft after hoisting the fixed wing aircraft to lift off, and taking-off of the fixed wing aircraft is achieved; the multi-rotor type aircraft flies to midair and is combined with the fixed wing aircraft, and hoists landing of the fixed wing aircraft.

Also way of non-limiting example, CN 109502018 discloses a combined unmanned aerial vehicle. The combined unmanned aerial vehicle comprises a rotorcraft 0296841816- and a fixed-wing aircraft, wherein the rotorcraft is provided with a gripping device; the fixed-wing aircraft is provided with a gripping docking mechanism matched with the gripping device; when the gripping device is connected with the gripping docking mechanism, the rotorcraft and the fixed-wing aircraft are integrally connected; and when the gripping device is separated from the gripping docking mechanism, the rotorcraft and the fixed-wing aircraft are separated into independent individuals. According to the combined unmanned aerial vehicle, the fixed-wing aircraft is gripped through the rotorcraft for combination, so that the fixed-wing aircraft with conventional layout has the ability of vertical takeoff and landing under a combined mode, and has high-efficiency cruising capability under a separation mode; and the combined unmanned aerial vehicle is relatively low in overall redundancy, high in cruising efficiency and strong in load capacity.

Also way of non-limiting example, US 5,000,398 discloses a Flying Multi-Purpose Aircraft Carrier (FMPAC) that comprises a runway body which is provided with V/STOL capability by at least two rotary wings, located outside the two lateral ends of the runway body in a side-by-side configuration. The rotary wings are, preferably, of a large diameter helicopter rotor blade type, and are powered by respective shaft turbine engines. A substantially flat runway platform is provided along the middle portion of the runway body, between the left and right helicopter rotary wings. The runway platform is located as low as possible, in order to secure flight stability of the composite aircraft. The top surface of the runway platform has a substantially flat and rectangular-like shape defining a conventional runway, and may allow a fixed wing CA to take-off from or to land on it, during flight of the FMPAC, allowing the pilot of the CA to operate his aircraft with a considerable margin of error. During composite flight, the brakes of the CA's landing gear should be actuated and in addition, its landing gear should be locked down to the surface of the FMPAC. Any CA may be assisted for V/STOL by means of a FMPAC, provided that its weight is not larger than the payload capability of the FMPAC. The V/STOL assisted flight of CA may be performed from any relatively flat ground surface, or alternatively, it may be performed from a water surface, if the FMPAC is equipped with a flying boat undercarriage. 0296841816- GENERAL DESCRIPTION According to a first aspect of the presently disclosed subject matter, there is provided a VTOL aerial vehicle comprising a body, a first propulsion system and a second propulsion system, wherein: the body; the first propulsion system comprises at least two first propulsion units, wherein the first propulsion system is pivotably mounted to the body and is configured for being selectively pivoted about a first pivot axis over a first pivot angle range with respect to the body; the second propulsion system comprises at least two second propulsion units, wherein the second propulsion system is pivotably mounted to the body and is configured for being selectively pivoted about a second pivot axis over a second pivot angle range with respect to the body; wherein the first propulsion system and the second propulsion system are configured for generating together sufficient thrust to enable vectored flight.

For example, the body is configured for being releasably engaged with respect to a payload, and wherein the first propulsion system and the second propulsion system are configured for generating together sufficient thrust to enable vectored flight at least when engaged with the payload.

Additionally or alternatively, for example, the first pivot axis and the second pivot axis are parallel to one another.

Additionally or alternatively, for example, the first pivot axis and the second pivot axis are parallel to a pitch axis of the VTOL aerial vehicle.

Additionally or alternatively, for example, the first propulsion system comprises a first body portion, the at least two first propulsion units being mounted to the first body portion in fixed spatial relationship with respect thereto, and wherein the first body portion is pivotably mounted with respect to the body about the first pivot axis. For example, each said first propulsion unit has a respective first thrust vector that is spatially fixed with respect to the first body portion. For example, said respective first thrust vectors are parallel to one another. Additionally or alternatively, for example, at least one said respective first thrust vector is orthogonal with respect to the first pivot axis. 0296841816- Additionally or alternatively, for example, the second propulsion system comprises a second body portion, the at least two second propulsion units being mounted to the second body portion in fixed spatial relationship with respect thereto, and wherein the second body portion is pivotably mounted with respect to the body about the second pivot axis. For example, each said second propulsion unit has a respective second thrust vector that is spatially fixed with respect to the second body portion. For example, said respective second thrust vectors are parallel to one another. Additionally or alternatively, for example, at least one said respective second thrust vector is orthogonal with respect to the second pivot axis.

Additionally or alternatively, for example, said first pivot angle range is between 0º and ±135º.

Additionally or alternatively, for example, the first propulsion system is configured for maintaining any desired first pivot angle within said first pivot angle range.

Additionally or alternatively, for example, said second pivot angle range is between 0º and ±135º.

Additionally or alternatively, for example, the second propulsion system is configured for maintaining any desired second pivot angle within said second pivot angle range.

Additionally or alternatively, for example, the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, in mutually co-rotational directions.

Additionally or alternatively, for example, the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, in mutually counter-rotational directions.

Additionally or alternatively, for example, the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, wherein the first pivot angle and the second pivot angle are substantially equal to one another. For example, the first pivot angle and the second pivot angle are each in a range between about 10º and about 30º. 0296841816- Additionally or alternatively, for example, the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, wherein the first pivot angle and the second pivot angle are substantially unequal with respect to one another. For example, the first pivot angle and the second pivot angle are each in a range between about 10º and about 30º.

Additionally or alternatively, for example, the VTOL aerial vehicle has each one of: a stored configuration, an autonomous configuration, and an engaged configuration, wherein: - in the stored configuration the first propulsion system and the second propulsion system are pivoted towards one another; - in the autonomous configuration the first propulsion system and the second propulsion system are configured to provide propulsive power to enable vectored thrust flight for the VTOL aerial vehicle by itself; - in the engaged configuration the first propulsion system and the second propulsion system are configured to provide propulsive power to enable vectored thrust flight for the VTOL aerial vehicle when engaged with the payload.

Additionally or alternatively, for example, the body comprises a port body portion and a starboard body portion, - wherein the port body portion includes at least one said first propulsion unit pivotably mounted to the port body portion and configured for being selectively pivoted about the first pivot axis over the first pivot angle range with respect to the port body portion, and wherein the port body portion includes at least one said second propulsion unit pivotably mounted to the port body portion and configured for being selectively pivoted about the second pivot axis over the second pivot angle range with respect to the port body portion; - wherein the starboard body portion includes at least one said first propulsion unit pivotably mounted to the starboard body portion and configured for being selectively pivoted about the first pivot axis over the first pivot angle range 0296841816- with respect to the starboard body portion, and wherein the starboard body portion includes at least one said second propulsion unit pivotably mounted to the starboard body portion and configured for being selectively pivoted about the second pivot axis over the second pivot angle range with respect to the starboard body portion.

For example, the body comprises a central body portion laterally spacing the port body portion and the starboard body portion with respect to one another. For example, the central body portion has an aerodynamically shaped transverse cross-section. Additionally or alternatively, for example, the body is configured for being releasably engaged with respect to the payload via the port body portion and the starboard body portion. Additionally or alternatively, for example, the body is configured for being releasably engaged with respect to the payload via the central body portion.

Additionally or alternatively, for example, the payload comprises a fixed wing air vehicle, and wherein the body is configured for being releasably engaged with respect to the payload at a ventral portion of the payload.

Additionally or alternatively, for example, the payload comprises a fixed wing air vehicle, and wherein the body is configured for being releasably engaged with respect to the payload at a dorsal portion of the payload.

Additionally or alternatively, for example, the payload comprises a fixed wing air vehicle having a port wing and a starboard wing, and wherein the body is configured for being releasably engaged with respect to the payload at the port wing and at the starboard wing.

Additionally or alternatively, for example, the first propulsion system and the second propulsion system are configured for together providing a thrust to weight ratio in a range between about 3 and about 15 or in a range between about 1.8 to about 15.

Additionally or alternatively, for example, the first propulsion system and the second propulsion system are configured for together providing a vertical thrust that exceeds a sum of a first weight of the VTOL aerial vehicle and a second weight of the payload. 0296841816- Additionally or alternatively, for example, the VTOL aerial vehicle comprises a controller for selectively controlling vectored flight of the VTOL aerial vehicle, and for selectively causing the first propulsion system to be pivoted about the first pivot axis to a desired first pivot angle with respect to the body, and for selectively causing the second propulsion system to be pivoted about the second pivot axis to a desired second pivot angle with respect to the body. For example, the controller is configured for selectively causing the first propulsion system to be pivoted about the first pivot axis to the desired first pivot angle with respect to the body, and for causing the second propulsion system to be pivoted about the second pivot axis to the desired second pivot angle with respect to the body, such as to enable vectored flight of the VTOL aerial vehicle with the payload concurrently engaged thereto, and for concurrently providing a forward speed to the VTOL aerial vehicle with the payload concurrently engaged thereto. For example, the payload is a fixed wing air vehicle, and wherein said forward speed is sufficient for enabling the fixed wing air vehicle to generate sufficient aerodynamic lift sufficient for enabling aerodynamic flight of the fixed wing air vehicle. Additionally or alternatively, for example, the controller is configured for selectively causing the first propulsion system to be pivoted about the first pivot axis to the desired first pivot angle with respect to the body, and for causing the second propulsion system to be pivoted about the second pivot axis to the desired second pivot angle with respect to the body, and for orienting the body at a desired angle of attack. Additionally or alternatively, for example, the payload is a fixed wing air vehicle having a stall speed, wherein the controller is configured for selectively causing the first propulsion system to be pivoted about the first pivot axis to the desired first pivot angle with respect to the body, and for causing the second propulsion system to be pivoted about the second pivot axis to the desired second pivot angle with respect to the body, such as to enable vectored flight of the VTOL aerial vehicle with the payload concurrently engaged thereto, and for concurrently matching a forward speed of the VTOL aerial vehicle to at least the stall speed of the payload concurrently engaged thereto.

Additionally or alternatively, for example, the VTOL aerial vehicle is configured for disengaging the payload when previously engaged thereto at a first predetermined altitude and a first forward speed. 0296841816- Additionally or alternatively, for example, the VTOL aerial vehicle is configured for engaging the payload thereto at a second predetermined altitude and a second forward speed.

Additionally or alternatively, for example, the VTOL aerial vehicle further comprises an auxiliary thrust system for selectively generating at least one of lateral thrust and law moments to the VTOL aerial vehicle.

Additionally or alternatively, for example, the controller is configured for receiving a command to provide a desired angle of attack for the body and a desired forward speed for the VTOL aerial vehicle, and generates suitable commands for selectively causing the first propulsion system to be pivoted about the first pivot axis to a corresponding said first pivot angle with respect to the body, for selectively causing the second propulsion system to be pivoted about the second pivot axis to a corresponding second pivot angle with respect to the body, for selectively causing the first prolusion system to generate a said first thrust, and for selectively causing the second prolusion system to generate a said second thrust, such as to provide said desired angle of attack for the body and said desired forward speed for the VTOL aerial vehicle According to a second aspect of the presently disclosed subject matter there is provided a composite air vehicle, comprising a VTOL aerial vehicle as defined herein regarding the first aspect of the presently disclosed subject matter, wherein the VTOL aerial vehicle is releasably engaged with respect to a payload.

For example, the payload is a fixed wing air vehicle.

According to a third aspect of the presently disclosed subject matter there is provided a method for operating a VTOL aerial vehicle for aerially releasing a payload, the method comprising: (a) providing a VTOL aerial vehicle as defined herein regarding the first aspect of the presently disclosed subject matter; (b) engaging a payload to the VTOL aerial vehicle, wherein the payload is a fixed wing air vehicle capable of aerodynamic flight at forward speeds exceeding a stall speed; 0296841816- (c) operating the composite air vehicle to operate in vectored flight mode for take-off, wherein the VTOL aerial vehicle provides the required vectored thrust for the composite air vehicle; (d) transitioning the VTOL aerial vehicle, while engaged to the payload, to the forward flight mode FFM; (e) disengaging the fixed wing air vehicle from the VTOL aerial vehicle, and flying the fixed wing air vehicle independently from the VTOL aerial vehicle.

For example, step (d) comprises: pivoting the first propulsion system about the first pivot axis and the second propulsion system about the second pivot axis to a desired said first pivot angle and a desired second pivot angle, respectively, to provide a forward speed to the composite air vehicle, wherein said forward speed exceeds said stall speed of the fixed wing air vehicle, and allowing the fixed wing air vehicle to generate aerodynamic lift.

According to a fourth aspect of the presently disclosed subject matter there is provided a method for operating a VTOL aerial vehicle for aerially capturing a payload, the method comprising: (a) providing a VTOL aerial vehicle as defined herein regarding the first aspect of the presently disclosed subject matter; providing a payload comprising a fixed wing air vehicle capable of aerodynamic flight; (b) causing the fixed wing air vehicle to fly in aerodynamic flight mode along a first trajectory; (c) causing the VTOL aerial vehicle to fly in vectored flight mode in a second trajectory, wherein at least one of the first trajectory and the second trajectory is an intercept trajectory with respect to the other one of the first trajectory and the second trajectory; (d) aerially aligning the VTOL aerial vehicle with respect to the fixed wing air vehicle in an engagement enabling position; (e) causing the fixed wing air vehicle to become engaged with the VTOL air vehicle to provide a composite air vehicle; 0296841816- (f) operating the VTOL aerial vehicle to progressively decrease the forward speed of the composite air vehicle and to increase vertical thrust to compensate corresponding fall in aerodynamic lift generated by the fixed wing air vehicle; (g) operating the VTOL aerial vehicle to vertically land the composite air vehicle.

