What is good for the goose is good for the wing commander

EDWARDS AIR FORCE BASE, Calif. -- Taking a cue from the world of geese, scientists are developing a system that will allow airplanes to fly autonomously in tight V-formations over long distances.

For geese, the carefully arranged formation saves energy on migratory flights. Scientists hope passenger, cargo and military planes will one day mimic the flight pattern to cut fuel consumption by as much as 20 percent.

Geese cut resistance by drafting, a technique also used in automobile and bicycle racing, where racers line up one behind another to cheat the wind.

The Autonomous Formation Flight project instead makes clever use of the swirling, horizontal tornado of air that flows from another plane's wing tips to literally surf that vortex.

By dipping a single wing into the upward-flowing portion of the vortex, the plane can use the additional lift it provides to cut fuel consumption.

"If you can find where that upward wind is, and put your airplane in it, you are essentially riding a wave," said Dick Ewers, a retired Marine Corps pilot helping to test the system.

Usually avoided

Pilots normally avoid vortices that persist for miles -- and minutes -- in the wake of other aircraft. Indeed, officials suspect such a whirl of air may have contributed to the November crash of American Airlines flight 587 in New York.

The goal of the joint project by the National Aeronautics and Space Administration, University of California, Los Angeles and The Boeing Co. is to exploit their potential benefit.

"It is possible you can use something that can be a detriment to flight -- that you can use the vortex as an enhancement as well," said Robert Meyer, director of aerospace projects at NASA's Dryden Flight Research Center at Edwards, where the program is being tested on a pair of F/A-18 fighter planes.

In December, two of the NASA jets demonstrated for the first time what scientists had long suspected: that formation flying can provide significant fuel savings.

During a 96-minute flight that took the jets cruising at 40,000 feet into Nevada and back, the trailing aircraft spent most of the time with its left wing inserted in the vortex spiraling off the lead jet's right wing.

The two planes flew just 55 feet apart, close enough for the glint of the sun on the lead aircraft's aluminum wing to flash in Ewers' eyes as he trailed.

Although the planes flew the same distance, initial results suggest the second plane used 660 pounds, or 12 percent, less fuel than did the lead plane.

"We could have extended the range of the aircraft by 117 miles," said Gerard Schkolnik, the project's manager at NASA.

The system relies on Global Positioning System units and an advanced autopilot system to work. By pinpointing each plane's position in space -- and shuttling that information from one to the other -- the system allows the jets to maintain distances that vary by a foot.