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

Claim 0:
1. A method of operating an electrically powered rotorcraft having a fuselage and a set of N rotors, N≥4, wherein each rotor has a rotor hub and a set of blades, each blade having an angle of incidence, the set of rotors driven by a set of electric motors and coupled to the fuselage, the rotorcraft having a system controller configured to control operation of the set of N rotors, the method comprising:
biasing each blade with a spring force to cause such blade to have an angle of incidence of approximately zero degrees when rotor torque on the rotor hub of such blade is absent, wherein the spring force is overcome when rotor torque on such rotor hub exceeds a threshold;
under a condition wherein a failure prevents supplying, to each rotor hub, rotor torque exceeding the threshold, operating the rotorcraft in a failsafe mode wherein (i) the spring force associated with each rotor hub such shall have caused blades thereof to have an angle of incidence of approximately zero degrees and (ii) autorotation is enabled in at least four of the rotors; and (iii) differential control of electrical braking of the set of rotors is enabled by the system controller to affect attitude of the rotorcraft.