A rotary wing aircraft that extends along a roll axis between a nose region and an aft region, comprising: at least one first single-blade rotor and at least one second single-blade rotor which are spaced apart from each other along the roll axis; at least one first electric machine and at least one second electric machine which are at least configured to drive in motor mode the at least one first single-blade rotor and the at least one second single-blade rotor for generating lift in hover condition of the rotary wing aircraft; at least one propulsion device that is at least configured to generate forward thrust in forward flight condition of the rotary wing aircraft; and a fixed-wing arrangement that is at least configured to provide lift in the forward flight condition.

A long-distance drone having a main body, a left hind wing, a right hind wing, a left forewing, and a right forewing. There is a left linear support connecting the left forewing to the left hind wing, and a right linear support connecting the right forewing to the right hind wing. A plurality of propellers are disposed on the left and the right linear supports.

A stoppable rotor, which includes a first and second blade and rotates about a substantially vertical axis, is stopped with the first blade pointing forward and the second blade pointing backward while the aircraft is mid-flight. Anti-torque is provided using a set of one or more combination rotors in a first mode of operation in order to counter torque produced by the stoppable rotor when the stoppable rotor is rotating where the set of combination rotors rotate about a substantially longitudinal axis. Forward thrust is provided using the set of combination rotors in a second mode of operation when the stoppable rotor is not rotating.

While an aircraft is mid-flight, a braking start point associated with a stoppable rotor is calculated where the stoppable rotor includes a first and second blade and the stoppable rotor is configured to rotate about a substantially vertical axis. A process to stop the stoppable rotor is started, while the aircraft is mid-flight, when the stoppable rotor reaches the braking start point, where the stoppable rotor is stopped with the first blade pointing forward and the second blade pointing backward.

A hub assembly having a first hub subassembly, a second hub subassembly, and a rotary guide. The first hub subassembly rotates a first blade assembly about an axis of rotation in a first plane. The second hub subassembly rotates a second blade assembly about the axis of rotation in a second plane. The rotary guide controls an axial position of the second hub subassembly relative to the first hub subassembly about the axis of rotation. The rotary guide is configured to adjust the axial position as a function of a lifting force generated by the first blade assembly or the second blade assembly.

A hub assembly having a first hub subassembly, a second hub subassembly, and a rotary guide. The first hub subassembly rotates a first blade assembly about an axis of rotation in a first plane. The second hub subassembly rotates a second blade assembly about the axis of rotation in a second plane. The rotary guide controls an axial position of the second hub subassembly relative to the first hub subassembly about the axis of rotation. The rotary guide is configured to adjust the axial position as a function of a lifting force generated by the first blade assembly or the second blade assembly.

An interconnect drive system for an aircraft has a driveline and clutch control system. The driveline comprises a shaft for each propulsion assembly, each shaft for transferring torque to and from the associated propulsion assembly, and a clutch operably coupling the shafts and configured for selective engagement. The clutch is capable of transferring a first amount of torque between the shafts while engaged and a second amount of torque between the shafts while disengaged. The system also has a clutch control system, comprising a computer operably connected to the clutch for controlling operation of the clutch and sensors for sensing torque applied to the driveline, output from the sensors being communicated to the computer. The computer commands operation of the clutch in response to the output from the sensors, the clutch being commanded to disengage to relieve a transient torque imbalance in the driveline.

A diverter duct for a propeller includes a second duct element having a semi-annular wedge shape, which is pivotably coupled to the first duct element, a first drive structure configured to drive a pivoting of the second duct element relative to the first duct element and a second drive structure configured to drive a rotation of the first and second duct elements about an axis of rotation of the propeller.

A diverter duct for a propeller includes a second duct element having a semi-annular wedge shape, which is pivotably coupled to the first duct element, a first drive structure configured to drive a pivoting of the second duct element relative to the first duct element and a second drive structure configured to drive a rotation of the first and second duct elements about an axis of rotation of the propeller.

Rotor assemblies for aircraft are described that include a plurality of blades that are disposed vertically on a common axis along different horizontal planes. When the rotor assemblies are free-wheeling, the blades form a vertically stacked configuration, and when the rotor assembly is driven in rotation to generate lift, the blades bloom out from the vertically stacked configuration. At least one of the blades in the rotor assembly has a blade geometry that is different with respect to other blades such that when the blades are vertically stacked and free-wheeling, the collective shape of the blades is aerodynamic in shape, based on the different blade geometry, that reduces aerodynamic drag on the rotor assembly.