Avgas and Jet A Contamination Results

[overdrive148]

I'm surprised to see one of your nozzles on the Jet truck is the standard round.. None of ours were like that, all were the "Hoover" nozzle. Personally I think all Jet should be single point, life would be so much easier!

The only reason I know of why we have the round one is because the police/medical choppers use them IIRC. Also, if it was easier to clamp down the single point in the first place I'd agree!

The solubility question has come up before on PoA - about a year ago. A general rule of solubility of organic compounds, like those in Jet-A and 100LL, are that if they are chemically similar they are therefore miscible, so are not going to "settle out." Relevant quote from Linus Pauling's "General Chemistry" in this older thread: http://www.pilotsofamerica.com/forum/showthread.php?p=1227702#post1227702

Great find. More valuable information

Great work, and fascinating.

I wonder what effect the cooler blue wavelength of an LED flashlight vs. incandescent flashlight would have?

Good question. If I can scare up a flashlight of each, I'll test it

1. Would a paper towel work as well as a piece of notebook paper? Seems like the Jet A should still leave behind an oily ring.

3. Does an unagitated mixture ever form a phase boundary if left to sit? (I think you said you're going to test this anyway)

4. What happens if the fuel mixture is well-agitated as it might be during high-rate fueling? I'm curious to what degree the Jet A is actually soluble in 100LL such that, after a few minutes of agitation as would be typical, it might not ever separate because one fuel dissolved in the other. To my thinking, they are both hydrocarbons and should be soluble or at least partially so in the time it takes to fuel an small airplane.

Would the Jet A mixture show up when either bottle was held up in front of a white panel? I hold mine up a couple of inches from the plane, although it's more cream than white, the blue is always very noticeable. I try to do it in direct sunlight, so the shadow is thrown behind the sample instead of looking toward the sun.

So basically, I have these tests lined up.

1. Paper towel evaporation test (adding sticky notes too, out of my own curiosity).

2. Extended contaminated fuel settling test (so far, sources say it won't ever separate out but in the name of experimentation I'll give it a shot).

3. Testing with sunlight behind and shadow in front (possibly in front of white/cream color).

Any other requests? Once it gets slower here I'll give it a try. Overcast layer at 1700 today so probably no joy on the sunlight from behind test just yet.

 

[overdrive148]

Okay, back with some more test results.

Evaporation Testing - Paper towel / Sticky Note
100LL Before

100LL After

Contaminated 100LL/JetA combined - Before

Contaminated 100LL/JetA combined - After

===

As you can see, it looks like no matter what paper you use, the effects are the same. I'd say it's more pronounced in the sticky note / regular paper than the paper towel, but it seems to work regardless.

===

As for viewing the sample against shade or white/cream color:

Against Shadow, down sun

Against white, down sun

Against white, up-sun

===

Unfortunately, it didn't seem to make a difference what angle the sample was viewed at.

I was only able to let a sample sit for ~20 mins, which did not yield any clear border or separation from the looks of it. Seems the miscible thing is true.

 

[Clark1961]

Okay, back with some more test results.
Seems the emulsion thing is true.

nitpick: it's a lack of emulsion thing...100LL and Jet-A are miscible...an emulsion is most definitely two phases (or more)

 

[overdrive148]

nitpick: it's a lack of emulsion thing...100LL and Jet-A are miscible...an emulsion is most definitely two phases (or more)

I knew there was an M in there somewhere, sorry, my bad. Long day

 

[Clark1961]

I knew there was an M in there somewhere, sorry, my bad. Long day

I've been so deep into this crap that it isn't even funny. Sorry for the nitpick. It is amazing what can trip (fail) an emulsion when you want one and it is equally amazing how persistent an emulsion can be when you don't want one.

 

[B350ATP]

Somebody please offer OP a job

Awesome work

 

[SCCutler]

Somebody please offer OP a job

Awesome work

+ 1,000

You helped here, and who knows- you may have saved a life (someday), right here today. Seriously.

Thanks!

 

[petrolero]

That mixture is blue no matter which way you look at it. That is scary.

On the other hand, I see absolutely no reason not to do the very simple paper test (we all carry paper towels) or, absent paper, a simple finger dip test. Hell if you don't want to do that, just pour some on the ground. If you can still see an oil spot after a few seconds, do more testing.

Thanks x1000 to the OP. I don't think it's too dramatic to say you may have saved a life with this.

 

[Clark1961]

Somebody please offer OP a job

Awesome work

I've got a job opening for a lease operator....in Wyoming...

 

[FlyingMonkey]

I will be carrying small post it notes from now on and dripping a few drops of sumped and measured gas on them for each preflight as long as I am flying rented planes that I have not supervised the fueling of. When I get my own plane I will supervise every fueling. Thank you OP.

 

[sferguson524]

Mods - Can we PLEASE get a sticky on this.. This could save someone's life.

 

[overdrive148]

I've been so deep into this crap that it isn't even funny. Sorry for the nitpick. It is amazing what can trip (fail) an emulsion when you want one and it is equally amazing how persistent an emulsion can be when you don't want one.

In fuels or some other chemistry work?

Somebody please offer OP a job

Awesome work

Thank you! I appreciate the job suggestion

+ 1,000

You helped here, and who knows- you may have saved a life (someday), right here today. Seriously.

Thanks!

Thanks x1000 to the OP. I don't think it's too dramatic to say you may have saved a life with this.

At the very least, I know I won't ever fall victim to Jet A in my 100LL.

I've got a job opening for a lease operator....in Wyoming...

If I had any experience whatsoever in the oil field industry I'd look into it, From what a few friends of mine said who have family in the business, you dont get much respect from just walking into a management/supervisor position. Plus I don't have much mechanical experience. Great of you to offer though, I appreciate it

Mods - Can we PLEASE get a sticky on this.. This could save someone's life.

Wouldn't be a bad idea, but up to them

I will be carrying small post it notes from now on and dripping a few drops of sumped and measured gas on them for each preflight as long as I am flying rented planes that I have not supervised the fueling of. When I get my own plane I will supervise every fueling. Thank you OP.

You are welcome. I'm glad that I'm in the position to be working around fuels and have the ability to do all this testing for a good cause.

 

[Clark1961]

In fuels or some other chemistry work?

Technically "other chemistry" since we tend to use stuff before it goes through the refinery and gets expensive. Sometimes we'll use diesel but that's getting tougher (almost impossible) to do from a regulatory point of view. We used to use it all the time but now have to use substitutes that can pass the environmental tests.

 

[MichaelO]

So, a ramp guy screws up, people die because of that person's negligence, and no one is held to account EXCEPT the pilot, who died? Is this how it works?

 

[PaulS]

So, a ramp guy screws up, people die because of that person's negligence, and no one is held to account EXCEPT the pilot, who died? Is this how it works?

The pilot is responsible for the flight, period. A connecting rod about to break? Undetectable and probably not the pilot's fault. Incorrect fuel? Should've been caught by the pilot. Pilots should learn from this error, adapt and move on.

If you pilot an aircraft, you accept the responsibility to do everything possible for a safe flight, checking the fuel is high on the list.

This poor guy made a mistake and paid the ultimate price, may he rest in peace.

 

[RalphInCA]

Excellent thread.

Although not as critical from a safety standpoint as mixing JetA with 100LL, I wonder if there is a way to detect MoGas / 100LL contamination?

Or, as I often do, am I worrying about something that is not a real problem?

 

[PaulS]

Excellent thread.

Although not as critical from a safety standpoint as mixing JetA with 100LL, I wonder if there is a way to detect MoGas / 100LL contamination?

Or, as I often do, am I worrying about something that is not a real problem?

It's not as easy as I was led to believe it was. A gentleman in this thread did an experiment and he did an excellent job. It's worth reading every post.

http://www.pilotsofamerica.com/forum/showthread.php?t=74702

 

[Vf6cruiser]

Very nicely done and hugely informative......a round of applause for this guy. I worked around Jet A for years and was always told you could toss a match in a puddle of it and it would go out, that the solid fuel was not that explosive, only the fumes. Full disclosure, your employment may be shortened if you are on the ramp trying the lit match thing with Jet A. I always laughed at the fire trucks and the aluminum people frantically scurrying over to our side of the ramp for the smallest fuel spill. They couldn't wait to cover everything in foam...........different strokes........

