Dead Reckoning

Dead Reckoning (DR) is a method of navigation where the pilot calculates the current position based on a previously known position, using heading, airspeed, elapsed time, and wind correction. No external navigation aids are required.

While largely superseded by GPS and other electronic navigation, dead reckoning remains a fundamental skill taught in pilot training and serves as a backup when electronic systems fail. The term is believed to derive from "deduced reckoning."