AMSMAN
Topic Author
Posts: 975
Joined: Mon Jan 28, 2002 6:24 pm

Dumping Fuel

Mon Mar 10, 2003 12:36 am

What happens to the fuel when an a/c dumps it? does it rain down, does it evaporate?

Can somebody help?

Thanks in advance
AMS
Aer Lingus, Proud to be Irish.
 
dan2002
Posts: 2024
Joined: Tue Dec 17, 2002 7:11 am

RE: Dumping Fuel

Mon Mar 10, 2003 1:36 am

When it comes out of the a/c it looks like a contrail. Some evaporates but most little dropplets rain down but are hardly noticed. If the a/c is high most of it doesnt even make it all the way down.

Hope this helps
A guy asks 'What's Punk?'. I kick over a trash can and its punk. He knocks over a trash can and its trendy.
 
AMSMAN
Topic Author
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Joined: Mon Jan 28, 2002 6:24 pm

RE: Dumping Fuel

Mon Mar 10, 2003 4:54 am

So the bits that do make it down, say on a person, doesnt it do any harm to that person? What type of fuel is it anyway?
Aer Lingus, Proud to be Irish.
 
doug_or
Posts: 3125
Joined: Sat Mar 18, 2000 9:55 am

RE: Dumping Fuel

Mon Mar 10, 2003 5:28 am

I was under the impression most fuel dumped above 5000' would evaporate.
When in doubt, one B pump off
 
Toner
Posts: 247
Joined: Sat Feb 15, 2003 11:53 pm

RE: Dumping Fuel

Mon Mar 10, 2003 6:04 am

It's basically kerosene, anf ib small amounts, harmless.
 
Guest

RE: Dumping Fuel

Mon Mar 10, 2003 7:08 am

I don't have any exact data on this, but several years ago a met a guy who had flown some of the certification test flights for Lear when they certified fuel dumping on the Lear 25. He told me that the fuel was basically atomized and evaporated within about 35 feet. He told me that they made progressively lower high-speed passes down the runway while dumping fuel and they never detected any fuel below above about 35' AGL. That's a Learjet, and the amount and flow rate of the dump would be significantly less than a larger airplane.
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Dumping Fuel

Mon Mar 10, 2003 2:19 pm

Water evaporates.

Fuel does the same thing, so where does it end up? Are people really that stupid, or do they just not get the concept? Does evaporation = hyperspace? How many times has this topic been covered? ANYTHING that evaporates stays in the ATMOSPHERE and will RETURN TO EARTH, most likely in a LIQUID FORM.

 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Dumping Fuel

Mon Mar 10, 2003 2:28 pm

Better yet,

Does a phase change mean something is "gone??" One can't SEE the WATER VAPOR in the air at 85% humidity, 97F...but IT'S STill THERE. Does anyone on this forum know anything about chemistry or basic science? PLEASE do a search on this topic. It has been repeated more than the winglet question.
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Dumping Fuel

Mon Mar 10, 2003 2:43 pm

What do you geniuses think acid rain is?

Byproducts of the COMBUSTION of HYDROCARBONS (largely sulfur) that remain IN THE ATMOSPHERE until CONDENSATION (rain!!!).
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Dumping Fuel

Mon Mar 10, 2003 2:46 pm

No, Sulfur is not a hydrocarbon...
 
Olympic A-340
Posts: 738
Joined: Mon Apr 24, 2000 3:28 am

RE: Dumping Fuel

Thu Mar 13, 2003 6:26 am

Hydrocarbon+ O2---> CO2 + H20...as you can see the byproduct is present within the water vapor in the atmosphere. It does not vanish (contrary to popular belief  Smile/happy/getting dizzy )
 
flyingbronco05
Posts: 3484
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RE: Dumping Fuel

Thu Mar 13, 2003 9:13 am

When it comes out of the a/c it looks like a contrail. Some evaporates but most little dropplets rain down but are hardly noticed. If the a/c is high most of it doesnt even make it all the way down.

Like this picture:


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Photo © Gerhard Plomitzer



and this one:


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Photo © Peter D. Baumgartner



[Edited 2003-03-13 01:14:29]

and this one:


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Photo © Mulder



[Edited 2003-03-13 01:15:58]
Never Trust Your Fuel Gauge
 
il75
Posts: 257
Joined: Tue May 08, 2001 7:35 pm

RE: Dumping Fuel

Thu Mar 13, 2003 5:18 pm

There was a recent incident in Auckland with a SIA B744 having a severe tail strike.

Witnesses reported a fire when the plane got airborne, and SIA sources mention a fire alarm triggered by APU damage.
In any case, the aircraft landed safely. It is stated that the crew circled the airport several times (apparently they never got higher than 1000 feet) in order to dump fuel.

It sounds strange to me you will dump fuel when you supposedly have a fire in the tail cone. Any comments on this particular?

Best regards
erico
 
CX Flyboy
Posts: 6039
Joined: Sun Dec 26, 1999 6:10 pm

RE: Dumping Fuel

Thu Mar 13, 2003 5:34 pm

The press reports that they did not dunp fuel, because of the fire alarm, and instead performed an overweight landing, which if performed properly is not big drama really.
 
Mr.BA
Posts: 3310
Joined: Sun Sep 24, 2000 12:26 pm

RE: Dumping Fuel

Thu Mar 13, 2003 6:44 pm

And also you would not have dumped it over populus area and should be done at least above 5,000 feet.
Boeing747 万岁!
 
il75
Posts: 257
Joined: Tue May 08, 2001 7:35 pm

RE: Dumping Fuel

Thu Mar 13, 2003 9:14 pm

Right. Thank you for the information, guys.
erico
 
gotAirbus
Posts: 791
Joined: Fri May 18, 2001 10:02 am

RE: Dumping Fuel

Fri Mar 14, 2003 3:51 pm

Il75

Witnesses reported a fire when the plane got airborne, and SIA sources mention a fire alarm triggered by APU damage.
In any case, the aircraft landed safely. It is stated that the crew circled the airport several times (apparently they never got higher than 1000 feet) in order to dump fuel.


I hope that the airport has extra shielding from the fuel being dumped by the 744...

Actually, that was my next question. Dump fuel at 1000ft and lower and it'll rain down, right?

(gotAirbus?)
(gotAIRBUS?) - (Got Commonality?) - (Have A Nice Flight!)
 
mirrodie
Posts: 6789
Joined: Wed Apr 19, 2000 3:33 am

RE: Dumping Fuel

Sun Mar 16, 2003 1:43 pm

EssentialPowr et al,

thanks for the very friendly explanation.
Forum moderator 2001-2010; He's a pedantic, pontificating, pretentious bastard, a belligerent old fart, a worthless st
 
TAA_Airbus
Posts: 491
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RE: Dumping Fuel

Mon Mar 24, 2003 6:54 pm

EssentialPower,

It looks like you are talking to yourself there buddy. You made 3 posts in a row.

In Australia, dumping fuel is no longer standard practice. When practical, it is recommended that fuel be burned off rather than dumped.

TAA, The Friendly Way

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