Aircraft having at least one propeller and a rotating wing equipped with two rotors carried by two half-wings

Abstract

The present invention relates to an aircraft (1) comprising two half-wings (81, 82) extending on either side of a cell (10). The aircraft (1) comprises at least one propeller (51) arranged in the rear part (12) of the cell (10). The aircraft (1) comprises a rotary wing (20) provided with two counter-rotating and synchronized rotors (30, 40) carried respectively by said half-wings (81, 82). The aircraft (1) comprises a power plant (50) comprising at least one engine (56, 57, 58, 59) as well as a mechanical interconnection system (60) connecting the power plant (50) on the one hand permanently to said rotors (30, 40) except in the event of failure and drive and on the other hand to said at least one propeller (51, 52). Abstract figure: figure 4

Description

Title of the invention: Aircraft having at least one propeller and a rotating wing equipped with two rotors carried by two half-wings

[0001] The present invention relates to an aircraft having at least one propeller and a rotary wing provided with two rotors carried by two half-wings.

[0002] A rotorcraft is an aircraft whose lift is provided totally or partially by at least one rotating wing. The rotating wing usually comprises at least one large diameter rotor.

[0003] The rotorcraft category includes several distinct types of aircraft.

[0004] First of all, the helicopter comprises at least one rotor. The rotor is driven by a suitable engine to provide both lift and propulsion for the aircraft.

[0005] A helicopter may be equipped with two rotors arranged one behind the other in a longitudinal direction extending between a nose and a tail of this helicopter. The first and second rotors are counter-rotating. The combined effect of the yaw torque of each rotor thus makes it possible to stabilize the rotorcraft relative to its yaw axis in straight flight, without wind. It should be noted that it is possible to synchronize the rotation speed of the rotors to ensure that the blades of these rotors do not collide. It is then said that the blades are meshing when they cross because the rotating blades of the first rotor have a constant azimuth phase shift relative to the rotating blades of the second rotor.

[0006] The autogyro is a rotorcraft whose rotor does not receive power, but provides lift by turning in autorotation under the effect of the forward speed of the rotorcraft.

[0007] Furthermore, the gyroplane is an intermediate rotorcraft between the helicopter and the autogyro whose rotor only provides lift. This rotor is normally driven by a power plant for the takeoff, hovering or vertical flight and landing phases, like the helicopter. A gyroplane also has an additional propulsion system different from the rotor assembly. In forward flight, the rotor still provides lift, but only in autorotation mode, that is to say without transmission of motive power to the rotor.

[0008] We also know the combined aircraft which takes off and lands like a helicopter, the combined aircraft which flies in cruise like an autogyro.

[0009] Furthermore, the convertible constitutes another particular formula of rotorcraft.

[0010] Another formula is called "hybrid helicopter" for convenience. This hybrid helicopter comprises a fuselage and a rotor. In addition, the hybrid helicopter is provided with at least one pusher propeller and two half-wings extending on either side of a central cell. The rotor and the propeller(s) are connected to at least one engine by a mechanical interconnection system.

[0011] With this configuration, this hybrid helicopter is remarkable in that the rotation speeds of the outputs of the engine, the rotor, the propeller(s) and the mechanical interconnection system are proportional to each other, the proportionality ratios being constant whatever the flight configuration of the hybrid helicopter under normal operating conditions of the integrated kinematic chain.

[0012] Consequently and advantageously, the rotor always remains driven in rotation by the engine(s), and always develops lift whatever the configuration of the hybrid helicopter, both in forward flight and in hovering flight. The hybrid helicopter is therefore neither an autogyro, nor a gyrodyne, nor a combined but another type of rotorcraft.

[0013] This hybrid helicopter allows missions to be carried out over extended periods of time in vertical flight, cruising flights at high speed, but also allows long distances to be covered, while allowing stationary flights and vertical takeoffs.

[0014] Document US 2017 / 034774 describes a hybrid helicopter having a central cell carrying two rotors located one behind the other in a longitudinal direction of this hybrid helicopter, two propellers and two half-wings.

[0015] Among the state of the art, the rotorcraft known under the name V22 comprises two tilting rotors.

[0016] The rotorcraft known as the S97 has two counter-rotating and coaxial rotors, as well as a propeller located at the rear of the rotorcraft.

[0017] The rotorcraft known as the "Cheyenne" has two half-wings, a main rotor, a tail rotor and a propeller.

