Only older gyro's actually use a gyroscope in them. Today they're mostly solid state piezo's. When an electric field is applied to a crystal it vibrates at certain rate depending on the geometry of it. Conversely, if a physical stress is applied to the crystal it will cause the resonant frequency to change which can be measured. Piezo gyro crystals are designed to be most sensitive to motion in a specific direction. You can use them for anything you want to react to changes in the rate of acceleration. Futaba's state of the art ones are SMM gyro's. I don't have a clue how they actually work but they involve actual moving parts built using the same processes as micro processor's so they're insanely tiny. The only downside to gyro's is they can only detect changes in the rate of acceleration not relative motion so they're useless for keeping a plane straight and level over any long period of time because they drift. But that makes them perfect for keeping helli's tails from spinning randomly by canceling out acceleration it detects.