If you’re flying an aircraft with a gyro-driven heading indicator (a directional gyro), you need to ensure it is properly synced with the compass both prior to takeoff and throughout the flight.

Otherwise, errors due to gyroscopic precession may result in inaccurate heading indications and navigation errors.

Quick Tip: In both X-Plane and Microsoft Flight Simulator, pressing the letter “D” on your keyboard will instantly synchronize your heading indicator with the magnetic compass.

You can remember this by thinking of the D in “Directional Gyro” (DG).