Title: Describe the HSI.
Course: Aircraft Pilot Training I (20053-I) > Section: Understanding Airport Operations

Description should include the following:

- The heading indicator is located below the artificial horizon and is normally modeled after an HSI.
- As in the case of the attitude indicator, the heading indicator receives its information from the magnetometer, which feeds information to the attitude and heading reference system (AHRS) unit and then out to the primary flight display (PFD) selected navigation facility or fix. They also provide pilotage information so the aircraft can be maneuvered to keep it on a predetermined path.
- The pilotage information can be in either two or three dimensions relative to the ground-based or space-based navigation information.

PLT355; PLT356