##### Course Deviation Indicator (CDI) A course deviation indicator is an avionics instrument used in aircraft navigation to determine an aircraft's lateral position in relation to a course to or from a radio navigation beacon. If the location of the aircraft is to the left of this course, the needle deflects to the right, and vice versa (pilot flies to the needle). >Covered in: >Mentioned in: [[C203 Week 3#VOR Indications|C203]] >References: [[WP CDI|🌍]] >Required by: > >Related to: