San Diego: Two jets in formation with independent on/off trails [Fuel Dump]

[WeedWhacker]

Approximately equivalent to five hundred million cubic miles at normal pressure and temperature.

Here's a visual:

Combined image....all of the water (both saline and fresh) on the left, and all the atmosphere when accumulated into a sphere (on the right), for comparison to the size of the Earth itself.

ETA the web page: http://www.nextnature.net/author/nextnature/

 

[Critical Thinker]

In the comments of the video, SoCal Skywatch (Syd Stevens) went on to say:

 

[WeedWhacker]

In the comments of the video, SoCal Skywatch (Syd Stevens) went on to say:

View attachment 7054

I think that "Syd Stevens" might be prevaricating a bit, there, in claiming that the "sprays did persist". Since we have determined it to be a simple fuel jettison event.

No, when fuel is jettisoned overboard, the "trails" made initially do NOT "persist".

 

[Mick West]

I think that "Syd Stevens" might be prevaricating a bit, there, in claiming that the "sprays did persist". Since we have determined it to be a simple fuel jettison event.

No, when fuel is jettisoned overboard, the "trails" made initially do NOT "persist".

Yes, you can see them fading away.

Which reminded me of:

And this initially made me think of a fuel dump, but then I got stuck on the idea of it being exhaust contrails.

 

[Gary Cook]

Would be interesting to have data that shows if there is a correlation to the amount of planes seemingly doing fuel-dumping in the sky and how often they have to technically.

 

[Mick West]

Would be interesting to have data that shows if there is a correlation to the amount of planes seemingly doing fuel-dumping in the sky and how often they have to technically.

It might be, but both numbers are basically impossible to determine - as well as being very small. I personally have NEVER seen a plane dumping fuel. It's something the airlines try very hard to avoid doing.

 

[David Fraser]

I was just Googling and the CAA ask that a report is generated for a fuel dump. Lots of bulletins on this site which looks interesting http://www.skybrary.aero/index.php/Main_Page

 

[KC-10FE]

I have dumped fuel twice, once for a landing gear malfunction on takeoff, and another time because the aircraft failed to pressurize on climb out. Pretty standard, both times we had enough time to coordinate with ATC to be vectored to a fuel dump holding pattern. However on something like an engine failure after V1 at maximum takeoff gross weight, those fuel dump valves are coming open after passing 400 feet.

 

[Jason]

However on something like an engine failure after V1 at maximum takeoff gross weight, those fuel dump valves are coming open after passing 400 feet.

Is this automated?

 

[KC-10FE]

Is this automated?

Apologies, I made it sound like it was. The fuel dump is activated by a push switch on the flight engineer's fuel panel. (On the KC-10, which still has an FE) This opens the fuel dump valves in the trailing edge of the wings, The FE completes the process by turning on all the transfer, crossfeed and engine fuel pumps. The point I was trying to make is that we try to dump at altitude over unpopulated areas, but in an emergency situation, or a critical phase of flight such as an engine failure shortly after takeoff, all bets are off, and I am going to dump fuel to lower my gross weight and allow us to climb out. Jet fuel consists of kerosene, which evaporates quite fast. I used to have a video of us dumping fuel over the desert, but I can't seem to find it anywhere.

 

[Soulfly]

Apologies, I made it sound like it was. The fuel dump is activated by a push switch on the flight engineer's fuel panel. (On the KC-10, which still has an FE) This opens the fuel dump valves in the trailing edge of the wings, The FE completes the process by turning on all the transfer, crossfeed and engine fuel pumps. The point I was trying to make is that we try to dump at altitude over unpopulated areas, but in an emergency situation, or a critical phase of flight such as an engine failure shortly after takeoff, all bets are off, and I am going to dump fuel to lower my gross weight and allow us to climb out. Jet fuel consists of kerosene, which evaporates quite fast. I used to have a video of us dumping fuel over the desert, but I can't seem to find it anywhere.

What percentage of dumped fuel is likely to reach the ground when it is dumped using normal procedures?

 

[Mick West]

What percentage of dumped fuel is likely to reach the ground when it is dumped using normal procedures?

None in theory. It's aerosolized as it exits, so forms a fine mist which is suspended in the air, and then it rapidly evaporates into a gas. Later breaking down in the atmosphere.

You can see this in action here:

The trail seems suspended in the air, and has evaporated a mile or so behind the plane.

 

[Soulfly]

None in theory. It's aerosolized as it exits, so forms a fine mist which is suspended in the air, and then it rapidly evaporates into a gas. Later breaking down in the atmosphere.

You can see this in action here:

The trail seems suspended in the air, and has evaporated a mile or so behind the plane.

