What does the Heading Indicator use to determine direction?

The Heading Indicator utilizes a gyroscope to determine direction. A gyroscope is a device that maintains orientation based on the principles of angular momentum. In aviation, the Heading Indicator functions as a type of directional gyro, which means it provides a stable reference for the aircraft's heading.

When an aircraft turns or changes orientation, the gyroscopic principles allow the Heading Indicator to remain relatively unaffected by the movement, making it a reliable source of directional information. This is crucial for pilots, as it helps maintain a consistent heading during flight, especially when visual references may be limited.

In comparison, magnetic deviation refers to errors in magnetic compass readings, GPS technology relies on satellite signals that can be affected by various factors, and inertial navigation systems involve complex computations to track an aircraft's position and heading based on initial positions and movements. These options do not serve the same immediate, stable purpose as the gyroscope in determining an aircraft's direction.