On the EHSI, what does the course deviation bar indicate?

The course deviation bar on the Electronic Horizontal Situation Indicator (EHSI) is a vital feature that provides pilots with critical situational awareness regarding their navigation. It indicates the relationship between the aircraft's current position and the selected course track. When the course deviation bar is centered, it means the aircraft is on the desired course. If the bar deflects to one side, it indicates that the aircraft is either left or right of the intended flight path. This feedback is essential for making timely adjustments to the aircraft's heading to stay aligned with the desired track, which is crucial during instrument flight rules (IFR) operations.

Understanding this function is fundamental for effective navigational control. The course deviation bar helps pilots ensure they are on the correct trajectory, which is especially important during approaches and when operating near airspace boundaries. Other choices do not relate to this specific indicator's functionality. Distance to waypoints pertains to navigational information from waypoints rather than course alignment, aircraft speed refers to a measure of how fast the aircraft is moving, and heading error indicates discrepancies between the aircraft's heading and the desired heading rather than course deviation from the selected path.