EP4558398A2

EP4558398A2 - Vertical take-off and landing aircraft

Info

Publication number: EP4558398A2
Application number: EP23727385.9A
Authority: EP
Inventors: Qinghua He; Xiping Chen; Yunrong MA; Yu Deng; Zhidong ZHOU; Yuting Liu; Yi Zhao; Jingliang GUO; Bin Liang
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2022-07-21
Filing date: 2023-05-24
Publication date: 2025-05-28
Also published as: CN218288104U; CN218806481U; WO2024017525A3; WO2024017525A2

Abstract

The application provides a vertical take-off and landing (VTOL) aircraft, comprising a fuselage, the fuselage comprising a nose, wherein the nose contour is configured to be symmetrical about the symmetry plane and extends from the leading edge point of the nose to the middle fuselage. The nose contour is divided into an upper surface and a lower surface by a horizontal plane passing through the leading edge point and perpendicular to the plane of symmetry. The lower surface bulges downward relative to the horizontal plane when the nose contour expands from the leading edge point to the middle fuselage, which is greater than the upper surface bulges upward relative to the horizontal plane when the nose contour expands from the leading edge point to the middle fuselage. The VTOL aircraft further comprises a pair of front wings connected to the nose and a pair of rear wings connected to the tail. The pair of front wings and the pair of rear wings are arranged in a tandem wing layout. The arrangement position of the pair of front wings on the nose is adjacent to the horizontal plane in the vertical direction perpendicular to the horizontal plane. The VTOL aircraft of this application can meet the requirements of small size and high load by using the combination of the lower convex nose contour and the tandem wing layout, and is especially suitable for urban air traffic scenes.

Description

Vertical Take-off and Landing Aircraft

Technical Field

The present application relates to the field of aircraft, in particular to a VTOL aircraft.

Background

Urban air mobility (UAM) is a new mode of transportation, which mainly involves shortdistance transportation within or between cities. UAM vehicles usually fly in low-altitude (100 metres to 1000 metres) or ultra-low-altitude (below 100 metres) airspace.

Vertical take-off and landing (VTOL) aircraft are a common type of UAM vehicle. In UAM scenarios, due to the limitations imposed by factors such as urban buildings, plants, road traffic and people, it is desired that VTOL aircraft meet the requirement for small size. At the same time, in order to improve the transportation efficiency, it is also desired that VTOL aircraft meet the requirement for high weight-bearing capacity. However, existing VTOL aircraft all struggle to meet the requirements for small size and high weight-bearing capacity at the same time.

Therefore, a novel VTOL aircraft is needed.

Summary of the Utility Model

In view of the above, the present application proposes a novel VTOL aircraft, to solve the problem described in the background art.

According to one aspect of the present application, a VTOL aircraft is provided, comprising: a fuselage, the fuselage comprising a nose, a tail, and a fuselage middle segment extending between the nose and the tail, a nose contour of the nose being configured to be symmetric with respect to a symmetry plane of the VTOL aircraft, and expanding from a leading edge point of the nose to the fuselage middle segment, the nose contour being divided into an upper surface and a lower surface by a horizontal plane passing through the leading edge point and perpendicular to the symmetry plane, and the extent to which the lower surface bulges downwards relative to the horizontal plane as the nose contour expands from the leading edge point to the fuselage middle segment being greater than the extent to which the upper surface bulges upwards relative to the horizontal plane as the nose contour expands from the leading edge point to the fuselage middle segment; and a pair of front wings connected to the nose and a pair of rear wings connected to the tail, the pair of front wings and the pair of rear wings being arranged in a tandem wing layout, and the arrangement positions of the pairof front wings on the nose being close to the horizontal plane in a vertical direction perpendicular to the horizontal plane.

In some embodiments, the horizontal plane and the nose contour intersect at a left boundary line and a right boundary line, the left boundary line and the fuselage middle segment intersect at a first left endpoint, and the right boundary line and the fuselage middle segment intersect at a first right endpoint; the symmetry plane and the nose contour intersect at an upper contour line and a lower contour line, the upper contour line and the fuselage middle segment intersect at an upper endpoint, and the lower contour line and the fuselage middle segment intersect at a lower endpoint; and the centroid of the shape of a cross-section of the nose contour cut by the symmetry plane is located at the side of the projection of the left boundary line on the symmetry plane that is closer to the lower endpoint, and located at the side of the perpendicular bisector of said projection that is closer to the leading edge point.

In some embodiments, the distance between the upper endpoint and the lower endpoint in the vertical direction defines the height of the nose, the height of the nose being H; the distance between the leading edge point and the upper endpoint in the vertical direction is hi , hi being in the range of 0 to 0.3H; and the distance between the leading edge point and the lower endpoint in the vertical direction is h2, h2 being in the range of 0.7H to H.

In some embodiments, hi is in the range of 0.1 H to 0.2H, and h2 is in the range of 0.8H to 0.9H.

In some embodiments, the upper contour line is an upward-sloping curved line of gradually increasing height in the direction from the leading edge point to the upper endpoint; and the lower contour line is a downward-sloping curved line of gradually decreasing height in the direction from the leading edge point to the lower endpoint.

In some embodiments, the upper surface and the lower surface are both continuous curved surfaces which expand from the leading edge point of the nose to the fuselage middle segment.

In some embodiments, the upper contour line and the lower contour line define boundaries of the shape of the projection of the nose contour on the symmetry plane. In some embodiments, the arrangement position of the front wing on the nose is closer to the upper endpoint than the lower endpoint in the vertical direction.

In some embodiments, the distance in the vertical direction between the upper endpoint and the arrangement position of the front wing on the nose is in the range of 0 to 0.3H.

In some embodiments, the arrangement position of the front wing on the nose is higher in the vertical direction than the arrangement position of the rear wing on the tail.

In some embodiments, the arrangement position of the front wing on the nose is closer to the leading edge point than the first left endpoint in a front-rear direction parallel to the symmetry plane and parallel to the horizontal plane.

In some embodiments, the distance in the front-rear direction between the leading edge point and the first left endpoint defines the length of the nose, the length of the nose being L, L being in the range of H to 1 ,5H; and the distance in the front-rear direction between the arrangement position and the leading edge point is in the range of 0 to 0.3L.

In some embodiments, the contour of the projection of the nose on the horizontal plane comprises a left contour line and a right contour line which separately extend from the leading edge point to the fuselage middle segment, the left contour line and the right contour line being symmetric with respect to the symmetry plane, and intersecting with the fuselage middle segment at a second left endpoint and a second right endpoint respectively; the second left endpoint is not higher than the first left endpoint in the vertical direction, and the distance between the second left endpoint and the first left endpoint in the vertical direction is h3, h3 being in the range of 0 to 0.4H.

In some embodiments, the distance between the second left endpoint and the second right endpoint in a transverse direction perpendicular to the symmetry plane defines the width of the nose, the width of the nose being W, W being in the range of H to 1 ,5H.

In some embodiments, the contours of the fuselage middle segment and the tail are tadpoleshaped or truncated-cone-shaped.

In some embodiments, the pair of front wings and the pair of rear wings have an X-shaped layout, with the front wings swept forward and the rear wings swept rearward; and a front wing area of the pair of front wings is smaller than a rear wing area of the pair of rear wings.

In some embodiments, the front wing area is 50% - 80% of the rear wing area.

In some embodiments, neither a forward sweep angle of a leading edge of the front wing nor a rearward sweep angle of a leading edge of the rear wing exceeds 25°. In some embodiments, each front wing in the pair of front wings comprises a front wing tip, a leading edge of the front wing tip being further forward than the leading edge point in a front-rear direction parallel to the symmetry plane and parallel to the horizontal plane.