For example, step (e) comprises: pivoting the first propulsion system about the first pivot axis and the second propulsion system about the second pivot axis to a desired said first pivot angle and a desired second pivot angle, respectively, to provide a forward speed to the composite air vehicle, wherein said forward speed matches the forward speed of the fixed wing air vehicle, and wherein the body is oriented to match the fixed wing air vehicle.

Additionally or alternatively, for example, in said an engagement enabling position, said VTOL aerial vehicle is vertically above the fixed wing air vehicle.

According to a fifth aspect of the presently disclosed subject matter there is provided a method for operating a VTOL aerial vehicle for transporting a payload, the method comprising: (a) providing a VTOL aerial vehicle as defined herein regarding the first aspect of the presently disclosed subject matter; (b) engaging a payload to the body (prior to flying the VTOL aerial vehicle) while on the ground to provide a composite air vehicle; (c) operating the composite air vehicle to operate in vectored flight mode for take-off, wherein the VTOL aerial vehicle provides the required vectored thrust for the composite air vehicle; (d) pivoting the first propulsion system about the first pivot axis and the second propulsion system about the second pivot axis to a desired said first pivot angle and a desired second pivot angle, respectively, to provide a forward speed to the composite air vehicle, to thereby transport the composite air vehicle along a desired trajectory having a range; 0296841816- (e) operating the composite air vehicle to operate in vectored flight mode for landing the composite air vehicle at a landing location, wherein the VTOL aerial vehicle provides the required vectored thrust for the composite air vehicle. For example, in step (b) the payload is engaged to the body prior to flying the VTOL aerial vehicle.

A feature of at least one example of the presently disclosed subject matter is that the respective VTOL aerial vehicle is capable of aerially disengaging with respect to the payload in a safe manner.

Another feature of at least one example of the presently disclosed subject matter is that the respective VTOL aerial vehicle is capable of matching flight conditions of the payload at least prior to aerially disengaging with respect to the payload.

Another feature of at least one example of the presently disclosed subject matter is that the respective VTOL aerial vehicle is capable of at least generating nominally zero pitch moment with respect to the payload at least prior to aerially disengaging with respect to the payload.

Another feature of at least one example of the presently disclosed subject matter is that the respective VTOL aerial vehicle is capable of cooperating with the payload over a wide variety of angles of attack, and over a wide range of forward velocities.

Another feature of at least one example of the presently disclosed subject matter is that the respective VTOL aerial vehicle is capable of concurrently and independently controlling each one of the respective vertical thrust, horizontal thrust, forward speed, angle of attack of the body angle, pitching moment thereof. 0296841816- BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the subject matter that is disclosed herein and to exemplify how it can be carried out in practice, examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Fig. 1A is a top view of a VTOL aerial vehicle engaged with a payload to provide a composite vehicle, according to an example of the presently disclosed subject matter; Fig. 1B is a side view of the example of Fig. 1A; Fig. 1C is a partial front view of the example of Fig. 1A; Fig. 1D is a side view of the VTOL aerial vehicle example of Fig. 1A, in which the respective first and second propulsion systems re pivoted with respect to the respective body.

Fig. 2A is a side view of the VTOL aerial vehicle example of Fig. 1A, in which the respective first and second propulsion systems are pivoted with respect to the respective body, and the body is nominally horizontal; Fig. 2B is a side view of the VTOL aerial vehicle example of Fig. 1A, in which the respective first and second propulsion systems are pivoted with respect to the respective body, the body is at a non-zero angle of attack to the horizontal, and the first and second propulsion systems are nominally horizontal; Fig. 2C is a side view of the VTOL aerial vehicle example of Fig. 1A, in which the respective first and second propulsion systems re pivoted with respect to the respective body, and the body is at an angle of attack to the horizontal; Fig. 2D is a side view of the VTOL aerial vehicle example of Fig. 1A, in which the respective first and second propulsion systems are pivoted towards the respective body; Fig. 2E is a side view of the VTOL aerial vehicle example of Fig. 1A, in the stowed mode.

Fig. 3A is a top view of an alternative variation of the example of Fig. 1A; Fig. 3B is a side view of the example of Fig. 3A.

Fig. 4A is a top view of another alternative variation of the example of Fig. 1A; Fig. 4B is a side view of the example of Fig. 4A. 0296841816- Fig. 5A is a top view of another alternative variation of the example of Fig. 1A; Fig. 5B is a side view of the example of Fig. 5A; Fig. 5C is a partial front view of the example of Fig. 5A.

Fig. 6A is a top view of another alternative variation of the example of Fig. 1A; Fig. 6B is a side view of the example of Fig. 6A.

Fig. 7 schematically illustrates a method of use of the example of Fig. 1, for aerially releasing the respective fixed wing air vehicle from the respective VTOL aerial vehicle.

Fig. 8 is a flow chart corresponding to the method example of Fig. 7.

Fig. 9 schematically illustrates a method of use of the example of Fig. 1, for aerially capturing the respective fixed wing air vehicle by the respective VTOL aerial vehicle.

Fig. 10 is a flow chart corresponding to the method example of Fig. 9.

DETAILED DESCRIPTION Referring to Figs. 1A, 1B and 1C, a VTOL aerial vehicle according to a first example of the presently disclosed subject matter, generally designated 100, comprises a body 200, a first propulsion system 400, and a second propulsion system 600.

The VTOL aerial vehicle 100is configured for being selectively reversibly engaged with, and for carrying, a suitable payload, for example payload 800. When thus engaged, the combination of the VTOL aerial vehicle 100and the payload 800is referred to herein as a composite air vehicle 900.

As will become clearer herein, the VTOL aerial vehicle 100is an aerial vehicle with VTOL (Vertical Take Off and Landing) capabilities, and is configured for vertical take-off, vertical landing, hover, as well as vectored thrust flight, either by itself (i.e., autonomously), or when carrying a payload 800. By vectored thrust flight is meant that the VTOL aerial vehicle 100generates sufficient lifting force for at least countering the weight W1of the VTOL aerial vehicle 100by itself, or together with the weight W2of the payload 800when 0296841816- engaged thereto, to enable powered vectored flight including climb, descent, acceleration, forward flight, maneuvering, etc., the lifting force being exclusively a (full or partial) vertical thrust force generated together by the first propulsion system 400and the second propulsion system 600.

Also as will become clearer herein, in at least this example, the VTOL aerial vehicle 100, in particular the body 200, is configured for being releasably engaged with respect to the payload 800. Furthermore the first propulsion system 400and the second propulsion system 600are configured for generating together sufficient thrust to enable vectored thrust flight at least when the VTOL aerial vehicle 100is engaged with the payload 800, and/or when the VTOL aerial vehicle 100is by itself and thus not engaged with the payload 800.

However, in at least some alternative variations of this example, the respective VTOL aerial vehicle, in particular the respective body, is not configured for being releasably engaged with respect to a payload, and optionally can carry a permanent payload, for example imaging sensors or other sensors. By "permanent payload" is meant that the payload is engaged with or otherwise coupled with respect to the VTOL aerial vehicle for the duration of a respective flight, including takeoff and landing associated with the flight. In such cases, the respective first propulsion system and the respective second propulsion system are configured for generating together sufficient thrust to enable vectored thrust flight of the respective VTOL aerial vehicle.

In at least this example, the first propulsion system 400comprises at least two first propulsion units 420, including a port first propulsion unit 420P and a starboard first propulsion unit 420S . Also in at least this example the second propulsion system 600comprises at least two second propulsion units 620, including a port second propulsion unit 620P and a starboard second propulsion unit 620S .

In at least some alternative variations of this or other examples herein, the respective first propulsion system can include any suitable number of first propulsion units, for example four, six, eight or more first propulsion units, equally divided into a port set of first propulsion units and a starboard set of first propulsion units. Similarly, the respective second propulsion system can include any suitable number of first propulsion units, for example four, six, eight or more second propulsion units, equally divided into a port set of second propulsion units and a starboard set of second propulsion units. Additionally or alternatively, 0296841816- the respective VTOL aerial vehicle can include one or more additional propulsion units, for example fixedly or pivotably mounted to the respective body.

In at least this example, and referring in particular to Fig. 1A, the four propulsion units 420P , 420S , 620P , 620S are arranged with respect to the body 200in polygonal arrangement in plan view, in particular in rectangular arrangement, for example in quadcopter-like arrangement, enclosing the center of gravity CG of the VTOL aerial vehicle within the respective polygonal arrangement.

The position of the center of gravity CG of the VTOL aerial vehicle 100is such as to allow for controllably and stably flying the VTOL aerial vehicle.

In at least one mode of operation, the VTOL aerial vehicle 100is operated in forward motion such that the first propulsion system 400is forward of the body 200, and the second propulsion system 600is aft of the body 200, whereas in at least one other mode of operation, the VTOL aerial vehicle 100can be optionally operated in forward motion such that the second propulsion system 600is forward of the body 200, and the first propulsion system 400is aft of the body 200.

In at least this example, the body 200has a H-shaped plan form, including a port body portion 220P and a starboard body portion 220S , joined to one another via a central body portion 250laterally spacing the port body portion 220P and the starboard body portion 220S with respect to one another, by lateral spacing LX .

For example, in at least this example, the central body portion 250can be in the form of a single strut, for example a rectilinear strut, for example as illustrated in Fig. 1A , or in the form of multiple struts or any other suitable load-bearing and spacing structure. However, in at least some alternative variations of this example, the respective central body portion can have any suitable form that provides a suitable lateral spacing between the respective port body portion and the respective starboard body portion. As will become clearer herein, such suitable lateral spacing LX can optionally be optimized for particular VTOL aerial vehicles, according to the type and size of the payload 800, for example.

The first propulsion system 400 is pivotably mounted to the body 200 and is configured for being selectively pivoted about a first pivot axis P1over a first pivot angle 0296841816- range PAR1with respect to the body 200, and for providing (and optionally for reversibly locking the first propulsion system 400with respect to the body 200at) any desired first pivot angle α1within the first pivot angle range PAR1.

The first propulsion system 400comprises a first body portion 440, the two first propulsion units 420 being mounted to the first body portion 440 in fixed spatial relationship with respect thereto. The first body portion 440is pivotably mounted with respect to the body 200about the first pivot axis P1.

In at least this example, the two first propulsion units 420are mounted to the first body portion 440 in the same fixed spatial relationship with respect to the first body portion 440. For example, the two first propulsion units 420are mounted to the first body portion 440such that the respective thrust vectors of two first propulsion units 420are parallel to one another and also orthogonal to the first body portion 440, and furthermore, the respective thrust vectors of two first propulsion units 420are axially displaced from the first pivot axis P1by equal axial spacings AS1.

However, in at least some alternative variations of the above examples, each one of the respective first propulsion units can be spatially fixed with the respective first body portion at different angular orientations one to the other. For example, when viewed in front view, the respective thrust vectors of the respective two first propulsion units are non-parallel to one another, for example converging in an upward direction, or converging in a downwards direction, with respect to one another.

In at least this example, the first body portion 440comprises a port first body portion 440P and a starboard first body portion 440S , which are not mechanically connected to one another directly. However, in at least some alternative variations of this example the respective port first body portion and the respective starboard first body portion can instead be directly connected mechanically to one another, for example via a first lateral strut, marked in dotted lines at 490 in Fig. 1A, such that the respective port first body portion and the respective starboard first body portion are constrained to move synchronously together as a rigid body via the first lateral strut 490 .

Thus, in at least this example, the port first propulsion unit 420P is mounted to the port first body portion 440P in fixed spatial relationship with respect thereto, and the 0296841816- port first body portion 440P is pivotably mounted with respect to the body 200, in particular to the port body portion 220P , about the first pivot axis P1.

Similarly, in at least this example, the starboard first propulsion unit 420S is mounted to the starboard first body portion 440S in fixed spatial relationship with respect thereto, and the starboard first body portion 440S is pivotably mounted with respect to the body 200, in particular to the starboard body portion 220S , about the first pivot axis P1.

In at least this example, the VTOL air vehicle 100comprises a suitable actuator system (not shown) for selectively pivoting the first propulsion system 400about the first pivot axis P1with respect to the body 200over the first pivot angle range PAR1. For example, the actuator system can comprise a first actuator mechanism including a port first actuator system and a starboard first actuator system. The port first actuator system is configured for selectively pivoting the port first propulsion unit 420P about the first pivot axis P1with respect to the body 200, in particular with respect to the port body portion 220P , over the first pivot angle range PAR1. The port first actuator system is also configured for selectively for providing (and optionally for selectively and reversibly locking the port first propulsion unit 420P with respect to the port body portion 220P , at) any desired first pivot angle α1. Similarly, the starboard first actuator system is configured for selectively pivoting the starboard first propulsion unit 420S about the first pivot axis P1with respect to the body 200, in particular with respect to the starboard body portion 220S , over the first pivot angle range PAR1. The starboard first actuator system is also configured for selectively for providing (and optionally for selectively and reversibly locking the starboard first propulsion unit 420S with respect to the starboard body portion 220S at) any desired first pivot angle α1.

