Twin-fuselage rotorcraft

Abstract

A rotorcraft (1) having: a lift rotor (5); a wing (10) extending from a first end (11) carrying a first propulsive propeller (21) to a second end (12) carrying a second propeller (22); landing gear (30); and a tail (40). The rotorcraft (1) is provided with two fuselages (51, 52) secured to said wing (10) between said first and second propulsive propellers (21, 22) in such a manner as to present an inter-fuselage space (60) having no propeller between said fuselages (51, 52), each fuselage (51, 52) including at least one undercarriage of said landing gear (30).

Claims

1. A rotorcraft comprising: a first fuselage having a first underside; a first landing gear undercarriage coupled to the underside of the first fuselage; a second fuselage spaced from the first fuselage, the second fuselage having a second underside; a second landing gear undercarriage coupled to the second underside of the second fuselage; a wing extending from a first end to a second end, the wing having an upper surface; a first propulsive propeller coupled with the wing; a second propulsive propeller coupled with the wing; and a vertical lift rotor coupled with the wing, wherein the first fuselage and the second fuselage are coupled with the wing between the first propulsive propeller and the second propulsive propeller to provide an inter-fuselage space, and the lift rotor is coupled to the upper surface of the wing between the first fuselage and the second fuselage and over the inter-fuselage space, wherein no propulsive propeller is coupled with the wing between the first and second propulsive propellers.

2. The rotorcraft of claim 1, wherein the first propulsive propeller is coupled with the wing proximate the first end and the second propulsive propeller is coupled with the wing proximate the second end.

3. The rotorcraft of claim 1, further comprising a tail boom coupled with the wing between the first fuselage and the second fuselage.

4. A rotorcraft comprising: a first fuselage having a first front portion, a first rear portion, a first central portion, a first cockpit and a first cabin; a first landing gear assembly coupled with the first fuselage; a second fuselage having a second front portion, a second rear portion, a second central portion, a second cockpit and a second cabin; a second landing gear assembly coupled with the second fuselage; a wing extending from a first end portion to a second end portion with a central portion therebetween the wing having an underside, the first central portion of the first fuselage being coupled to the underside of the wing at the central wing portion and the second central portion of the second fuselage being coupled to the underside of the wing at the central wing portion, the second fuselage being spaced from the first fuselage to define a gap therebetween below the central wing portion, wherein no propulsive propeller is disposed within the gap; a first propulsive propeller coupled with the first end portion of the wing; a second propulsive propeller coupled with the second end portion of the wing; and a vertical lift rotor coupled with the central portion of the wing and extending above the wing.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the following description of embodiments given by way of illustration and with reference to the accompanying figures, in which:

(2) FIGS. 1 and 2 show a first embodiment;

(3) FIGS. 3 and 4 show a second embodiment;

(4) FIG. 5 is a diagram for explaining a procedure for embarking passengers;

(5) FIG. 6 is a diagram showing the arrangement of winching systems;

(6) FIG. 7 is a diagram showing the arrangement of a hoist system; and

(7) FIG. 8 is a diagram showing cabins in the fuselages of a rotorcraft of the invention.

(8) Elements present in more than one of the figures are given the same references in each of them.

DETAILED DESCRIPTION OF THE INVENTION

(9) FIGS. 1 and 2 show a first embodiment of a rotorcraft 1, and FIGS. 3 and 4 show a second embodiment of a rotorcraft 1.

(10) With reference to FIG. 1, and independently of the embodiment, the rotorcraft 1 has a lift rotor 5 comprising a plurality of blades 8. This lift rotor may possibly contribute to propelling the rotorcraft 1.

(11) The rotorcraft 1 also has a fixed wing including a wing 10 extending spanwise from a first end 11 towards a second end 12, and passing through an anteroposterior plane of symmetry P1 of the rotorcraft. The wing may be continuous, or it may be discontinuous, presenting a plurality of segments.

(12) The lift rotor 5 is then carried by the wing 10. For example, the wing 10 carries a main gearbox 7 for driving a rotor mast 6. The rotor mast 6 then drives the lift rotor 5 in rotation about an axis of rotation.

(13) Furthermore, the rotor 1 has a first propulsive propeller 21 and a second propulsive propeller 22. The first propulsive propeller 21 is arranged at the first end 11 of the wing 10, with the second propulsive propeller 22 being arranged at the second end 12 of the wing 10.

(14) It should be observed that the term “end of the wing” is used to cover an end zone of a wing. The wing may thus include lift surfaces on both sides of a propeller in a variant that is not shown, or it may include a lift surface on one side only of a propeller as in the variant shown, in which each propeller is arranged at the tip of a wing.