In some embodiments, the wingspan of the pair of front wings is shorter than the wingspan of the pair of rear wings; each front wing in the pair of front wings comprises a front wing tip, a front wing root, and a front wing body extending between the front wing tip and the front wing root; each rear wing in the pair of rear wings comprises a rear wing tip, a rear wing root, and a rear wing body extending between the rear wing tip and the rear wing root; the VTOL aircraft further comprises a pair of elongated connecting rods arranged symmetrically with respect to the symmetry plane, each elongated connecting rod in the pair of elongated connecting rods extending substantially parallel to the symmetry plane, being connected to one corresponding front wing in the pair of front wings at the front wing tip of the corresponding front wing, and connected to one corresponding rear wing, corresponding to the corresponding front wing, in the pair of rear wings at the rear wing body of the corresponding rear wing; and the VTOL aircraft comprises multiple rotors, the multiple rotors being arranged on the connecting rods symmetrically with respect to the symmetry plane, and configured to supply vertical motive power to the VTOL aircraft.

In some embodiments, the multiple rotors comprise at least six rotors.

In some embodiments, the connecting rod comprises a middle segment between the front wing tip and the rear wing body, a front segment extending beyond the front wing tip from the middle segment, and a rear segment extending beyond the rear wing body from the middle segment, with rotors arranged on the middle segment, the front segment and the rear segment.

In some embodiments, a rotation axis of each rotor of the multiple rotors is oriented perpendicular to the horizontal plane.

In some embodiments, the multiple rotors are arranged at the side of the connecting rods that faces away from the horizontal plane.

In some embodiments, the rotor comprises blades and a coupling mechanism that couples the blades rotatably to the connecting rod; at least the blades of the rotor are positioned higher than the fuselage in the vertical direction.

In some embodiments, each rear wing in the pair of rear wings comprises a rear wing tip, a vertical tail being arranged at the rear wing tip; the vertical tail comprises a fixed vertical stabilizer, and a rudder which is operable to control the heading. In some embodiments, the VTOL aircraft comprises a pair of horizontal propulsors, arranged symmetrically with respect to the symmetry plane and configured to supply horizontal motive power to the VTOL aircraft, each horizontal propulsor in the pair of horizontal propulsors being connected to one corresponding rear wing in the pair of rear wings at a leading edge or trailing edge of the corresponding rear wing, close to the rear wing root of the corresponding rear wing, and the pair of horizontal propulsors being a pair of ducted fans or a pair of screw propellers.

In some embodiments, the VTOL aircraft further comprises a pair of landing gears arranged symmetrically with respect to the symmetry plane. Each landing gear in the pair of landing gears comprises: a first support leg, the first support leg comprising a first end connected to the fuselage, and a second end opposite the first end; a second support leg, the second support leg comprising a third end connected to the fuselage, and a fourth end opposite the third end; and a middle segment connected between the second end and the fourth end; the middle segment comprises a first segment connected to the second end, a second segment connected to the fourth end, and a bent segment connecting the first segment and the second segment; the bent segment is configured to be bent towards the fuselage, so that when the VTOL aircraft is parked on a flat base surface, the first segment and the second segment contact the base surface, but the bent segment does not contact the base surface.

In some embodiments, the first segment and the second segment are elongated, and the first segment and the second segment are collinear.

In some embodiments, the first segment and the second segment are both oriented in a frontrear direction parallel to the symmetry plane and parallel to the horizontal plane.

In some embodiments, the contours of cross sections of the first support leg that are cut by planes parallel to the horizontal plane are all drop-shaped, to reduce resistance.

In some embodiments, the contours of cross sections of the second support leg that are cut by planes parallel to the horizontal plane are all drop-shaped, to reduce resistance.

In some embodiments, the first support leg is elongated, and forms an angle of 45° - 135° with the first segment.

In some embodiments, the second support leg is elongated, and forms an angle of 45° - 135° with the second segment.

In some embodiments, the first support leg, the second support leg, the first segment and the second segment are coplanar in a first plane, the first plane being inclined relative to the symmetry plane; and the bent segment is offset relative to the first plane in a direction away from the symmetry plane. In some embodiments, the bent segment is parallel to the symmetry plane.

In some embodiments, the bent segment comprises a first part connected to the first segment, a second part connected to the second segment, and a third part connecting the first part and the second part, the third part being parallel to the first segment and the second segment.

According to another aspect of the present application, a landing apparatus for an aircraft is provided, the aircraft comprising a fuselage, characterized in that the landing apparatus comprises a pair of landing gears configured to be arranged symmetrically with respect to a symmetry plane of the fuselage, each landing gear in the pair of landing gears comprising: a first support leg, the first support leg comprising a first end connected to the fuselage, and a second end opposite the first end; a second support leg, the second support leg comprising a third end connected to the fuselage, and a fourth end opposite the third end; and a middle segment connected between the second end and the fourth end; the middle segment comprises a first segment connected to the second end, a second segment connected to the fourth end, and a bent segment connecting the first segment and the second segment; the bent segment is configured to be bent towards the fuselage, so that when the aircraft is parked on a flat base surface, the first segment and the second segment contact the base surface, but the bent segment does not contact the base surface.

In some embodiments, the first segment and the second segment are both oriented in a direction parallel to the symmetry plane and parallel to a plane perpendicular to the symmetry plane.

In some embodiments, the contours of cross sections of the first support leg that are cut by planes perpendicular to the symmetry plane are all drop-shaped, to reduce resistance.

In some embodiments, the contours of cross sections of the second support leg that are cut by planes perpendicular to the symmetry plane are all drop-shaped, to reduce resistance.

In some embodiments, the first support leg, the second support leg, the first segment and the second segment are coplanar in a first plane, the first plane being inclined relative to the symmetry plane; and the bent segment is offset relative to the first plane in a direction away from the symmetry plane.

In some embodiments, the bent segment is parallel to the symmetry plane. In some embodiments, the angle between the first plane and the symmetry plane is between 0° and 50°. Preferably, the angle is 40°.

By making use of the combination of the downward-bulging nose contour and the tandem wing layout, the VTOL aircraft of the present application is able to meet the requirements for small size and high weight-bearing capacity, and is especially suitable for UAM scenarios.

Brief description of the drawings

A more thorough understanding of the abovementioned and other aspects of the present application will be gained below with reference to the drawings. It should be noted that the drawings are merely schematic, and not drawn to scale. In the drawings:

Fig. 1 shows schematically a 3D drawing of a VTOL aircraft according to a preferred embodiment of the present application.

Fig. 2 shows schematically another 3D drawing of the VTOL aircraft shown in Fig. 1 .

Fig. 3 shows schematically a side view of the VTOL aircraft shown in Fig. 1 .

Fig. 4 shows schematically a front view of the VTOL aircraft shown in Fig. 1 .

Fig. 5 shows schematically a rear view of the VTOL aircraft shown in Fig. 1 .

Fig. 6 shows schematically a top view of the VTOL aircraft shown in Fig. 1 .

Fig. 7 shows schematically a bottom view of the VTOL aircraft shown in Fig. 1 .

Fig. 8 shows schematically the nose contour of the nose of the VTOL aircraft shown in Fig. 1 .

Fig. 9 shows schematically the contour of a cross section, cut by the symmetry plane, of the fuselage of the VTOL aircraft shown in Fig. 1.

Fig. 10 shows schematically the contour of a cross section, cut along line l-l in Fig. 6, of the nose of the VTOL aircraft shown in Fig. 1 ; and

Fig. 11 shows schematically the contour of a cross section, cut along line ll-ll in Fig. 3, of the left-side landing gear of the VTOL aircraft shown in Fig. 1 .

