Emergency Flight Brain Teaser

A sailor 1000 miles from Hawaii has gotten sick and needs medicine immediately.

Luckily a number of identical airplanes are available, but they are only capable of carrying enough gas to go 1000 miles and the owner won't sacrifice an airplane for the mission.

Assuming the planes can refuel each other instantaneously in flight, how can the sailor be saved without sacrificing any airplanes? How many planes will it take?

Brain Teaser Answer