Mission-adaptive rotor blade

1. A method comprising:

selecting a rotorcraft comprising an airframe and a rotor, the rotor rotatably connected to the airframe and comprising a hub and a rotor blade, the rotor blade connected to the hub to extend radially away therefrom and comprising biasing fibers arranged in a spiral within the rotor blade;

rotating the rotor with respect to the airframe at an angular velocity having a first value;

increasing the centrifugal force acting on the rotor blade by transitioning the angular velocity of the rotor with respect to the airframe from the first value to a second value greater than the first value; and

inducing automatically, by the biasing fibers in response to the increasing, greater twist in the rotor blade.

2. The method of claim 1 , wherein the transitioning comprises prerotating the rotor.

3. The method of claim 1 , wherein the transitioning comprises executing an in-flight maneuver.

4. The method of claim 3 , wherein the in-flight maneuver comprises hovering.

5. The method of claim 1 , wherein the rotor blade further comprises a root, tip, root portion located proximate the root, and tip portion located proximate the tip, the root portion defining a root angle of attack, the tip portion defining a tip angle of attack.

6. The method of claim 5 , wherein the greater twist comprises an increase in the root angle of attack with respect to the tip angle of attack.

7. The method of claim 6 , further comprising adjusting, after the inducing, the pitch of the rotor blade to keep the tip angle of attack from going negative.

8. The method of claim 5 , wherein the biasing fibers comprise root-biasing fibers corresponding to the root portion and tip-biasing fibers corresponding to the tip portion.

9. The method of claim 8 , wherein the root-biasing fibers corresponding to a given side of the rotor blade are oriented substantially parallel to the tip-biasing fibers corresponding to the given side.