Which display function is provided by the Horizontal Situation Indicator (HSI)?

• A. Primary heading, navigation display, course selection, NAV source, and localizer
• B. Attitude indicator and airspeed
• C. Engine parameters and CAS messages
• D. Weather radar display

Answer: (A)

The Horizontal Situation Indicator combines heading information with navigation cues in one instrument, making it easier to fly precise courses. It shows your current heading on a rotating compass card with a fixed aircraft symbol, and it also displays the course you’ve selected with the course knob. The pointer and the deviation bar (the CDI) guide you back to the chosen course when you’re off track. It also clearly indicates which navigation source is active (for example VOR/LOC or GPS), so you know which navaid the CDI is using. When you’re aligning with a localizer, the localizer cue appears to help you stay on the runway centerline. This integration is what makes the HSI the go-to display for navigation, unlike instruments that show only attitude/airspeed, engine parameters, or weather radar.