Water in my tanks

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IlyaK18

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IlyaK18
Hello

I'm getting my PPL on a Piper Archer 3 and I have noticed that a large amount of water comes out of the tanks when I pre-flight. I use one of those large gats fuel testers
(http://www.flyplatinum.com/store/16-31-zoomed/gats-jar-fuel-tester.jpg).

Sometimes the whole things gets filled with water, I empty it out, and sump the tank again, then about 50% of it gets filled with water. So quite a lot water comes out. My instructor says it's okay, however I have spoken to a lot of other people and they all say that it's not normal.

Should I be concerned?

Thanks

Also - I have been told that the fuel cap has been replaced recently.
 
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That's not normal. Sounds like your fuel cap rubber gaskets need to be replaced.
 
No, it's not normal. A CFI should know it's not normal.

The fuel cap gaskets are easily replaced on a PA-28 and when the gaskets leak they do let rainwater in the tank. Never hurts to give the tanks a good visual inspection but they are pretty tough compared to the structure around them (excepting the spar of course). The gaskets are cheap. Supposedly the Piper OEM gaskets are better (last longer) than the other brands available. I dunno.
 
I'd be concerned that a CFI/company renting you the airplane would claim that is normal. If such a common, cheap, and easy maintenance item hasn't been addressed I'd hate to think what else could be going on!
 
It doesn't sound good, that's for sure. For what it's worth, the only time I found water in the tank was when I spent probably 15 minutes trying to unscrew the stupid fuel cap from the top of the tank. I don't remember whether it had rained the night before, but I can't imagine there was any way it was getting through the top. Maybe humidity? It was in a Mid-Atlantic summer. Maybe that's what's going on in your case?

But that one time I drained about a quarter cup of water from the 18 gallon tank...this seems like a whooolllleeee lot more water. Are you regularly draining that much from both tanks?
 
I'd be concerned. I've only seen a few drops of water before, not a whole container.
 
The other possibility is your fuel source is contaminated. As I said, rainwater leaking past the caps is the most likely cause.
 
In twelve years of flying, and two owned airplanes, I've never sumped a drop of water.

No it's not normal.

maybe humidity?
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No way.

As others have said, it's either contaminated fuel or the caps. Is it parked outside?

TUPilot said:
I'd be concerned that a CFI/company renting you the airplane would claim that is normal. If such a common, cheap, and easy maintenance item hasn't been addressed I'd hate to think what else could be going on!
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+1,000
 
That seems like a heck of a lot of water to get out of fuel tanks on a PA28. Not saying it can't happen, but out if all the PA28s and PA32s I've flown, I've never seen a drop of water. Seems like the cap design is pretty good at keeping water out. Only airplane I've gotten that much water out of is my 1948 170....wretched recessed cap design.

Are you getting water from both tanks, or just one? If both tanks, I'd suspect it is coming from the source (truck). If just one and it is a regular occurrence, Id wonder about an opening in the wing somewhere. PA28s are a wet wing, correct?

Definitely NOT normal.
 
How many sumps on an Archer 3? Are you getting this amount form each sump? From the gascolator sump?
 
jpower said:
It doesn't sound good, that's for sure. For what it's worth, the only time I found water in the tank was when I spent probably 15 minutes trying to unscrew the stupid fuel cap from the top of the tank. I don't remember whether it had rained the night before, but I can't imagine there was any way it was getting through the top. Maybe humidity? It was in a Mid-Atlantic summer. Maybe that's what's going on in your case?

But that one time I drained about a quarter cup of water from the 18 gallon tank...this seems like a whooolllleeee lot more water. Are you regularly draining that much from both tanks?
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It is not always a full cup of water, but there is always some water. I will check the O rings next time I fly it . The same fuel truck fuels up the whole fleet and this is the only one with water in it, so its not the fuel I think.
 
Mooneys were very susceptible to this IF left outside the 201 I flew some quit on takeoff at teterboro just after an annual due to being left outside and the seals on the gas caps leaking. The annual should have caught the trouble it caused in the filter under the seat according to the mechanic at teterboro. If the runway had been shorter or had I requested an intersection takeoff I would have died. And yes, I always drained the sumps before flying.
 
Yeah...That is not normal. I was in training for 10 months before I saw my first drop of water from a tank. And it was some other guy's plane at the FBO where I was doing a ground school course:yikes::yikes::yikes:. He came in and showed all of us in the breakroom what he had found- I could tell this was his FIRST time seeing the stuff in the tester too!!!! A teaching moment for all...havnt seen any since, and that was in July 2013!

As others have said..check those gaskets on the caps. The engine does not like drinking water so I have been told!
 
