Dumping fuel over Miami

Everskyward said:
I've never posted it before and I don't know what thread you are referring to.
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Now I can't find it...it's the recent one where shutdown was threatened of an airport in Arizona and PoA obliterated the online poll.
 
Jaybird180 said:
Now I can't find it...it's the recent one where shutdown was threatened of an airport in Arizona and PoA obliterated the online poll.
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There was no poll posted on PoA about Sedona.
 
I wonder what the environmental impact of dumped fuel vs. burnt fuel is?
 
Jaybird180 said:
Now I can't find it...it's the recent one where shutdown was threatened of an airport in Arizona and PoA obliterated the online poll.
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What did that thread have to do with dumping fuel?
 
GCA319 said:
I wonder what the environmental impact of dumped fuel vs. burnt fuel is?
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One is turned into CO2 by the aircrafts engine, the other is turned into CO2 by microbes in the surface soil.

Farmers used to mix herbicides and pesticides with diesel fuel to improve dispersion. If you spread fuel thinly enough, it gets broken down by soil bacteria in a short time. That is how the EPA decontaminates whole superfund sites.
 
I fly "that generation" of airplanes, too, and I don't know of any cases where we're trailing fuel during landing. I guarantee that were this the case, we'd be notified, just as we're notified about noise issues. A hangar window was damaged by rocks on the ramp as I powered up recently, and I spent 12 hours writing a report as a result: I very much doubt that anyone simply accepts dumping fuel on final as the norm, or large quantities of raw fuel coming out of the sky as acceptable.

No sir and I'd fight it as wrongful termination in court and I'd win.
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You might fight it in court. You wouldn't win. Especially in Florida against a firm like Amerijet. The company doesn't need a reason to terminate an employee in an "at will" state like Florida. Wrongful termination? Not a chance.

http://www.akers-boswell.com/yl/atwill.html

As for the First Officer's response when the FE is dumping fuel, the FO can't see the FE panel, nor is there any annunciation available to the FO that would alert him to the dumping. The FE's panel sits behind the FO; the Captain can see the panel easily and observe what's being done, but the FO cannot. Further, the FO can't do anything about what's going on with the FE or his panel.

Fuel dumping occurs with 50 psi jettison-override pumps at the rate of several thousand pounds a minute, depending on the number of pumps in use. If you figure a descent rate on final of 700-800 fpm, from the point described by the original poster (ANGLER), there are two minutes of dumping available before reaching the runway. If only 2,000 lbs needed to be dumped, only a portion of that time would be involved in dumping, assuming only 2,000 lbs was dumped. Considerably more than that would be burned during a go-around.

Generally one needs a good reason to go around: it's not like going around in a light airplane. Our go-around fuel flows are are above 50,000 lbs/hour. While one may be landing with minimum IFR reserves appropriate to the type of flight being conducted, you can see that if arriving at 25,000 lbs of fuel remaining, a go-around followed by any appreciable delays could be a real problem.
 
DouglasBader said:
I guarantee that were this the case, we'd be notified, just as we're notified about noise issues.
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I think if an airplane was dumping fuel over downtown Miami someone would notice and report it, not because they thought it was fuel but because they thought it was smoke or something wrong with the airplane. Even a small airplane (LR-35) dumping fuel creates some nice white streamers.
 
DouglasBader said:
I fly "that generation" of airplanes, too, and I don't know of any cases where we're trailing fuel during landing.
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No, you are not dumping fuel. But you have inefficient engines that blow out unburnt fuel and soot in regular operation every day, all year long (in total probably more than the couple of pounds mentioned here).
 
Every time I open this thread I think, "Are they STILL talking about taking a dump on Miami?" :) ;) :nono:
 
But you have inefficient engines that blow out unburnt fuel and soot in regular operation every day, all year long (in total probably more than the couple of pounds mentioned here)
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Actually, we have very efficient powerplants.

What unburned fuel are we "blowing out?"
 
I don't think any fuel gets through the engine unburned. It's atomized and injected straight into a ball of fire. It's a continuous burn and I just can't see any of it getting through the burn can unburned.
 