For example, each one of the port first actuator system and the starboard first actuator system can comprise at least one suitable linear actuator, for example a linear electrical actuator, a linear hydraulic actuator, or a linear pneumatic actuator, mechanically coupled between the respective port first propulsion unit 420P and the port body portion 220P , or between the respective starboard first propulsion unit 420S and the starboard body portion 220S . Alternatively, each one of the port first actuator system and the starboard first actuator system can comprise at least one suitable rotary actuator, for 0296841816- example an electrical rotary motor mechanically coupled between the respective port first propulsion unit 420P and the port body portion 220P , or between the respective starboard first propulsion unit 420S and the starboard body portion 220S .

In at least this example, pivoting of the port first body portion 440P and of the starboard first body portion 440S about the first pivot axis P1is synchronized such that in operation of the VTOL air vehicle 100, both the port first body portion 440P and the starboard first body portion 440S are pivoted over the same first pivot angle range PAR1, and at any time, both the port first body portion 440P and the starboard first body portion 440S are at the same first pivot angle α1with respect to the respective port body portion 220P and starboard body portion 220S .

Each said first propulsion unit 420 is configured for generating a respective vertical first thrust T1having a respective first thrust vector TV1that is spatially fixed with respect to the first body portion 440.

Thus, the port first propulsion unit 420P is configured for generating a respective port first thrust having a respective port first thrust vector that is spatially fixed with respect to the port first body portion 440P , and that is spatially fixed with respect to the first pivot axis P1, while the starboard first propulsion unit 420S is configured for generating a respective starboard first thrust having a respective starboard first thrust vector that is spatially fixed with respect to the starboard first body portion 440S and that is spatially fixed with respect to the first pivot axis P1.

In at least this example, the port first thrust vector and the starboard first thrust vector are parallel to one another. However, in at least some alternative variations of this example, the port first thrust vector and the starboard first thrust vector can be non-parallel to one another, for example diverging or converging with respect to one another, when viewed in front view for example; such arrangements can provide stability in hover and/or can assist in or provide generation of yaw moments.

Also in at least this example, each one of the port first thrust vector and the starboard first thrust vector is orthogonal with respect to the first pivot axis P1.

In at least this example, each first propulsion unit 420 includes a respective propeller 421having a rotor axis RA co-axial with the respective first thrust vector TV1, 0296841816- the propeller 421being coupled with one or more electric motors and/or one or more liquid fuel combustion engines (not shown), for example turboshaft engines. Accordingly, the VTOL air vehicle 100comprises suitable batteries and/or fuel tanks operatively coupled to the electric motors and/or the liquid fuel combustion engines, respectively.

Furthermore, in at least this example, the VTOL aerial vehicle 100comprises a controller 290, for example housed in the body 200, and configured for controlling operation of the first propulsion system 400, and for selectively controlling the magnitude of the first pivot angle α1between the first propulsion system 400and the body 200.

In at least some alternative variations of this example, and referring for example to Fig. 3A and Fig. 3B, each respective first propulsion unit includes two propellers 461having a common rotor axis co-axial with the respective first thrust vector TV1, the propellers in each such pair being configured for rotating in mutually opposite rotational directions and coupled with respect to one or more electric motors and/or one or more liquid fuel combustion engines (not shown), for example turboshaft engines.

In at least some other alternative variations of this example, each first propulsion unit 420includes a shrouded fan arrangement, including one fan or two fans (for example counter-rotating fans) or more than two fans, in each case having a common rotor axis co-axial with the respective first thrust vector TV1, the shrouded fan(s) being coupled with one or more electric motors and/or one or more liquid fuel combustion engines (not shown), for example turboshaft engines.

The second propulsion system 600is pivotably mounted to the body 200and is configured for being selectively pivoted about a second pivot axis P2over a second pivot angle range PAR2with respect to the body 200, and for providing (and optionally for reversibly locking the second propulsion system 600with respect to the body 200at) any desired second pivot angle α2within the second pivot angle range PAR2.

The second propulsion system 600comprises a second body portion 640, the two second propulsion units 620 being mounted to the second body portion 640 in fixed spatial relationship with respect thereto. The second body portion 640 is pivotably mounted with respect to the body 200about the second pivot axis P2. 0296841816- In at least this example, the two second propulsion units 620are mounted to the second body portion 640in the same fixed spatial relationship with respect to the second body portion 640. For example, the two second propulsion units 620are mounted to the second body portion 640such that the respective thrust vectors of two second propulsion units 620are parallel to one another and also orthogonal to the second body portion 640, and furthermore, the respective thrust vectors of two second propulsion units 620are axially displaced from the second pivot axis P2by equal axial spacings AS2.

However, in at least some alternative variations of the above examples, each one of the respective second propulsion units can be spatially fixed with the respective second body portion at different angular orientations one to the other. For example, when viewed in aft view, the respective thrust vectors of the respective two second propulsion units are non-parallel to one another, for example converging in an upward direction, or converging in a downwards direction.

In at least this example, the second body portion 640comprises a port second body portion 640P and a starboard second body portion 640S , which are not mechanically connected to one another directly. However, in at least some alternative variations of this example the respective port second body portion and the respective starboard second body portion can instead be directly connected mechanically to one another, for example via a second lateral strut, marked in dotted lines at 690in Fig. 1A , such that the respective port second body portion and the respective starboard second body portion are constrained to move together synchronously as a rigid body via the second lateral strut 690.

Thus, in at least this example, the port second propulsion unit 620P is mounted to the port second body portion 640P in fixed spatial relationship with respect thereto, and the port second body portion 640P is pivotably mounted with respect to the body 200, in particular to the port body portion 220P , about the second pivot axis P2.

Similarly, in at least this example, the starboard second propulsion unit 620S is mounted to the starboard second body portion 640S in fixed spatial relationship with respect thereto, and the starboard second body portion 640S is pivotably mounted with respect to the body 200, in particular to the starboard body portion 220S , about the second pivot axis P2. 0296841816- In at least this example, the VTOL air vehicle 100comprises a suitable actuator system (not shown) for selectively pivoting the second propulsion system 600about the second pivot axis P2with respect to the body 200over the second pivot angle range PAR2. For example, the actuator system can comprise a second actuator mechanism including a port second actuator system and a starboard second actuator system. The port second actuator system is configured for selectively pivoting the port second propulsion unit 620P about the second pivot axis P2with respect to the body 200, in particular with respect to the port body portion 220P , over the second pivot angle range PAR2. The port second actuator system is also configured for selectively for providing (and optionally for selectively and reversibly locking the port second propulsion unit 620P with respect to the port body portion 220P at) any desired second pivot angle α 2. Similarly, the starboard second actuator system is configured for selectively pivoting the starboard second propulsion unit 620S about the second pivot axis P2with respect to the body 200, in particular with respect to the starboard body portion 220S , over the second pivot angle range PAR 2. The starboard second actuator system is also configured for selectively for providing (and optionally for selectively and reversibly locking the starboard second propulsion unit 620S with respect to the starboard body portion 220S at) any desired second pivot angle α2.

For example, each one of the port second actuator system and the starboard second actuator system can comprise at least one suitable linear actuator, for example a linear electrical actuator, a linear hydraulic actuator, or a linear pneumatic actuator, mechanically coupled between the respective port second propulsion unit 620P and the port body portion 220P , or between the respective starboard second propulsion unit 620S and the starboard body portion 220S . Alternatively, each one of the port second actuator system and the starboard second actuator system can comprise at least one suitable rotary actuator, for example an electrical rotary motor mechanically coupled between the respective port second propulsion unit 620P and the port body portion 220P , or between the respective starboard second propulsion unit 620S and the starboard body portion 220S .

In at least this example, pivoting of the port second body portion 640P and of the starboard second body portion 640S about the second pivot axis P2is synchronized such that in operation of the VTOL air vehicle 100, both the port second body portion 640P 0296841816- and the starboard second body portion 640S are pivoted over the same second pivot angle range PAR2, and at any time, both the port second body portion 640P and the starboard second body portion 640S are at the same second pivot angle α2 with respect to the respective port body portion 220P and starboard body portion 220S .

Each said second propulsion unit 620is configured for generating a respective second thrust T2having a respective second thrust vector TV2that is spatially fixed with respect to the second body portion 640.

Thus, the port second propulsion unit 620P is configured for generating a respective port second thrust having a respective port second thrust vector that is spatially fixed with respect to the port second body portion 640P , while the starboard second propulsion unit 620S is configured for generating a respective starboard second thrust having a respective starboard second thrust vector that is spatially fixed with respect to the starboard second body portion 640S .

In at least this example, the port second thrust vector and the starboard second thrust vector are parallel to one another. However, in at least some alternative variations of this example, the port second thrust vector and the starboard second thrust vector can be non-parallel to one another, for example diverging or converging with respect to one another, when viewed in front view; such arrangements can provide stability in hover and/or can assist in or provide generation of yaw moments.

Also in at least this example, each one of the port second thrust vector and the starboard second thrust vector is orthogonal with respect to the second pivot axis P2.

In at least this example, each second propulsion unit 620includes a respective propeller 621having a rotor axis RA co-axial with the respective second thrust vector TV2, the propeller 621being coupled with one or more electric motors and/or one or more liquid fuel combustion engines (not shown), for example turboshaft engines. Accordingly, the VTOL air vehicle 100comprises suitable batteries and/or fuel tanks operatively coupled with respect to these electric motors and/or the liquid fuel combustion engines, respectively.

Furthermore, in at least this example, the controller 290, for example housed in the body 200, is also configured for controlling operation of the second propulsion system 0296841816- 600, and for selectively controlling the magnitude of the second pivot angle α2between the second propulsion system 600and the body 200.

In at least some alternative variations of this example, each respective second propulsion unit includes two propellers having a common rotor axis co-axial with the respective second thrust vector TV2, the propellers in each such pair being configured for rotating in mutually opposite rotational directions and coupled with one or more electric motors and/or one or more liquid fuel combustion engines (not shown), for example turboshaft engines.

In at least some other alternative variations of this example, each respective first propulsion unit includes a shrouded fan arrangement, including one fan or two fans (for example counter-rotating fans) or more than two fans, in each case having a common rotor axis co-axial with the respective second thrust vector TV2, the shrouded fans being coupled with respect to one or more electric motors and/or one or more liquid fuel combustion engines (not shown), for example turboshaft engines.

In at least this example the first pivot axis P1and the second pivot axis P2are parallel to one another.

Furthermore, in at least this example, the first pivot axis P1and the second pivot axis P 2are parallel to a pitch axis P of the VTOL aerial vehicle 100.

Referring to Fig. 1D, a central plane CP can be defined on which both the first pivot axis P1 and the second pivot axis P2 are lying. In other words, the central plane CP is parallel, and coplanar with, the first pivot axis P1and the second pivot axis P2.

In at least this example, a first plane PL1can be defined as orthogonal to a plane on which the first thrust vectors TV1are lying; the first pivot axis P1is also lying on the first plane PL1.

Thus, the first pivot angle α1can be defined as the angular displacement between the first plane PL1and the central plane CP . Thus, when the first propulsion system 400is oriented with respect to the body 200such that the first plane PL1and the central plane CP are parallel to one another or co-planar with one another, the first pivot angle α 1is zero. 0296841816- In the side view of Fig. 1B or Fig. 1D, as the first plane PL1is pivoted with respect to the central plane CP in a counterclockwise direction away from a top surface 201of the body 200(i.e., in a pitch down direction), the first pivot angle α1is positive, while as the first plane PL1is pivoted with respect to the central plane CP in a direction towards the top surface 201of the body 200, the first pivot angle α1 is negative.

For example, the first pivot range PAR1 can be one or more of: between +90º and -90º; between 0º and +90º; between 0º and -90º; between 0º and +60º; between 0º and +30º; between +10º and +30º; between 0º and +20º.

The VTOL aerial vehicle 100 , and in particular the first propulsion system 400 , is configured for selectively pivoting with respect to the body 200 to any desired first pivot angle α1 , and for maintain the first pivot angle α1 at any desired magnitude within the first pivot angle range PAR1 , for example at any one of the following: -90º; 0º; +90º; +30º; +20º.

In at least this example, a second plane PL2 can be defined as orthogonal to a plane on which the second thrust vectors TV2 are lying; the second pivot axis P2 is also lying on the second plane PL2 .

Thus, the second pivot angle α2 can be defined as the angular displacement between the second plane PL2 and the central plane CP . Thus, when the second propulsion system 600 is oriented with respect to the body 200 such that the second plane PL2 and the central plane CP are parallel to one another or co-planar with one another, the second pivot angle α2 is zero.

In the side view of Fig. 1B or Fig. 1D, as the first plane PL1 is pivoted in a counterclockwise direction with respect to the central plane CP in a direction towards the top surface 201of the body 200(i.e., in a pitch up direction), the second pivot angle α2is positive, while as the second plane PL2is pivoted with respect to the central plane CP in a direction away from the top surface 201of the body 200, the second pivot angle α2is negative.

For example, the second pivot range PAR2can be one or more of: between +90º and -90º; between 0º and +90º; between 0º and -90º; between 0º and +60º; between 0º and +30º; between +10º and +30º; between 0º and +20º. 0296841816- The VTOL aerial vehicle 100, and in particular the second propulsion system 600, is configured for selectively pivoting with respect to the body 200to any desired second pivot angle α2, and for maintain the second pivot angle α2 at any desired magnitude within the second pivot angle range PAR2, for example at any one of the following: -90º; 0º; +90º; +30º; +20º.

