A helicopter is described comprising a fuselage elongated along a first axis and extending between a nose and a tail boom; a tailplane with a pair of first aerodynamic surfaces elongated along a second axis; the first and second axis define a first plane; the helicopter comprises a pair of elements transversal to the first aerodynamic surfaces; and a pair of second aerodynamic surfaces generating respective second aerodynamic forces, connected to first elements, and facing and spaced from respective first aerodynamic surfaces; each second aerodynamic surface comprises one first root end connected to the respective said element, a second free end spaced from said tail boom, a first leading edge, a first trailing edge opposite to said first leading edge, a first chord at said first root end and a second chord at said second free end parallel to said first axis; the first and the second chord define a second plane tilted with respect to said first plane.

In an aspect, a vertical take-off and landing (VTOL) aircraft is disclosed. The VTOL aircraft includes at least a lift component affixed to the aft end of a boom, wherein the lift component is configured to generate lift. The VTOL includes a fuselage comprising a fore end and an aft end. Additionally, VTOL aircraft includes a tail affixed to the aft end of a fuselage. A tail includes a plurality of vertically projecting elements, wherein the plurality vertically projecting elements are affixed at the aft end of the boom and positioned outside of the wake from the at least a lift component.

This disclosure describes a tension torsion strap for part of rotor head of a rotary wing aircraft. The tension torsion strap includes, in a direction of a longitudinal axis, a first peripheral area with a connection eye, a central section, and a second peripheral area with a connection eye. The tension torsion strap may be of one-piece made of a multiplicity of joined layers. Improved production and installation is of the tension torsion strap may be achieved by that disclosed in this disclosure, resulting in, among other advantages, more simplified maintenance because the tension torsion strap has an overall asymmetric shape relatively to a transverse axis due to two unequally shaped peripheral areas which cannot be brought into alignment when folding around the transverse axis.

The present invention provides a changeable linear speed reduction clutch, which is formed by connecting a changeable linear speed double-layer planetary gear train and a brake, and is transmission machinery with functions of both a speed reducer and a clutch. A planetary carrier of the changeable linear speed double-layer planetary gear train is used as an input end, one central gear as an output end, the other central gear as a braking end, and the braking end is directly connected to the brake; and the changeable linear speed double-layer planetary gear train adopts one of two types of planetary gear trains. The brake at least has two states, that is, braking and non-braking states, wherein the braking state of the brake is equivalent to an engaged state of the clutch, and the non-braking state of the brake is equivalent to a disengaged state of the clutch. The method of setting the changeable linear speed double-layer planetary gear train, and the application method of the present invention are provided herein. Compared with a device in which a multi-stage speed reducer and a clutch are arranged independently, the changeable linear speed reduction clutch in the present invention is small and light and has a simple structure.

The present invention provides a changeable linear speed reduction clutch, which is formed by connecting a changeable linear speed double-layer planetary gear train and a brake, and is transmission machinery with functions of both a speed reducer and a clutch. A planetary carrier of the changeable linear speed double-layer planetary gear train is used as an input end, one central gear as an output end, the other central gear as a braking end, and the braking end is directly connected to the brake; and the changeable linear speed double-layer planetary gear train adopts one of two types of planetary gear trains. The brake at least has two states, that is, braking and non-braking states, wherein the braking state of the brake is equivalent to an engaged state of the clutch, and the non-braking state of the brake is equivalent to a disengaged state of the clutch. The method of setting the changeable linear speed double-layer planetary gear train, and the application method of the present invention are provided herein. Compared with a device in which a multi-stage speed reducer and a clutch are arranged independently, the changeable linear speed reduction clutch in the present invention is small and light and has a simple structure.

A rotary wing aircraft includes an airframe including an extending tail. The airframe includes a longitudinal axis that extends through the extending tail. The rotary wing aircraft also includes a main rotor assembly including at least one rotor hub supporting a plurality of rotor blades configured and disposed to rotate about a main rotor axis, at least one elevator arranged at the extending tail, and a control system operably connected to the main rotor assembly and the at least one elevator. The control system is configured and disposed to adjust each of a pitch rate and an attitude of the airframe by selectively adjusting a position of the at least one elevator.

A rotary wing aircraft includes an airframe including an extending tail. The airframe includes a longitudinal axis that extends through the extending tail. The rotary wing aircraft also includes a main rotor assembly including at least one rotor hub supporting a plurality of rotor blades configured and disposed to rotate about a main rotor axis, at least one elevator arranged at the extending tail, and a control system operably connected to the main rotor assembly and the at least one elevator. The control system is configured and disposed to adjust each of a pitch rate and an attitude of the airframe by selectively adjusting a position of the at least one elevator.

A control valve for a multi-stage hydraulic actuator includes a valve body defining a translation axis, a spool disposed within the valve body and movable along the translation axis, and a flange. The flange is fixed relative to the spool and has an aperture disposed externally of the valve body to removably fix the spool to a spool of a redundant control valve independently connected to the multi-stage hydraulic actuator for mitigating force fights between actuators coupled to the control valve.

The present invention discloses an unmanned helicopter, and belongs to the technical field of unmanned aerial vehicles. The unmanned helicopter includes an air inlet system, an exhaust system, a cooling system and a dynamic balance system. The air inlet system is fixed on a second side; the exhaust system is fixed on a third side; and the cooling system is fixed on a first side, and the dynamic balance system is fixed on a tail. The airflow at the outside of the unmanned helicopter flows into the air inlet system smoothly, quickly and efficiently under the action of its own flow velocity relative to the unmanned helicopter, therefore the technical problem in the prior art that the air entering the fuselage with a unit volume is burnt insufficiently, which generates adverse effects on the normal flight of the unmanned helicopter, is solved.

The present invention discloses an unmanned helicopter, and belongs to the technical field of unmanned aerial vehicles. The unmanned helicopter includes an air inlet system, an exhaust system, a cooling system and a dynamic balance system. The air inlet system is fixed on a second side; the exhaust system is fixed on a third side; and the cooling system is fixed on a first side, and the dynamic balance system is fixed on a tail. The airflow at the outside of the unmanned helicopter flows into the air inlet system smoothly, quickly and efficiently under the action of its own flow velocity relative to the unmanned helicopter, therefore the technical problem in the prior art that the air entering the fuselage with a unit volume is burnt insufficiently, which generates adverse effects on the normal flight of the unmanned helicopter, is solved.