In many cases when you take a commercial flight, the plane pilots itself with the automatic pilot software. All the pilot does is take off and land the plane. 

Typically when the plane has reached a certain height the pilot sets the automatic pilot. 

This is the way the algorithm apparently works: the pilot sets the automatic pilot on a line going from A to B and the software maintains the plane on the line. 

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Anyone have first-hand information on this software?