Four corporate jets fly in close formation above New Jersey in this undated photograph. In the future, planes on overseas or long-haul flights could fly in V-shaped formations for fuel savings of up to 12 percent, according to the IMechE report.
Geese and other birds use this strategy to save energy on long flights. As air hits a bird in flight, it flows down the wings and creates vortices, which impose drag on a lone flyer. When flying in formation, the birds behind can ride on top of the vortices created by those in front, reducing drag on the overall formation. (Related: "Quieter Aircraft to Take Cues From Birds, NASA Expert Says.")
Engineers have long wanted to try out formation flying with planes, but the difficulty has been gauging lateral distances between the planes well enough for them to safely fly so close together.
"I think we have very good instruments for understanding vertical distances" between stacked planes or between planes and the ground, Gillen said. "We're improving a great deal with lateral distances, but there's still a certain amount of variability."
IMechE's Oldham thinks the technology to enable formation flying is almost ready: "Due to the advancement in avionics technology, airplanes can now almost lock on to the plane in front of them through remote-sensing infrared cameras," she said.
Long-distance flights would benefit the most from formation flying, she added. "If, say, you had several flights leaving from London, they would all join up over the Atlantic into a formation, and as they fly across the ocean, they would all benefit from the fuel savings," Oldham said.
"And then one could break off and fly to New York, another to Boston, and so on."