Detailed description of the invention Particular embodiments of the present application are described in detail below in conjunction with examples. It should be understood that these exemplary embodiments do not imply any limitation on the present application. Furthermore, in the absence of conflict, features in embodiments of the present application may be combined. Identical components are shown with the same reference signs in different drawings, and other components are omitted for conciseness, but this does not mean that the VTOL aircraft of the present application cannot include other components. In addition, for conciseness, not all components of the VTOL aircraft are labelled in the drawings and described hereinbelow. It should also be understood that the dimensions, proportional relationships and quantities of the components in the drawings are not limitations on the present application.

Figs. 1 - 7 depict a VTOL aircraft 1 according to a preferred embodiment of the present application. The VTOL aircraft 1 may be used as a UAM vehicle, for carrying people or goods. The VTOL aircraft 1 comprises a fuselage 3, the fuselage 3 comprising a nose 5, a tail 7 and a fuselage middle segment 9 extending between the nose 5 and the tail 7. In addition, as will be described below, the VTOL aircraft 1 further comprises a vertical propulsion apparatus and a horizontal propulsion apparatus, for supplying motive power to the VTOL aircraft 1. Specifically, the vertical propulsion apparatus is configured to supply vertical motive power to the VTOL aircraft 1 , and the horizontal propulsion apparatus is configured to supply horizontal motive power to the VTOL aircraft 1 . It should be understood that the vertical propulsion apparatus and horizontal propulsion apparatus may be propulsion apparatuses of any suitable type in the art, and may be the same propulsion apparatus or different propulsion apparatuses. For example, the vertical propulsion apparatus and horizontal propulsion apparatus may be provided by the same tilting motive power system. In the case where the VTOL aircraft 1 has two motive power systems - the vertical propulsion apparatus and the horizontal propulsion apparatus - these two motive power systems complement each other, and can increase the safety and reliability of the VTOL aircraft 1 .

As shown in Figs. 4 - 7, a nose contour of the nose 5 is configured to be symmetric with respect to a symmetry plane A of the VTOL aircraft 1 , and expands from a leading edge point P1 of the nose 5 to the fuselage middle segment 9. As used in the present application, the symmetry plane A of the VTOL aircraft 1 is an imaginary plane that divides the VTOL aircraft 1 into two halves, which are substantially mirror images of each other. However, it should be understood that this does not mean that the VTOL aircraft 1 of the present application is limited to being completely symmetric with respect to the symmetry plane A. For example, the VTOL aircraft 1 may have certain components or parts on one side of the symmetry plane A, and have no such components or parts on the other side. In addition, as used in the present application, the leading edge point P1 of the nose 5 is the point or region (which region may be approximately an imaginary point) that is foremost in the direction of movement (i.e. the front-rear direction) of the VTOL aircraft 1 . Thus, the leading edge point P1 of the nose 5 is on the symmetry plane A. In otherwords, the symmetry plane A passes through the leading edge point P1 of the nose 5. In addition, as used in the present application, the “contour” is a definition of periphery that forms and defines a peripheral edge of a figure or object, and represents the overall external form of the figure or object.

Continuing to refer to Figs. 1 - 4, the nose contour of the nose 5 is divided into an upper surface 51 and a lower surface 53 by a horizontal plane B which passes through the leading edge point P1 and is perpendicular to the symmetry plane A. The horizontal plane B is also an imaginary plane. As shown best in Figs. 1 - 3, the extent to which the lower surface 53 of the nose 5 bulges downwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9 is greater than the extent to which the upper surface 51 of the nose 5 bulges upwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9. Consequently, the nose contour of the nose 5 has a downward-bulging form.

Referring to Figs. 1 - 2 and 6 - 7, the VTOL aircraft 1 further comprises a pair of front wings 11 connected to the nose 5 and a pair of rear wings 13 connected to the tail 7. The pair of front wings 11 and the pair of rear wings are arranged in a tandem wing configuration. That is to say, the front wing 11 and the rear wing 13 are arranged one behind the other, and the front wing 11 and the rear wing 13 are not only lift surfaces but also trim surfaces for each other. In such a tandem wing layout, the aerodynamic centre of the VTOL aircraft 1 is located between the front wing 11 and the rear wing 13. The arrangement positions of the pair of front wings 11 on the nose 5 are close to the horizontal plane B in a vertical direction 15 perpendicular to the horizontal plane B. As used in the present application, the arrangement position of a wing is the position where the leading edge point of the root of the wing is located.

The inventors have realized that the combination of the downward-bulging nose contour and the tandem wing layout of the VTOL aircraft 1 of the present application provides significant advantages. Specifically, by making use of the combination of the downward-bulging nose contour and the tandem wing layout, the VTOL aircraft 1 of the present application is able to meet the requirements for small size and high weight-bearing capacity, and is especially suitable for UAM scenarios.

Firstly, due to the fact that the front wing 11 and the rear wing 13 are not only lift surfaces but also trim surfaces for each other, the VTOL aircraft 1 can realize a large aerodynamic lift area with a small span. This facilitates miniaturization of the VTOL aircraft 1 , to suit the take-off/landing and storage requirements in UAM scenarios. Furthermore, it enables the VTOL aircraft to have a high weight-bearing capacity with a small size.

A conventional nose contour generally has an upward-bulging form (i.e. corresponding to a situation in which the extent to which the lower surface 53 of the nose 5 bulges downwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9 is less than the extent to which the upper surface 51 of the nose 5 bulges upwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9) or a symmetric form (i.e. corresponding to a situation in which the extent to which the lower surface 53 of the nose 5 bulges downwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9 is the same as the extent to which the upper surface 51 of the nose 5 bulges upwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9).

When the arrangement position of the front wing 11 on the nose 5 is close to the horizontal plane B in the vertical direction 15, the downward-bulging nose contour of the nose 5 enables the nose 5 (the leading edge point P1) to be disposed closer to the front wing 5, compared with the conventional upward-bulging contour and symmetric contour. Thus, for the same fuselage volume, compared with the conventional upward-bulging contour and symmetric contour, the downwardbulging nose contour of the nose 5 enables the front wing 11 to be arranged further forward relative to the rear wing 13, such that the distance between the front wing 11 and the rear wing 13 is larger. This can significantly shorten the length of the fuselage 3, thereby reducing the proportion of the weight taken up by the fuselage mechanism, and increasing the weight-bearing capacity of the VTOL aircraft 1. Furthermore, the aerodynamic centre of the VTOL aircraft 1 can be arranged further rearward. In the field of aircraft, in order to ensure flight static stability in a level flying state, the centre of gravity of the aircraft needs to be located in front of the aerodynamic centre. In the case of the VTOL aircraft 1 of the present application, because the aerodynamic centre can be arranged further rearward, a larger range of adjustment of the centre of gravity can be provided for the VTOL aircraft 1.

In addition, the fact that the front wing 11 and the rear wing 13 are not only lift surfaces but also trim surfaces for each other can considerably increase the lift-to-drag ratio of the VTOL aircraft 1 , for higher aerodynamic efficiency. The fact that the front wing 11 and the rear wing 13 are trim surfaces for each other can also provide a larger range of adjustment of the centre of gravity for the VTOL aircraft 1 . A larger range of adjustment of the centre of gravity implies greater weight-bearing flexibility of the VTOL aircraft 1 .

As can be seen, compared with VTOL aircraft in the prior art, by making use of the combination of the downward-bulging nose contour and the tandem wing layout, the VTOL aircraft 1 of the present application is able to meet the requirements for small size and high weight-bearing capacity, and is especially suitable for UAM scenarios.

