Migrating birds, NASCAR drivers and Tour de France bicyclists already get it. And now the Air Force is thinking about flying gas-guzzling cargo aircraft in formation -- 'dragging' off one another -- on long-haul flights across the oceans.

Flight tests with C-17s "vortex surfing" at Edwards Air Force Base, CA have demonstrated potentially large savings of fuel and money by doing what geese do naturally. A series of test flights involving two aircraft at a time allowed the trailing aircraft to "surf" the vortex of the lead aircraft, positioning itself in the updraft to get additional lift without burning extra fuel.

Early indications from the tests promise a reduction of fuel consumption by up to 10 percent for the duration of a flight. Over long distances and with even a small fraction of Air Mobility Command's average of more than 80,000 flights a year, the fuel and cost savings could reach into the millions of dollars, experts say.

Larger air mobility aircraft like the C-17 can fly in formations that are potentially easy to maintain and which do not require the planes to be exceptionally close together. Mmodified C-17 formation flight system software enabled precise auto-pilot and auto-throttle systems to ensure the trailing aircraft achieved and maintained proper flight position without active assistance from pilots.