The first pivot angle α1 and the second pivot angle α2can be synchronized to be equal to one another. Alternatively, the first pivot angle α1and the second pivot angle α2can be different from one another, i.e., unequal to one another.

The VTOL aerial vehicle 100 can be operated in a variety of vectored flight modes, including: vertical flight mode VFM ; forward flight mode FFM . In addition, the VTOL aerial vehicle 100can also be transitioned to a stowed mode STM .

As will become clearer herein, in at least some examples of the vertical flight mode VFM ; and the forward flight mode FFM , the first propulsion system 400and the second propulsion system 600are configured for being selectively pivoted about the first pivot axis P1 and the second pivot axis P2, respectively, in mutually co-rotational directions.

Referring again to Fig. 1A, in a first example of vertical flight mode VFM , the first propulsion system 400 is aligned with the body 200, and the second propulsion system 600is also aligned with the body 200, such that the first pivot angle α1is zero, and the second pivot angle α2is also zero. The central plane CP , the first plane PL1, and the second plane PL2are nominally horizontal.

Accordingly, in at least this example, the first thrust vectors TV1are vertical and the second thrust vectors TV2are also vertical (at least in side view). The total thrust T generated by the VTOL aerial vehicle 100is thus: T = 2*T1 + 2*T In at least some alternative variations of this example in which the respective first thrust vectors are not parallel to one another, but are instead diverging or converging in an upward direction with respect to one another, the respective vertical thrusts T1are the respective vertical components of the respective first thrust generated by the respective 0296841816- first propulsion units. Similarly, in at least some alternative variations of this example in which the respective second thrust vectors are not parallel to one another, but are instead diverging or converging in an upward direction with respect to one another, the respective vertical thrusts T2are the respective vertical components of the respective second thrust generated by the respective second propulsion units.

The magnitude of the total thrust T can be varied according to requirements.

For example, when the VTOL aerial vehicle 100is not carrying any payload, the magnitude of the total thrust T can be greater than the weight W1of the VTOL aerial vehicle 100to enable vertical take-off and/or vertical climb, or, the magnitude of the total thrust T can equal the weight W1of the VTOL aerial vehicle 100to enable hover, or, the magnitude of the total thrust T can be less than the weight W1of the VTOL aerial vehicle 100to enable vertical descent and/or vertical landing.

In another example in which the VTOL aerial vehicle 100is carrying a payload, for example payload 800having weight W2, the magnitude of the total thrust T can be greater than the combined weight WT (= W1+ W2) of the VTOL aerial vehicle 100and the payload 800 to enable vertical take-off and/or vertical climb of the composite air vehicle 900, or, the magnitude of the total thrust T can equal the combined weight WT of the VTOL aerial vehicle 100and the payload 800to enable the composite air vehicle 900to hover, or, the magnitude of the total thrust T can be less than the combined weight WT of the VTOL aerial vehicle 100and the payload 800to enable the composite air vehicle 900to vertically descend and/or vertical land.

Referring to Fig. 2B, in at least a second example of vertical flight mode VFM , the first propulsion system 400is pivoted with respect to the body 200by first pivot angle α1, and the second propulsion system 600is also pivoted with respect to the body 200by second pivot angle α2, such that the first pivot angle α1is equal to the second pivot angle α2, and both are non-zero. Thus, while the first plane PL1and the second plane PL2are both nominally horizontal, the central plane CP is now at an angle of attack α0to the forward direction or the horizontal, this angle of attack α0being nominally equal to the first pivot angle α1or to the second pivot angle α2. In at least this example, the first thrust vectors TV1are vertical, and the second thrust vectors TV2are also vertical, and the total thrust T generated by the VTOL aerial vehicle 100is thus: 0296841816- T = 2*T1 + 2*T The VTOL aerial vehicle 100, by itself or with the payload 800to provide the composite air vehicle 900, can be operated in this example of vertical flight mode VFM similarly to that described above for the first example of vertical flight mode VFM of Fig. 1A, mutatis mutandis, the main difference being that in the second example of vertical flight mode VFM illustrated in Fig. 2B the body 200is oriented at a non-zero angle of attack α 0to the horizontal. Accordingly, when the VTOL aerial vehicle 100is carrying a payload 800and operates in second example of vertical flight mode VFM , the payload 800is similarly tilted by angle of attack α0.

It is to be noted that in each of the above examples of vertical flight mode VFM , the magnitudes of the two first thrust T1are equal to one another, the magnitudes of the two second thrust T2are equal to one another, and magnitudes of the two first thrust T1are equal to the magnitudes of the two second thrust T2. However, the relative magnitudes of the two first thrusts T1with respect to one another can be varied, and/or, the relative magnitudes of the two second thrusts T2with respect to one another can be varied, and/or the magnitudes of one or both of the two first thrusts T1can be varied with respect to the magnitudes of one or both of the two second thrusts T2, to thereby provide control moments in pitch, yaw and roll.

Referring to Fig. 1D and Fig. 2A, in a first example of forward flight mode FFM , the first propulsion system 400is pivoted with respect to the body 200by first pivot angle α 1, and the second propulsion system 600is also pivoted with respect to the body 200by second pivot angle α2, such that the first pivot angle α1is equal to the second pivot angle α2, and both are each non-zero.

In this example of forward flight mode FFM the central plane CP is nominally horizontal, while the first plane PL1 and the second plane PL2 are at the first pivot angle α1 and the second pivot angle α2 to the horizontal.

Accordingly, the first thrust vectors TV1 are at tilted from the vertical (in pitch) by the first pivot angle α1 , and the second thrust vectors TV2 are also tilted from the vertical (in pitch) by the second pivot angle α2 . 0296841816- Thus, each one of the first thrusts T1 generated by the first propulsion system 400 now has a corresponding first horizontal thrust component T1H and a corresponding first vertical thrust component T1V as follows: T1H = T1*sin(α1) T1V = T1*cos(α1) Similarly, each one of the second thrusts T2 generated by the second propulsion system 600 now has a corresponding second horizontal thrust component T2H and a corresponding vertical thrust component T2V as follows: T2H = T2*sin(α2) T2V = T2*cos(α2) The total vertical thrust TVT generated by the VTOL aerial vehicle 100 is thus: TVT = 2*T1V + 2*T2V The total horizontal thrust THT generated by the VTOL aerial vehicle 100 is thus: THT = 2*T1H + 2*T2H The magnitude of the total vertical thrust TVT and of the total horizontal thrust THT can be varied according to requirements.

The total horizontal thrust THT can be utilized to provide forward speed and/or forward acceleration to the VTOL aerial vehicle 100, by itself, or to the composite air vehicle 900 when the VTOL aerial vehicle 100 is carrying payload 800, while concurrently the total vertical thrust TVT can be utilized to balance the weight W1of the VTOL aerial vehicle 100, when by itself, or to balance the weight WT of the composite air vehicle 900when the VTOL aerial vehicle 100is carrying payload 800, to hover, or to exceed or decrease the respective total vertical thrust TVT to concurrently climb or descend, respectively.

For example, when the VTOL aerial vehicle 100is not carrying any payload, the magnitude of the total vertical thrust TVT can be greater than the weight W1of the VTOL aerial vehicle 100 to enable vertical climb concurrently with having a forward acceleration, or, the magnitude of the total thrust T can equal the weight W1of the VTOL aerial vehicle 100 to enable travel with forward speed at constant altitude, or, the 0296841816- magnitude of the total thrust T can be less than the weight W1of the VTOL aerial vehicle 100to enable vertical descent concurrently with forward deceleration.

In another example in which the VTOL aerial vehicle 100is carrying a payload, for example payload 800having weight W2, to provide the composite air vehicle 900, the magnitude of the total vertical thrust TVT can be greater than the combined weight WT of the VTOL aerial vehicle 100and the payload 800to enable vertical climb and concurrent forward acceleration of the composite air vehicle 900, or, the magnitude of the total thrust T can equal the combined weight WT (= W1+ W2) of the VTOL aerial vehicle 100and the payload 800to enable the composite air vehicle 900to travel with forward speed at constant altitude, or, the magnitude of the total thrust T can be less than the combined weight WT of the VTOL aerial vehicle 100and the payload 800to enable the composite air vehicle 900 to vertically descend concurrently with forward deceleration.

The VTOL aerial vehicle 100is configured with a suitable thrust to weight ratio T/WT such that the VTOL aerial vehicle 100can carry the weight W2of the payload 800, and also concurrently with the respective thrust vectors TV1, TV2being at the maximum expected first pivot angle α1and second pivot angle α2, respectively, with respect to the vertical.

For example, such a thrust to weight ratio T/WT can be in the range of about 1.to about 2.5 at sea level, for example, generally depending for example on one or more of: - the type of control the propulsion units are configured for (for example, whether variable pitch or variable rpm); - the relative positions of the propulsion units; - the moment of inertia of the composite air vehicle including the VTOL aerial vehicle and payload.

The lower limit of the thrust to weight ratio T/WT can be further lowered depending on mission altitude. For example, the thrust to weight ratio T/WT can be reduced from 1.4 to about 1.2, if a lower mission altitude is being contemplated, providing a thrust to weight ratio T/WT range of between about 1.2 to about 2.5 at sea level. 0296841816- Correspondingly, the thrust to weight ratio T/W1 of the VTOL aerial vehicle 100itself can be much greater than that of the composite air vehicle 900. For example the thrust to weight ratio T/W1of the VTOL aerial vehicle 100itself can be in the range between about 3 and about 15 at sea level, or about 1.8 to about 15 depending on mission altitude. For example in examples in which W2 is equal to W1 , the thrust to weight ratio T/W1 of the VTOL aerial vehicle 100 can be in the range of about 2.8 to about 5, or between 2.4 to 5 at sea level, depending on mission altitude.

In at least a second example of the forward flight mode FFM , the first propulsion system 400is pivoted with respect to the body 200by first pivot angle α1, and the second propulsion system 600is also pivoted with respect to the body 200by second pivot angle α2, such that the first pivot angle α 1is equal to the second pivot angle α2, and each one of the first pivot angle α1and the second pivot angle α2is non-zero. However, in this example of forward flight mode FFM the central plane CP is also inclined to the horizontal for example at a non-zero angle of attack α0.

In such circumstances, the first plane PL1 and the second plane PL2 are respectively at a first inclination angle  1and at a second inclination angle  2to the horizontal.

The angle of attack α0is defined as positive if the first pivot axis P1is vertically above the second pivot axis P2, and negative if the first pivot axis P1is vertically below the second pivot axis P2.

Thus, the first inclination angle  1and the second inclination angle  2can be determined as follows: 1 = α1 – α2 = α2 – α Accordingly, the first thrust vectors TV1 are at tilted from the vertical by the first inclination angle  1 , and the second thrust vectors TV2 are also tilted from the vertical by the second inclination angle  2 .

Thus, each one of the first thrusts T1 generated by the first propulsion system 400 now has a corresponding first horizontal thrust component T1Hand a corresponding first vertical thrust component T1V as follows: 0296841816- T1H = T1*sin( 1) T1V = T1*cos( 1) Similarly, each one of the second thrusts T2 generated by the second propulsion system 600 now has a corresponding second horizontal thrust component T2H and a corresponding vertical thrust component T2V as follows: T2H = T2*sin(2) T2V = T2*cos( 2) The total vertical thrust TVT generated by the VTOL aerial vehicle 100 is thus: TVT = 2*T1V + 2*T2V The total horizontal thrust THT generated by the VTOL aerial vehicle 100 is thus: THT = 2*T1H + 2*T2H The magnitude of the total vertical thrust TVT and of the total horizontal thrust THT can be varied according to requirements, and will depend on the magnitudes of the first pivot angle α1 , the second pivot angle α2 , and the angle of attack α0 .

The VTOL aerial vehicle 100, by itself or with the payload 800to provide the composite air vehicle 900, can be operated in this second example of forward flight mode FFM similarly to that described above for the first example of forward flight mode FFM of Fig. 2A, mutatis mutandis, the main difference being that in the second example of forward flight mode FFM illustrated in Fig. 2C the body 200is oriented at a non-zero angle of attack α0to the horizontal, and thus the first thrusts T1and second thrusts T2are oriented with respect to the vertical at the first inclination angle  1 and second inclination angle  2, respectively, rather than at the first pivot angle α1and the second pivot angle α2, respectively. Furthermore, when the VTOL aerial vehicle 100is carrying a payload 800and operates in second example of vertical flight mode VFM , the payload 800is similarly tilted by angle of attack α0.

It is to be noted that in each of the above examples of forward flight mode FFM , the magnitude of the first thrust T1is the same as the magnitude of the second thrust T2. However, the relative magnitudes of the two first thrusts T1can be varied, and/or, the relative magnitudes of two second thrusts T2can be varied, and/or, the magnitudes of 0296841816- each of the two first thrusts T1can be varied with respect to the relative magnitudes of two second thrusts T2, to provide control moments in pitch, yaw and roll.

It is also to be noted that in each of the above examples of forward flight mode FFM , the magnitude of the first pivot angle α 1can be the same as the magnitude of the second pivot angle α2, or alternatively, the magnitude of the first pivot angle α1 can be the different from the magnitude of the second pivot angle α2. In at least some examples of forward flight mode FFM , in which the magnitude of the first pivot angle α1 is different from the magnitude of the second pivot angle α2, the magnitude of the first thrust T1can be caused to be proportionally different with respect to the magnitude of the second thrust T2in order to provide a zero net pitching moment, for example.