Fig. 8 shows schematically the nose contour of the nose 5 of the VTOL aircraft 1 . Fig. 9 shows schematically the contour of a cross section, cut by the symmetry plane A, of the fuselage 3 of the VTOL aircraft 1 ; a boundary line between the nose 5 and the fuselage middle segment 9 is shown schematically by the imaginary line C in Fig. 9. Fig. 10 shows schematically the contour of a cross section, cut along line l-l in Fig. 6, of the nose 5 of the VTOL aircraft 1 ; this cross-section contour may for example be the contour of a boundary between the nose 5 and the fuselage middle segment 9.

As shown in Fig. 8, the horizontal plane B and the nose contour intersect at a left boundary line S1 and a right boundary line S2. The left boundary line S1 and the fuselage middle segment 9 intersect at a first left endpoint PL1 ; the right boundary line S2 and the fuselage middle segment 9 intersect at a first right endpoint PR1 . Since the nose contour of the nose 5 is symmetric with respect to the symmetry plane A, the left boundary line S1 and the right boundary line S2 are also symmetric with respect to the symmetry plane A. The symmetry plane A and the nose contour intersect at an upper contour line S3 and a lower contour line S4. The upper contour line S3 and the fuselage middle segment 9 intersect at an upper endpoint PU; the lower contour line S4 and the fuselage middle segment 9 intersect at a lower endpoint PD. In some embodiments, the upper contour line S3 and the lower contour line S4 define boundaries of the shape of the projection of the nose contour on the symmetry plane A. That is to say, the upper contour line S3 and the lower contour line S4 define the outermost contours of the nose 5 in the vertical direction 15. In some other embodiments, the upper contour line S3 and the lower contour line S4 may not be the outermost contours of the nose 5 in the vertical direction 15.

As shown in Fig. 9, the projection of the first left endpoint PL1 on the symmetry plane A is PL1 ’, and the projection of the left boundary line S1 on the symmetry plane A is a line connecting P1 and PL1’. Correspondingly, the projection of the first right endpoint PR1 on the symmetry plane A coincides with PL1 ’, and the projection of the right boundary line S2 on the symmetry plane A coincides with the line connecting P1 and PL1 ’. The downward-bulging nose contour of the nose 5 may be such that: the centroid M of the shape of a cross-section of the nose contour cut by the symmetry plane A is located at the side of the projection of the left boundary line S1 on the symmetry plane A (i.e. the line connecting P1 and PL1’) that is closer to the lower endpoint PD, and located at the side of the perpendicular bisector D of said projection that is closer to the leading edge point P1 . Such a downward-bulging nose contour is especially beneficial for providing the abovementioned advantages.

Continuing to refer to Fig. 9, the distance between the upper endpoint PU and the lower endpoint PD in the vertical direction 15 defines the height of the nose 5, the height of the nose 5 being H. In some embodiments, the upper endpoint PU and the lower endpoint PD are aligned in the vertical direction 15. In some other embodiments, the upper endpoint PU may not be aligned with the lower endpoint PD in the vertical direction 15, i.e. they may be offset from each other. The distance between the leading edge point P1 and the upper endpoint PU in the vertical direction 15 is hi , and the distance between the leading edge point P1 and the lower endpoint PD in the vertical direction is h2. In some embodiments, hi is in the range of 0 to 0.3H, and h2 is in the range of 0.7H to H. For example, when hi is 0, h2 is H, the distance between the leading edge point P1 and the upper endpoint PU in the vertical direction 15 is 0, and the upper contour line S3 is a straight line. In this case, when the upper contour line S3 and the lower contour line S4 define the outermost contours of the nose 5 in the vertical direction 15, the upper surface 51 is a flat surface extending from the leading edge point P1 to the fuselage middle segment 9. That is to say, the extent to which the upper surface 51 bulges upwards relative to the horizontal plane B as the nose contour expands from the leading edge point P1 to the fuselage middle segment 9 is zero. Preferably, hi is in the range of 0.1 H to 0.2H, and h2 is in the range of 0.8H to 0.9H. More preferably, hi is 0.15H, and h2 is 0.85H. In some embodiments, H may be in the range of 1 .2 metres to 2 metres. Preferably, it is in the range of 1 .2 metres to 1 .6 metres.

In some embodiments, as shown best in Fig. 9, the upper contour line S3 is an upward-sloping curved line of gradually increasing height in the direction from the leading edge point P1 to the upper endpoint PU. The lower contour line S4 is a downward-sloping curved line of gradually decreasing height in the direction from the leading edge point P1 to the lower endpoint PD. In one of these examples, the upper surface 51 and the lower surface 53 are both continuous curved surfaces expanding from the leading edge point P1 of the nose 5 to the fuselage middle segment 9. Such continuous curved surfaces help to improve aerodynamic performance.

As shown best in Figs. 2 and 4, the arrangement position of the front wing 11 on the nose 5 is closer to the upper endpoint PU than the lower endpoint PD in the vertical direction 15. In some embodiments, the distance in the vertical direction 15 between the upper endpoint PU and the arrangement position of the front wing 11 on the nose 5 is in the range of 0 to 0.3H. In some embodiments, the arrangement position where the front wing 11 is connected to the nose 5 is higher than the arrangement position of the rear wing 13 on the tail 7. However, it should be understood that the present application is not limited to this.

In addition, as shown best in Figs. 2, 4, 6 and 7, the arrangement position of the front wing 11 on the nose 5 is closer to the leading edge point P1 than the first left endpoint PL1 (or the first right endpoint PR1) in a front-rear direction 19 parallel to the symmetry plane A and parallel to the horizontal plane B. The distance between the leading edge point PI and the first left endpoint PL1 in the front-rear direction 19 defines the length of the nose 5 (i.e. the length of the line connecting P1 and PL1 ’), the length of the nose 5 being L. L may be any suitable value. For example, L is in the range of H to 1 ,5H. As another example, L may be less than H or greater than 1 ,5H.

In some embodiments, the distance in the front-rear direction 19 between the leading edge point P1 and the arrangement position of the front wing 11 on the nose 5 is in the range of 0 to 0.3L. This is a benefit provided by the downward-bulging nose contour. However, it should be understood that the present application is not limited to this.

As shown in Fig. 7, the contour of the projection of the nose 5 on the horizontal plane B (e.g. the contour in the bottom view of the nose 5 shown in Fig. 7) comprises a left contour line S5 and a right contour line S6 which separately extend from the leading edge point P1 to the fuselage middle segment 9. The left contour line S5 and right contour line S6 are symmetric with respect to the symmetry plane A, and intersect with the fuselage middle segment 9 at a second left endpoint PL2 and a second right endpoint PR2 respectively (Fig. 10). The distance between the second left endpoint PL2 and the second right endpoint PR2 in a transverse direction 21 perpendicular to the symmetry plane A defines the width of the nose 5, the width of the nose 5 being W. W may be any suitable value. For example, W may be in the range of H to 1.5H. As another example, W may be less than H or greater than 1 ,5H.

The second left endpoint PL2 may not be higher than the first left endpoint PL1 in the vertical direction 15. The distance between the second left endpoint PL2 and the first left endpoint PL1 in the vertical direction 15 is h3, h3 being in the range of 0 (the second left endpoint PL2 and the first left endpoint PL1 coincide) to 0.4H. In some other embodiments, the second left endpoint PL2 may be higher than the first left endpoint PL1 in the vertical direction 15.

In some embodiments, as shown best in Figs. 1 and 4, the lower surface 53 of the nose 5 of the VTOL aircraft 1 may be provided with at least one window 40. The at least one window 40 may take up 60%, 70%, 80% or even 90% of the area of the lower surface 53. When the VTOL aircraft 1 is used to carry people for example, this can provide the pilot (if present) and passengers with a good field of view.

