Definition
A cockpit display that presents the aircraft's heading, course, navigation deviation, and bearing information on an electronic screen rather than a mechanical instrument. The EHSI combines the functions of a directional gyro and a course deviation indicator into a single integrated display, often showing additional data such as wind, distance to waypoint, and selected navigation source.
Plain English
An electronic screen in the cockpit that shows which way the aircraft is pointed and whether it is on the correct path to where the pilot wants to go. It replaces the older mechanical compass-and-needle instrument with a digital version that can show more information at once.
Context Anchor
Seen on instrument panels in aircraft equipped with electronic flight displays, especially when following navigation guidance during instrument flight.
Derivation
The 'Horizontal Situation Indicator' was originally a mechanical instrument that combined heading and course information into one face, giving the pilot a top-down 'horizontal' view of the aircraft's situation. Adding 'Electronic' simply means that same display is now generated on a screen rather than driven by gyros and gears.
Why Pilots Care
Combines multiple navigation instruments into one display, reducing pilot workload and improving situational awareness.
Intuition Check
“Situation” here does not mean an emergency or problem. It means the aircraft’s position and direction picture in relation to the selected course.
Example Sentence 1
After selecting the new course, the pilot checked the EHSI to confirm the aircraft was tracking toward the waypoint.
Example Sentence 2
During the ILS approach the EHSI clearly showed course deviation and heading alignment.