Keep sumping!

tonycondon

tonycondon

Gastons CRO (Chief Dinner Reservation Officer)
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Tony
Before yesterdays 421 flight, had an interesting preflight. The left tip tank sump showed some water. in fact it showed a lot of water. on a standard 5 or 6inch tall fuel sampler i bet there was an inch and a half of water. had to walk outside the hangar to dump it so i decided to sump the right wing since it was closer to the door. right wing was totally clean. back to the left wing but did the inboard sumps first. first sampler filled up. no demarcation line between water and fuel, but dang it just didnt look quite right. smelled it and i could smell avgas but shoot that sampler reeks of avgas anyway. showed it to my copilot and we both concluded that, in fact, the entire sampler was full of water!

dumped it and sampled again, another full sampler of water. i think there may have been a third full sample of water before finally a layer of gunk (copilot described it as a "goober") came out and then blue fuel. after a couple more samples from that sump it was clean fuel. the next some outboard had a little water but was quickly clean. back out to the tip tank and only a small amount of water was found which was quickly cleaned up. all in all we took a hell of a lot of water out of the sumps!

since it was only in the one wing i suspect that the problem was at the truck. our guys sump the truck regularly but i suspect with the rainy weather lately contamination found its way in. IMO leaky caps on fuel tanks is the biggest contributor to water in the fuel.

Interesting point is that it seems like every time I sample the 421 at least one of the sumps has a little water or dirt in it. The 172s and 182RG, fueled from the same source, seem to always be clean. I think the 421 must just have better placement of fuel sumps to collect the water and debris.
 
tonycondon said:
Interesting point is that it seems like every time I sample the 421 at least one of the sumps has a little water or dirt in it. The 172s and 182RG, fueled from the same source, seem to always be clean. I think the 421 must just have better placement of fuel sumps to collect the water and debris.
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That is not a very comforting thought.

One of my instructors suggested rocking the wings and pushing down on the tail of the 172RG before sumping to help move any water to the sumps. Wonder if I chould add that to my checklist as a reminder?
 
I use a GATTS jar with its larger capacity, but I have a standard sampler in case I misplace the jar. Usually the samples are clean, but occasionally I'll get a ball of water. I'm assuming condensation as I have to leave an air gap at the top of the tanks on the IAR otherwise the fuel just runs out the vents.

It takes so little time to sump the tanks.
 
Tony, Have you considered a GATS jar? I like it for 2 reasons. You can put the sumped fuel back in the tank (strainer/water seperator), and you can take a good sample (mine can hold 12oz).

http://www.sportys.com/acb/showdetl.cfm?DID=19&Product_ID=1279

One additional benefit I didn't think of right away is that this fuel tester is mine, and I don't have to worry about my fellow club members absconding with the one in the plane :)

Pete
 
My primary CFI told me of flying the Aztec one day and pulling four samples of 100% water before he got to any fuel.

Personally, I have never found water in my fuel that I can remember. But, I sump 'em anyway - That's a killer item.
 
airplane was washed this week, and could've been fueled in the rain on wedensday. im leaning towards the washing that did it, since it was only the left wing. I bet theres a leaky cap on one of those tanks...
 
I learned to fly in a Symphony (see avatar picture) and pulled water nearly every time I sumped the wings. It's fuel caps were flush against the wing surface. I also used a GATTs jar, but I never put the samples back in because 1) I didn't trust the water/gas screen, and 2) I would have had to pull out the ladder again.

I have yet to pull any water out of a Skyhawk, but I do sump religiously.

My DPE asked me how I could tell the difference between a sampler full of water (with a little fuel for color/smell) and a sampler full of avgas. The answer was the feel of the sample on your fingers, and the evaporation from your fingers. (Though in North Carolina in the summer, water evaporated as fast as the gas.)
 
flyingcheesehead said:
My primary CFI told me of flying the Aztec one day and pulling four samples of 100% water before he got to any fuel.

Personally, I have never found water in my fuel that I can remember. But, I sump 'em anyway - That's a killer item.
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I heard a similar story about an Aztec... the pilot did a visual inspection first, and it looked full. No demarcation line in any of the samples, and it was blue(ish) and smelled like fuel.
But after both engines quit while taxiing to the active and failed to restart, it turned out the tanks contained mostly water! :eek:

It had been sitting outside during a long spell of heavy (tropical) rain... classic leaky-cap story.

