Heading Indicator
What is heading indicator?
The heading indicator is a gyroscopic flight instrument that displays the aircraft's magnetic heading. Because it has no magnetic sensing of its own, it must be set to match the magnetic compass before and during taxi, and rechecked before takeoff (it should read within 5° of the known runway or taxiway direction). It also drifts over time due to gyroscopic precession, so it must be periodically realigned with the magnetic compass in flight. Think of it as a steady, easy-to-read heading display that "borrows" its accuracy from the magnetic compass.
Also known as: HI, directional gyro, DG, heading indicator
Studying for an FAA written test?
Terms like heading indicator show up on the FAA knowledge test. Study them in context with ACS-aligned practice questions, AI explanations, and the cited FAA handbook reference behind every answer — free to start.
Learn more in the library
Related terms
- gyroscopic precession
- hand propping
- hazardous attitudes
- heading bug
- headwind component
- high performance aircraft
- HIRL
- holding pattern