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[Music]

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>>Over 41,000 airports are scattered across
our planet, housing more than 23,000 airplanes.

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Everyday, everywhere, air traffic controllers
keep pilots and passengers safe from not only

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collisions, but also wake encounters, which
can be just as dangerous.

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[Airplane flying]

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>>Behind an aircraft, you have these counter-rotating vortices.

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There is this invisible wake with this upwash
portion on the outboard part of that counter-rotating,

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and then a downward on the inside.

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Just think of them as horizontal tornadoes.

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[Music]

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>>Engineers at NASA's Armstrong Flight Research
Center are testing new technologies and methods

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to help aircraft identify where wakes are,
and avoid them- or even ride them.

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[Music/cockpit ambience]

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>>It's really biologically inspired.

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If you've ever seen a flock of geese, the
reason they fly in a 'v' is that the trailing

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birds are really gaining efficiency from the
lead bird by flying in the upwash caused by

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vortices generated by the wing in flight.

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>>So if you fly in the area where the air is rising, it's like gliders that soar in thermal updrafts.

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You can extract energy from that.

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The ultimate objective of flying in the upwash portion of the wake is to reduce the

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fuel burn and the emissions of the trailing
airplane.

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[Music/jet engine revving up]

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>>Ok, it's pilot's airplane.

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>>Copy that, and let's go ahead and start moving
on to Card 9, and give 808 the lead.

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>>We would begin first by positioning ourselves about 4000 feet back

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and to the side of and above of where we estimated where the wake would be.

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>>PPA is engaged...

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>>TCS released...

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>>saw the engage...

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roll command
is climbing...

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we're getting some long-term oscillations, so I think we're close...

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>>we're
gonna do a 5 foot step-in, to a cross-track

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of minus 75...

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>>ok...

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>>activating new command, 3, 2, 1-
activate...

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>>we're getting a little bit of buffeting, very slight, can you guys feel that in back?

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>>Just a little bit, but yeah.

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>>What we're noticing about this flight, I think,
is that the power required to maintain a constant

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position when our wing tip is in the wake
is less, than is required when we're not in

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the wake, which means we're gonna save fuel,
that's the idea.

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[Airplane landing]

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[Music]

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>>I was even surprised by some of the flight
dynamics, and things that we saw in flight.

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There really is no substitute for taking an
experiment to flight.

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You learn things that sometimes you don't
want to learn, but you also see the beauty