Thanks for the explanation. Just something I've wondered about in the past.

 

[Mick West]

Thanks for the explanation. Just something I've wondered about in the past.

Yes, I think the automatic thing to imagine when you hear about thousands of gallons of fuel being dumped is to think of it more like:

 

[Jason]

Yes, I think the automatic thing to imagine when you hear about thousands of gallons of fuel being dumped is to think of it more like:

But when fuel is dumped at 400 feet like KC 10FE said during emergencies after take off, would that fuel have enough time to evaporate 40 stories up. I understand its an emergency and all bets are off, so there isn't much concern about the fuel as there is with getting the passengers and plane safely back on the ground. But at this altitude would the fuel evaporate or come raining down?

 

[Mick West]

But when fuel is dumped at 400 feet like KC 10FE said during emergencies after take off, would that fuel have enough time to evaporate 40 stories up. I understand its an emergency and all bets are off, so there isn't much concern about the fuel as there is with getting the passengers and plane safely back on the ground. But at this altitude would the fuel evaporate or come raining down?

A 400 feet fuel dump would be very rare. But remember that KC-10 at takeoff speed is still going at over 150 mph. The fuel is still aerosolized into a fine mist, and it's still coming out at relatively low rate (compare to the firefighting plane above). Some of it will probably end up in the environment, but I think it's mostly still going to evaporate (depending on weather conditions).

 

[Soulfly]

Some of it will probably end up in the environment,

Does fuel that has evaporated not got into the environment?

 

[Mick West]

Does fuel that has evaporated not got into the environment?

It's a gas (like what you smell at a gas station), so yes, but not really a lot in the grand scheme of things. It's vastly diluted by the air, and breaks down. See:
http://www.atsdr.cdc.gov/toxprofiles/tp76-c5.pdf

I'm not saying it's harmless, but it's a pretty small contributor to overall pollution. You probably get more hydrocarbons evaporating from the oil on bicycle chains.

 

[Soulfly]

It's a gas (like what you smell at a gas station), so yes, but not really a lot in the grand scheme of things. It's vastly diluted by the air, and breaks down. See:
http://www.atsdr.cdc.gov/toxprofiles/tp76-c5.pdf

I'm not saying it's harmless, but it's a pretty small contributor to overall pollution. You probably get more hydrocarbons evaporating from the oil on bicycle chains.

Yeah, one plane dumping fuel every so often isn't going to be a big problem. Now if they all did it, all the time, probably a different story.

Fun fact WD-40 (the best thing for bike chains imo) was invented to prevent corrosion in nuclear missiles, by displacing the standing water that causes it.
http://en.wikipedia.org/wiki/WD-40

Who said death and destruction never yielded anything useful?

 

[Mick West]

And some perspective around 10 million gallons of oil spilled per year.
http://www.epa.gov/oem/docs/oil/fss/fss04/etkin_04.pdf

 

[Soulfly]

And some perspective around 10 million gallons of oil spilled per year.
http://www.epa.gov/oem/docs/oil/fss/fss04/etkin_04.pdf

How does this compare to the increase/decrease of ship traffic?

 

[Mick West]

How does this compare to the increase/decrease of ship traffic?

I think that's discussed in the PDF.

 

[Soulfly]

I think that's discussed in the PDF.

/doh

I somehow completely missed seeing the link, thanks.

 

[Jason]

And some perspective around 10 million gallons of oil spilled per year.
http://www.epa.gov/oem/docs/oil/fss/fss04/etkin_04.pdf

How can there be an increase in the number of spills yet the total number of gallons spilled has declined over the last 20+ yrs.... And I'm curious to know of the 304 millions gallons spilled over the time period above, how much of it was recovered. And this is alarming and seems irresponsible;

Extrapolating to EPA jurisdiction spills, there would
be about
4.3 million spills llion spills
since 1980.

 

[Hevach]

How can there be an increase in the number of spills yet the total number of gallons spilled has declined over the last 20+ yrs.... And I'm curious to know of the 304 millions gallons spilled over the time period above, how much of it was recovered. And this is alarming and seems irresponsible;

I can't speak to how much was recovered, but increasing number of spills but decreasing gallons means more small spills and less large ones - for example, a reduction in ship spills combined with an increase in truck spills.

Speculation: Since the media mainly covers big spills, the attention they've cast on aging ship fleets or offshore rigs may not have done much to raise awareness of aging truck fleets. There's a lot more trucks carrying oil than ships, but their individual capacity is far lower.

 

[WeedWhacker]

And I'm curious to know of the 304 millions gallons spilled over the time period above...

I thought I'd look up the potential for impact, overall.