(15) Furthermore, the rotorcraft 1 has two fuselages 51, 52 that are secured to the wing 10 between the first propulsive propeller 21 and the second propulsive propeller 22. The first fuselage 51 and the second fuselage 52 are spaced apart from each other by an inter-fuselage space 60. Consequently, the first fuselage 51 is arranged between the anteroposterior plane P1 and the first propulsive propeller 21, while the second fuselage 52 is arranged between the anteroposterior plane P1 and the second propulsive propeller 22.

(16) The lift rotor 5 is then secured to the wing 10 over the inter-fuselage space 60. Likewise, the rotor mast 6 for driving the lift rotor 5 in rotation is arranged in the anteroposterior plane of symmetry P1 of the wing 10 over the inter-fuselage space 60.

(17) The inter-fuselage space thus does not contain a rotary element, and in particular it does not receive a propulsive propeller.

(18) With reference to FIGS. 2 and 4, each fuselage 51, 52 has at least one door 70 facing the inter-fuselage space 60.

(19) In addition, each fuselage 51, 52 is fitted with at least one undercarriage of landing gear 30. For example, each fuselage 51, 52 has a front undercarriage 31 and a rear undercarriage 32, each comprising at least one wheel 33.

(20) The undercarriages are advantageously, but not necessarily, retractable into a respective compartment in the associated fuselage.

(21) With reference to FIG. 5, passengers can then embark in the aircraft by passing through the inter-fuselage space 60 along the arrows shown.

(22) With reference to FIG. 1, the inter-fuselage space 60 extends transversely away from an undercarriage of the first fuselage 51, referred to for convenience as the “left” undercarriage, to an undercarriage of the second fuselage 52, referred to for convenience as the “right” undercarriage, with “left” and “right” being relative to the sheets of the figures. The first transverse distance D1 is then maximized so as to optimize the stability of the aircraft, in particular in roll.

(23) Conversely, the second transverse distance D2 between the undercarriages of a fuselage and the adjacent propulsive propeller is minimized. This serves to optimize the amount of ground slope that is acceptable during landing.

(24) The angle of inclination a of a straight line passing via a low point of a propeller and a point of contact of the landing gear with the ground is maximized without increasing the height of the fuselages.

(25) For this purpose, each undercarriage may be offset along arrows F relative to the plane of symmetry P2, P3 of the associated fuselage in order to be located closer to a propeller.

(26) Furthermore, and with reference to FIGS. 2 and 4, the rotorcraft 1 includes a power plant for driving rotation of the lift rotor 5, of the first propulsive propeller 21, and of the second propulsive propeller 22.

(27) This power plant may then comprise at least one “lateral” engine 101, 102 carried by each fuselage, and/or at least one “central” engine 103 carried by the wing 10. The engines are connected together by a drive train for transmitting power to the lift rotor and to the propulsive propellers.

(28) In addition, the rotorcraft 1 has a tail 40. The tail may have vertical fins 41 for controlling the rotorcraft in yaw, and/or horizontal stabilizers 42 for controlling the rotorcraft in pitching. For example, two vertical fins are connected together by a horizontal stabilizer.

(29) On either side of the anteroposterior plane of symmetry P1, each fin may comprise fixed surfaces, or it may also include movable control surfaces such as flaps.

(30) In the first embodiment of FIG. 2, the rotorcraft 1 has a single tail beam 15 secured to the wing 10 in order to carry the tail 40. The single tail beam 15 may connect the wing 10 to a horizontal stabilizer 42.

(31) In the second embodiment of FIG. 4, the rotorcraft has two tail beams. Thus, each fuselage 51, 52 has a tail beam 16, 17 for carrying the tail 40.

(32) With reference to FIG. 6, at least one fuselage 51, 52 carries a winching system 80. Each winching system is arranged in the inter-fuselage space 60. A searchlight 85 may be carried by the wing, e.g. under the rotor mast.

(33) Each winching system 80 is advantageously carried under the wing 10 so as to be protected from the stream of air coming from the lift rotor.

(34) With reference to FIG. 7, the rotorcraft 1 is optionally fitted with a hoist system 90 in the inter-fuselage space 60. The hoist system 90 is then fastened to the wing 10 under the rotor mast 6, for example. By way of example, the hoist system 90 includes at least one hook 91, or indeed means for moving the hook.

(35) Furthermore, in the variant of FIG. 2, each fuselage is fitted with a buoyancy device 95, of conventional type.

(36) In addition, at its front end, each fuselage carries a thermal camera 96, such as a device known under the acronym FLIR.

(37) Under such circumstances, and with reference to FIG. 8, each fuselage may include a cockpit 53 for a pilot. Each pilot then has a thermal camera available.

(38) Furthermore, each fuselage shown receives a cabin 54 containing two rows of seats 55 without an aisle. The number of seats present in each fuselage does not require a member of the crew to be present in the cabin and therefore does not require an aisle to be present. This increases the amount of space available for each passenger.

(39) Furthermore, the fuselage may be of minimized height. All of the seats are directly accessible from the outside via side doors. There is therefore no need for a passenger to move about inside the fuselage.

(40) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.