Horizontal Situation Indicator (HSI) The Horizontal Situation Indicator (HSI) is a critical instrument in aviation, combining heading, navigation, and course deviation into one display. Key Components: 🛩️ Navigation & Guidance: • Lubber Line – Indicates the current aircraft heading. • Compass Card – Displays cardinal and intermediate headings. • Course Select Pointer – Shows the selected navigation course. • TO/FROM Indicator – Determines if the aircraft is flying toward or away from a navigation station. ⚡ Flight Path & Deviation Indicators: • Course Deviation Bar (CDI) – Shows lateral course deviation. • Glideslope Deviation Scale & Pointers – Helps maintain proper vertical descent. 🚨 Warnings & Adjustments: • NAV & Compass Warning Flags – Indicate a loss of signal or instrument failure. • Course & Heading Select Knobs – Allow pilots to adjust the desired course and heading. Essential for precision navigation and instrument landings, the HSI enhances situational awareness and flight control.