In at least some examples, and referring to Fig. 2D for example, the first propulsion system 400is pivoted with respect to the body 200by first pivot angle α1in one rotational direction, and the second propulsion system 600is also pivoted with respect to the body 200by second pivot angle α2in the opposite rotational direction, such that for example the first pivot angle α1is negative while the second pivot angle α2is positive. Optionally the first pivot angle α1and the second pivot angle α2are numerically equal. Such examples can be useful, for example to enhance stability in hover or to provide forward braking or deceleration when in forward flight mode FFM .

In the stowed mode STM , and referring to Fig. 2E, the first propulsion system 400and the second propulsion system 600are not being operated and generate zero thrust. Correspondingly, the first propulsion system 400and the second propulsion system 600are configured for being selectively pivoted about the first pivot axis P1and the second pivot axis P2, respectively, in mutually counter-rotational directions, for example to enable transiting from the vertical flight mode VFM , or to enable transiting from the forward flight mode FFM to the stowed mode STM .

In a first example of stowed mode STM , the first propulsion system 400 is inclined at a maximum negative first pivot angle α1with respect to the body 200, and the second propulsion system 600is inclined at a maximum positive second pivot angle α2with respect the body 200, to provide a compact form, having minimal external dimensions. For example, the first pivot angle α1can be -90º, and the second pivot angle α2 can be +90º. In this manner, with the central plane CP nominally horizontal, the VTOL 0296841816- aerial vehicle 100 can be stored or transported in a compact manner. In at least some alternative variations of this example, in the stowed mode STM the first pivot angle α1 can be numerically greater than -90º, for example up to about -135º and the second pivot angle α2 can be numerically greater than +90º, for example up to about -135º .

In at least this example, the first propulsion system 400can be pivoted at a first pivot angle α1with respect to the body 200, the first pivot angle α1being in the range 0º to about ±135º, and the second propulsion system 600can be pivoted at second pivot angle α2with respect the body 200, the second pivot angle α2being in the range 0º to about ±135º.

Referring to Fig. 4A and Fig. 4B, the VTOL aerial vehicle 100can optionally include an auxiliary thrust system 500, configured for selectively providing a lateral side force to the VTOL aerial vehicle and/or for inducing yaw moments to the VTOL aerial vehicle 100.

In at least this example, the auxiliary thrust system 500comprises a pair of axially spaced auxiliary thrust units 520A , 520B , which are mounted to the body 200, for example on an outboard side of the port body portion 220P . It is to be noted that in at least some alternative variations of this example, the respective pair of axially spaced auxiliary thrust units can be instead mounted to the starboard body portion 220S .

Each of the two auxiliary thrust units 520A , 520B is configured for selectively generating a respective lateral thrust TLA , TLB respectively, having respective thrust vectors TLAV , TLBV .

In at least this example, the thrust vectors TLAV , TLBV are parallel to one another and to the pitch axis P of the VTOL aerial vehicle 100, and the thrust vectors TLAV , TLBV are each axially spaced (i.e., in a direction parallel to the longitudinal axis LA of the aerial air vehicle 100) by a respective spacing SA , SB from the center of gravity CG of the VTOL aerial vehicle 100, the respective spacings SA , SB being on opposite axial sides of the center of gravity CG .

Operation of the two auxiliary thrust units 520A , 520B to generate equal levels of lateral thrust TLA , TLB provides a net lateral thrust force in one direction parallel to the pitch axis P . 0296841816- In at least some alternative variations of this example, in which the respective auxiliary thrust units each comprise a variable pitch fan, the respective fans can each be selectively operated to provide a net lateral thrust in the starboard direction or in the port direction, by controlling the pitch of the fan blades.

Operation of the two auxiliary thrust units 520A , 520B to generate unequal levels of lateral thrust TLA , TLB provides a net yaw moment in a clockwise or counterclockwise direction, depending on which of the two lateral thrusts is the greater. Optionally, yaw moments can instead be generated in one or the other direction by generating lateral thrust by one or the other only of the two auxiliary thrust units 520A , 520B .

In at least some alternative variations of this example, the respective spacing SA , SB from the center of gravity CG can be unequal to one another, and in such cases the relative magnitudes of the lateral thrust TLA , TLB can be manipulated to generate zero yaw moment, and thus only a lateral force, or to generate a yaw moment in the desired direction.

In at least this example each auxiliary thrust unit 520A , 520B comprises a ducted fan arrangement in which the respective thrust vectors TLAV , TLBV are coaxial with the respective rotary axes of the auxiliary thrust unit 520A , 520B . In at least some alternative variations of this example, the respective auxiliary thrust units can be unducted propellers, for example. Optionally, the propellers van be variable pitch and are optionally capable or reversing the direction of thrust along the respective rotary axes of the auxiliary thrust units.

In at least some alternative variations of this example, and referring to Fig. 5A for example, the respective auxiliary thrust system 500' can instead comprise two pairs of axially spaced auxiliary thrust units, which are mounted to the body. For example one pair of axially spaced auxiliary thrust units 520P F, 520P A is mounted to an outboard side of the respective port body portion, while the other pair of axially spaced auxiliary thrust units 520SF , 520SA , is mounted to an outboard side of the respective starboard body portion. This arrangement allows sideslip and yaw control to be provided as follows: - a front-port mounted auxiliary thrust unit 520PF and an aft-starboard auxiliary thrust unit 520SA to be operated together to generate a yaw moment in one direction; 0296841816- - a front-starboard mounted auxiliary thrust unit 520SF and an aft-port auxiliary thrust unit 520PA to be operated together to generate a yaw moment in the other direction; - the front-port mounted auxiliary thrust unit 520PF and the aft-port auxiliary thrust unit 520PA to be operated together to generate a side force in one lateral direction; - the front-starboard mounted auxiliary thrust unit 520SF and the aft-starboard auxiliary thrust unit 520SA to be operated together to generate a side force in the other lateral direction.

In at least some alternative variations of this example, and referring to Fig. 6A and 6B, for example, the respective auxiliary thrust system 500" can instead comprise two auxiliary thrust units, which are mounted to the body. For example one auxiliary thrust unit 520P is mounted to an outboard side of the respective port body portion, while the other auxiliary thrust unit 520S , is mounted to an outboard side of the respective starboard body portion. Each one of the port auxiliary thrust unit 520P and the starboard auxiliary thrust unit 520S generates a respective side force TA that is parallel to the itch axis of the VTOL aerial vehicle 100, and that passes through the center of gravity CG thereof. This arrangement allows sideslip to be provided as follows: - the port auxiliary thrust unit 520P can be operated to generate a side force in one lateral direction from the port wing tip and towards the center of gravity CG ; - the starboard auxiliary thrust unit 520S can be operated to generate a side force in the opposite lateral direction from the starboard wing tip and towards the center of gravity CG .

According to an aspect of the presently disclosed subject matter, and referring again to Fig. 1A and Fig. 1B, the payload 800is a fixed wing air vehicle, particularly referred to herein with reference numeral 850, and the VTOL aerial vehicle 100 is configured for enabling for in-flight releasing and/or in-flight capturing of the fixed wing air vehicle 850. The VTOL aerial vehicle 100 and fixed wing air vehicle 850 thus have an engaged configuration EC and a non-engaged configuration NC . In the engaged configuration EC , the VTOL aerial vehicle 100and fixed wing air vehicle 850are mechanically connected to 0296841816- one another to form a composite air vehicle 900and fly together as a single unit. In the non-engaged configuration NC , the VTOL aerial vehicle 100and fixed wing air vehicle 850are not connected to one another, and each one of the VTOL aerial vehicle 100and fixed wing air vehicle 850is independent of, and can fly independently of, the other one of the VTOL aerial vehicle 100and fixed wing air vehicle 850, respectively.

In at least the examples of Figs. 1A to 6C, the fixed-wing air vehicle 850is a powered air vehicle, and comprises a fuselage 810, main wings 820(including port wing 820P and starboard wing 820S ), empennage 830(for example in the form of a T-tail in the examples of Figs. 1A, 1B, 4A to 6C), and air vehicle propulsion system 860, which in at least this example comprises a single tractor propeller at the nose of the fuselage 810. However, in other examples, the fixed wing air vehicle can have any suitable configuration. For example, in the example illustrated in Fig. 3A and Fig. 3B, the respective empennage is in the form of a high boom tail having twin booms, and the respective air vehicle propulsion system 860is in the form of a pusher propeller. In yet other alternative variations of these examples, the respective air vehicle propulsion system can include more than one propeller, or one or more ducted fans, or one or more turbofans or one or more turbojets, and so on.

The fixed-wing air vehicle 850is capable of aerodynamic flight at forward speeds VFWD exceeding the stall speed VSTALL of the fixed wing air vehicle 850, for example when powered by the air vehicle propulsion system 860or when accelerated by the VTOL aerial vehicle (when engaged thereto) to such forward speeds.

According to this aspect of the presently disclosed subject matter, in at least one example, the VTOL aerial vehicle 100and the fixed-wing air vehicle 850are, in the engaged configuration EC, superposed with respect to one another such that the center of gravity CG of the VTOL aerial vehicle 100and the center of gravity CGP of the fixed-wing air vehicle 850are overlaid one on the other within a predetermined small envelope. For example such an envelope extends longitudinally and/or laterally, and is sufficient to ensure that the composite air vehicle is controllable and stable.

The VTOL aerial vehicle 100comprises an engagement system 700that cooperates with the fixed-wing air vehicle 850to enable the fixed-wing air vehicle 850to be selectively engaged and disengaged with respect to the VTOL aerial vehicle 100. 0296841816- In the illustrated examples, the engagement system 700is configured for enabling selectively engaging the fixed-wing air vehicle 850with respect to the VTOL aerial vehicle 100such that that the VTOL aerial vehicle 100is superposed over the fixed-wing air vehicle 850in the composite air vehicle 900. However, in at least some alternative variations of these examples, the respective the engagement system is instead configured for enabling selectively engaging the fixed-wing air vehicle with respect to the VTOL aerial vehicle such that that the respective the fixed-wing air vehicle is superposed over the respective VTOL aerial vehicle in the respective composite air vehicle.

In at least the examples of Fig. 1A, Fig. 1B, Fig. 3A, Fig. 3B, Fig. 4A, Fig. 4B, the main wings 820are mounted on an upper portion of the fuselage 810, i.e., ventrally. In such examples, the body 200, in particular the central body portion 250, can be configured for being vertically spaced from the upper surface of the main wings 820, such as not to significantly interfere with the airflow over the wings, and thus enable the wings 820to generate aerodynamic lift. Furthermore, the central body portion 250can be rounded or have an aerodynamic cross-sectional shape for minimizing drag in the engaged configuration EC or when the VTOL aerial vehicle 100 is operating on its own, i.e., in the non-engaged configuration NC .

The central body portion 250, can be configured for being vertically spaced from the upper surface of the main wings 820via pylons 870. In at least this example, two such pylons 870are provided, a first pylon 870connecting between the starboard body portion 220S and a central portion of the starboard wing of the main wings 820, and a second pylon 870connecting between the port body portion 220H and a central portion of the port wing of the main wings 820. Optionally, additionally or alternatively, one or more such pylons 870can be provided, connecting between the central body portion 250and a central portion of the main wings 820and/or an upper portion of the fuselage 810.

The pylons 870 can be integrally connected to the VTOL aerial vehicle 100 (in particular to the body 200) , and reversibly coupleable with respect to the payload 800(in particular with respect to the fixed-wing air vehicle 850, in particular with respect to the main wings 820and/or the fuselage 810thereof) via the engagement system 700.

Alternatively, the pylons 870can be integrally connected to the payload 800(in particular with respect to the fixed-wing air vehicle 850, in particular with respect to the 0296841816- main wings 820and/or the fuselage 810thereof), and reversibly coupleable with respect to the VTOL aerial vehicle 100(in particular to the body 200) via the engagement system 700.

Alternatively, the pylons 870can be reversibly coupleable to the payload 800(in particular with respect to the fixed-wing air vehicle 850, in particular with respect to the main wings 820and/or the fuselage 810 thereof), and reversibly coupleable with respect to the VTOL aerial vehicle 100(in particular to the body 200) , for example via the engagement system 700.

In the example of Fig. 5A, Fig. 5B, Fig. 5C, the main wings 820are mounted on a central portion of the fuselage 810 (or indeed on bottom part of the fuselage 810, i.e., anhedrally). In such an example, the body 200, in particular the central body portion 250, can also be configured for being in vertical spaced relationship, and thus not closely abutting, the upper surface of the main wings 820. Optionally, the central body portion 250can also be configured for being in vertical spaced relationship as well with respect to the upper surface of the fuselage via pylons 870i n the engaged configuration EC .

In such examples, and referring to Fig. 5B, the central body portion 250 can optionally also be rounded or can be aerodynamically shaped to minimize drag at least when the central body portion 250 is abutting the main wings 820 via the spacers 280 in the engaged configuration EC .

As mentioned above, in at least the above examples, the VTOL aerial vehicle 100comprises suitable engagement mechanism 700for selectively and reversibly engaging the VTOL aerial vehicle 100with respect to any suitable payload 800including air vehicle 850.

The engagement mechanism 700is configured at least for enabling aerial release of the fixed wing air vehicle 850from the VTOL aerial vehicle 100at a desired altitude and forward speed. In at least some of the above examples, the engagement mechanism 700is also configured at least for enabling aerial capture of the fixed wing air vehicle 850by the VTOL aerial vehicle 100at a desired altitude and forward speed.