 

[Jim Logajan]

So, a ramp guy screws up, people die because of that person's negligence, and no one is held to account EXCEPT the pilot, who died? Is this how it works?

That is not how it works. The FAA regulation in 91.3 that states the PIC is the final authority and responsible for the aircraft only affects the FAA's potential actions, not those of other entities. Civil lawsuits, on the other hand, are not (well should not, at least) be affected by anything other than an actual analysis of facts and fault apportionment. It is not difficult to find accidents where the FAA or NTSB found the pilot at fault per the 91.3 pre-assumption but a civil court found a different party wholly or partially at fault for the same accident.

There is no reason in my humble opinion why a civil court should not find the FBO at least partially at fault for the accident that spawned the OP's useful investigation.

Pragmatically speaking the pilot should have been more alert for their own sake anyway - but just as pragmatically there is a limit to how much responsibility should be dumped on a single person. Holding others responsible for their mistakes is important even if some regulation attempts to dump final responsibility onto someone else. After all, 91.3 could be said to imply that even someone who maliciously, rather than accidentally, added Jet-A to a fuel tank could not be held responsible for a subsequent accident because the pilot didn't verify the proper fuel was added.

 

[Jaybird180]

That is not how it works. The FAA regulation in 91.3 that states the PIC is the final authority and responsible for the aircraft only affects the FAA's potential actions, not those of other entities. Civil lawsuits, on the other hand, are not (well should not, at least) be affected by anything other than an actual analysis of facts and fault apportionment. It is not difficult to find accidents where the FAA or NTSB found the pilot at fault per the 91.3 pre-assumption but a civil court found a different party wholly or partially at fault for the same accident.

There is no reason in my humble opinion why a civil court should not find the FBO at least partially at fault for the accident that spawned the OP's useful investigation.

Pragmatically speaking the pilot should have been more alert for their own sake anyway - but just as pragmatically there is a limit to how much responsibility should be dumped on a single person. Holding others responsible for their mistakes is important even if some regulation attempts to dump final responsibility onto someone else. After all, 91.3 could be said to imply that even someone who maliciously, rather than accidentally, added Jet-A to a fuel tank could not be held responsible for a subsequent accident because the pilot didn't verify the proper fuel was added.

Jim- I am going to transpose this to another thread, since it works so well.

 

[overdrive148]

Excellent thread.

Although not as critical from a safety standpoint as mixing JetA with 100LL, I wonder if there is a way to detect MoGas / 100LL contamination?

Or, as I often do, am I worrying about something that is not a real problem?

Good question. I might look into testing that. Not sure though, both are gasoline so I doubt they'd fall out of each other (due to hydrocarbon overlapping). Would it be as bad as Jet A in piston engines though? I think in a pinch we used 100LL in the avgas truck once or twice in a pinch and it still ran, just with more difficulty.

It's not as easy as I was led to believe it was. A gentleman in this thread did an experiment and he did an excellent job. It's worth reading every post.

http://www.pilotsofamerica.com/forum/showthread.php?t=74702

The pilot is responsible for the flight, period. A connecting rod about to break? Undetectable and probably not the pilot's fault. Incorrect fuel? Should've been caught by the pilot. Pilots should learn from this error, adapt and move on.

If you pilot an aircraft, you accept the responsibility to do everything possible for a safe flight, checking the fuel is high on the list.

This poor guy made a mistake and paid the ultimate price, may he rest in peace.

Precisely why I did the testing. Seriously if I was still in flight training, I would've looked at the sample, saw it was blue, and threw it out without a second thought. Now I know better

Very nicely done and hugely informative......a round of applause for this guy. I worked around Jet A for years and was always told you could toss a match in a puddle of it and it would go out, that the solid fuel was not that explosive, only the fumes. Full disclosure, your employment may be shortened if you are on the ramp trying the lit match thing with Jet A. I always laughed at the fire trucks and the aluminum people frantically scurrying over to our side of the ramp for the smallest fuel spill. They couldn't wait to cover everything in foam...........different strokes........

