Air Force Lab Test Out "Aircraft Surfing" Technique To Save Fuel 205
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."
Big, clumsy, fast and close (Score:4, Interesting)
Re:Who's up first? (Score:4, Interesting)
Actually, in most examples of drafting, the benefit extends to the leader as well, reducing the tail drag associated with a solo player. As I recall, the benefit generally increases as you add cars to the train as the lead drag and tail drag are spread over more units.
Mythbusters (Score:5, Interesting)
The Airlines should take notice. (Score:4, Interesting)
The Airlines should take notice.
Judging by the formations of geese and pelicans I've watched flying by in large groups, I have to assume this effect can be carried from one flyer to the next in a chain and isn't confined to just two flyers. The next question would be "Do all trailing flyers receive this 10% fuel savings, or is there some sort of diminishing return at play?"
If all of the flyers receive the savings, then the airlines might find that sending a small squadron of aircraft, say five DC-10 sized aircraft in formation as opposed to one large "super-liner", is economically beneficial both in terms of lower costs AND lower CO2 emissions. It would also relieve a common problem with current flight scheduling--empty seats. If the "flight" (I'm referring to the squadron idea) did not sell all the seats, they could simply send one less plane--it allows for options in balancing demand vs resource allocation, which would, I assume, allow the airlines to lower costs across the board including ticket prices. It would also allow the airlines to scale specific routes based on demand more accurately--if there is a sudden surge in demand on specific route, they simply increase the squadron size as required.
There is the added benefit of "diluting" the severity in repercussions as a result of mechanical failures/human error--when a super-liner suffers catastrophic failure, everyone dies. In a squadron of planes, a failure on one craft wouldn't mean the death of everyone. Not putting one's eggs in one basket has it's benefits.
Wait a Minute (Score:4, Interesting)
Re:drafting... (Score:4, Interesting)
But there are other kinds of flocking behavior: think of starlings, who make those big, pulsating clouds that are so mezmerizing to watch. I don't know if those are for feeding or protection or what, but they're certainly not optimized for distance as geese are. Maybe those are the descendants of the birds that couldn't stick to the formation and stopped their migrations in different places, met like-minded fowl and created their own flocking legacy.
Actually it's called "wake turbulence"... (Score:5, Interesting)
...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 [google.com].
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?"
Re:Mytbusters episode (Score:3, Interesting)
The important things to remember, are
1) No matter how big your plane is, it's tiny in comparison to the air;
2) There is a mind-blowingly huge amount of energy in the atmosphere, especially around thunderstorms and changes in the land. It can be beneficial (see gliders and updrafts) or detrimental (low level wind shear & downdrafts), and you must pay constant attention to it.
Re:drafting... (Score:4, Interesting)
Not really true - I do it occasionally in my 19" skiff in heavy water - I'll tail a bigger fishing boat like a 60 -70' seiner. He's bouncing around at 10 - 15 knots and not having a care in the world. In such seas, I would be limited to 7-8 knots and the boat (and my back) would be getting clobbered. I sit about 100 feet back in the wake and as long as the wind isn't blowing so that I have inhale his diesels, it saves fuel, my back and gives me a speed boost.
The nice thing about water is you can see the wake 'vortex', no additional software required.