I've found traces a few times, but only had to take more than two samples once. Whenever I do find water, even if I get a clean sample after, I take more time to taxi and run up, just in case.
 
Glad you caught it.

AT an airport right by house a linesman just got fired for putting 200 gallons of 100LL into a Citation. They jets crew took off and figured something was not right and made it back safely. But I wonder if they had done some sort of fuel inspection (not sure they sump) would they have found the lineman's mistake.

BTW when you put 100LL into a jet engine what do you have to do with the engines? Is there some sort of inspection, rebuild, or what?
 
smigaldi said:
Glad you caught it.

AT an airport right by house a linesman just got fired for putting 200 gallons of 100LL into a Citation. They jets crew took off and figured something was not right and made it back safely. But I wonder if they had done some sort of fuel inspection (not sure they sump) would they have found the lineman's mistake.

BTW when you put 100LL into a jet engine what do you have to do with the engines? Is there some sort of inspection, rebuild, or what?
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We can run AvGas or even AutoGas, but we have to 1) stay below 18,000 feet (prefer 10K), 2) keep the aux fuel pumps on at all times, 3) flush the system and borescope the hot section if it's less than 10 hours and do a full hot section inspection if it's used for more than 10 hours. The engines will take it, they just won't like it.

And no, we don't sump our tanks (the mechanics do, but pilots aren't allowed).
 
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Been there. As a CFI watched, I started moving on (I have 4 sumps) and we both realized that the sampler had dirt floating in it. Smell. Touch. It's water. The whole tube. Another half tube was water.

I opened all 4 sumps and drained and drained from the center while moving the fuel selector to each tank.

This was when the plane was parked outside. The fuel cap seals let rainwater in during a downpour. I had the seals replaced.

I got the Sporty's fuel tester with the float ball. It looks like they don't have it any more.
 
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I've only found contamination in sumped sample once. Not sure what that junk coming out of that 182s tank was, but it wasn't water or fuel. Almost looked like leaves from a tree. That plane didn't fly again until the whole fuel system was checked and cleaned. Never did hear what the junk was, either.
 
Teller1900 said:
We can run AvGas or even AutoGas, but we have to 1) stay below 18,000 feet (prefer 10K), 2) keep the aux fuel pumps on at all times, 3) flush the system and borescope the hot section if it's less than 10 hours and do a full hot section inspection if it's used for more than 10 hours. The engines will take it, they just won't like it.

And no, we don't sump our tanks (the mechanics do, but pilots aren't allowed).
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We would throw 100LL in the turbine AirTractors (flying PT-6A's) if we were stuck with no other options (pilot wants to get home, we are out of Jet-A on our truck, po-dunk airport doesn't sell Jet-A). Some of the pilots said it killed any algae that might have formed in the tanks and gave the system a good cleaning out. They didn't like to do a lot of spray 'work' with it, though - mostly just finish up a field and ferry home. Something about having a flame-out with high octane fuel doesn't sound very fun to me. ;)
 
CJones said:
We would throw 100LL in the turbine AirTractors (flying PT-6A's) if we were stuck with no other options (pilot wants to get home, we are out of Jet-A on our truck, po-dunk airport doesn't sell Jet-A). Some of the pilots said it killed any algae that might have formed in the tanks and gave the system a good cleaning out. They didn't like to do a lot of spray 'work' with it, though - mostly just finish up a field and ferry home. Something about having a flame-out with high octane fuel doesn't sound very fun to me. ;)
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I'm sure the mighty PT-6 (what we use) could take a lot more abuse than the FAA lets us dish out. But ya, I don't think I'd want to be doing their kind of flying with anything other than clean and reliable Jet-A. I've heard the ITTs get downright scary with high octane fuel. 1000 C just doesn't sound fun to me.
 
Teller1900 said:
I'm sure the mighty PT-6 (what we use) could take a lot more abuse than the FAA lets us dish out. But ya, I don't think I'd want to be doing their kind of flying with anything other than clean and reliable Jet-A. I've heard the ITTs get downright scary with high octane fuel. 1000 C just doesn't sound fun to me.
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Afraid the engine would reach warp speed before the airframe could catch up with it? :)
 
tonycondon said:
airplane was washed this week, and could've been fueled in the rain on wedensday. im leaning towards the washing that did it, since it was only the left wing. I bet theres a leaky cap on one of those tanks...
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Next time you preflight or fuel it, check the fuel caps. If they're like the ones on the RV, there is a nylon lined lock nut on the back side of the cap. If you tighten it down, it squashes the rubber washer out and makes a tighter seal. If you loosen it, it releases pressure and the washer sucks back in for a looser fit. We usually need to tighten or loosen it in between change from winter to summer and vice versa. I'm thinking it has a tendency to 'swell' in the summer and 'shrink' in the winter, but can't remember exactly. Might be time for Beaver to adjust the fuel cap washers. ;)
 