I've heard the same thing but my boss definitely wouldn't like me throwing matches into fuel!

 

[Capt. Geoffrey Thorpe]

Good question. I might look into testing that. Not sure though, both are gasoline so I doubt they'd fall out of each other (due to hydrocarbon overlapping). Would it be as bad as Jet A in piston engines though? I think in a pinch we used 100LL in the avgas truck once or twice in a pinch and it still ran, just with more difficulty.

They mix just fine - I usually use auto fuel but add 100LL when traveling. The only issues would be with octane (mix will be lower than 100) and vapor pressure. E-10 is not good for some of the rubber components often found in aircraft, but a one time contamination is not likely to make a difference.

 

[overdrive148]

Found a good source from AOPA on things to watch for with fuel in general today, specifically...

• Make sure you have the proper fuel type and
grade.

• Hold your sample container against a white
background to gauge the color of the fuel.

• The most common aviation gasoline is 100LL
(low lead), which is a pale blue color; 80
octane gasoline is red. You’re unlikely to find
straight 100 octane (green).

• Jet fuel is clear or slightly yellow in color and
it takes a high concentration of jet fuel in gasoline
before you’ll notice a color change. A better
test is to put a drop of fuel on plain bond
paper or a business card. Avgas will evaporate
quickly. Jet fuel takes longer and will leave a
ring of discoloration on the paper.

• Does the sample smell like gasoline? Jet fuel
has a distinctly

Back in 2005 and they were saying that the color test is a poor one to detect contamination

flighttraining.aopa.org/pdfs/SA16_Fuel_Awareness.pdf ‎ for those who are interested.

 

[overdrive148]

Looks like it's confirmed mis-fueling with the 421 that went down in TX this month:

According to the responding Federal Aviation Administration (FAA) inspector the airplane experienced a dual engine failure after departure and the pilot made a forced landing onto the highway. The airplane came to rest in the grassy median and the right fuel tank ruptured during the accident sequence. The smell of Jet-A fuel was prominent at the accident scene.

Fuel records obtained from KLFK revealed that the accident airplane was fueled with 53 gallons of Jet-A on the previous day.

http://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20150417X20434&key=1

 

[Dennis McKim]

Looks like it's confirmed mis-fueling with the 421 that went down in TX this month

Per the all-knowing Wikipedia:

Some 421s have been modified to accept turboprop engines, making them very similar to the Cessna 425, which itself is a turboprop development of the 421.

Is it reasonable to think that, while being present during the fueling of one's plane is always advisable, it is even more important if similar looking but turbine-powered aircraft exist?

Edited to add: I ask that because I sometimes peruse the comments section of AirNav's FBO listings, and frequently see laudatory comments similar to "when we returned in the morning, they had already pulled it from the hangar and fueled it, just as we requested." I'm now seeing the downside of this...

 

[exncsurfer]

Makes you wonder why they don't dye the jet-a, red perhaps, red and blue makes purple, you got purple, you got a problem.

I would've said yellow but that would make green which is 100.

Awesome job to OP on this thread!

 

[exncsurfer]

Also, never handled Jet-A how would you describe the distinct smell? Kerosene?

 

[MAKG1]

A little Jet A would be hard to spot, regardless of dye. A lot is not blue.

The standard way to test for Jet A in gasoline is to drip it on white paper and let it evaporate. Gasoline evaporates readily. The Jet A won't.

 

[exncsurfer]

Right, I see that from OP photos, I think CFI's should add this to standard pre-flight routine. POH should add it to checklist items.

 

[overdrive148]

Is it reasonable to think that, while being present during the fueling of one's plane is always advisable, it is even more important if similar looking but turbine-powered aircraft exist?

Edited to add: I ask that because I sometimes peruse the comments section of AirNav's FBO listings, and frequently see laudatory comments similar to "when we returned in the morning, they had already pulled it from the hangar and fueled it, just as we requested." I'm now seeing the downside of this...