[0018] The rotorcraft known as the "KA-22" has two half-wings extending from either side of a central cell. The rotorcraft has two power units at its two ends. Each power unit has an engine, a rotor and a propeller.

[0019] A concept of this type was presented at an air show in Tianjin in 2017.

[0020] Various drones are known. For example, document US 2016 / 0207625 describes a drone having four independent rotors and one propeller.

[0021] Artist's views, notably of an autogyro, are also visible on the internet at the address https: / / www.deviantart.com / cutangus / art.

[0022] The present invention therefore aims to propose an innovative rotary wing aircraft, which is neither an autogyro, nor a combined nor a gyrodyne.

[0023] The invention thus aims at an aircraft comprising:

[0024] - a cell extending longitudinally along an anteroposterior plane of a part back to a nose,

[0025] - a rotary wing equipped with two counter-rotating rotors,

[0026] - at least one propeller arranged in the rear part,

[0027] - a power plant comprising at least one motor,

[0028] - a mechanical interconnection system connecting the power plant on the one hand in permanence to said rotors except in the event of breakdown and drive and on the other hand to said at least one propeller,

[0029] - two half-wings extending on either side of the cell.

[0030] The two rotors are carried respectively by the half-wings and arranged respectively above said half-wings, the two rotors being synchronized or possibly meshing.

[0031] The expression "and arranged above said half-wings" means that each rotor comprises blades which move above at least one half-wing when the aircraft is resting on the ground in a normal position, namely when the landing gear(s) of the aircraft are resting on the ground.

[0032] The two half-wings can form a discontinuous or continuous wing.

[0033] Therefore, in level flight or even in all phases of flight and generally when the propeller(s) are driven in rotation, the rotors and the propeller(s) are set in rotation, by the mechanical system, at respective proportional speeds with constant ratios. The aircraft is therefore not an autogyro.

[0034] The two rotors are arranged on the half-wings respectively on either side of the anteroposterior plane and are synchronized, i.e. they rotate at identical speeds. This arrangement makes it possible to prevent the air flow passing through one rotor from disturbing the other rotor during forward flight.

[0035] According to a possible variant, the two rotors are also meshed. The rotor blades therefore cross each other with a constant azimuth phase shift. Since the rotors are meshed, the transverse size of the aircraft is limited.

[0036] Furthermore, the two rotors make it possible in particular to easily control the yaw movement of the aircraft. The arrangement of the two counter-rotating rotors on the half-wings also avoids the use of a specific anti-torque device consuming significant mechanical power. In particular, the propeller(s) may have the sole function of participating in the propulsion of the aircraft, and not of participating in the yaw control of this aircraft.

[0037] Furthermore, the rotors present a limited danger, due to their arrangement above the half-wings, for passengers wishing to board or disembark the aircraft.

[0038] In forward flight, the rotors are always driven by the power plant, in except in cases of failure or simulation of failure cases as part of a flight training mission. However, in fast forward flight, these rotors essentially participate in the lift of the aircraft in addition to the half-wings, propulsion being essentially provided by the propeller(s).

[0039] At high speed, the rotation speed of the rotors can be adapted so as not to exceed a speed threshold at the tip of the advancing blade of the two rotors. The resulting drop in lift is compensated by the half-wings.

[0040] The aforementioned characteristics make it possible to obtain in synergy an aircraft having the maneuverability of a conventional helicopter in hovering flight and at low speed and having the possibility of reaching high air speeds thanks to the propeller(s).

[0041] This combination makes it possible to obtain an aircraft with a long range and high forward speed, presenting an optimized level of safety on the ground.

[0042] The aircraft may have one or more of the following characteristics, taken alone or in combination.

[0043] For example, the propeller(s) may be faired to improve the safety of people on the ground.

[0044] According to another possibility compatible with the previous one, the mechanical system can comprise an inhibitor for disconnecting said at least one propeller from said power plant.

[0045] The inhibitor may comprise a clutch or an equivalent for example.

[0046] The propeller(s) are useful for achieving high forward speeds. At low speed, in hovering flight, the propeller(s) may be stopped. For example, approach maneuvers, takeoff maneuvers may be performed without rotating the propeller(s) with the powerplant. For example, in hovering flight, the inhibitor may inhibit the operation of the propeller(s), the rotors being sufficient for yaw control of the aircraft.