Referring to Figs. 1 - 7 and 9, the contours of the fuselage middle segment 9 and the tail 7 are also symmetric with respect to the symmetry plane A. In some embodiments, the contours of the fuselage middle segment 9 and the tail 7 are tadpole-shaped. Specifically, the fuselage 3 narrows sharply from the widest part of the fuselage middle segment 9 to the tail 7. The tadpole-shaped fuselage middle segment 9 and tail 7 can effectively support a laminar boundary layer, and reduce the wetted area of the aircraft. However, it should be understood that the contours of the fuselage middle segment 9 and the tail 7 of the present application are not limited to this. For example, the contours of the fuselage middle segment 9 and the tail 7 may also be truncated-cone-shaped. In this case, the contour of the tail 7 is approximately a truncated cone or a trapezoidal prism.

Referring to Figs. 6 and 7, the pair of front wings 11 and the pair of rear wings 13 have an X- shaped layout, with the front wings swept forward and the rear wings swept rearward. Such an X- shaped layout can further increase the distance between the front wing 11 and the rear wing 13, and can thus provide the VTOL aircraft 1 with a larger range of adjustment of the centre of gravity.

In some embodiments, a front wing area of the pair of front wings 11 is smaller than a rear wing area of the pair of rear wings 13. Making the front wing area smaller than the rear wing area is conducive to shifting the aerodynamic centre rearward. Preferably, the front wing area is 50% - 80% of the rear wing area. More preferably, the front wing area is 60% - 70% of the rear wing area. In some embodiments, the front wing area of the front wings is 8 - 10 square metres.

In some embodiments, neither a forward sweep angle of a leading edge of the front wing 11 nora rearward sweep angle of a leading edge of the rearwing 13 exceeds 25°. As used in the present application, the forward sweep angle and rearward sweep angle are the angle between the projection of the leading edge or a trailing edge of the wing on the horizontal plane B and the transverse direction 21 perpendicular to the symmetry plane A. Preferably, the forward sweep angle of the leading edge of the front wing 11 is 10°, and the rearward sweep angle of the leading edge of the rear wing 13 is 15°.

Continuing to refer to Figs. 6 and 7, each front wing 11 comprises a front wing tip 11 a, a front wing root 11 b, and a front wing body 11 c extending between the front wing tip 11 a and the front wing root 11 b; and each rear wing 13 comprises a rear wing tip 13a, a rear wing root 13b, and a rear wing body 13c extending between the rear wing tip 13a and the rear wing root 13b. In some embodiments, each front wing 11 in the pair of front wings 11 comprises a front wing tip 11 a. A leading edge of the front wing tip 11 a is further forward than the leading edge point P1 in the front-rear direction 19 parallel to the symmetry plane A and parallel to the horizontal plane B.

In some embodiments, a vertical tail 20 is arranged at the rear wing tip 13a of the rear wing 13. The vertical tail 20 comprises a fixed vertical stabilizer (not marked), and a rudder (not marked) which can be operated to control the heading. In one of these embodiments, the vertical tail 20 comprises an upper segment 20a extending beyond the rear wing 13 in the vertical direction 15, and a lower segment 20b which is opposite the upper segment 20a and extends beyond the rear wing 13 in the vertical direction 15. For example, the rudder may be disposed on the upper segment 20a. As another example, the rudder may be disposed on the lower segment 20b. As a further example, the rudder may be split into two parts, disposed on the upper segment 20a and the lower segment 20b respectively.

In some embodiments, the wingspan of the pair of front wings 11 is shorter than the wingspan of the pair of rear wings 13. The VTOL aircraft 1 may further comprise a pair of elongated connecting rods 23 arranged symmetrically with respect to the symmetry plane A. Each elongated connecting rod 23 extends substantially parallel to the symmetry plane A, being connected to one corresponding front wing 11 in the pair of front wings 11 at the front wing tip 11a of the corresponding front wing 11 , and connected to one corresponding rear wing 13, corresponding to the corresponding front wing 11 , in the pair of rear wings 13 at the rear wing body 13c of the corresponding rear wing 13. The vertical propulsion apparatus comprises multiple rotors 25 arranged on the connecting rods 23 symmetrically with respect to the symmetry plane A. The multiple rotors 25 are configured to supply vertical motive power to the VTOL aircraft 1 . Thus, the VTOL aircraft 1 is a hybrid VTOL aircraft comprising tandem wings and rotors. The rotors 25 may for example be driven electrically.

Such a configuration, combining connection by connecting rods with the shorter wingspan of the front wings compared to the wingspan of the rear wings, can make the spanwise external form of the wings continuous, which is beneficial for aerodynamic performance. Furthermore, such a configuration, combining connection by connecting rods with the shorter wingspan of the front wings compared to the wingspan of the rear wings, is conducive to shortening the distance of force transmission by the connecting rods 23 through the wings, reducing position and angle variation in the rotors 25 due to wing rigidity during vertical take-off and landing.

In some embodiments, the multiple rotors 25 comprise at least six rotors 25. In one of these embodiments, as shown best in Figs. 1 - 3 and 6, the multiple rotors 25 comprise eight rotors 25. In some embodiments, each connecting rod 23 comprises a middle segment 23a between the front wing tip 11a and the rear wing body 13c, a front segment 23b extending beyond the front wing tip 11 a from the middle segment 23a, and a rear segment 23c extending beyond the rear wing body 13c from the middle segment 23a. Rotors 25 are arranged on the middle segment 23a, the front segment 23b and the rear segment 23c. In one of these embodiments, as shown best in Figs. 1 - 3 and 6, two rotors 25 are arranged on the middle segment 23a of each connecting rod 23, and one rotor 25 is arranged on each of the front segment 23b and the rear segment 23c. Such an arrangement of rotors is especially beneficial for compensating for variation in the centre of gravity of the machine as a whole, and can provide the VTOL aircraft 1 with a larger range of adjustment of the centre of gravity.

In some embodiments, a rotation axis of each rotor 25 of the multiple rotors 25 is oriented perpendicular to the horizontal plane B. In some other embodiments, the rotation axis of each rotor 25 of the multiple rotors 25 may not be oriented perpendicular to the horizontal plane B. In some embodiments, the multiple rotors 25 are arranged at the side of the connecting rods 23 that faces away from the horizontal plane B.

As shown in Figs. 1 and 2, the rotor 25 comprises blades 25a and a coupling mechanism 25b that couples the blades 25a rotatably to the connecting rod 23. At least the blades 25a of the rotor 25 are positioned higher than the fuselage 3 in the vertical direction 15. Preferably, the range of rotation of the blades 25a of the rotor 25 does not overlap the front wing 11 , the rear wing 13 and the fuselage 3 in the vertical direction 15.

Although the VTOL aircraft 1 is described above as comprising the rotors 25 connected to the front wings 11 and rear wings 13 by means of the connecting rods 23, it should be understood that the VTOL aircraft 1 may also comprise rotors of other types, and the present application is not limited to this. For example, the VTOL aircraft 1 may comprise a single rotor coupled to the fuselage middle segment 9, to supply vertical motive power to the VTOL aircraft 1. As another example, the VTOL aircraft 1 may comprise tandem rotors arranged on two sides of the fuselage 3 by means of a suitable mechanism, to supply vertical motive power to the VTOL aircraft 1 .