Captain said:
I don't think any fuel gets through the engine unburned. It's atomized and injected straight into a ball of fire. It's a continuous burn and I just can't see any of it getting through the burn can unburned.
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You put enough fuel through, it won't all burn.
 
Unburned fuel causes hlot section damage down the hot section. It's not like a piston engine where adding additional fuel only causes a temperature decrease, and decreases burn efficiency. In a turbine engine, if you add more fuel you get hotter temperatures. There's no mixture to regulate: burn more fuel, see higher temps. Too much fuel, especially too much fuel not burning in the cans, ends up burning downrange in the engine and causing streaking, burner can damage, and damage to turbine inlet guide vanes and turbine blades. It burns somewhere, whether in the cans or downstream. Unburned fuel passing the cans shows up as damage.

Some of our thrust is raw jet thrust, but most of it is off the fan.
 
Captain said:
I don't think any fuel gets through the engine unburned. It's atomized and injected straight into a ball of fire. It's a continuous burn and I just can't see any of it getting through the burn can unburned.
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If the fuel:air ratio exceeds the UEL (upper explosive limit) then there will be unburned fuel going through the engine until it hits some available oxygen. Remember, burning is the process of rapid oxidation, not enough O2 and not everything gets oxidized.
 
DouglasBader said:
Actually, we have very efficient powerplants.

What unburned fuel are we "blowing out?"
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This was about a 727 operation right ? They have JT8-D(x) engines of some sort of another.

At takeoff power, they emit 0.12lbs/sec of unburned hydrocarbons (or volatile organic compounds). In cruise, it is about 0.11lbs/sec. At idle about 0.05lb/sec.

During 5 hrs in cruise with a 727 (18000sec), you are emitting 1980lbs of unburned hydrocarbons. Oh wait, that is pretty close to the 2000lbs mentioned in the fuel dump over Miami ;) .

Newer engine designs emit a lot less VOC relative to pounds/kN of thrust generated.

(I am not making this up, this is based on data submitted to ICAO by the manufacturer. http://www.caa.co.uk/docs/702/1PW006_01102004.pdf For every kg of fuel you burn in a JT8-D(x), you are putting 5grams of HC out the tailpipe. The numbers above are from a 1999 EPA report that uses those published manufacturer data converted to a lb/sec metric http://www.epa.gov/oms/regs/nonroad/aviation/r99013.pdf )
 
At takeoff power, they emit 0.12lbs/sec of unburned hydrocarbons (or volatile organic compounds). In cruise, it is about 0.11lbs/sec. At idle about 0.05lb/sec.
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None of that reaches the ground to form a slick in someone's yard, or an oily finish on their home, as others here have suggested. It just doesn't happen. You're talking about combustion byproducts and components of fuel, not fuel that's made it out the back of the engine.
 
weilke said:
This was about a 727 operation right ? They have JT8-D(x) engines of some sort of another.

At takeoff power, they emit 0.12lbs/sec of unburned hydrocarbons (or volatile organic compounds). In cruise, it is about 0.11lbs/sec. At idle about 0.05lb/sec.

During 5 hrs in cruise with a 727 (18000sec), you are emitting 1980lbs of unburned hydrocarbons. Oh wait, that is pretty close to the 2000lbs mentioned in the fuel dump over Miami ;) .

Newer engine designs emit a lot less VOC relative to pounds/kN of thrust generated.

(I am not making this up, this is based on data submitted to ICAO by the manufacturer. http://www.caa.co.uk/docs/702/1PW006_01102004.pdf For every kg of fuel you burn in a JT8-D(x), you are putting 5grams of HC out the tailpipe. The numbers above are from a 1999 EPA report that uses those published manufacturer data converted to a lb/sec metric http://www.epa.gov/oms/regs/nonroad/aviation/r99013.pdf )
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How do you know all that? I'm not doubting what you say...it sounds legit. But HOW would you know that? What have you done in you're life to happen to know particulate levels coming out the back of a random engine to such detail?
 
Captain said:
How do you know all that? I'm not doubting what you say...it sounds legit. But HOW would you know that? What have you done in you're life to happen to know particulate levels coming out the back of a random engine to such detail?
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... Uhm, did you bother to look at the manufacturer certification data he linked to and you quoted?
 
