Dead reckoning is a navigational method primarily based on which two factors?

Dead reckoning is a navigational technique that calculates one's current position by using a previously determined position and advancing that position based on known or estimated speeds over elapsed time, along with the course direction. The primary factors involved in this methodology are the direction and speed of travel.

When navigating by dead reckoning, a pilot records their heading (the direction in which they are traveling) and maintains an estimate of how far they have traveled based on their ground speed. This allows for continuous updates on the aircraft's position relative to the initial fixed point. Unlike other navigation methods, dead reckoning does not depend on external references such as GPS, visual landmarks, or actual coordinates but relies solely on these two factors, hence making them the foundational elements of this navigational approach.

This reliance on direction and speed is crucial, particularly when flying in areas where visual cues or landmarks may be sparse, enhancing the effectiveness of dead reckoning as a navigation method.