The horizontal propulsion apparatus of the VTOL aircraft 1 may comprise a pair of horizontal propulsors, arranged symmetrically with respect to the symmetry plane A and configured to supply horizontal motive power to the VTOL aircraft 1 . For example, each horizontal propulsor is configured and oriented to accelerate the flow of air in the front-rear direction 19. Each horizontal propulsor is connected to one corresponding rear wing 13 in the pair of rear wings 13 close to the rear wing root 13b of the corresponding rear wing 13. Such an arrangement position of the horizontal propulsor is favourable for covering as large an area of the rear wing as possible, so as to improve the liftincreasing effect and thus improve aerodynamic efficiency. In the case of the tandem wing layout of the present application, it is more advantageous to provide greater lift at the rear wings 13. In addition, having the horizontal propulsors connected to the rear wings 13 is conducive to balancing the centre of gravity of the VTOL aircraft 1 as a whole. In some embodiments, the horizontal propulsor may be connected to one corresponding rear wing 13 at the trailing edge of the corresponding rear wing 13. This can further help to balance the centre of gravity of the VTOL aircraft 1 as a whole. In some other embodiments, the horizontal propulsor may also be connected to one corresponding rear wing 13 at the leading edge of the corresponding rear wing 13. Since the wake speed of the horizontal propulsor is generally higher than the inflow speed, such an arrangement position of the horizontal propulsor can further improve the lift-increasing effect and thus improve aerodynamic efficiency.

The pair of horizontal propulsors may be a pair of ducted fans (e.g. ducted fans 27 shown in Figs. 1 - 7) or a pair of screw propellers, and each of the pair of horizontal propulsors defines a rotation axis. In some embodiments, the rotation axis of the horizontal propulsor extends parallel to the symmetry plane A and parallel to the horizontal plane B. In some embodiments, the rotation axis of the horizontal propulsor is configured to be oriented in the front-rear direction 19, and is higher than the chord plane of the rear wing 13 in the vertical direction 15 perpendicular to the symmetry plane A. Such an arrangement of the horizontal propulsor can accelerate surface airflow on the rear wing, to further improve the lift-increasing effect and thus improve aerodynamic efficiency.

As shown in Figs. 1 - 7, the VTOL aircraft 1 further comprises a pair of landing gears 30. Each landing gear 30 comprises: a first support leg 31 , comprising a first end 31 a connected to the fuselage 3, and a second end 31 b opposite the first end 31a; a second support leg 33, comprising a third end 33a connected to the fuselage 3, and a fourth end 33b opposite the third end 33a; and a middle segment 35 connected between the second end 31 b and the fourth end 33b. The middle segment 35 comprises a first segment 35a connected to the second end 31 b, a second segment 35b connected to the fourth end 33b, and a bent segment 35c connecting the first segment 35a and the second segment 35b. The bent segment 35c is configured to be bent towards the fuselage, so that when the VTOL aircraft 1 is parked on a flat base surface, the first segment 35a and the second segment 35b contact the base surface, but the bent segment 35c does not contact the base surface. As used in the present application, the base surface is a surface where the VTOL aircraft 1 can be parked, such as an apron or a road surface.

The inventors have realized that the landing gear 30 of the VTOL aircraft 1 of the present application can provide significant advantages. Firstly, since only the first segment 35a and second segment 35b of the middle segment 35 contact the base surface when the VTOL aircraft 1 is parked on the flat base surface, stress is concentrated on the first segment 35a and second segment 35b. When the first segment 35a and second segment 35b suffer the impact of the base surface, the bent segment 35c can allow the first segment 35a and second segment 35b to deform slightly, in order to cushion the impact. Secondly, since the bent segment 35c is bent towards the fuselage 3, the bent segment 35c can form a boarding step; this can reduce the amount of manufacturing materials and lower the weight of the aircraft. For example, a tread surface may be formed on the bent segment 35c.

In some embodiments, as shown best in Fig. 7, the first segment 35a and second segment 35b are elongated, and the first segment 35a and second segment 35b are collinear. For example, the first segment 35a and second segment 35b are both oriented in the front-rear direction 19 parallel to the symmetry plane A and parallel to the horizontal plane B.

In some embodiments, as shown best in Fig. 11 , the contours of cross sections of the first support leg 31 that are cut by planes parallel to the horizontal plane B are all drop-shaped, to reduce resistance. Similarly, the contours of cross sections of the second support leg 33 that are cut by planes parallel to the horizontal plane B are all drop-shaped.

In some embodiments, the first support leg 31 is elongated, and forms an angle of 45° - 135° with the first segment 35a. In some embodiments, the second support leg 33 is elongated, and forms an angle of 45° - 135° with the second segment 35b.

In some embodiments, as shown best in Figs. 4 and 5, the first support leg 31 , second support leg 33, first segment 35a and second segment 35b are coplanar in a first plane (not shown). The first plane is inclined relative to the symmetry plane A. Preferably, the angle between the first plane and the symmetry plane A is between 0° and 50°, preferably 40°. In one of these embodiments, as shown in Figs. 4 and 5, the bent segment 35c is offset relative to the first plane in a direction away from the symmetry plane A. For example, the bent segment 35c may be parallel to the symmetry plane A. Compared with the case where the bent segment 35c is not offset relative to the first plane, such a configuration of the bent segment 35c can increase the distance between the bent segment 35c and the fuselage 3 in the transverse direction 21 , so that a suitable boarding step can be provided with a shorter dimension of outward extension of the landing gear. This can further reduce the amount of manufacturing materials, thereby lowering the weight of the aircraft.

In some embodiments, the bent segment 35c comprises a first part 351 connected to the first segment 35a, a second part 352 connected to the second segment 35b, and a third part 353 connecting the first part 351 and the second part 352. The third part 353 is parallel to the first segment 35a and the second segment 35b. The dimensions of the landing gear 30 may be configured to support the VTOL aircraft so as to elevate the front wings 11 , the rear wings 13 and the connecting rods 23, so that they are far away from the tops of the heads of the people boarding. For example, the dimensions of the landing gear 30 may be configured to elevate the front wings 1 1 , the rear wings 13 and the connecting rods 23 to not lower than 1 .8 metres.

It should be understood that the landing gear 30 may also be used for other types of aircraft, to provide the abovementioned advantages. That is to say, the present application also proposes a landing apparatus for an aircraft, the landing apparatus comprising the abovementioned pair of landing gears 30. The aircraft may for example be any suitable unmanned or manned aircraft, and have any suitable wing and motive power configurations. Similarly to as described above with reference to the VTOL aircraft 1 , the pair of landing gears 30 is configured to be arranged symmetrically with respect to a symmetry plane (e.g. the abovementioned symmetry plane A) of a fuselage of the aircraft. Each landing gear 30 comprises: a first support leg 31 , comprising a first end 31 a connected to the fuselage of the aircraft, and a second end 31 b opposite the first end 31 a; a second support leg 33, comprising a third end 33a connected to the fuselage of the aircraft, and a fourth end 33b opposite the third end 33a; and a middle segment 35 connected between the second end 31 b and the fourth end 33b. The middle segment 35 comprises a first segment 35a connected to the second end 31 b, a second segment 35b connected to the fourth end 33b, and a bent segment 35c connecting the first segment 35a and the second segment 35b. The bent segment 35c is configured to be bent towards the fuselage of the aircraft, so that when the aircraft is parked on a flat base surface, the first segment 35a and the second segment 35b contact the base surface, but the bent segment 35c does not contact the base surface. As used in the present application, the symmetry plane of the aircraft is an imaginary plane that divides the aircraft into two halves, which are substantially mirror images of each other. However, it should be understood that this does not mean that the aircraft is limited to being completely symmetric with respect to the symmetry plane.

