Updraft assisted rotorcraft take-off

A system comprising:

• a rotorcraft comprising:
• a frame;
• an engine coupled to the frame;
• a rotor hub coupled to the engine;
• and
• a plurality of rotor blades coupled to the rotor hub, each rotor blade configured to be adjusted to a negative pitch angle prior to a vertical take-off operation such that each blade is oriented at a negative angle of attack, wherein rotation of the plurality of rotor blades at the negative pitch angle generates an updraft that persists for a time and that, during the vertical take-off operation, applies an upward force to the rotorcraft to supplement lift generated by the plurality of rotor blades after each of the rotor blades is adjusted from the negative pitch angle to a positive pitch angle for the vertical take-off operation;
• and
• a ground-based station configured to supply energy used to rotate the plurality of rotor blades prior to initiation of the vertical take-off operation.

A method of performing a vertical take-off operation of a rotorcraft, the method comprising:

• adjusting a plurality of rotor blades of a rotor to a negative pitch angle such that the plurality of rotor blades are oriented at a negative angle of attack;
• rotating the rotor and plurality of rotor blades at a take-off speed at the negative angle of attack;
• generating, by rotation of the plurality of rotor blades at the negative angle of attack, an updraft that exerts an upward force on the rotorcraft;
• after generating the updraft, adjusting the plurality of rotor blades to a positive pitch angle such that the plurality of rotor blades are oriented at a positive angle of attack to generate lift;
• and
• vertically taking-off, by the rotorcraft, using the lift provided by the plurality of rotor blades and using the upward force of the updraft.