[0047] In addition, the inhibitor can inhibit the operation of the propeller(s) on the ground. This results in significant advantages. The noise pollution generated on the ground by the aircraft is thus minimized, with no propeller generating harmful noise on the ground. In addition, no propeller represents a danger to people operating near the aircraft, for example when carrying out a loading / unloading operation on the aircraft. This advantage is maximized by the arrangement of the propeller(s) in the rear part of the aircraft.

[0048] According to another possibility compatible with the previous ones, the half-wings can constitute a low wing or even an intermediate wing.

[0049] Alternatively, the half-wings can form a high wing.

[0050] The rotors being carried by the half-wings, this characteristic makes it possible to optimize the distance between the rotors and the cell or the ground to maximize the safety of individuals. operating near the aircraft, particularly on a platform.

[0051] In particular for this purpose and according to another possibility compatible with the previous ones, each half-wing can have a positive dihedral.

[0052] The rotors can then be relatively close to the half-wings, which optimizes the mechanical system, while remaining far from the cell and the ground.

[0053] Alternatively, a zero or even negative dihedral is possible. In this case, the rotors can be arranged well above the half-wings.

[0054] According to another possibility compatible with the previous ones, the mechanical system can comprise a lateral power transmission box per rotor, each lateral transmission box being carried by a half-wing.

[0055] Each lateral power transmission box is for example located at a free end zone of a half-wing.

[0056] Each side power transmission box can be positioned in a nacelle carried by a half-wing.

[0057] According to another possibility compatible with the previous ones, the mechanical system can comprise a main power transmission box connected to said at least one motor as well as to each rotor and to said at least one propeller.

[0058] For example, the main power transmission box is connected by two lateral mechanical links to two lateral power transmission boxes and by a rear mechanical link to a rear power transmission box of each propeller.

[0059] According to another possibility compatible with the previous ones, said power plant may comprise at least one engine located in said cell.

[0060] The engine(s) are optionally placed above a cabin. The cell may include protective covers protecting the engine(s) and reducing aerodynamic drag.

[0061] Where appropriate, the motor(s) may be connected by respective “motor” links to a main power transmission box.

[0062] According to another possibility compatible with the previous ones, said power plant may comprise at least two motors carried respectively by said half-wings.

[0063] The engines may be arranged in nacelles, for example at the wingtip. The engines may each be connected to a lateral power transmission box, this lateral power transmission box opening onto a rotor and a main power transmission box also connected to the propeller(s).

[0064] According to another possibility compatible with the previous ones, in the presence of two rotors which cross, and therefore mesh, the two rotors can cross in an overlap zone located above said cell.

[0065] The aircraft's size is thus transversely optimized.

[0066] According to another possibility compatible with the previous ones, the rear part of the aircraft may comprise a stabilizer assembly carrying said at least one propeller.

[0067] A stabilizer assembly may comprise at least one elevator tail and / or at least one stabilizer as well as tail or stabilizer flaps to provide static return in incidence and control of skidding in turns.

[0068] The stabilizer assembly is, for example, carried by a tail boom of the cell and carries one or more propellers.

[0069] According to another possibility compatible with the previous ones, the aircraft may comprise a said propeller arranged in the anteroposterior plane.

[0070] For example, the propeller is located at the end of the stabilizer assembly, behind the tail or tails and any stabilizers with respect to a direction of advance of the aircraft.

[0071] In a complementary or alternative manner, the aircraft may comprise two propellers arranged on either side of the anteroposterior plane.

[0072] The use of two propellers, instead of one propeller, makes it possible to achieve higher cruising speeds and / or to obtain the desired thrust with a lower propeller rotation speed, which reduces the acoustic footprint of the aircraft.

[0073] For example, a stabilizer assembly has a Y shape having a central branch and two lateral branches, said two propellers being carried respectively by said two lateral branches, and for example at the ends of the lateral branches. In this case, the possible rear mechanical connection may comprise an intermediate power transmission box connected to rear power transmission boxes of the propellers.

[0074] Each propeller may be arranged at the leading edge or the trailing edge of the corresponding side branch. An arrangement at the leading edge tends to reduce the sound intensity of the generated noise.

[0075] According to another possibility compatible with the previous ones, each half-wing can comprise at least one aircraft control device, such as a rudder and / or flap for example. It is possible to use these control devices to control the pitch or roll angle of the aircraft at high speed, the main rotors then participating only in the lift of the aircraft. The control devices also make it possible to control the distribution of lift between the half-wings and the rotary wing, and to reduce the interactions between this rotary wing and the half-wings.

