What do pilots use to detect changes in angular velocity?

Pilots utilize gyros to detect changes in angular velocity because these instruments are specifically designed to measure and maintain orientation based on the principles of angular momentum. Gyros work by spinning in a particular axis, and any change in the aircraft's orientation will cause the gyro to precess, which is the tendency of a rotating body to move perpendicular to the direction of the applied force. This property allows gyros to provide accurate information about the aircraft's attitude and rotational movements along its pitch, roll, and yaw axes.

In the context of aviation, gyroscopes are integral to various instruments such as the artificial horizon and the turn coordinator, which help pilots understand their aircraft's position relative to the horizon and its rate of turn. Thus, gyros serve a crucial role in flight stability and navigation, enabling pilots to respond appropriately to maneuvers and maintain control.

The other options do not serve the purpose of measuring angular velocity. Altitude meters measure altitude rather than angular movement, gimbals are used primarily to allow for free movement of gyros but do not detect angular velocity themselves, and magnetometers measure magnetic fields, which are unrelated to changes in an aircraft’s angular position.