Patent ID: 11964771
Assignee: SIFLY AVIATION, INC.
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 12:
13. An electrically powered rotorcraft comprising:
four rotors driven by a set of electric motors, each rotor comprising a rotor hub and a set of blades;
a system controller configured to control operation of the four rotors and the set electric motors;
each rotor comprising a spring, the spring providing a spring force and being coupled to the rotor hub and the set of blades;
wherein the spring force biases each set of blades to have an angle of incidence of approximately zero degrees when rotor torque is absent, wherein the spring force is overcome when the rotor torque exceeds a threshold;
wherein, in the presence of rotor torque below the threshold, autorotation of the four rotors is enabled and the system controller is configured to cause differential electrical braking of the four rotors to adjust an orientation of the rotorcraft.