[0076] According to another possibility compatible with the previous ones, the aircraft can comprise a collective control system modifying a pitch of the rotor blades in the same way, a cyclic pitch control system cyclically modifying the pitch of the rotor blades in the same way, a cyclic roll control system cyclically modifying the pitch of the rotor blades in the same way, a system of cyclic yaw control cyclically modifying the pitch of the rotor blades differently between the two rotors, a collective control device modifying a pitch of the blades of said at least one propeller in the same manner.

[0077] At low speed, lift control is achieved using the collective control system by collectively varying the pitch of the rotor blades identically. Pitch and roll control is achieved using the pitch and roll cyclic control systems. Yaw control is achieved by a differential nose-down or nose-up cyclic pitch applied to both rotors by the yaw cyclic control system.

[0078] For example, each rotor has a standard set of swashplates controlled to control the lift, pitch and roll of the aircraft.

[0079] To increase the forward speed of the rotorcraft, the pitch of the blades of the propeller(s) is modified and / or the discs described by the rotor blades are inclined forwards.

[0080] At high forward speed, lift is provided by both rotors and the half-wings. The pitch movement can be balanced at constant incidence. A tail flap can optimize the pitch balance. Yaw movement is controlled in the same way as at low speed or even with the aid of a rudder flap.

[0081] The invention and its advantages will appear in more detail in the context of the description which follows with examples given for illustrative purposes with reference to the appended figures which represent:

[0082] [Fig-1] [Fig.l], a top view of a single-propeller aircraft,

[0083] [Fig.2] [Fig.2], a side view of the aircraft of [Fig.l],

[0084] [Fig.3] [Fig.3], a front view of the aircraft of [Fig.l],

[0085] [Fig.4] [Fig.4] a top view of an aircraft according to the invention in which the cell is made transparent to present the power plant and the mechanical interconnection system,

[0086] [Fig.5] [Fig.5], a top view of a twin-propeller aircraft,

[0087] [Fig.6] [Fig.6] a front view of a stabilization assembly carrying two propellers at the trailing edge,

[0088] [Fig.7] [Fig.7] a side view of a stabilization assembly carrying two propellers at the trailing edge made partially transparent,

[0089] [Fig.8] [Fig.8] a front view of a stabilization assembly carrying two propellers on the leading edge,

[0090] [Fig.9] [Fig.9] a side view of a stabilization assembly carrying two propellers on the leading edge made partially transparent, and

[0091] [Fig. 10] [Fig. 10], a diagram illustrating a system for piloting an aircraft according to the invention.

[0092] Elements present in several distinct figures are assigned a single reference.

[0093] Figures 1 to 9 illustrate embodiments of an aircraft 1 according to the invention.

[0094] Whatever the embodiment and with reference to [Fig.l], an aircraft 1 comprises a cell 10. The cell 10 extends longitudinally along an anteroposterior plane PI from a rear part 12 towards a nose 11. The anteroposterior plane PI may be a plane of symmetry of the cell 10 or even of the aircraft 1. Optionally, the cell 10 comprises successively, starting from the nose 11, a front part 13 which comprises for example a cabin 15, an intermediate part 14 which comprises for example at least one tail boom and the rear part 12.

[0095] The aircraft 1 is further equipped with a fixed wing carried by the cell 10. This fixed wing comprises two half-wings 81, 82 which extend transversely on either side of the cell 10. The two half-wings 81, 82 can jointly form a continuous or discontinuous wing.

[0096] Each half-wing 81, 82 may comprise flaps and / or control surfaces for example.

[0097] Furthermore, the rear part 12 may comprise a stabilizer assembly 85. This stabilizer assembly 85 may comprise an end section 86 of the tail boom 14, if any. To stabilize the aircraft 1, the stabilizer assembly 85 may be provided with at least one horizontal or inclined tail member 87 participating at least in the pitch stabilization of the aircraft 1 and / or at least one drift member 88 participating at least in the yaw stabilization of the aircraft 1. A tail member 87 and / or a drift member 88 may be made movable via at least one actuator. Alternatively, a portion of a tail member 87 and / or a portion of a drift member 88 may be made movable via at least one actuator.

[0098] According to the example of [Fig.l], the stabilizer assembly 85 comprises an end section 86 carrying two drift members 88 located on either side of the end section 86 in elevation. In addition, the end section 86 carries two tail members 87 located on either side of the end section 86 transversely.