IlyaK18 said:
It is not always a full cup of water, but there is always some water. I will check the O rings next time I fly it . The same fuel truck fuels up the whole fleet and this is the only one with water in it, so its not the fuel I think.
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Both tanks, or just one?
 
Does it sit outside? The mooney, as I remember had replacement, improved fuel caps that were purchased after my close call. It was also moved into a hangar. No more problems and switched to different mechanic.
 
Jimmy cooper said:
Mooneys were very susceptible to this IF left outside the 201 I flew some quit on takeoff at teterboro just after an annual due to being left outside and the seals on the gas caps leaking. The annual should have caught the trouble it caused in the filter under the seat according to the mechanic at teterboro. If the runway had been shorter or had I requested an intersection takeoff I would have died. And yes, I always drained the sumps before flying.
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Yep. If mine had to sit out I had special covers that I installed that covered the recessed fuel caps. That's in addition to replacing the gas cap seals every annual.
 
I'd worry about the seals on the caps. Never good to be getting a great amount of water on sumping the tanks. Aircraft engines don't like water.
 
frfly172 said:
I'd worry about the seals on the caps. Never good to be getting a great amount of water on sumping the tanks. Aircraft engines don't like water.
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Even if the seals are bad, I am having a hard time seeing how the OP could be getting as much water from the sumps as he describes due to the cap design. Piper caps are raised and overlap the opening.
 
Guess it would depend on wether the tanks are full or not,outside temp. And how much room for condensation build up ,if seals are not tight.
 
frfly172 said:
Guess it would depend on wether the tanks are full or not,outside temp. And how much room for condensation build up ,if seals are not tight.
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I suppose with the right humidity/temp conditions, it is possible, but seems strange to be such a continuing problem.
 
frfly172 said:
Guess it would depend on wether the tanks are full or not,outside temp. And how much room for condensation build up ,if seals are not tight.
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OWT...you can do the math on it and easily determine that it's not possible. 20 gallons of air at a 100% humidity, 20 degree daily range, over thirty days will still only produce about an ounce of water (IIRC, I've done the math here before).

AND that assumes:

1. a full exchange of air in the tanks every day...and that ain't gonna happen.

and

2. that the air in the tanks gets as cold at night as the ambient temperature does...and that ain't gonna happen either.

Condensation simply doesn't produce enough liquid to show up while sumping unless the plane sits idle for months...or years...at a time.
 
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In case the message hasn't been delivered clearly enough. #1 Water, any water, in the fuel tank is very unusual and needs to be dealt with immediately. #2 Always sump your fuel tank, every time, no exceptions.

I've been flying for almost 20 years. I've sumped water maybe twice and never more than a few tablespoons. Immediately replaced the O-rings on my fuel caps and fixed the issue.

Of the easiest to prevent and generally stupidest things that kill pilots: #1 - Running out of gas, Fuel Contamination is probably in the top five.
 
timwinters said:
OWT...you can do the math on it and easily determine that it's not possible. 20 gallons of air at a 100% humidity, 20 degree daily range, over thirty days will still only produce about an ounce of water (IIRC, I've done the math here before).



AND that assumes:



1. a full exchange of air in the tanks every day...and that ain't gonna happen.



and



2. that the air in the tanks gets as cold at night as the ambient temperature does...and that ain't gonna happen either.



Condensation simply doesn't produce enough liquid to show up while sumping unless the plane sits idle for months...or years...at a time.
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This. ^^^ And thank you, as I've done the math, too.

I find it fascinating how many old wives tales are propagated in aviation.
 
I train in a PA28. I found like four drops of water in one tank once. These planes are not hangered and are located in NJ so we get a fair amount of rain and wind. There is no reason for water in the tanks.
 
You sure nobody is trying to kill you (or your instructor)? Because it seems strange that every time you go to fly you find what oddly appears to be the equivalent volume of a standard water bottle in your fuel tank...:dunno:
 
Silvaire said:
You sure nobody is trying to kill you (or your instructor)? Because it seems strange that every time you go to fly you find what oddly appears to be the equivalent volume of a standard water bottle in your fuel tank...:dunno:
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The CFI is just checking to insure you are doing a good pre-flight! :P
 
I highly suspect contaminated fuel from your FBO, especially if you hangar your plane. Sump your fuel after every fill, that will tell you where the water is comimg from.
 
drotto said:
I train in a PA28. I found like four drops of water in one tank once. These planes are not hangered and are located in NJ so we get a fair amount of rain and wind. There is no reason for water in the tanks.
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Clip4 said:
I highly suspect contaminated fuel from your FBO, especially if you hangar your plane. Sump your fuel after every fill, that will tell you where the water is comimg from.
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My airplane is tied down outside, and in many hundreds of flights I have never gotten water during sumping. Additionally, I have always sumped after filling, something I rarely see people do :confused:.
 