Referring to Fig. 1B in particular, the engagement mechanism 700comprises one or more selectively actuable part 710provided in the VTOL aerial vehicle 100. Each selectively actuable part 710is configured to selectively cooperate with a respective engageable part 720provided in the fixed wing air vehicle 850to enable the engaged configuration EC , and 0296841816- to selectively release the engageable part 720provided in the fixed wing air vehicle 850to enable the non-engaged configuration EC .

In at least this example, the one or more selectively actuable part 710can be located in the respective struts 870, while the corresponding one or more engageable part 720is provided in the upper portions of the main wing 820. However, in at least some alternative variations of this example, the one or more selectively actuable part 710can be located in the lower parts of the central body portion 250, while the corresponding one or more engageable part 720is provided in the respective struts 870.

For example, each selectively actuable part 710 can include a pin having a ball element at a free end thereof, and each engageable part 720can include a frustroconical structure having an open larger end and an electromagnetic grip at the smaller end thereof. During engagement, the pin and ball are inserted into the large open end of the frustroconical structure, the conical walls thereof guiding the ball into the smaller end thereof, enabling the electromagnetic grip to be electrically activated to close onto and grip the ball to thereby engage the selectively actuable part 710 with respect to the engageable part 720. To disengage, the electromagnetic grip is opened, allowing the ball and pin to be extracted from the frustroconical structure. Other examples of engagement mechanisms are known in the art.

Referring to Fig. 7 and Fig. 8, an example of a method 1000 for aerially releasing a fixed wing air vehicle 850from a VTOL aerial vehicle 100includes the following steps: Step 1100 ~ providing a VTOL aerial vehicle 100as disclosed herein; Step 1200 ~ engaging a payload 800(in the form of a fixed-wing air vehicle 850) to the VTOL aerial vehicle 100to provide a composite air vehicle 900; Step 1300 ~ operating the composite air vehicle 900to operate in vertical flight mode VFM for take-off, wherein the VTOL aerial vehicle 100provides the required vectored thrust for the composite air vehicle 900; Step 1400 ~ transitioning the VTOL aerial vehicle 100, while engaged to the payload 800, to the forward flight mode FFM ; 0296841816- Step 1500 ~ disengaging the fixed wing air vehicle 850from the VTOL aerial vehicle 100, and flying the fixed wing air vehicle 850independently from the VTOL aerial vehicle 100.

Step 1200 can generally be performed prior to commencement of flight, for example on the ground by a suitable ground crew or other user. In at least this example, the payload 800is in the form of fixed-wing air vehicle 850, which as disclosed above is capable of aerodynamic flight at forward speeds exceeding the stall speed VSTALL of the fixed wing air vehicle 850.

For example, and referring again to Fig. 7 (marked at A1 ), the VTOL aerial vehicle 100can for example be in the stowed mode STM prior to executing the method 1000 . When needed, the VTOL aerial vehicle 100is transitioned from the stowed mode STM such that the first propulsion system 400is aligned with the body 200, and the second propulsion system 600is also aligned with the body 200, such that the first pivot angle α1is zero, and the second pivot angle α2is also zero (i.e., the central plane CP , the first plane PL1, and the second plane PL2 are nominally parallel and nominally horizontal or at a small angle thereto), thereby enabling the VTOL aerial vehicle 100to be operated in vertical flight mode VFM.

In Step 1200 , and marked at A2in Fig. 7, the VTOL aerial vehicle 100is brought into vertical alignment with the fixed wing air vehicle 850 and then into engagement therewith, wherein the engagement mechanism 700selectively and reversibly engages the VTOL aerial vehicle 100 with respect to the fixed wing air vehicle 850 to provide the engaged configuration EC .

Once the composite vehicle 900 is assembled via such engagement, it can be operated via the controller 290to operate in vertical flight mode VFM to take off to a desired altitude, in Step 1300 (marked at A3in Fig. 7).

The take-off location TOL can be in the same geographical location as where step 1200 was executed, or at a different location.

The take-off location TOL can be a land location (for example a land base) or a sea location (for example a ship or other sea faring platform), and/or, the take-off location TOL 0296841816- can be static or moving. Such moving take-off location TOL can be a moving truck or other land vehicle, or a moving ship of other sea-faring platform that is moving.

At least initially in Step 1300 , the VTOL aerial vehicle 100 is operated with the first pivot angle α1 set at 0º and the second pivot angle α2 set at 0º, and the respective thrust vectors VT1 and VT2 being nominally or predominantly vertical (at least in side view).

In Step 1300 , the first propulsion system 400 and the second propulsion system 600 are operated to generate a total thrust T that at least initially exceeds the combined weight WT of the VTOL aerial vehicle weight W1 and the fixed wing air vehicle weight W2 , enabling the composite air vehicle 900 to climb.

In Step 1400 the VTOL aerial vehicle 100is operated to transition to forward flight mode FFM , and thus to concurrently impart a forward speed VF to the composite aerial vehicle 900, and thus to the fixed wing air vehicle 850. The VTOL aerial vehicle 100accelerates forward to a forward speed VF exceeding the stall speed VSTALL of the fixed wing air vehicle 850by a suitable safety margin. For example, such a safety margin can be 10% to 20% of stall speed VSTALL .

Step 1400 can be executed essentially by pivoting the first propulsion system 400about the first pivot axis P1and the second propulsion system 600about the second pivot axis P2 to provide a desired first pivot angle α1 and a desired second pivot angle α2, respectively. This in turn provides a forward speed VF to the composite air vehicle, wherein the forward speed VF eventually exceeds the stall speed VSTALL of the fixed wing air vehicle 850, allowing the fixed wing air vehicle 850to generate aerodynamic lift via its wings.

In at least this example, Step 1400 can be executed in two sub-steps. In a first sub-step, marked at A4' in Fig. 7, the inclination of the fixed wing air vehicle 850 is first changed while maintaining the thrust vectors TV1 and TV2 nominally vertical. Such an inclination provides a maximum angle of attack for the air vehicle to thereby maximize lift of the fixed wing air vehicle 850 with forward speed VF .

For example, the controller 290operates to pivot the first propulsion system 400about the first pivot axis P1to a non-zero first pivot angle α1, and to concurrently and synchronously pivot the second propulsion system 600about the second pivot axis P2to a non-zero second pivot angle α2, for example as disclosed above relating to Fig. 2B . In such 0296841816- an operation, the first pivot angle α 1and the second pivot angle α2are equal to one another, and apply an equal-magnitude angle of attack α0to the fixed wing air vehicle 850.

Optionally, the main wings 820can be configured as high lift mild stall wings, i.e., each one of the main wings 820is configured for providing high lift mild stall characteristics.

Such high lift mild stall wings can be configured with single element aerofoils, and/or with two element slotted aerofoils and/or to aerofoils having more than one or two elements, each being configured for providing high lift mild stall characteristics. In these or other examples, for example, the wings can each have leading edge slats that provide high lift mild stall effect, which can have the effect of increasing the maximum angle of attack and maximum lift coefficient.

In this connection, single element aerofoils and two-element slotted aerofoils are known, and examples of high lift mild stall single element aerofoils and two-element slotted aerofoils are disclosed for example in US 8,109,473, assigned to the present assignee, and the contents of which are incorporated herein.

Furthermore WO 2016/055990 (also assigned to the present assignee) also discloses examples of high lift mild stall two-element slotted aerofoils, in particular pages 7, 20 to 37, Figs. 3 to 18 thereof, and the contents of which are incorporated herein by reference thereto.

Thus, in at least some examples, in the first sub-step, marked at A4' in Fig. 7, the inclination of the fixed wing air vehicle 850is changed to provide an angle of attack α 0to the fixed wing air vehicle 850that lies within the plateau of high lift mild stall, for example in the range 15º to about 18º, and such that aerodynamic lift can be generated at or close to the maximum lift coefficient for the main wings 820.

Such high lift mild stall wings can provide a low stall speed VSTALL enabling the composite air vehicle 900 to reach step 1500 relatively quickly, and the mild stall characteristics provide aerodynamic robustness to the air vehicle 850, minimizing risk of stall, for example tip stall.

However, in at least some alternative variations of this example, the main wings 820of the air vehicle 850do not require to be high lift mild stall wings, and can include wings 0296841816- having regular stall characteristics, i.e., with no lift plateau in the respective variation of corresponding lift coefficient vs angle of attack.

The angle of attack α0can be set such as to provide the optimal acceleration and generation of lift to the fixed wing air vehicle 850to thereby generate sufficient aerodynamic lift L to overcome the weight W2.

For example, in this sub-step the inclination of the fixed wing air vehicle 850is changed via the central body portion 250to provide an angle of attack α0to the fixed wing air vehicle 850such that aerodynamic lift can be generated as the composite vehicle 900is accelerated in a horizontal direction; as the angle of attack α 0is increased (near to but not exceeding the maximum lift coefficient) and the forward speed is increased, the aerodynamic lift generated by the main wings 820is increased.

In the next sub-step, marked at A4" in Fig. 7, the first pivot angle α1and the second pivot angle α2are increased, while maintaining the angle of attack α0of the fixed wing air vehicle 850at the optimum value for maximizing aerodynamic lift. The first pivot angle α1and the second pivot angle α2can be increased while remaining equal to one another, or the first pivot angle α1and the second pivot angle α2can be different to one another. In any case, the non-zero values for the first pivot angle α1and the second pivot angle α2result in the respective thrust vectors TV1and TV2being non-vertical (in side view), while the angle of attack α0of the fixed wing air vehicle 850remains unchanged. A forward component of the thrust T1and T2provides forward momentum to the composite air vehicle 900thereby increasing the forward speed VF from zero and accelerating the composite air vehicle 900in a forward direction. Concurrently, the vertical component of the thrust T (= T1 + T2) balances the combined weight WT (= W1+ W2) of the composite air vehicle 900.

As the forward speed VF of the composite air vehicle 900, airflow over the wings of the fixed-wing air vehicle 850generates aerodynamic lift L at the angle of attack α0of the fixed wing air vehicle 850.

The composite air vehicle 900can be accelerated in a forward direction by increasing the total thrust T and concurrently increasing the first pivot angle α1and the second pivot angle α2, while concurrently optimizing the angle of attack α0. 0296841816- This forward acceleration can continue at least until the forward speed VF exceeds the stall speed VSTALL of the fixed wing air vehicle 850, preferably by a desired safety margin, for example between 10% to 20% of stall speed VSTALL .

At this point, the aerodynamic lift L generated by the fixed wing air vehicle 850is sufficient to overcome the weight W2of the fixed wing air vehicle 850. The angle of attack α 0 can be reduced while accelerating the composite air vehicle 900 to maintain the aerodynamic lift L equal greater the weight W2.

Thus, in step 1500 , and as marked at A5 in Fig. 7, the fixed wing air vehicle 850is disengaged from the VTOL aerial vehicle 100. Essentially, the controller 290operates the engagement mechanism 700to selectively disengage the VTOL aerial vehicle 100 with respect to the fixed wing air vehicle 850to provide the engaged configuration EC .

It is to be noted that up to and at least at the moment of disengagement, the VTOL aerial vehicle 100can be controlled by the controller 290to provide vectored thrust flight when still engaged with the fixed wing air vehicle 850 such that, while engaged in the engaged configuration EC , the VTOL aerial vehicle 100 does not apply any pitching moments to the fixed wing air vehicle 850. In particular, the first pivot angle α1and the second pivot angle α2 are such as to generate a zero pitch moment, while concurrently maintaining the angle of attack α 0at the desired value.

Furthermore, prior to such disengagement, and for example as the fixed wing air vehicle 850is being accelerated forward by the VTOL aerial vehicle 100, the air vehicle propulsion system 860can be operated to generate forward thrust.

Correspondingly, and while in the engaged configuration EC , as the fixed wing air vehicle 850is generating aerodynamic lift L and its own forward thrust, the VTOL aerial vehicle 100can correspondingly reduce the magnitude of the thrusts T1, T2generated by the first propulsion system 400and the second propulsion system 600, respectively, pro-rata.

At the point where it is possible to provide disengagement of the composite vehicle 900to the disengaged configuration DC , the VTOL aerial vehicle 100is only generating sufficient thrusts T1and T2such that the vertical component thereof nominally balances the weight W1and such that the horizontal components thereof provide a forward speed forward 0296841816- speed VF that exceeds the stall speed VSTALL of the fixed wing air vehicle 850by the desired safety margin.

Concurrently, the fixed wing air vehicle 850is generating sufficient thrust via its own air vehicle propulsion system 860to balance drag at the same matched forward speed as the VTOL aerial vehicle 100, and sufficient aerodynamic lift to balance its own weight W2.

Thus, there are no nominal loads or moments being transmitted between the VTOL aerial vehicle 100and the fixed wing air vehicle 850via the engagement mechanism 700at this point.

Accordingly, the VTOL aerial vehicle 100and the fixed wing air vehicle 850can transition to the disengaged configuration DC in a safe manner, with nominal zero risk of collision after disengagement.

Thereafter, and as marked at A6 in Fig. 7, the fixed wing air vehicle 850is flown independently from the VTOL aerial vehicle 100. For example the fixed wing air vehicle 850can continue with a particular mission, while the VTOL aerial vehicle 100can be landed in vertical flight mode VFM .

