What drives the attitude indicator in aircraft using a vacuum system?

The attitude indicator in aircraft using a vacuum system is driven by vacuum pressure. This instrument operates based on gyroscopic principles, where a gyroscope is spun inside the indicator. The vacuum system creates a low-pressure environment that allows the gyroscope to maintain its orientation against the forces of gravity and the movement of the aircraft. When the aircraft maneuvers, the gyroscope remains stable and provides accurate readings of the aircraft's pitch and bank angles.

The use of vacuum pressure is essential, as it enables the gyroscope to spin freely and maintain its gyroscopic stability, which is crucial for determining the aircraft's attitude in three-dimensional space. Other systems, such as electrical or hydraulic, do not apply to the operation of the attitude indicator in this context, nor does the pitot-static pressure, which is typically used for measuring airspeed and altitude rather than attitude.