[0099] According to another aspect, the aircraft may comprise at least one landing gear, with skids or wheels, cooperating with the cell, a half-wing or even the rear part.

[0100] Furthermore, the aircraft 1 comprises at least one propeller provided with blades 53. The propeller(s) are arranged in the rear part 12, and possibly carried by a stabilizer assembly 85. Figures 1 to 4 illustrate an aircraft with one propeller 51 while Figures 5 to 9 illustrate the arrangement of two propellers 51, 52.

[0101] Furthermore and whatever the embodiment, the aircraft 1 comprises a rotary wing 20. The rotary wing 20 is equipped with two counter-rotating rotors 30, 40. One rotor 30 rotates around its axis of rotation in a direction F1 and the other rotor 40 rotates around its axis of rotation in a direction F2 opposite to the first direction F1. One of the rotors rotates in a clockwise direction and the other rotor in a counterclockwise direction.

[0102] The rotors 30, 40 are carried respectively by the half-wings 81, 82. The rotors can be spaced apart from each other transversely. Alternatively, the blades 31 of a rotor 30 can cross the blades 41 of the other rotor 40 in an overlap zone 100. This overlap zone 100 is for example arranged above the cell 10, in a direction going from a landing gear towards the rotors, and for example at least partially or even totally above the front part 13.

[0103] With reference to [Fig.2] and to move the blades 31, 41 of the rotors 30, 40 away from the ground, the two half-wings 81, 82 may be parts of a high wing, namely one which extends at the level of an upper part of the cell 10.

[0104] With reference to [Fig.3], the two half-wings 81, 82 may have a positive dihedral.

[0105] With reference to [Fig.4] and whatever the embodiment, to set the rotors 30, 40 and the propeller(s) 51, 52 in motion, the aircraft 1 comprises a power plant 50 comprising at least one engine 56, 57, 58, 59 and a mechanical interconnection system 60.

[0106] For example, the power plant 50 comprises at least one engine, or even at least two engines 56, 57 arranged in the cell 10, for example in the front part 13 or even above the cabin 15. The cell 10 may comprise aerodynamic fairings around the engine(s) 56, 57.

[0107] In a complementary or alternative manner, the power plant 50 may comprise at least two engines 58, 59 carried respectively by the half-wings 81, 82, for example at the level of free end zones 83, 84 of the half-wings 81, 82. Each free end zone 83, 84 is a section of a wing 81, 82 comprising the tip of the half-wing and sections of the half-wing closer to the tip of the half-wing than to the cell 10. For example, the two half-wings 81, 82 carry two nacelles 551, 552 respectively accommodating two engines 58, 59.

[0108] The mechanical system 60 mechanically and kinematically connects the rotors 30, 40, the motor(s) 56, 57, 58, 59 and the propeller(s) 51, 52. More specifically, the mechanical system 60 mechanically and kinematically connects the motor(s) 56, 57, 58, 59 permanently to the rotors 30, 40, except in the event of a breakdown or drive failure. Therefore, the motor(s) 56, 57, 58, 59 comprise power shafts that can rotate at a speed proportional to a rotational speed of the rotors 30, 40, the rotors 30, 40 being synchronized and moving at the same rotational speed.

[0109] In addition, the mechanical system 60 mechanically and kinematically links the or the motors 56, 57, 58, 59, to the propeller(s) 51, 52 permanently or at the request of a human or automatic pilot in the presence of an inhibitor 70. When the propeller(s) 51, 52 are set in motion, the propeller(s) 51, 52 have a rotation speed proportional to the rotation speed of the power shaft(s).

[0110] The mechanical system 60 may comprise a main power transmission box 61 arranged in the cell 10. The main power transmission box 61 may be a central element connected by shafts, directly or via other power transmission boxes, to the motor(s) 56, 57, 58, 59, to the rotors 30, 40 and to the propeller(s) 51, 52.

[0111] For example, the mechanical system 60 may comprise a lateral power transmission box 62, 63 per rotor 30, 40. Each lateral transmission box 62, 63 may comprise a rotor mast integral in rotation with the associated rotor 30, 40. The two lateral transmission boxes 62, 63 are then carried respectively by the two half-wings 81, 82. Optionally, the two lateral transmission boxes 62, 63 are located in the end zones 83, 84 of the half-wings 81, 82.

