A rotorcraft, and, more particularly, to a rotorcraft with a fuselage having a center line, at least one main rotor that generates vortices during operation, and a stabilizer wing, whereby the stabilizer wing has a planform that reduces the unsteady aerodynamic loads caused by the wake of the at least one main rotor. In particular, the stabilizer wing may be provided with a left wing tip, a right wing tip, a quarter chord line with a non-zero curvature, such that an interaction between the vortices generated by the at least one main rotor and the quarter chord line is spread out over time, a leading edge that is arc-shaped, and a trailing edge that is arc-shaped.

A rotorcraft, and, more particularly, to a rotorcraft with a fuselage having a center line, at least one main rotor that generates vortices during operation, and a stabilizer wing, whereby the stabilizer wing has a planform that reduces the unsteady aerodynamic loads caused by the wake of the at least one main rotor. In particular, the stabilizer wing may be provided with a left wing tip, a right wing tip, a quarter chord line with a non-zero curvature, such that an interaction between the vortices generated by the at least one main rotor and the quarter chord line is spread out over time, a leading edge that is arc-shaped, and a trailing edge that is arc-shaped.

According to one implementation, a rotorcraft includes a first rotorcraft and at least one second rotorcraft. The first rotorcraft has a first main rotor and a first tail rotor. The at least one second rotorcraft has a second main rotor and a second tail rotor. The at least one second rotorcraft are attachable and detachable to and from the first rotorcraft. Further, according to one implementation, a method of controlling the above-mentioned rotorcraft includes: flying the first rotorcraft, to which the at least one second rotorcraft has been attached, to a destination; and separating the at least one second rotorcraft from the first rotorcraft at the destination.

A manned or unmanned aircraft has a main body with a circular shape and a circular outer periphery. One or more rotor blades extend substantially horizontally outward from the main body at or about the circular outer periphery. In addition, one or more counter-rotation blades extend substantially horizontally outward from said main body at or about the circular outer periphery, but vertically offset from the main rotor blades.

A compound aircraft includes a convertible thruster that pivots between an anti-torque position, a forward thrust position, and intermediate positions. A pilot has two inceptors to control thruster rotor pitch in the anti-torque and forward thrust positions. A mixer mechanically blends the signals from the two inceptors during transition between the anti-torque and forward thrust positions. A transfer rod coaxial with the pivot axis of the convertible thruster conveys convertible thruster pitch commands from the pilot to a pitch control actuator. The pitch control actuator may be located partially within the rotor of an electric motor that rotates the convertible thruster rotor. The electric motor and pitch control actuator are unitary. Both the electric motor and pitch control actuator pivot with the convertible thruster. The pitch actuator output shaft is coaxial to and disposed within a hollow electric motor output shaft.

A compound aircraft includes a convertible thruster that pivots between an anti-torque position, a forward thrust position, and intermediate positions. A pilot has two inceptors to control thruster rotor pitch in the anti-torque and forward thrust positions. A mixer mechanically blends the signals from the two inceptors during transition between the anti-torque and forward thrust positions. A transfer rod coaxial with the pivot axis of the convertible thruster conveys convertible thruster pitch commands from the pilot to a pitch control actuator. The pitch control actuator may be located partially within the rotor of an electric motor that rotates the convertible thruster rotor. The electric motor and pitch control actuator are unitary. Both the electric motor and pitch control actuator pivot with the convertible thruster. The pitch actuator output shaft is coaxial to and disposed within a hollow electric motor output shaft.

A rotary wing aircraft that extends along an associated roll axis between a nose region and an aft region. The rotary wing aircraft comprises a main rotor; a propeller that is at least configured to propel the rotary wing aircraft in forward flight condition, wherein the propeller forms a circular propeller disc in rotation around an associated rotation axis; and a shrouded duct that is arranged in the aft region and that forms an inner air duct which accommodates at least partly the propeller, wherein the shrouded duct comprises a yaw and pitch stability enhancement unit for improving yaw and pitch stability of the rotary wing aircraft in the forward flight condition.

A rotary wing aircraft that extends along an associated roll axis between a nose region and an aft region. The rotary wing aircraft comprises a main rotor; a propeller that is at least configured to propel the rotary wing aircraft in forward flight condition, wherein the propeller forms a circular propeller disc in rotation around an associated rotation axis; and a shrouded duct that is arranged in the aft region and that forms an inner air duct which accommodates at least partly the propeller, wherein the shrouded duct comprises a yaw and pitch stability enhancement unit for improving yaw and pitch stability of the rotary wing aircraft in the forward flight condition.

An aircraft drive shaft including an outer shaft having a first diameter configured to couple a first gearbox and a second gearbox to provide power transfer between the two gearboxes, an inner shaft concentric with the outer shaft and having a second diameter configured to provide structural support to the outer shaft, a gap defined between an outer peripheral surface of the inner shaft and an inner peripheral surface of the outer shaft, wherein the gap is sized according to a ballistic projectile cross-section size that the aircraft is considered to encounter on an upcoming mission, and a sleeve located at least at first end of the outer shaft connecting the outer shaft to the inner shaft.

An example unmanned aerial vehicle includes a housing; a wireless communication module; a plurality of propulsion systems; and a navigation circuit. At least one of the plurality of propulsion systems includes a motor; and a propeller assembly rotatably connected to the motor. The propeller assembly comprises: a hub structure including a surface facing away from the motor; a first connecting member including a first post and a second post extending in parallel to and spaced apart from the first post, and the first post and the second post are fixed to the surface and are able to move elastically in a second direction perpendicular to the first direction; a first blade detachably coupled to the first connecting member and comprising an opening to which the first post and the second post are coupled; and a cap detachably coupled to the top of the first connecting member.