Azimuth Deviation Indicator

An Azimuth Deviation Indicator (ADI) is a navigation instrument used in aircraft to display the deviation of the aircraft's heading from the desired course. It provides pilots with real-time information about the aircraft's position relative to the intended flight path.

The ADI typically consists of a circular dial with a fixed aircraft symbol in the center, representing the aircraft's heading. Around the dial, there are markings indicating the desired course or heading. The ADI also includes a needle or pointer that moves to indicate the deviation of the aircraft's heading from the desired course.

When the aircraft is flying on the desired course, the needle or pointer will be centered on the dial. However, if the aircraft deviates from the desired course, the needle will move to the left or right, indicating the amount of deviation. The pilot can then make adjustments to the aircraft's heading to correct the deviation and return to the desired course.

The ADI is an important instrument for maintaining accurate navigation during flight, especially in situations where visual references may be limited, such as during instrument flight or in poor weather conditions. It helps pilots to stay on track and navigate safely to their intended destination.