In some embodiments, the first segment 35a and second segment 35b are elongated, and the first segment 35a and second segment 35b are collinear. In some embodiments, the first segment 35a and second segment 35b are both oriented in a direction (e.g. the abovementioned front-rear direction 19) parallel to the symmetry plane and parallel to a plane (e.g. the abovementioned horizontal plane B) perpendicular to the symmetry plane. In some embodiments, the contours of cross sections of the second support leg 33 that are cut by planes perpendicular to the symmetry plane are all drop-shaped, to reduce resistance. In some embodiments, the first support leg 31 is elongated, and forms an angle of 45° - 135° with the first segment 35a. In some embodiments, the second support leg 33 is elongated, and forms an angle of 45° - 135° with the second segment 35b. In some embodiments, the first support leg 31 , second support leg 33, first segment 35a and second segment 35b are coplanar in a first plane (not shown). The first plane is inclined relative to the symmetry plane. Preferably, the angle between the first plane and the symmetry plane is between 0° and 50°, preferably 40°. In one of these embodiments, the bent segment 35c is offset relative to the first plane in a direction away from the symmetry plane. For example, the bent segment 35c may be parallel to the symmetry plane. In some embodiments, the bent segment 35c comprises a first part 351 connected to the first segment 35a, a second part 352 connected to the second segment 35b, and a third part 353 connecting the first part 351 and the second part 352. The third part 353 is parallel to the first segment 35a and the second segment 35b.

It should be understood that the terms “first”, “second”, “third” and “fourth” are only used to distinguish one element or part from another element or part, but these elements and/or or parts should not be limited by such terms.

The present application has been described in detail above with reference to particular embodiments. Obviously, all of the embodiments described above and shown in the drawings should be understood to be exemplary, without limiting the present application. To a person skilled in the art, various changes or amendments that do not depart from the scope of the present application could be made to the present application without departing from the spirit thereof.

Claims

1. Vertical take-off and landing (VTOL) aircraft (1), characterized in that the VTOL aircraft (1) comprises: a fuselage (3), the fuselage (3) comprising a nose (5), a tail (7), and a fuselage middle segment (9) extending between the nose (5) and the tail (7), a nose contour of the nose (5) being configured to be symmetric with respect to a symmetry plane (A) of the VTOL aircraft (1), and expanding from a leading edge point (P1) of the nose (5) to the fuselage middle segment (9), the nose contour being divided into an upper surface (51) and a lower surface (53) by a horizontal plane (B) passing through the leading edge point (P1) and perpendicular to the symmetry plane (A), and the extent to which the lower surface (53) bulges downwards relative to the horizontal plane (B) as the nose contour expands from the leading edge point (P1) to the fuselage middle segment (9) being greater than the extent to which the upper surface (51) bulges upwards relative to the horizontal plane (B) as the nose contour expands from the leading edge point (P1) to the fuselage middle segment (9); and a pair of front wings (11 ) connected to the nose (5) and a pair of rear wings (13) connected to the tail (7), the pair of front wings (11) and the pair of rear wings (13) being arranged in a tandem wing layout, and the arrangement positions of the pair of front wings (11) on the nose (5) being close to the horizontal plane (B) in a vertical direction (15) perpendicular to the horizontal plane (B).

2. VTOL aircraft (1) according to Claim 1 , characterized in that: the horizontal plane (B) and the nose contour intersect at a left boundary line (S1) and a right boundary line (S2), the left boundary line (S1) and the fuselage middle segment (9) intersect at a first left endpoint (PL1), and the right boundary line (S2) and the fuselage middle segment (9) intersect at a first right endpoint (PR1); the symmetry plane (A) and the nose contour intersect at an upper contour line (S3) and a lower contour line (S4), the upper contour line (S3) and the fuselage middle segment (9) intersect at an upper endpoint (PU), and the lower contour line (S4) and the fuselage middle segment (9) intersect at a lower endpoint (PD); and the centroid (M) of the shape of a cross-section of the nose contour cut by the symmetry plane (A) is located at the side of the projection of the left boundary line (S1) on the symmetry plane (A) that is closer to the lower endpoint (PD), and located at the side of the perpendicular bisector (D) of said projection that is closer to the leading edge point (P1).

3. VTOL aircraft (1) according to Claim 2, characterized in that: the distance between the upper endpoint (PU) and the lower endpoint (PD) in the vertical direction (15) defines the height of the nose (5), the height of the nose (5) being H; the distance between the leading edge point (P1) and the upper endpoint (PU) in the vertical direction (15) is hi , hi being in the range of 0 to 0.3H; and the distance between the leading edge point (P1) and the lower endpoint (PD) in the vertical direction (15) is h2, h2 being in the range of 0.7H to H.

4. VTOL aircraft (1) according to Claim 3, characterized in that: hi is in the range of 0.1 H to 0.2H, and h2 is in the range of 0.8H to 0.9H.

5. VTOL aircraft (1) according to Claim 3, characterized in that: the upper contour line (S3) is an upward-sloping curved line of gradually increasing height in the direction from the leading edge point (P1) to the upper endpoint (PU); and the lower contour line (S4) is a downward-sloping curved line of gradually decreasing height in the direction from the leading edge point (P1) to the lower endpoint (PD).

6. VTOL aircraft (1) according to Claim 5, characterized in that: the upper surface (51) and the lower surface (53) are both continuous curved surfaces which expand from the leading edge point (P1) of the nose (5) to the fuselage middle segment (9).

7. VTOL aircraft (1) according to any one of Claims 2 - 6, characterized in that: the upper contour line (S3) and the lower contour line (S4) define boundaries of the shape of the projection of the nose contour on the symmetry plane (A).

8. VTOL aircraft (1) according to any one of Claims 3 - 6, characterized in that: the arrangement position of the front wing (11) on the nose (5) is closer to the upper endpoint (PU) than the lower endpoint (PD) in the vertical direction (15).

9. VTOL aircraft (1) according to Claim 8, characterized in that: the distance in the vertical direction (15) between the upper endpoint (PU) and the arrangement position of the front wing (11) on the nose (5) is in the range of 0 to 0.3H.

10. VTOL aircraft (1) according to any one of Claims 2 - 6 and 9, characterized in that: the arrangement position of the front wing (11) on the nose (5) is higher in the vertical direction (15) than the arrangement position of the rear wing (13) on the tail (7).

11 . VTOL aircraft (1) according to any one of Claims 3 - 6 and 9, characterized in that: the arrangement position of the front wing (11 ) on the nose (5) is closer to the leading edge point (P1) than the first left endpoint (PL1) in a front-rear direction (19) parallel to the symmetry plane (A) and parallel to the horizontal plane (B).

12. VTOL aircraft (1) according to Claim 11 , characterized in that: the distance in the front-rear direction (19) between the leading edge point (P1) and the first left endpoint (PL1) defines the length of the nose (5), the length of the nose (5) being L, L being in the range of H to 1 ,5H; and the distance in the front-rear direction (19) between the arrangement position and the leading edge point (P1) is in the range of 0 to 0.3L.

13. VTOL aircraft (1) according to any one of Claims 3 - 6, 9 and 12, characterized in that: the contour of the projection of the nose (5) on the horizontal plane (B) comprises a left contour line (S5) and a right contour line (S6) which separately extend from the leading edge point (P1) to the fuselage middle segment (9), the left contour line (S5) and the right contour line (S6) being symmetric with respect to the symmetry plane (A), and intersecting with the fuselage middle segment (9) at a second left endpoint (PL2) and a second right endpoint (PR2) respectively; and the second left endpoint (PL2) is not higher than the first left endpoint (PL1) in the vertical direction, and the distance between the second left endpoint (PL2) and the first left endpoint (PL1) in the vertical direction (15) is h3, h3 being in the range of 0 to 0.4H.

14. VTOL aircraft (1) according to Claim 13, characterized in that: the distance between the second left endpoint (PL2) and the second right endpoint (PR2) in a transverse direction perpendicular to the symmetry plane (A) defines the width of the nose (5), the width of the nose (5) being W, W being in the range of H to 1 ,5H.

