A yaw control system for a helicopter having an airframe that includes a tailboom includes one or more tail rotors rotatably coupled to the tailboom and a flight control computer implementing an airframe protection module. The airframe protection module includes an airframe protection monitoring module configured to monitor one or more flight parameters of the helicopter and an airframe protection command module configured to modify one or more operating parameters of the one or more tail rotors based on the one or more flight parameters of the helicopter, thereby protecting the airframe of the helicopter.

A yaw control system coupled to a tailboom of a helicopter includes tail rotors. The tail rotors include a clockwise tail rotor and a counterclockwise tail rotor. The clockwise tail rotor is configured to rotate in a first rotational direction. The counterclockwise tail rotor is configured to rotate in a second rotational direction, the second rotational direction opposite of the first rotational direction.

An electrically distributed yaw control system for a helicopter having a tailboom includes a plurality of tail rotors rotatably coupled to the tailboom and a flight control computer implementing a tail rotor balancing module. The tail rotor balancing module includes a tail rotor balancing monitoring module configured to monitor one or more parameters of the helicopter and identify a first set of one or more tail rotors in the plurality of tail rotors based on the one or more parameters. The tail rotor balancing module also includes a tail rotor balancing command module configured to modify one or more operating parameters of the first set of tail rotors.

According to an aspect, a clevis assembly includes a shackle having two ends, each end respectively including an aperture, a structure connecting the apertures and housing a bearing, and a shearing device that includes a frangible point and is in operable communication with the bearing, where the shearing device is housed in a hollow portion of the structure.

An aircraft rotor system including a hub having a hub axis about which the hub is configured to rotate; a plurality of rotor blades configured to extend from the hub and rotate about the hub axis, at least one of the rotor blades rotatable about a respective pitch change axis; wherein the hub is configured to be rotated about the hub axis only by the plurality of rotor blades. Another aspect includes a method of operating the rotor system.

An anti-torque system for a rotorcraft includes a first tail fan assembly including a plurality of first fan blades and a second tail fan assembly including a plurality of second fan blades. The first tail fan assembly has a larger diameter than the second tail fan assembly. The first fan blades have a larger rotational inertia than the second fan blades such that the second fan blades experience a larger angular acceleration than the first fan blades in response to torque, thereby providing yaw control for the rotorcraft.

A flying passenger rotor lifted vehicle that is capable of taking off and landing vertically, that is relatively light-weight, has responsive control, and increased safety against failure of propulsion/thrust systems. The flying vehicle can include a body having a tail section, a central thrust unit arranged along the longitudinal axis of the vehicle, at a distance from the rotation axis of the main rotor, a mounting support on either side of the body, and a side thrust unit mounted to each mounting support. The central thrust unit includes a fan which provides air flow with a flow component perpendicular to a virtual vertical midplane of the vehicle. Each of the side thrust units includes a fan which provides air flow with a flow component parallel to the virtual vertical midplane. At least one of the thrust units has controllable air deflection to deflect the corresponding output air flow in a controllable manner.

A rotor assembly includes a pitch spider, rotor blade assemblies, and pitch horn joints. The pitch spider has a body and pitch spider legs extending from the body. Each blade rotor assembly includes a rotor blade, a pitch adapter joined to the rotor blade and connecting the rotor blade to the rotor hub, and a pitch horn. Each pitch horn joint joins one of the rotor blade assemblies to a corresponding pitch spider leg. Each pitch horn joint includes a pitch horn joint bolt extending from the pitch horn of the rotor blade assembly to the pitch spider leg along a pitch horn joint axis, the pitch horn joint bolt fixed to the pitch horn; a spherical bearing having an inner ring and an outer ring; and a slider sleeve coupled to the spherical bearing, the slider sleeve enabling the pitch horn to translate along the pitch horn joint axis.

Tail boom drive systems for helicopters are described which utilize a fan internal to the tail boom to provide yaw control, and an external propulsor to provide forward thrust. In one embodiment, the tail boom drive system includes a shaft, a fan, and a propulsor. The shaft is disposed lengthwise within an interior space of the tail boom, and the shaft has a first end and a second end. The fan is mechanically coupled coaxially to the shaft within the interior space between the first end and the second end, and the fan generates a variable airflow directed towards the second end that is ejected from the interior space substantially perpendicular to the tail boom. The propulsor is external to the tail boom and is mechanically coupled coaxially to the shaft at the second end, and the propulsor generates a variable thrust directed towards the first end.

Embodiments include an aircraft comprising a fuselage; a wing connected to the fuselage; and first and second propulsion systems connected to the wing on opposite sides of the fuselage, wherein at least a portion of each of the first and second propulsion systems and at least a portion of the wing are tiltable between a first position in which the aircraft is in a hover mode and a second position in which the aircraft is in a cruise mode, wherein each of the propulsion systems includes pylon and a rotor assembly comprising a plurality of rotor blades.