I work at a car company that sits right at the end of a big airport runway. So we get all the landing aircraft most of the time, and I have noticed that alot of these large (737, 757, 767,727, etc) are dumping fuel as they are landing. We are the last thing they fly over, and I see liquid/vapor comming from the tips of their wings. I've noticed SouthWest Airlines as the major culprit here...but I want to know why are they doing this, and what can i do about this? I think it is hazardous to work under planes dumping fuel on you. Any advise?
2007-07-10 09:16:27 · 17 answers · asked by ilih2006 1 in Cars & Transportation ➔ Aircraft
Airliners do not dump fuel unless they are making emergency landings. Emergency landings are very rare. The vapors you see are contrails from the jets water vapors (normal byproduct of burning jet fuel) condensing
2007-07-10 09:30:57 · answer #1 · answered by mark 7 · 0⤊ 3⤋
They are not dumping fuel. That is in case of extreme emergency. The cost would be enormous if they dumped all the time.
Large airliners create vortices which can become visible under compression. The air under the wings becomes highly compressed when the wing flaps and leading edges are deployed. In humid areas you can see these all the time. In a sense they are squeezing the water out of the air.Military fighters show this effect in air shows when they turn the aircraft hard and vapour trails can be seen. Here is a great pic.
http://commons.wikimedia.org/wiki/Image:FA-18F_vapor_over_wings_1.jpg
I wouldn't worry about the fuel dumping. It would not happen near an airport. If they had to it is over designated areas at a minimum altitude.
2007-07-10 11:53:20 · answer #2 · answered by Get A Grip 6 · 1⤊ 0⤋
That's not fuel. Fuel dumping is an emergency procedure (fuel is expensive!!) only, used when a heavily loaded airplane has a takeoff emergency and must return to land immediately.
What you are seeing is water vapor condensing in the wing tip vortex (part of how the wing generates lift).
737 (the only airplane Southwest operates) does not even have fuel jettison, I believe- only the long range airplanes usually need it (ones that take off at weights they can't land at).
2007-07-10 14:58:17 · answer #3 · answered by DT3238 4 · 0⤊ 0⤋
There's no way that it's fuel from the aircraft that you've described. The 737, 757, and 767 don't have the ability to dump fuel. It's obviously the condensation from the wingtip vortices.
2007-07-11 13:07:46 · answer #4 · answered by grumpy geezer 6 · 0⤊ 0⤋
I seriously doubt that what you are seeing is fuel. They're likely "wing tip vortices" - harmless water vapors. Even a "glider" like the space shuttle will leave vapor trails behind its wing tips as it lands in the humid Florida air.
"A different type of contrail or condensation trail is caused when a wing surface or winglet causes a cavitation of air in very humid conditions. This results in a unique vapor trail that is not formed due to exhaust gases. The next time you fly in a commercial aircraft through a rain cloud, look for the vapor trails that form over and around the wing. Typical fighter wingtip contrails are shown below."
2007-07-10 09:45:02 · answer #5 · answered by Anonymous · 3⤊ 1⤋
They are not dumping fuel, this is just the moisture getting squeezed out of the air as the vortex forms at the wingtip.
Airliners only dump fuel if they are about to do an emergency landing and they have a full tank-o-gas. And there are usually pre-planned areas for this near every airport....and it wouldn't be over any populated areas.
2007-07-10 09:30:41 · answer #6 · answered by Paul H 4 · 7⤊ 1⤋
Those are Wingtip Vortices. Usually happens on high humid days. 737 and 757 without winglets are more common because of the high wing loading. If you're really close and you are downwind you'll hear it. It'll take 5-10 seconds for it to reach you and it sounds like the plane is ripping a hole through the air.
Don't worry, it's nothing coming out of the plane. You must live in a high humid area if you see it all the time.
2007-07-10 10:00:54 · answer #7 · answered by stolsai 5 · 4⤊ 2⤋
What your are seeing is NOT fuel being released from the aircraft. You are seeing the effects of wingtip vortexes that are often revealed by vapor trails that typically form in humid air when the wings are producing a great amount of lift. Under high-lift configurations when full flaps and slats are extended to allow controlled approaches at slow airspeeds, the partial vacuum over the wings can reveal the moisture as it is condensed out of the air as these little swirls of "clouds". In short, its just water.
2007-07-10 09:36:08 · answer #8 · answered by ? 6 · 5⤊ 1⤋
I don't think they are supposed to dump fuel over populated areas except in emergencies. However because of what you did not say, I don't think they are. Aviation fuels stinks. You would know if you were being dumped on. The fuel would also kill any plants and probably ruin the paint on any vehicle that got hit. The boiling point for fuel is high enough that liquid would hit the ground if they were dumping fuel. I suspect you are seeing water vapor condensing at the wing tips.
2007-07-10 09:26:50 · answer #9 · answered by davidmi711 7 · 2⤊ 4⤋
Are you sure it's fuel and not just liquid from being at a higher altitude. I would talk with the airport and see if they can give an explanation as to what is coming off of the planes.
I guess I think it's crazy that they would even dump fuel due to the effect it would have on the environment.
I have heard of it happening in case of emergency, but not as a common practice.
2007-07-10 09:25:53 · answer #10 · answered by swimbike21 4 · 1⤊ 3⤋