15. VTOL aircraft (1) according to Claim 1 , characterized in that: the contours of the fuselage middle segment (9) and the tail (7) are tadpole-shaped or truncated- cone-shaped.

16. VTOL aircraft (1) according to Claim 1 , characterized in that: the pair of front wings (11) and the pair of rear wings (13) have an X-shaped layout, with the front wings swept forward and the rear wings swept rearward; and a front wing area of the pair of front wings (11 ) is smaller than a rear wing area of the pair of rear wings (13).

17. VTOL aircraft (1) according to Claim 16, characterized in that: the front wing area is 50% - 80% of the rear wing area; and/or neither a forward sweep angle of a leading edge of the front wing (11) nor a rearward sweep angle of a leading edge of the rear wing (13) exceeds 25°.

18. VTOL aircraft (1) according to Claim 16 or 17, characterized in that: each front wing (11) in the pair of front wings (11) comprises a front wing tip (11 a), a leading edge of the front wing tip (11a) being further forward than the leading edge point (P1) in a front-rear direction (19) parallel to the symmetry plane (A) and parallel to the horizontal plane (B).

19. VTOL aircraft (1) according to any one of Claims 1 - 6, 9, 12 and 14 - 17, characterized in that: the wingspan of the pair of front wings (11) is shorter than the wingspan of the pair of rear wings (13); each front wing (11) in the pair of front wings (11) comprises a front wing tip (11 a), a front wing root (11 b), and a front wing body (11 c) extending between the front wing tip (11 a) and the front wing root (11 b); each rear wing (13) in the pair of rear wings (13) comprises a rear wing tip (13a), a rear wing root (13b), and a rear wing body (13c) extending between the rear wing tip (13a) and the rear wing root (13b); the VTOL aircraft (1) further comprises a pair of elongated connecting rods (23) arranged symmetrically with respect to the symmetry plane (A), each elongated connecting rod (23) in the pair of elongated connecting rods (23) extending substantially parallel to the symmetry plane (A), being connected to one corresponding front wing (11) in the pair of front wings (11) at the front wing tip (11 a) of the corresponding front wing (11), and connected to one corresponding rear wing (13), corresponding to the corresponding front wing (11), in the pair of rear wings (13) at the rear wing body (13c) of the corresponding rear wing (13); and the VTOL aircraft (1) comprises multiple rotors (25), the multiple rotors (25) being arranged on the connecting rods (23) symmetrically with respect to the symmetry plane (A), and configured to supply vertical motive power to the VTOL aircraft (1).

20. VTOL aircraft (1) according to Claim 19, characterized in that: the multiple rotors (25) comprise at least six rotors (25); and/or the connecting rod (23) comprises a middle segment (23a) between the front wing tip (11 a) and the rear wing body (13c), a front segment (23b) extending beyond the front wing tip (11 a) from the middle segment (23a), and a rear segment (23c) extending beyond the rear wing body (13c) from the middle segment (23a), with rotors (25) arranged on the middle segment (23a), the front segment (23b) and the rear segment (23c).

21. VTOL aircraft (1) according to Claim 19, characterized in that: a rotation axis of each rotor (25) of the multiple rotors (25) is oriented perpendicular to the horizontal plane (B); and/or the multiple rotors (25) are arranged at the side of the connecting rods (23) that faces away from the horizontal plane (B).

22. VTOL aircraft (1) according to Claim 20 or 21 , characterized in that: the rotor (25) comprises blades (25a) and a coupling mechanism (25b) that couples the blades (25a) rotatably to the connecting rod (23); at least the blades (25a) of the rotor (25) are positioned higher than the fuselage (3) in the vertical direction (15).

23. VTOL aircraft (1) according to any one of Claims 1 - 6, 9, 12, 14 - 17, 20 and 21 , characterized in that: each rear wing (13) in the pair of rear wings (13) comprises a rear wing tip (13a), a vertical tail (20) being arranged at the rear wing tip (13a); the vertical tail (20) comprises a fixed vertical stabilizer, and a rudder which is operable to control the heading.

24. VTOL aircraft (1) according to any one of Claims 1 - 6, 9, 12, 14 - 17, 20 and 21 , characterized in that: the VTOL aircraft (1) comprises a pair of horizontal propulsors, arranged symmetrically with respect to the symmetry plane (A) and configured to supply horizontal motive power to the VTOL aircraft (1), each horizontal propulsor in the pair of horizontal propulsors being connected to one corresponding rear wing (13) in the pair of rear wings (13) at a leading edge or trailing edge of the corresponding rear wing (13), close to the rear wing root (13b) of the corresponding rear wing (13), and the pair of horizontal propulsors being a pair of ducted fans (27) or a pair of screw propellers.

25. VTOL aircraft (1) according to any one of Claims 1 - 7, 9, 11 , 13 - 17, 20 and 21 , characterized in that the VTOL aircraft (1) further comprises: a pair of landing gears (30) arranged symmetrically with respect to the symmetry plane (A), each landing gear (30) in the pair of landing gears (30) comprising: a first support leg (31), the first support leg (31) comprising a first end (31 a) connected to the fuselage (3), and a second end (31 b) opposite the first end (31 a); a second support leg (33), the second support leg (33) comprising a third end (33a) connected to the fuselage (3), and a fourth end (33b) opposite the third end (33a); and a middle segment (35) connected between the second end (31 b) and the fourth end (33b); the middle segment (35) comprises a first segment (35a) connected to the second end (31 b), a second segment (35b) connected to the fourth end (33b), and a bent segment (35c) connecting the first segment (35a) and the second segment (35b); the bent segment (35c) is configured to be bent towards the fuselage (3), so that when the VTOL aircraft (1) is parked on a flat base surface, the first segment (35a) and the second segment (35b) contact the base surface, but the bent segment (35c) does not contact the base surface.

26. VTOL aircraft (1) according to Claim 25, characterized in that: the first segment (35a) and the second segment (35b) are elongated, and the first segment (35a) and the second segment (35b) are collinear.

27. VTOL aircraft (1) according to Claim 25 or 26, characterized in that: the first segment (35a) and the second segment (35b) are both oriented in a front-rear direction (19) parallel to the symmetry plane (A) and parallel to the horizontal plane (B).

28. VTOL aircraft (1) according to Claim 25 or 26, characterized in that: the contours of cross sections of the first support leg (31) that are cut by planes parallel to the horizontal plane (B) are all drop-shaped, to reduce resistance; and/or the contours of cross sections of the second support leg (33) that are cut by planes parallel to the horizontal plane (B) are all drop-shaped, to reduce resistance.

29. VTOL aircraft (1) according to Claim 25 or 26, characterized in that: the first support leg (31) is elongated, and forms an angle of 45° - 135° with the first segment (35a); and/or the second support leg (33) is elongated, and forms an angle of 45° - 135° with the second segment (35b).

30. VTOL aircraft (1) according to Claim 25 or 26, characterized in that: the first support leg (31), the second support leg (33), the first segment (35a) and the second segment (35b) are coplanar in a first plane, the first plane being inclined relative to the symmetry plane (A); and the bent segment (35c) is offset relative to the first plane in a direction away from the symmetry plane (A).

31. VTOL aircraft (1) according to Claim 30, characterized in that: the bent segment (35c) is parallel to the symmetry plane (A).

32. VTOL aircraft (1) according to Claim 26, characterized in that: the bent segment (35c) comprises a first part (351) connected to the first segment (35a), a second part (352) connected to the second segment (35b), and a third part (353) connecting the first part (351) and the second part (352), the third part (353) being parallel to the first segment (35a) and the second segment (35b).