CJones said:
Next time you preflight or fuel it, check the fuel caps. If they're like the ones on the RV, there is a nylon lined lock nut on the back side of the cap. If you tighten it down, it squashes the rubber washer out and makes a tighter seal. If you loosen it, it releases pressure and the washer sucks back in for a looser fit. We usually need to tighten or loosen it in between change from winter to summer and vice versa. I'm thinking it has a tendency to 'swell' in the summer and 'shrink' in the winter, but can't remember exactly. Might be time for Beaver to adjust the fuel cap washers. ;)
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yea, Jeff tightened down the main tank cap, need to get the aux done too.
 
Add me to the list of those who:

1) have never found water in fuel (7 years of flying, two planes, but always hangared)
2) always rock the wings, very first thing when walking up to the plane
3) ALWAYS sump.
 
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Teller1900 said:
I'm sure the mighty PT-6 (what we use) could take a lot more abuse than the FAA lets us dish out. But ya, I don't think I'd want to be doing their kind of flying with anything other than clean and reliable Jet-A. I've heard the ITTs get downright scary with high octane fuel. 1000 C just doesn't sound fun to me.
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I can't imagine why high octane (resistance to detonation) would increase ITT. In any case I'd think you could manage ITT with the throttles. AFaIK the major issue is that gasoline is a much poorer lubricant than jet-A and fuel pump damage is possible using gasoline for an extended period.

That said I have no personal experience running turbines on gasoline (or jet fuel for that matter).
 
rottydaddy said:
I've found traces a few times, but only had to take more than two samples once. Whenever I do find water, even if I get a clean sample after, I take more time to taxi and run up, just in case.
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I've never found more than a drop or two in my Baron tanks and I have to admit that I don't sample all tanks each flight. If the plane's been hangared since that last time I checked, it seems like overkill.
 
lancefisher said:
I can't imagine why high octane (resistance to detonation) would increase ITT. In any case I'd think you could manage ITT with the throttles. AFaIK the major issue is that gasoline is a much poorer lubricant than jet-A and fuel pump damage is possible using gasoline for an extended period.

That said I have no personal experience running turbines on gasoline (or jet fuel for that matter).
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The big risk is, indeed, the fuel pumps. That's why the aux pumps are required to be on at all times with anything but Jet-A. The high pressure pumps will cavitate quickly and start to tear themselves apart, from what I hear, if they don't have the back pressure from the aux pumps when using other than Jet-A. I don't know for certain why avgas would raise the ITTs, but that's what they told us in ground and that's what our book says to watch out for. It's easily managed by reducing power, but by the same regard we'll loose the ability to generate full power if we have to fight high ITTs.
 
I learned that lesson the very first flight I had as an official PPL. I took my father up to celebrate the occasion. The rental had just been out in the pattern (and returned about 10mins late:mad:), but I dutifully did my preflight inspection.

I will never forget telling my dad that, "well, the plane just came in, and that person would obviously have done a pre-flight, but I'll do it anyway because I promised my wife that I would be a very safe pilot."

Sump left wing. No worries. Proceed with pre-flight.

Get to right wing. Sump. Hmmmm. That don't look right. The little floaty ball in the fuel tester didn't float. Still, I've NEVER seen H2O in fuel, so it can't be that. Smell. Nada. Hold up to sky. Nada. Still, I've never seen fuel contaminated. But why isn't the ball floating? Hmm. Sump again. Again. 12x later the ball floats a bit on an obviously light blue cushion of 100LL. Took me about 15 samples to get clear.

The pilot who had the plane before me hadn't flown in about 8 months (I spoke to her in the FBO while she was returning the clipboared) and just wanted to take a few trips around the pattern. For some reason, she flew on the left tank. Had she been on the right tank, who knows what would have happened. Had I been lazy, and assumed that the pilot before me, having landed safely, would have obviated the need to preflight, I might have had a very unpleasant experience at best.

Always sump the tanks!!!!
 
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