What are the two primary mechanisms used in an attitudinal gyro?

The two primary mechanisms used in an attitudinal gyro are the gyroscope and the vacuum system. The gyroscope is crucial because it provides a stable reference plane for orientation. When the aircraft changes attitude—pitching, rolling, or yawing—the gyroscope maintains its orientation, allowing the pilot to perceive changes in the airplane's attitude relative to the horizon.

The vacuum system is instrumental in powering the gyroscope. Many general aviation aircraft use a vacuum system to drive the gyroscopic instruments. By sucking air through the gyroscope, it spins at high speed, which is essential for maintaining the gyroscopic effect, stability, and accuracy of the instrument readings.

This combination ensures that pilots can effectively manage their aircraft's orientation in flight, especially during turns, climbs, and descents, where visual references might be limited.