Captain said:
How do you know all that? I'm not doubting what you say...it sounds legit. But HOW would you know that? What have you done in you're life to happen to know particulate levels coming out the back of a random engine to such detail?
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In order to get landing rights in countries that care about this stuff, the manufacturer has to publish that data and put it on deposit with ICAO.

Btw. the hydrocarbon emissions of a Trent 1000 as used on the 787 are lower by a factor of 50. Puts out 3 times the Nox hinting at a higher combustion temperature.
 
Everskyward said:
What did that thread have to do with dumping fuel?
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She complained about the environmental impact and claimed that it was affecting her (and neighbors) health. The letter you posted states otherwise.
 
Jaybird180 said:
GATS jar
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Not to hijack my own thread...

but does anyone really do that with the GATS jar? If I sumped and it was straight fuel I'd pour it back in the tank. But if there's water in it does anyone really pour it back into the tank and pray the filter filters it?
 
Jaybird180 said:
She complained about the environmental impact and claimed that it was affecting her (and neighbors) health. The letter you posted states otherwise.
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The letter I posted only deals with fuel dumping in the air, not fuel in general. I'm not sure how you are making the connection. When fuel is dumped from an airplane in the air it atomizes and evaporates. It's not as if droplets rain down upon the ground.
 
Captain said:
Not to hijack my own thread...

but does anyone really do that with the GATS jar? If I sumped and it was straight fuel I'd pour it back in the tank. But if there's water in it does anyone really pour it back into the tank and pray the filter filters it?
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Try this experiement for yourself:

Put some fuel in the GATS
Add some water
Pour the fuel into another container (read the GATS directions first)
Observe the results
 
Everskyward said:
The letter I posted only deals with fuel dumping in the air, not fuel in general. I'm not sure how you are making the connection. When fuel is dumped from an airplane in the air it atomizes and evaporates. It's not as if droplets rain down upon the ground.
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If the EPA says 'no impact' for dumping raw fuel, she would have a tough time substantiating a claim of harm for burned fuel.
 
Jaybird180 said:
If the EPA says 'no impact' for dumping raw fuel, she would have a tough time substantiating a claim of harm for burned fuel.
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It evaporates and doesn't even hit the ground. Also, as they say, it's a pretty rare event. I'm not saying that burned fuel is a problem, but that letter doesn't do anything to address it.
 
Captain said:
It's not my fault people on this forum don't care about forum sections and are tolerant of random posts in any old section. I've grouped my posts to appropriate sections iaw the labels listed on each section.

Hangar talk is just that. Cleared For the Approach, imho, is for a more serious discussion.

I am new and am sort of learning the ropes. For some reason I thought a part of 'learning the ropes' would involve reading the rules. Turns out the rules don't apply. That's okay. But I choose to follow them. No disrespect to Aunt Peggy or anyone else.
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If people on this board weren't tolerant of a lot I would have been banned long ago.

Tolerance is a good thing.

Now to my dumb question about your post - what happens to all that fuel when you "dump" it? How high up are you? Would I be walking down the street and get jet fuel on my jeans?
 
Gosh darn it this thread has three pages. Sorry about that, I need more coffee. Now I see that all the fuel just evaporates.
 
Jaybird180 said:
Try this experiement for yourself:

Put some fuel in the GATS
Add some water
Pour the fuel into another container (read the GATS directions first)
Observe the results
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I've done that experiment and was NOT impressed. As a result I've always just added 'look around' to the beginning of my dump fuel on the ramp checklist.
 
Captain said:
I've done that experiment and was NOT impressed. As a result I've always just added 'look around' to the beginning of my dump fuel on the ramp checklist.
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JOOC, what did you find? Why weren't you impressed?
 
DouglasBader said:
None of that reaches the ground to form a slick in someone's yard, or an oily finish on their home, as others here have suggested. It just doesn't happen. You're talking about combustion byproducts and components of fuel, not fuel that's made it out the back of the engine.
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Right, it coats them in slimy, smeary, black soot.:rolleyes2:
 
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