Patent US 9,738,394

A zero fuel time is determined and presented to an operator of an unmanned aerial vehicle (UAV). Zero fuel time may be determined based on a fuel burn rate and an amount of remaining fuel. A return to base time is determined and presented to an operator of a UAV. Return to base time may be determined based on a location of the UAV and a location of a base. Zero fuel time and return to base time are presented to an operator of a UAV proximate to one another using contrasting and/or varying visual characteristics to ease comparison and identification of this data.