Flight Plan

When a pilot prepares for a flight, he/she must file a flight plan.  This involves determining the directional heading that the pilot must set in the aircraft to reach his/her destination.  The directional heading is determined by the desired course and the current wind conditions.  In other words, if the pilot simply pointed the aircraft in the direction of the destination, he/she would be blown off course by the wind.  Setting up and solving a vector triangle allows the pilot to set the aircraft heading to compensate for the effect of the wind.

Solving the triangle for the value of h gives the correct heading for the aircraft.  This triangle may be solved using the Law of Sines.