[0112] Where appropriate, the main power transmission box 61 may be connected by two lateral mechanical links 67 to two lateral power transmission boxes 62, 63 respectively. Each lateral mechanical link 67 may comprise at least one shaft, at least one connection member...

[0113] The main power transmission box 61 may be connected by a rear mechanical connection 69 to a rear power transmission box of each propeller 51, 52. The rear transmission box(es) 64, 65 may comprise a propeller mast integral in rotation with the associated propeller 51, 52. The rear mechanical connection 69 may comprise at least one shaft, at least one connecting member. The rear mechanical connection 69 may comprise, between two shafts, an inhibitor 70 capable of separating the propeller(s) 51, 52 from the engine(s) 56, 57, 58, 59. Such an inhibitor 70 may comprise a clutch, or an equivalent for example, possibly supplemented by a means for locking the rear mechanical connection 69 to prevent the clutch from slipping.

[0114] Therefore, at least one motor 56, 57 can be connected by a motor link to the main power transmission box 61 and / or at least one motor 58, 59 can be connected by a motor link to a side power transmission box 62, 63.

[0115] Independently of these aspects, according to the example of [Fig.4], the aircraft 1 comprises a single propeller 51 arranged in the anteroposterior plane PL. The propeller 51 is, for example, carried by the end section 86 of the tail boom 14. A rear transmission box 64 can be arranged in this end section 86.

[0116] According to [Fig.5], two helices 51, 52 are arranged on either side of the anteroplane posterior PI. The two propellers 51,52 are, for example, carried by the stabilizer assembly 85.

[0117] For example and as illustrated in [Fig.6], the stabilizer assembly 85 can then have a Y shape. Therefore, the stabilizer assembly 85 has a central branch 91 forming a drift member and two lateral branches 92, 93 having an acute or right angle with the anteroposterior plane PI. The central branch 91 and the lateral branches 92, 93 can be carried by an end section 86 of the tail boom. In this case, an intermediate transmission box 66 of the rear mechanical link 69 can be located in the end section 86 and can be connected by at least two shafts to two rear transmission boxes 64, 65.

[0118] According to figures 6 and 7, the propellers 51, 52 can be located at the trailing edge of the lateral branches 92, 93.

[0119] According to figures 8 and 9, the propellers 51, 52 can be located at the leading edge of the lateral branches 92, 93.

[0120] According to another aspect, [Fig. 10] illustrates a piloting system of the aircraft 1.

[0121] This piloting system may comprise a collective control system 96 collectively modifying a pitch of the blades 31, 41 of the rotors 30, 40 in the same manner for the blades 31, 41 of the two rotors 30, 40.

[0122] For example, each rotor 30, 40 comprises blades 31, 41 articulated to a hub 32, 42. In addition, the blades 31, 41 cooperate with a swashplate system for each rotor 30, 40. Such a swashplate system may comprise a plate 34, 44 articulated to servocontrols 36, 46 and a second plate 33, 43 connected to each blade 31, 41 of the corresponding rotor 30, 40 by pitch rods 35, 45.

[0123] Therefore, the collective control system 96 can control all the servocontrols in the same manner. For example, the collective control system 96 can comprise a collective control interface 961 controlling the servocontrols 36, 46 in the same manner via a mechanical or electromechanical architecture 962.

[0124] The piloting system may comprise a cyclic pitch control system 95 cyclically modifying the pitch of the blades 31, 41 of the rotors 30, 40 in the same way for the blades 31, 41 of the two rotors 30, 40. The cyclic pitch control system 95 may longitudinally tilt the rotor disks of the two rotors in the same way to pitch down or to pitch up. According to the example illustrated, the cyclic pitch control system 95 may comprise a cyclic pitch control interface 951 controlling the servocontrols 36, 46 in the same way via a mechanical or electromechanical architecture 952.

[0125] The piloting system may comprise a cyclic roll control system 97 cyclically modifying the pitch of the blades 31, 41 of the rotors 30, 40 of the same manner for the blades 31, 41 of the two rotors 30, 40. The roll cyclic control system 97 can transversely tilt the rotor disks of the two rotors in the same manner. According to the example illustrated, the roll cyclic control system 97 can comprise a roll cyclic control interface 971 controlling the servocontrols 36, 46 in the same manner via a mechanical or electromechanical architecture 972. The pitch cyclic control interface 951 and the roll cyclic control interface 971 can be formed by the same stick movable along two different axes for example.

