Aircraft Course Deviation Indicator

A course deviation indicator (CDI) is an instrument in an aircraft’s cockpit that displays the aircraft’s position relative to a selected navigational course. It helps pilots determine if they are on the correct flight path or if they need to adjust their heading to return to the desired course.

Course deviation indicators work by receiving signals from navigation aids such as VOR (VHF Omnidirectional Range) stations or GPS satellites. The aircraft’s deviation from the selected course is displayed on a horizontal bar, with a central needle that moves left or right to indicate off-course deviations. Pilots use this information to make heading adjustments and stay on the correct flight path.

The benefits of using a CDI in navigation include enhanced situational awareness, precise course tracking, and easier navigation adjustments. A CDI helps pilots stay on the correct flight path, reducing the risk of navigational errors and improving overall flight safety. It is a valuable tool for both VFR and IFR operations.

Course deviation indicators are typically calibrated as part of the overall avionics system calibration. This calibration schedule is determined by the aircraft's maintenance program and relevant airworthiness directives (ADs). Adhering to these guidelines is essential to ensuring the CDI provides accurate and reliable information.