Which instrument uses a directional gyro to display heading with respect to magnetic north?

• A. The magnetic compass uses a directional gyro.
• B. The standby attitude indicator uses a directional gyro.
• C. The heading indicator uses a directional gyro to display heading with respect to magnetic north.
• D. The Attitude director indicator uses a compass.

Answer: (C)

The heading indicator uses a directional gyro to provide a stable reference for the aircraft’s heading, displayed with respect to magnetic north. The directional gyro senses yaw about the vertical axis and drives the instrument’s compass rose, so the reading corresponds to how many degrees the aircraft is from magnetic north. In practice, pilots regularly align the heading indicator with the magnetic compass to correct for gyro drift, ensuring the displayed heading stays accurate.

This instrument is different from a magnetic compass, which directly points to magnetic north but is subject to turning and acceleration errors and is slower to respond to rapid changes. Attitude indicators (standby or ADI) show pitch and roll, not heading, so they don’t provide heading relative to magnetic north.