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.

Tail rotor control system is described for helicopters. A pedal position sensor operable by a pilot yields greater tail rotor RPM relative to the main rotor RPM, giving the pilot increased control over the vehicle. This proves especially useful in certain situations, such as high altitude, where increasing tail rotor speed from main rotor speed can give a pilot increased maneuverability and stability.

Tail rotor control system is described for helicopters. A pedal position sensor operable by a pilot yields greater tail rotor RPM relative to the main rotor RPM, giving the pilot increased control over the vehicle. This proves especially useful in certain situations, such as high altitude, where increasing tail rotor speed from main rotor speed can give a pilot increased maneuverability and stability.

A vertical take-off and landing (VTOL) aircraft (10) includes a fuselage and first and second forward wings (20, 22), each wing (20, 22) having a fixed leading edge and a trailing control surface (50) which is pivotal about a generally horizontal pivot axis. The aircraft (10) includes first and second electric motors (60) each having rotors (70), the electric rotors (70) being pivotal with the trailing control surface (50) between a first position in which each rotor (70) has a generally vertical axis of rotation, and a second position in which each rotor (70) has a generally horizontal axis of rotation, a control system (90) is configured to selectively operate the first electric motor (60) and the second electric motor (60) at different rotational speeds to generate a turning moment to pivot the control surface (50) about the pivot axis (33).

A vertical take-off and landing (VTOL) aircraft (10) includes a fuselage and first and second forward wings (20, 22), each wing (20, 22) having a fixed leading edge and a trailing control surface (50) which is pivotal about a generally horizontal pivot axis. The aircraft (10) includes first and second electric motors (60) each having rotors (70), the electric rotors (70) being pivotal with the trailing control surface (50) between a first position in which each rotor (70) has a generally vertical axis of rotation, and a second position in which each rotor (70) has a generally horizontal axis of rotation, a control system (90) is configured to selectively operate the first electric motor (60) and the second electric motor (60) at different rotational speeds to generate a turning moment to pivot the control surface (50) about the pivot axis (33).

Systems and methods for controlling a coaxial rotary-wing aircraft including a co-axial main rotor assembly and a pusher-propeller. One system includes an electronic controller configured to receive a reference velocity of the aircraft and receive a reference flight path angle of the aircraft. The electronic controller is also configured to simultaneously control the co-axial main rotor assembly and the pusher-propeller based on the reference velocity of the aircraft and the reference flight path angle of the aircraft, by simultaneously generating a commanded thrust of the pusher-propeller and a commanded thrust of the co-axial main rotor assembly using a multiple input, multiple output algorithm applying dynamic inversion.

An unmanned rotorcraft includes an airframe, rotor blades that are coupled to the airframe for rotation therewith, a propulsion unit having a propeller, and an actuator that is coupled to the airframe and adapted to temporarily reorient the propulsion unit such that an axis of the propeller moves out of alignment with an axis of the rotor blades. Rotation of the propeller causes counter-rotation of the airframe and rotor blades. The rotor blades and blades of the propeller are adapted to deploy from collapsed positions when flight of the rotorcraft is initiated. A method of operation by the rotorcraft includes, when it is determined that a current heading does not correspond to a determined flight path, causing the actuator to temporarily reorient the propulsion unit in accordance with an angular orientation of the actuator relative to the current heading.

A fully compounding rotorcraft includes a fuselage having first and second wings extending therefrom and configured to provide lift compounding responsive to forward airspeed. A twin boom includes first and second tail boom members that extend aftward from the first and second wings. An empennage is coupled between the aft ends of the tail boom members. An anti-torque system includes a tail rotor that is rotatably coupled to the empennage. An engine is disposed within the fuselage and is configured to provide torque to a main rotor assembly via an output shaft and a main rotor gearbox. An auxiliary propulsive system is coupled to the fuselage and is configured to generate a propulsive thrust to offload at least a portion of a thrust requirement from the main rotor during forward flight, thereby providing propulsion compounding to increase the forward airspeed of the rotorcraft.

A fully compounding rotorcraft includes a fuselage having first and second wings extending therefrom and configured to provide lift compounding responsive to forward airspeed. A twin boom includes first and second tail boom members that extend aftward from the first and second wings. An empennage is coupled between the aft ends of the tail boom members. An anti-torque system includes a tail rotor that is rotatably coupled to the empennage. An engine is disposed within the fuselage and is configured to provide torque to a main rotor assembly via an output shaft and a main rotor gearbox. An auxiliary propulsive system is coupled to the fuselage and is configured to generate a propulsive thrust to offload at least a portion of a thrust requirement from the main rotor during forward flight, thereby providing propulsion compounding to increase the forward airspeed of the rotorcraft.

A method of facilitating the piloting of a hybrid rotorcraft that comprises a lift rotor and at least one propulsion rotor together with at least one engine operating in compliance with at least one rating. For at least one rating, onboard calculator determines a first power margin of the power plant that is available for the lift rotor and at least one second power margin that is available for said at least one propulsion rotor. A single indicator displays a line together with a first index pointing to said line to illustrate a current operating point of the lift rotor, and a second index pointing to said line to illustrate a current operating point of said at least one propulsion rotor. For each monitored rating, a first symbol is spaced apart from the first index by a first distance illustrating the first power margin. A second symbol is spaced apart from the second index by a second distance illustrating the second power margin.