What do you guys with Comanches do for fuel sumping? The under-body fuel drain actuated by the lever in the cabin does not lend itself to easy sumping....
 
dans2992 said:
What do you guys with Comanches do for fuel sumping? The under-body fuel drain actuated by the lever in the cabin does not lend itself to easy sumping....
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What you don't see can't hurt you ... right?? ;)
 
Fearless Tower said:
Even if the seals are bad, I am having a hard time seeing how the OP could be getting as much water from the sumps as he describes due to the cap design. Piper caps are raised and overlap the opening.
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FT, the Archer 3 caps are recessed, I think a design shared only with the Saratoga(?) - rain water lies in the recess and drops unhelpfully into the tank whenever you remove the caps, even if (like me) you try to blow most of it out first.

OP, I too have been getting rainwater ingress. Usually, a very small amount in the bottom of the tester, but occasionally up to a half pint in one tank. The recessed caps look good but are terrible compared to the old type that sits proud.

This is not contamination, as our club's Challenger 180 (with the old type caps!) or other local aircraft do not suffer and use the same tanker. Our aircraft sit out overnight as there's no hangarage. First time I discovered it, I had the gaskets replaced, even though they looked perfect. No change. Then I asked the mechanic to bend the cap (tines? the bits that lock the cap onto the tank collar - you know what I mean) slightly to ensure a tighter fit. This worked on the problem tank. The other one's now letting water in - the last time this was after a lot of rainfall and an overnight freeze. I was de-icing the aircraft and the cap recesses were frozen solid so the caps would not move. I suspect water freezing around the gaskets let water in during the freezing and thawing.

Let us know if any of the above help you...
 
b3bmcwi said:
FT, the Archer 3 caps are recessed, I think a design shared only with the Saratoga(?) - rain water lies in the recess and drops unhelpfully into the tank whenever you remove the caps, even if (like me) you try to blow most of it out first.
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Interesting. Any idea when they changed it? I don't think I have flown a PA28 or 32 newer than 1980.
 
ElPaso Pilot said:
This. ^^^ And thank you, as I've done the math, too.

I find it fascinating how many old wives tales are propagated in aviation.
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I've heard this "condensation myth" alleged before, supposedly by HVAC "experts" and others who have "done the math." However, after decades, apparently no one has been able to convince the FAA or NTSB, both of which continue to promote the risk of aircraft fuel tank condensation.

Now, I would agree that condensation is an impractical explanation for a large quantity of water, and would bet in the OP's case the problem is at the caps. If my aircraft had recessed caps, I think that I would be looking for a good solution to cover them while the aircraft is on the ground exposed to the elements.


JKG
 
This is timely, as there was an accident analysis in this month's Flying magazine involving a Cherokee 6.

It had been sitting in a hangar for 2 months, about half full of fuel. When the pilot went to fly it after that period of inactivity he had the FBO top it off. Line men interviewed after the accident noticed he did a "quick" pre-flight with minimal fuel inspection.

The plane lost power shortly after take off and crashed into the roof of a house. Pilot died. Not sure about the unfortunate occupants of the house....

NTSB determined that the fuel had water due to condensation/moisture build up over those 2 months of inactivity and, based on interviews and witnesses, the pilot did not properly drain/examine fuel.....

The article pointed out that there are just 3 ways water can get into the tanks:
1.) condensation
2.) bad seals on caps
3.) contaminated fuel source

#2 was ruled out because the plane was in a dry hangar
#3 was ruled out because 6 other planes were fueled within an hour of the accident plane and none had any problems. They also did a test of the fuel in the truck immediately after the accident.
 
JGoodish said:
I've heard this "condensation myth" alleged before, supposedly by HVAC "experts" and others who have "done the math." However, after decades, apparently no one has been able to convince the FAA or NTSB, both of which continue to promote the risk of aircraft fuel tank condensation.

Now, I would agree that condensation is an impractical explanation for a large quantity of water, and would bet in the OP's case the problem is at the caps. If my aircraft had recessed caps, I think that I would be looking for a good solution to cover them while the aircraft is on the ground exposed to the elements.


JKG
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Let me clarify --

1) If someone is finding significant quantities of water in an aircraft fuel tank that is flown and sumped regularly, it is highly likely that the source is something other than condensation.

2) In this case, telling the OP to keep his tanks full and the problem will be solved is doing him a dangerous disservice. He/she needs to find the real root cause, as you mentioned.

3) Condensation can occur over long periods of time, particularly in aircraft that are rarely / never sumped. There is no need to "convince" the FAA otherwise.

4) Again, the guys that are frequently finding large quantities of water need to find the non-condensation related source.
 
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