What is the function of the Heading Bug in aviation systems?

The function of the Heading Bug in aviation systems is to set the desired heading for navigation. This tool assists pilots in maintaining a specific flight path by allowing them to indicate their intended direction on the navigation display or heading indicator. When pilots adjust the Heading Bug, they are effectively marking a specific heading that they wish to follow, which can then be used in conjunction with autopilot systems or for manual navigation.

The Heading Bug is particularly useful during flight planning and in-flight adjustments, enabling pilots to keep track of course changes as they respond to air traffic control or other situational demands. It provides a visual reference that helps in maintaining situational awareness regarding the aircraft's intended direction as compared to its current heading.