[0126] The piloting system may comprise a cyclic yaw control system 98 cyclically modifying the pitch of the rotor blades differently between the two rotors 30, 40. According to the example illustrated, the cyclic yaw control system 98 may comprise a cyclic yaw control interface 981, a rudder bar for example, piloting the servocontrols 36, 46 via a mechanical or electromechanical architecture 982.

[0127] The control system may comprise a collective control device 99 collectively modifying a pitch of the blades 53 of the propeller(s) 51, 52 in the same manner for the blades 53 of the propeller(s) 51, 52. For example, the collective control device 99 may comprise a collective control interface 991 controlling one or more propeller actuators in the same manner via a mechanical or electromechanical architecture 992.

[0128] Naturally, the present invention is subject to numerous variations as to its implementation. Although several embodiments have been described, it is understood that it is not conceivable to exhaustively identify all possible modes. It is of course conceivable to replace a means described by an equivalent means without departing from the scope of the present invention.

Claims

Claims

1. Aircraft (1) comprising: - a cell (10) extending longitudinally along an anteroposterior plane (PI) from a rear part (12) to a nose (11), - a rotary wing (20) provided with two counter-rotating rotors (30, 40), - at least one propeller (51, 52) arranged in said rear part (12), - a power plant (50) comprising at least one engine (56, 57, 58, 59), - a mechanical interconnection system (60) connecting the power plant (50) on the one hand permanently to said rotors (30, 40) except in the event of failure and drive and on the other hand to said at least one propeller (51, 52), - two half-wings (81, 82) extending on either side of the cell (10), characterized in that that said two rotors (30, 40) are carried respectively by said half-wings (81, 82) and arranged respectively above said half-wings (81, 82), said two rotors (30, 40) being synchronized, said aircraft (1) comprising two said propellers (51,52) arranged on either side of the anteroposterior plane (PI), said rear part (1) comprising a stabilizing assembly (85), said stabilizing assembly (5) having a Y shape having a central branch (91) and two lateral branches (92, 93), said two helices (51, 52) being carried respectively by said two lateral branches (92, 93).,

2. Aircraft (1) according to claim 1, characterized in that said mechanical system (60) comprises an inhibitor (70) for disconnecting said at least one propeller (51, 52) from said power plant (50).

3. Aircraft according to any one of claims 1 to 2, characterized in that said half-wings (81, 82) form a high wing.

4. Aircraft according to any one of claims 1 to 3, characterized in that each half-wing (81, 82) has a positive dihedral.

5. Aircraft according to any one of claims 1 to 4, characterized in that said mechanical system (60) comprises a lateral power transmission box (62, 63) per rotor (30, 40), each lateral transmission box (62, 63) being carried by a half-wing (81, 82).

6. Aircraft according to claim 5, characterized in that each lateral power transmission box (62, 63) is located at a free end zone (83, 84) of a half-wing (81, 82).

7. Aircraft according to any one of claims 1 to 6, characterized in that the mechanical system (60) comprises a main power transmission box (61) connected to said at least one engine (56, 57, 58, 59) as well as to each rotor (30, 40) and to said at least one propeller (51, 52).

8. Aircraft according to any one of claims 1 to 7, characterized in that said power plant (50) comprises at least one engine (56, 57) located in said cell (10).

9. Aircraft according to any one of claims 1 to 7, characterized in that said power plant (50) comprises at least two engines (58, 59) carried respectively by said half-wings (81, 82).

10. Aircraft according to any one of claims 1 to 9, characterized in that said two rotors (30, 40) cross.

11. Aircraft according to claim 10, characterized in that said two rotors (30, 40) intersect in an overlapping zone (100) located above said cell (10).

12. Aircraft according to any one of claims 1 to 11, characterized in that said aircraft (1) comprises a collective control system (96) modifying a pitch of the blades (31, 41) of the rotors (30, 40) in the same manner, a cyclic pitch control system (95) cyclically modifying the pitch of the blades (31, 41) of the rotors (30, 40) in the same manner, a cyclic roll control system (97) cyclically modifying the pitch of the blades (31, 41) of the rotors (30, 40) in the same manner, a cyclic yaw control system (98) cyclically modifying the pitch of the blades of the rotors differently between the two rotors (30, 40), a collective control device (99) modifying a pitch of the blades (53) of said at least one propeller (51, 52) in the same way.

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