Smoke generators show the twisting paths of wingtip vortices behind two NASA Dryden F/A-18's used in the Autonomous Formation Flight (AFF) program during flight #743. The lead aircraft, F-18 #845 (NASA Dryden's Systems Research Aircraft), piloted by Craig Bomben, is followed closely by another F-18, #847, piloted by Dick Ewers.

A vortex is a spiraling current of air emanating from aircraft wingtips as they fly. By mapping the vortex pattern and using sophisticated software to put the trailing aircraft in the optimum location, the energy of the vortex could result in fuel savings for the follower aircraft of 15 percent or more.

Autonomous Formation Flight (AFF) intended to allow an aircraft to fly in close formation over long distances using advanced positioning and controls technology. It utilized Global Positioning System satellites and inertial navigation systems to position two or more aircraft in formation, with an accuracy of a few inches. This capability was expected to yield fuel efficiency improvements.