If I owned a 421 or 425, I would absolutely go out of my way to make it expressly known what to fuel with and would double check fuel sumping/receipts if I couldn't supervise fueling myself. Any aircraft I've flown since this I did the testing has been subject to the paper test at the expense of maybe 1 minute in the preflight.

Makes you wonder why they don't dye the jet-a, red perhaps, red and blue makes purple, you got purple, you got a problem.

I would've said yellow but that would make green which is 100.

Awesome job to OP on this thread!

Thank you!

Isn't/wasn't 80 octane red though? Also not sure how they'd combine color wise considering I know little about the chemistry involved but the choice behind the straw color for Jet A is interesting/questionable maybe.

Also, never handled Jet-A how would you describe the distinct smell? Kerosene?

It has a sharp edge to it, like kerosene or nail polish. Ours includes Prist which is an anti-icing additive, but I don't think that has any effect on the smell. Could be wrong though.

Mostly bumping the thread for awareness and because it mirrors what happened last year and I'm sure a few more times before that. Tell your friends!

 

[Cpt_Kirk]

Just now saw this thread. Good work.

 

[exncsurfer]

Not trying to beat this thread to death but I had one last thought on this, Question for the scientists/engineers out there. Wouldn't it be possible to design a sensor for this sort of thing? Have a nice idiot light on the annunciator panel, fuel ERROR,

I mean if a Kia can tell you if the tire is low or the oil needs changing based on a viscosity detector, c'mon.

 

[Geico266]

Not trying to beat this thread to death but I had one last thought on this, Question for the scientists/engineers out there. Wouldn't it be possible to design a sensor for this sort of thing? Have a nice idiot light on the annunciator panel, fuel ERROR,

I mean if a Kia can tell you if the tire is low or the oil needs changing based on a viscosity detector, c'mon.

The sensor is called the PIC, but that would be a good idea.

 

[Chrisj13]

No need to carry paper around to test which fuel is which....One should taste like straw, one like blueberries or something...

 

[overdrive148]

Raising this thread up from the dead for more awareness, especially since flying season is upon us again.

 

[SixPapaCharlie]

What an awesome thread!!!

 

[PaulMillner]

Not trying to beat this thread to death but I had one last thought on this, Question for the scientists/engineers out there. Wouldn't it be possible to design a sensor for this sort of thing? Have a nice idiot light on the annunciator panel, fuel ERROR, I mean if a Kia can tell you if the tire is low or the oil needs changing based on a viscosity detector, c'mon.

Sure, a vibrating reed densitometer could distinguish between jet and gasoline, or a near-IR analyzer could distinguish between 50 octane jet fuel and 100 octane gasoline... who wants the cost and weight penalty for such an unlikely (though not of course impossible) error?

Paul

 

[nrpetersen]

Maybe the know-mores can answer but my guess is the Jet A fraction only has to be more than a couple of percent before a piston engine would begin detonating. Right?

 

[NordicDave]

Alway save your fuel receipts with your tail number.

A few years ago in my area Shell sold contaminated fuel. No incidents occurred, but they bought new engines for everyone who had a fuel receipt within a certain time window.

 

[Pinecone]

Old thread, and interesting.

A couple of things. In the day, USAF used JP-4, which was a 50/50 mix of kerosene and gasoline. So it is unlikely that a mixture of Jet A and 100LL will ever separate. The Navy used JP-5 which more kerosene based. It was lower vapor pressure and harder to ignite to safer on board carriers. Currently the military uses JP-8, which is kerosene based. They even use this in ground based diesel equipment.

In the old days (even before my time) there were 4 grades of AVGAS. 80/87 (Red), 91/96 (Blue), 100/130 (Green), and 115/145 (Purple). With those, if they were mixed, the dyes were supposed to react and the fuel would be clear. So when you sumped the tanks, you wanted to see color.

There would be no way of knowing if you mixed MOGAS and 100LL. They would just mix. For your car, the station only has two grades of fuel, regular and premium (normally 87 and 91 or 83). The mid grade of 89 is a mixture of the two, mixed at the pump.

And 94UL is the same as 100LL, but without the lead. So unless they dye it with a different color AND that the dyes work like in the old days, they are the same so mix perfectly.