There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (326 million trillion gallons) ...

http://science.howstuffworks.com/environmental/earth/geophysics/question157.htm

Taking the 304 million (oil) compared to 326 quintillion (water) as a percentage, I got 9.3251534e-13...or, 0.0000093251534.

This is comparing to the total liquid water on Earth, but of course localized concentrations (and your mileage) will vary.

 

[Jason]

I thought I'd look up the potential for impact, overall.

There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (326 million trillion gallons) ...

http://science.howstuffworks.com/environmental/earth/geophysics/question157.htm

Taking the 304 million (oil) compared to 326 quintillion (water) as a percentage, I got 9.3251534e-13...or, 0.0000093251534.

This is comparing to the total liquid water on Earth, but of course localized concentrations (and your mileage) will vary.

Why do we never hear of oil spills on land? Or at least I can't remember ever hearing about one in the news. Its seems like most oil spills happen at sea, but in the link Mick provided from the EPA its stated that Texas and California are the worst states in the country and they are responsible for something like 93 million gallons of oil spilled. Why don't we ever hear about that in the news?

 

[WeedWhacker]

Why do we never hear of oil spills on land?

Purely a guess here. The ones that involve transportation (shipping) usually are more "newsworthy" because of possible environmental impacts on coastlines.

There is more hazard involved, also, with using ships to transport oil (as opposed to facilities that store oil for processing, on land).

But then, of course, there are oil pipelines (overland) that pose their own risks to breakage and leakage. But, I'd suppose that there are periodic valve stations along the routes, so a breach can be isolated quickly, resulting in only minor spillages (this, just off the top of my head, mind you...will take more research).

 

[Mick West]

Why do we never hear of oil spills on land? Or at least I can't remember ever hearing about one in the news. Its seems like most oil spills happen at sea, but in the link Mick provided from the EPA its stated that Texas and California are the worst states in the country and they are responsible for something like 93 million gallons of oil spilled. Why don't we ever hear about that in the news?

Even the ones that happen at sea, you don't hear about much except locally.
http://www.click2houston.com/news/t...ast-beach-reopen-following-oil-spill/25503114

There are simply thousands of moderate sized oil spills. An average of 20 a day. It takes a lot to make the news. Deepwater Horizon was 210 million gallons. Exxon Valdez was 11 million gallons, but closer to the beach.

 

[wotgorilla]

Here's a visual:

Combined image....all of the water (both saline and fresh) on the left, and all the atmosphere when accumulated into a sphere (on the right), for comparison to the size of the Earth itself.

ETA the web page: http://www.nextnature.net/author/nextnature/

This is interesting, as to me at least, it just looks wrong if I allow my primitive money brain do the thinking for me. I guess I can't speak for others, but just looking at a satellite photo of the earth, it would appear intuitive that there would be much more water, and it's volume greater than that of the atmosphere. This goes to the genesis of many conspiracy theories, IMO. People will pin their beliefs to gut reactions, and let paranoia do the rest. Any attempts to point out that although you don't want to ignore your intuition, you can't base any conclusions on it alone are dismissed out of hand. This is why critical thinking skills are invaluable. An externally based mechanism must be used to evaluation the validity of what you choose to believe.

 

[WeedWhacker]

...but just looking at a satellite photo of the earth, it would appear intuitive that there would be much more water, and it's volume greater than that of the atmosphere.

Yes, I too had the same reaction, in my primitive monkey brain. (or, maybe the reptile portion in the stem?)

But, upon reflection (and checking the math calculations many times), it is indeed a matter of perception. This planet that we all live on is HUGE!

In terms of its mass, and dimensions, compared to the "consumables" like water and atmosphere.

But, back to atmosphere....this represents all of it, up into the mesosphere...and this is approaching what is determined as "space" (although not yet a perfect vacuum):

(Sorry this image above seems blurred....perhaps I can find a better example).

This might help:

 

[wotgorilla]

(or, maybe the reptile portion in the stem?)

Reptilian? That can't be good. No relation to the Queen of England, hopefully.

Yes, I realize it to be a matter of perception. I think it's likely the one with the oceans is due to the apparent depth when you're on, or in one, then screwing up the extrapolation in your subconscious when you view a photo of the earth.
Like I said, intuition's not always your friend. You've probably heard the one involving Pi, but some readers may not have.
So, the earth is approximately 8kmiles in dia. Wrap a rope around it, then take this 25,000 mile long rope and add a mere 9'. How much does that raise the rope off the earth? 1 foot around the entire globe. Easy. Obvious. No brainer. Yet, the monkey brain still screams, "NO NO NO, 1 foot around the entire world from a percentage increase in length of .0000068? Impossible."

Guess I'm getting far afield of topic with that one. Remove if required.