It is to be noted that at least in some alternative variations of the example of Fig. and Fig. 8, the payload 800can be in the form of a non-powered air vehicle, for example a glider, and once released from the VTOL aerial vehicle 100, the glider glides aerodynamically to a desired location.

In yet some other alternative variations of the example of Fig. 7 and Fig. 8, the payload 800is not in the form of a fixed wing air vehicle, and the respective payload can be incapable of aerodynamic flight by itself, for example. For example the payload 800can be in the form of a cargo pallet, and once released from the VTOL aerial vehicle 100, the cargo pallet can descend for example via parachute to a desired location.

Referring to Fig. 9 and Fig. 10.an example of a method 2000 for aerially capturing a fixed wing air vehicle 850by the VTOL aerial vehicle 100includes the following steps: Step 2100 ~ providing a VTOL aerial vehicle 100as disclosed herein; 0296841816- Step 2200 ~ providing a payload 800comprising a fixed wing air vehicle 850capable of aerodynamic flight, for example as disclosed herein; Step 2300 ~ causing the fixed wing air vehicle 850to fly in aerodynamic flight mode along a first trajectory TJ1; Step 2400 ~ causing the VTOL aerial vehicle 100to fly in vectored flight mode in a second trajectory TJ2, wherein at least one of the first trajectory and the second trajectory is an intercept trajectory with respect to the other one of the first trajectory and the second trajectory; Step 2500 ~ aerially aligning the VTOL aerial vehicle 100with respect to the fixed wing air vehicle 850in an engagement enabling position; Step 2600 ~ causing the fixed wing air vehicle 850 to become engaged with the VTOL air vehicle 100to provide a respective composite air vehicle 900; Step 2700 ~ operating the VTOL aerial vehicle 100to progressively decrease the forward speed VF of the composite air vehicle 900and to increase vertical thrust to compensate corresponding fall in aerodynamic lift generated by the fixed wing air vehicle 850; Step 2800 ~ operating the VTOL aerial vehicle 100to vertically land the composite air vehicle 900.

Step 2300 can be selectively implemented when it is desired to land a fixed wing air vehicle 850at a landing site LS .

Prior to step 2300 , the fixed wing air vehicle 850is already airborne and flying on its own, i.e., not engaged with the VTOL aerial vehicle 100, for example near to a desired landing site LS ( B2 , Fig. 9).

In step 2300 , ( B3 , Fig. 9) the fixed wing air vehicle 850 is caused to fly in aerodynamic flight mode along a first trajectory TJ1. For this purpose, suitable commands can be transmitted to the fixed wing air vehicle 850 (which includes a suitable communication system to thereby receive and process such commands) from a command center for example, to actively fly the fixed wing air vehicle 850along the first trajectory 0296841816- TJ1. Alternatively, the fixed wing air vehicle 850includes a navigation and guidance system that operates to fly the fixed wing air vehicle 850along the first trajectory TJ1, for example towards a ground beacon at or in the vicinity of the landing site LS . Optionally, for example, the fixed wing air vehicle 850is flown along a predictable path, for example a straight and level course, defining the first trajectory TJ1.

Concurrently, or in close succession with respect to step 2300 , step 2400 is implemented, in which the VTOL aerial vehicle 100is caused to fly in vectored flight mode in a second trajectory TJ2 ( B4 , Fig. 9). For this purpose, suitable commands can be transmitted to the VTOL aerial vehicle 100 (which includes a suitable communication system to thereby receive and process such commands) for example from a command center, to actively fly the VTOL aerial vehicle 100along the second trajectory TJ2. Alternatively, the VTOL aerial vehicle 100includes a navigation and guidance system that operates to fly the VTOL aerial vehicle 100along the second trajectory TJ2, for example towards a ground beacon at or in the vicinity of the landing site LS . Optionally, for example, the VTOL aerial vehicle 100 is flown along a predictable path, for example a straight and level course, defining the second trajectory TJ2.

Prior to implementing step 2400 , the VTOL aerial vehicle 100 can already be airborne, or, the VTOL aerial vehicle 100is a ground location GL , and takes off towards the second trajectory TJ2 ( B1 , Fig. 9).

It is to be noted that one of the first trajectory TJ1and the second trajectory TJ2is an intercept trajectory with respect to the other one of the first trajectory TJ1and the second trajectory TJ2. Such an intercept trajectory is configured for enabling the VTOL aerial vehicle 100 and the fixed wing air vehicle 850 to intercept one another at an intercept location IL and at a predetermined vertical spacing between the two in a generally superposed configuration, such as to enable step 2500 .

For example, the first trajectory TJ1can be predetermined, and the second trajectory TJ2can be calculated by the VTOL aerial vehicle 100(for example the controller 290) or by a human user that subsequently flies remotely the VTOL aerial vehicle 100along the second trajectory in order to intercept the fixed wing air vehicle 850. 0296841816- Alternatively, for example, the second trajectory TJ2can be predetermined, and the first trajectory TJ1can be calculated by the fixed wing air vehicle 850(for example via an on-board computer) or by a human user that subsequently flies remotely the fixed wing air vehicle 850along the first trajectory TJ1in order to intercept the VTOL aerial vehicle 100.

Alternatively, both the first trajectory TJ1and the second trajectory TJ2are actively and concurrently determined, for example via a control center, such as to actively fly the VTOL aerial vehicle 100 and the fixed wing air vehicle 850 to one another along the respective first trajectory TJ1and second trajectory TJ2.

In step 2500 , once the VTOL aerial vehicle 100and the fixed wing air vehicle 850have intercepted one another at the interception location IL and are vertically spaced with respect to one another, the VTOL aerial vehicle 100and the fixed wing air vehicle 850continue to be flown along parallel trajectories, maintaining their superposed configuration ( B5 , Fig. 9).

Then, the VTOL aerial vehicle 100is aerially aligned with respect to the fixed wing air vehicle 850in an engagement enabling position. The engagement enabling position is such as to enable the VTOL aerial vehicle 100and the fixed wing air vehicle 850to become engaged to one another aerially via the engagement mechanism 700.

In at least this example, in said engagement enabling position, the VTOL aerial vehicle 100is vertically above the fixed wing air vehicle 850.

For example, in the engagement enabling position, the VTOL aerial vehicle 100and the fixed wing air vehicle 850continue to fly along parallel trajectories and at the same forward speed. Furthermore, the VTOL aerial vehicle 100is operated to provide an angle of attack α0to the central body 250that matches the angle of attack of the fixed wing air vehicle 850, while at the same time ensuring that the VTOL aerial vehicle 100does not generate any pitching moment.

The thrusts T1, T2generated by the first propulsion system 400and the second propulsion system 600, respectively, and the respective first pivot angle α1and the second pivot angle α2, as well as the angle of attack α0, are each controllable independently of one another. As disclosed above, the first propulsion system 400can be pivoted about the first pivot axis P1independently of the second propulsion system 600being pivoted about the 0296841816- second pivot axis P2, to thereby provide any desired values for first pivot angle α1and the second pivot angle α2, while maintaining the angle of attack α0matched with respect to the fixed wing air vehicle 850. Furthermore, also as disclosed above, the magnitudes of the first thrusts T1generated by the first propulsion system 400are independent with respect to the magnitudes of the second thrusts T2generated by the second propulsion system 600.

The magnitudes of the first thrusts T1 and of the second thrusts T2 , and the values for first pivot angle α1 and the second pivot angle α2 , can be independently controlled to provide the required forward speed to the VTOL aerial vehicle 100, and to provide the required vertical thrust to balance the weight W1of the VTOL aerial vehicle 100.

The controller 290thus controls the magnitudes of the first thrust T1, the second thrusts T2, first pivot angle α1, the second pivot angle α2, and the angle of attack α0, such as to ensure that: - the vertical component of the total thrust T is sufficient to at least support the weight W1of the VTOL aerial vehicle 100along the current trajectory, and to increase or decrease the total thrust T to enable the VTOL aerial vehicle 100to climb or descend respectively, or to turn, during flight; - the horizontal component of the total thrust T is sufficient to counter the drag of the VTOL aerial vehicle 100while providing the required velocity along the current trajectory to enable interception with the fixed wing air vehicle 850, and to match the velocity of the fixed wing air vehicle 850at least after interception.

In the engagement enabling position, the selectively actuable part 710provided in the VTOL aerial vehicle 100or in the fixed wing air vehicle 850, is spatially (for example, vertically) aligned with the respective engageable part 720provided in the other one of VTOL aerial vehicle 100or in the fixed wing air vehicle 850.

At this point, in step 2600 the fixed wing air vehicle 850 is caused to become engaged with the VTOL air vehicle 100to provide a respective composite air vehicle 900( B6 , Fig. 9). This engagement is carried out via the engagement mechanism 700, wherein the selectively actuable part 710provided in the VTOL aerial vehicle 100or in the fixed wing air vehicle 850, is engaged with the respective selectively actuable part 710at the other one of the VTOL aerial vehicle 100or in the fixed wing air vehicle 850, by first bringing 0296841816- together the VTOL aerial vehicle 100and the fixed wing air vehicle 850, and then actuating the engageable part 720to engage therewith.

Thus, at step 2600 the VTOL aerial vehicle 100and the fixed wing air vehicle 850are engaged together to provide the composite vehicle 900, which is then flown as a single entity.

In at least this example, the VTOL aerial vehicle 100is engaged with respect to the fixed wing air vehicle 850, such that the VTOL aerial vehicle 100is vertically above the fixed wing air vehicle 850, and thus the fixed wing air vehicle 850is engaged from above by the VTOL aerial vehicle 100.

In step 2700 ( B7 , Fig. 9), the VTOL aerial vehicle 100is operated (while in the composite vehicle 900) to progressively decrease the forward speed VF of the composite air vehicle 900 and to increase vertical thrust T to compensate corresponding fall in aerodynamic lift generated by the fixed wing air vehicle 850.

This can be accomplished by reducing the angle of attack α0 of the composite vehicle 900and thus of the fixed wing air vehicle 850, and by reducing the magnitudes of the first pivot angle α1and the second pivot angle α2, while concurrently increasing the magnitudes of the first thrusts T1and the second thrust T2. This can continue until the forward speed is zero, wherein the first pivot angle α1and the second pivot angle α2are each nominally zero, and the total thrust generated by the VTOL aerial vehicle balances the total weight WT of the composite vehicle 900.

Concurrently, the air vehicle propulsion system 860is switch off in step 2800 , so that forward thrust generated by the fixed wing air vehicle reduces to zero.

Thereafter, in step 2800 ( B8 , Fig. 9), the VTOL aerial vehicle 100is operated to vertically land the composite air vehicle 900and the landing site LS , and this can be done by progressively reducing the magnitude of the total thrust TW .

After landing ( B9 , Fig. 9), the composite air vehicle 900 can optionally be disassembled by separating the VTOL aerial vehicle 100from the fixed wing air vehicle 850. Optionally, the VTOL aerial vehicle 100can then be transitioned to the stowed mode STM . According to another aspect of the presently disclosed subject matter, the VTOL 0296841816- aerial vehicle 100can also be operated to transport a payload from one ground location to another ground location.

According to this aspect of the presently disclosed subject matter, the VTOL aerial vehicle 100 can also be operated to be engaged with the payload 800 at a first ground location, after which the VTOL air vehicle is 100operated in vertical flight mode VFM to take off to a desired altitude. Thereafter the VTOL air vehicle is 100transitioned to forward flight mode FFM to transport the payload along a desired range to an altitude above the second ground location. Thereafter the VTOL air vehicle is 100transitioned back to vertical flight mode VFM to vertically land with the payload at the second ground location. Thereafter the payload can be disengaged from the VTOL aerial vehicle 100. Such a payload 800can be in the form of the fixed wing air vehicle 850, or can include any non-aerodynamic structure, for example a pallet.

Optionally, such a payload 800can instead be disengaged in mid-air from the VTOL aerial vehicle 100, and allowed to fall to the ground under gravity, with or without a parachute.

In the method claims that follow, alphanumeric characters and Roman numerals used to designate claim steps are provided for convenience only and do not imply any particular order of performing the steps.

Finally, it should be noted that the word "comprising" as used throughout the appended claims is to be interpreted to mean "including but not limited to".

While there has been shown and disclosed examples in accordance with the presently disclosed subject matter, it will be appreciated that many changes can be made therein without departing from the scope of the presently disclosed subject matter as set out in the claims.

Claims (50)

- 54 - 0296841816- CLAIMS:

1. A VTOL aerial vehicle comprising a body, a first propulsion system and a second propulsion system, wherein: the body; the first propulsion system comprises at least two first propulsion units, wherein the first propulsion system is pivotably mounted to the body and is configured for being selectively pivoted about a first pivot axis over a first pivot angle range with respect to the body; the second propulsion system comprises at least two second propulsion units, wherein the second propulsion system is pivotably mounted to the body and is configured for being selectively pivoted about a second pivot axis over a second pivot angle range with respect to the body; wherein the first propulsion system and the second propulsion system are configured for generating together sufficient thrust to enable vectored flight.

2. The VTOL aerial vehicle according to claim 1, wherein the body is configured for being releasably engaged with respect to a payload, and wherein the first propulsion system and the second propulsion system are configured for generating together sufficient thrust to enable vectored flight at least when engaged with the payload.

3. The VTOL aerial vehicle according to any one of claims 1 to 2, wherein the first pivot axis and the second pivot axis are parallel to one another.

4. The VTOL aerial vehicle according to any one of claims 1 to 3, wherein the first pivot axis and the second pivot axis are parallel to a pitch axis of the VTOL aerial vehicle.

