Definition
A panel instrument that displays the aircraft's heading using a gyroscope as its stable reference. Because the gyro holds its orientation in space, the instrument shows heading changes smoothly and immediately, without the lag, dip, or northerly/southerly turning errors of a magnetic compass. It must be periodically aligned with the magnetic compass during straight-and-level, unaccelerated flight.
Plain English
A heading instrument that uses a spinning gyro to give a steady, accurate reading of which way the aircraft is pointing. It reacts cleanly to turns, but it drifts over time and has to be reset against the magnetic compass.
Context Anchor
Seen in instrument flying and timed-turn practice when the pilot needs a stable heading reference while turning or rolling out on a desired heading.
Derivation
From Greek gyros, meaning 'circle' or 'ring' — the spinning wheel inside the instrument. The gyro provides the steady reference; the indicator simply displays it.
Why Pilots Care
Provides a stable heading reference when the magnetic compass is swinging or unreliable, allowing precise control during turns and instrument flight.
Intuition Check
Do not assume the gyro heading indicator automatically finds north like a compass. It is a stable direction display that the pilot sets and checks against the magnetic compass.
Example Sentence 1
Before starting the timed turn, the pilot aligned the gyro heading indicator with the magnetic compass.
Example Sentence 2
In IMC the gyro heading indicator gave a reliable reference while the magnetic compass lagged behind the actual heading.