Slashdot Mirror
Air Force Lab Test Out "Aircraft Surfing" Technique To Save Fuel
coondoggie writes "It's not a totally new concept, but the Air Force is testing the idea of flying gas-guzzling cargo aircraft inline allowing the trailing aircraft to utilize the cyclonic energy coming off the lead plane — a concept known as vortex surfing — over long distances to save large amounts of fuel. According to an Air force release, a series of recent test flights involving two aircraft at a time, let the trailing aircraft surf the vortex of the lead aircraft, positioning itself in the updraft to get additional lift without burning extra fuel."
(They were actually sparrow scratches, but never mind that.)
Apparently things are a bit more complicated in the air...
Drafting helps by reducing air resistance (drag) and requires you to be really close, this technique is a bit more subtle in that it involves using trailing air vortices to get free "lift". The article had a handy link to explain this... http://www.av8n.com/fly/vortex.htm
Of course I'm sure that someone will draw such an analogy in a pop-science article...
I see folks at the DoD have been watching Mythbusters. As well they should.
Today's Sesame Street was brought to you by the number e.
I think you are attending the wrong dance clubs ...
"Flame away, I wear asbestos underwear"
We're caught in his jetwash! Flame out! We're going in a flat spin! Eject! Eject! Hightway to the danger zone!
It's not drafting, it's flying in a V like birds. The lead bird works harder than the rest, and the lead changes when the front gets tired. Birds have "known" about this phenomenon for thousands of years (at least). But I'm surprised someone didn't patent it and charge the military for doing it.
Learn to love Alaska
Obviously they didn't have their ducks in a row.
Firstly, this isn't drafting. Secondly, the lead would likely swap periodically, as birds have done for thousands of years. Drafting airplanes won't work for the same reason helicopters hovering can crash wile under full power (google "settling with power" for an areodynamic description of what would happen when multiple wings travel through the same air). Yes, I am a pilot.
Learn to love Alaska
Drafting is also used in racing leagues that turn right and have drivers and fans educated enough to read.
But I'm surprised someone didn't patent it and charge the military for doing it.
The innovation isn't in the concept of "drafting" another plane. The innovation is in the autopilot system that does it safely and automatically. As shown on Mythbusters the concept is viable, but a human is not capable of keeping the plane in the "sweet spot" safely for an extended period of time.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
I think it is learned behaviour of not flying in the poop-stream of the bird directly in front of you.
racing leagues that turn right and have drivers and fans educated enough to read.
Q) What has two hundred legs and twelve teeth?
A) The front row at a Willie Nelson concert.
Drafting, defined as "following someone/something in a manner to reduce your aerodynamic drag by traveling in air moving at a lower relative velocity" excludes this act.
If you feel it is drafting, please state the definition of drafting you are using, as I've not seen a definition of drafting that would include this.
It does not depend on mitigating detrimental vorticies. NASCAR drafting does, and the lead car gets the benefit from the reduced drag. This does not benefit the vehicle in the front and is the following car using a predicted vortex to its advantage, while traveling through otherwise undisturbed air. Thus "drafting" where the folower uses the lead car to "break the air" is not happening.
Rather than having to define "drafting" to a bunch of morons who are too stupid/lazzy to google, I'd rather discuss the efffect of this on commercial aircraft for the rest of us, flight lanes with airplane flocks saving fuel. Or discussions on how much the winglets affect this effect. But no, it's all a discussion of the definition of "drafting" with a bunch of google-illiterite people.
Learn to love Alaska
...not jetwash. Jetwash is the turbulent stream of air behind a jet coming from out of the back of the engines. That is mostly dangerous while on the ground, when there is a small, light aircraft sitting behind the jet.
Wake Turbulence comes off the wingtips of *all* airplanes in flight, while the wing is generating lift. It's like horizontal tornadoes spinning off the wingtips. It can flip another airplane upside down Lots of pictures of what it looks like here.
I almost got rolled 90 degrees on short final while landing at EAA Airventure in Oshkosh, WI a few years ago landing behind a P-51 Mustang. I was in a Van's RV-8, which fortunately is very aerobatic and has a quick roll rate. It took full right stick to get the aircraft rightside up again and the whole event was over in a split second, and I landed normally. but with quite the adrenalin dump flowing in my bloodstream, and almost experienced a brown smelly dump flowing in my pants! As soon as I touched down, the tower controller said, "Nice job RV.... Uh, sorry bout that..... (sheepishly) Uh, caution wake turbulence?"