5. The VTOL aerial vehicle according to any one of claims 1 to 4, wherein the first propulsion system comprises a first body portion, the at least two first propulsion units being mounted to the first body portion in fixed spatial relationship with respect thereto, and wherein the first body portion is pivotably mounted with respect to the body about the first pivot axis.

6. The VTOL aerial vehicle according to claim 5, wherein each said first propulsion unit has a respective first thrust vector that is spatially fixed with respect to the first body portion.

7. The VTOL aerial vehicle according to claim 6, wherein said respective first thrust vectors are parallel to one another. - 55 - 0296841816-

8. The VTOL aerial vehicle according to any one of claims 6 and 7, wherein at least one said respective first thrust vector is orthogonal with respect to the first pivot axis.

9. The VTOL aerial vehicle according to any one of claims 1 to 8, wherein the second propulsion system comprises a second body portion, the at least two second propulsion units being mounted to the second body portion in fixed spatial relationship with respect thereto, and wherein the second body portion is pivotably mounted with respect to the body about the second pivot axis.

10. The VTOL aerial vehicle according to claim 9, wherein each said second propulsion unit has a respective second thrust vector that is spatially fixed with respect to the second body portion.

11. The VTOL aerial vehicle according to claim 10, wherein said respective second thrust vectors are parallel to one another.

12. The VTOL aerial vehicle according to any one of claims 10 and 11, wherein at least one said respective second thrust vector is orthogonal with respect to the second pivot axis.

13. The VTOL aerial vehicle according to any one of claims 1 to 12, wherein said first pivot angle range is between 0º and ±135º.

14. The VTOL aerial vehicle according to any one of claims 1 to 13, wherein the first propulsion system is configured for maintaining any desired first pivot angle within said first pivot angle range.

15. The VTOL aerial vehicle according to any one of claims 1 to 14, wherein said second pivot angle range is between 0º and ±135º.

16. The VTOL aerial vehicle according to any one of claims 1 to 15, wherein the second propulsion system is configured for maintaining any desired second pivot angle within said second pivot angle range.

17. The VTOL aerial vehicle according to any one of claims 1 to 16, wherein the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, in mutually co-rotational directions.

18. The VTOL aerial vehicle according to any one of claims 1 to 17, wherein the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, in mutually counter-rotational directions. - 56 - 0296841816-

19. The VTOL aerial vehicle according to any one of claims 1 to 18, wherein the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, wherein the first pivot angle and the second pivot angle are substantially equal to one another.

20. The VTOL aerial vehicle according to claim 19, wherein the first pivot angle and the second pivot angle are each in a range between about 10º and about 30º.

21. The VTOL aerial vehicle according to any one of claims 1 to 18, wherein the first propulsion system and the second propulsion system are configured for being selectively pivoted about the first pivot axis and the second pivot axis, respectively, wherein the first pivot angle and the second pivot angle are substantially unequal with respect to one another.

22. The VTOL aerial vehicle according to claim 21, wherein the first pivot angle and the second pivot angle are each in a range between about 10º and about 30º.

23. The VTOL aerial vehicle according to any one of claims 1 to 22, having a stored configuration, an autonomous configuration, and an engaged configuration, wherein: - in the stored configuration the first propulsion system and the second propulsion system are pivoted towards one another; - in the autonomous configuration the first propulsion system and the second propulsion system are configured to provide propulsive power to enable vectored thrust flight for the VTOL aerial vehicle by itself; - in the engaged configuration the first propulsion system and the second propulsion system are configured to provide propulsive power to enable vectored thrust flight for the VTOL aerial vehicle when engaged with the payload.

24. The VTOL aerial vehicle according to any one of claims 1 to 23, wherein the body comprises a port body portion and a starboard body portion, - wherein the port body portion includes at least one said first propulsion unit pivotably mounted to the port body portion and configured for being selectively pivoted about the first pivot axis over the first pivot angle range with respect to the port body portion, and wherein the port body portion includes at least one said second propulsion unit pivotably mounted to the port body portion and configured for being selectively pivoted about the second - 57 - 0296841816- pivot axis over the second pivot angle range with respect to the port body portion; - wherein the starboard body portion includes at least one said first propulsion unit pivotably mounted to the starboard body portion and configured for being selectively pivoted about the first pivot axis over the first pivot angle range with respect to the starboard body portion, and wherein the starboard body portion includes at least one said second propulsion unit pivotably mounted to the starboard body portion and configured for being selectively pivoted about the second pivot axis over the second pivot angle range with respect to the starboard body portion.

25. The VTOL aerial vehicle according to claim 24, wherein the body comprises a central body portion laterally spacing the port body portion and the starboard body portion with respect to one another.

26. The VTOL aerial vehicle according to claim 25, wherein the central body portion has an aerodynamically shaped transverse cross-section.

27. The VTOL aerial vehicle according to any one of claims 24 to 26, wherein the body is configured for being releasably engaged with respect to the payload via the port body portion and the starboard body portion.

28. The VTOL aerial vehicle according to any one of claims 25 to 27, wherein the body is configured for being releasably engaged with respect to the payload via the central body portion.

29. The VTOL aerial vehicle according to any one of claims 1 to 28, wherein the payload comprises a fixed wing air vehicle, and wherein the body is configured for being releasably engaged with respect to the payload at a ventral portion of the payload.

30. The VTOL aerial vehicle according to any one of claims 1 to 28, wherein the payload comprises a fixed wing air vehicle, and wherein the body is configured for being releasably engaged with respect to the payload at a dorsal portion of the payload.

31. The VTOL aerial vehicle according to any one of claims 1 to 28, wherein the payload comprises a fixed wing air vehicle having a port wing and a starboard wing, and wherein the body is configured for being releasably engaged with respect to the payload at the port wing and at the starboard wing.

32. The VTOL aerial vehicle according to any one of claims 1 to 31, wherein the first propulsion system and the second propulsion system are configured for together - 58 - 0296841816- providing a thrust to weight ratio in a range between about 3 and about 15 or in a range between about 1.8 to about 15.

33. The VTOL aerial vehicle according to any one of claims 1 to 32, wherein the first propulsion system and the second propulsion system are configured for together providing a vertical thrust that exceeds a sum of a first weight of the VTOL aerial vehicle and a second weight of the payload.

34. The VTOL aerial vehicle according to any one of claims 1 to 33, comprising a controller for selectively controlling vectored flight of the VTOL aerial vehicle, and for selectively causing the first propulsion system to be pivoted about the first pivot axis to a desired first pivot angle with respect to the body, and for selectively causing the second propulsion system to be pivoted about the second pivot axis to a desired second pivot angle with respect to the body.

35. The VTOL aerial vehicle according to claim 34, wherein the controller is configured for selectively causing the first propulsion system to be pivoted about the first pivot axis to the desired first pivot angle with respect to the body, and for causing the second propulsion system to be pivoted about the second pivot axis to the desired second pivot angle with respect to the body, such as to enable vectored flight of the VTOL aerial vehicle with the payload concurrently engaged thereto, and for concurrently providing a forward speed to the VTOL aerial vehicle with the payload concurrently engaged thereto.

36. The VTOL aerial vehicle according to claim 34, wherein the payload is a fixed wing air vehicle, and wherein said forward speed is sufficient for enabling the fixed wing air vehicle to generate sufficient aerodynamic lift sufficient for enabling aerodynamic flight of the fixed wing air vehicle.

37. The VTOL aerial vehicle according to any one of claims 34 to 36, wherein the controller is configured for selectively causing the first propulsion system to be pivoted about the first pivot axis to the desired first pivot angle with respect to the body, and for causing the second propulsion system to be pivoted about the second pivot axis to the desired second pivot angle with respect to the body, and for orienting the body at a desired angle of attack.

38. The VTOL aerial vehicle according to any one of claims 34 to 37, wherein the payload is a fixed wing air vehicle having a stall speed, wherein the controller is configured for selectively causing the first propulsion system to be pivoted about the first pivot axis to the desired first pivot angle with respect to the body, and for causing the - 59 - 0296841816- second propulsion system to be pivoted about the second pivot axis to the desired second pivot angle with respect to the body, such as to enable vectored flight of the VTOL aerial vehicle with the payload concurrently engaged thereto, and for concurrently matching a forward speed of the VTOL aerial vehicle to at least the stall speed of the payload concurrently engaged thereto.

39. The VTOL aerial vehicle according to any one of claims 1 to 38, configured for disengaging the payload when previously engaged thereto at a first predetermined altitude and a first forward speed.

40. The VTOL aerial vehicle according to any one of claims 1 to 39, configured for engaging the payload thereto at a second predetermined altitude and a second forward speed.

41. The VTOL aerial vehicle according to any one of claims 1 to 40, further comprising an auxiliary thrust system for selectively generating at least one of lateral thrust and law moments to the VTOL aerial vehicle.

42. The VTOL aerial vehicle according to any one of claims 34 to 41, wherein the controller is configured for receiving a command to provide a desired angle of attack for the body and a desired forward speed for the VTOL aerial vehicle, and generates suitable commands for selectively causing the first propulsion system to be pivoted about the first pivot axis to a corresponding said first pivot angle with respect to the body, for selectively causing the second propulsion system to be pivoted about the second pivot axis to a corresponding second pivot angle with respect to the body, for selectively causing the first prolusion system to generate a said first thrust, and for selectively causing the second prolusion system to generate a said second thrust, such as to provide said desired angle of attack for the body and said desired forward speed for the VTOL aerial vehicle

43. A composite air vehicle, comprising a VTOL aerial vehicle as defined in any one of claims 1 to 42, wherein the VTOL aerial vehicle is releasably engaged with respect to a payload.

44. The composite air vehicle according to claim 43, wherein the payload is a fixed wing air vehicle.

45. A method for operating a VTOL aerial vehicle for aerially releasing a payload, the method comprising: (a) providing a VTOL aerial vehicle as defined in any one of claims 1 to 42; - 60 - 0296841816- (b) engaging a payload to the VTOL aerial vehicle, wherein the payload is a fixed wing air vehicle capable of aerodynamic flight at forward speeds exceeding a stall speed; (c) operating the composite air vehicle to operate in vectored flight mode for take-off, wherein the VTOL aerial vehicle provides the required vectored thrust for the composite air vehicle; (d) transitioning the VTOL aerial vehicle, while engaged to the payload, to the forward flight mode FFM; (e) disengaging the fixed wing air vehicle from the VTOL aerial vehicle, and flying the fixed wing air vehicle independently from the VTOL aerial vehicle.

46. The method according to claim 45, wherein step (d) comprises: pivoting the first propulsion system about the first pivot axis and the second propulsion system about the second pivot axis to a desired said first pivot angle and a desired second pivot angle, respectively, to provide a forward speed to the composite air vehicle, wherein said forward speed exceeds said stall speed of the fixed wing air vehicle, and allowing the fixed wing air vehicle to generate aerodynamic lift.

47. A method for operating a VTOL aerial vehicle for aerially capturing a payload, the method comprising: (a) providing a VTOL aerial vehicle as defined in any one of claims 1 to 42; (b) providing a payload comprising a fixed wing air vehicle capable of aerodynamic flight; (c) causing the fixed wing air vehicle to fly in aerodynamic flight mode along a first trajectory; (d) causing the VTOL aerial vehicle to fly in vectored flight mode in a second trajectory, wherein at least one of the first trajectory and the second trajectory is an intercept trajectory with respect to the other one of the first trajectory and the second trajectory; (e) aerially aligning the VTOL aerial vehicle with respect to the fixed wing air vehicle in an engagement enabling position; (f) causing the fixed wing air vehicle to become engaged with the VTOL air vehicle to provide a composite air vehicle; - 61 - 0296841816- (g) operating the VTOL aerial vehicle to progressively decrease the forward speed of the composite air vehicle and to increase vertical thrust to compensate corresponding fall in aerodynamic lift generated by the fixed wing air vehicle; (h) operating the VTOL aerial vehicle to vertically land the composite air vehicle.

48. The method according to claim 47, wherein step (e) comprises: pivoting the first propulsion system about the first pivot axis and the second propulsion system about the second pivot axis to a desired said first pivot angle and a desired second pivot angle, respectively, to provide a forward speed to the composite air vehicle, wherein said forward speed matches the forward speed of the fixed wing air vehicle, and wherein the body is oriented to match the fixed wing air vehicle.

49. The method according to any one of claims 47 to 48, wherein in said an engagement enabling position, said VTOL aerial vehicle is vertically above the fixed wing air vehicle.

50. A method for operating a VTOL aerial vehicle for transporting a payload, the method comprising: (a) providing a VTOL aerial vehicle as defined in any one of claims 1 to 42; (b) engaging a payload to the body while on the ground to provide a composite air vehicle; (c) operating the composite air vehicle to operate in vectored flight mode for take-off, wherein the VTOL aerial vehicle provides the required vectored thrust for the composite air vehicle; (d) pivoting the first propulsion system about the first pivot axis and the second propulsion system about the second pivot axis to a desired said first pivot angle and a desired second pivot angle, respectively, to provide a forward speed to the composite air vehicle, to thereby transport the composite air vehicle along a desired trajectory having a range; (e) operating the composite air vehicle to operate in vectored flight mode for landing the composite air vehicle at a landing location, wherein the VTOL aerial vehicle provides the required vectored thrust for the composite air vehicle. - 62 - 0296841816- For the Applicants, REINHOLD COHN AND PARTNERS By: