Refueling after a flight?

jaymark6655

jaymark6655

Pre-takeoff checklist
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jaymark6655
So does everyone refuel after a flight? What do you do if you need less than a full tank for weight and balance, but after your last flight you filled the tanks and there is no defuel option?

Refueling makes sense to me from a keeping moisture out of the tanks stand point, but the logistics of not knowing what weight I might need to carry on my next flight and having no way to defuel always had me questioning this practice.
 
I don't. I will do 3-4 flights before refueling. So far, I have never seen a drop of water in the fuel.
 
Our flight school's planes are on a fueling schedule. Our Cessnas get topped off. Warriors and Archers are fueled to tabs. SR20 is topped off and SR22 is to tabs. If a student or renter needs less fuel we put a note
On the note on our scheduling system.
 
Water in fuel scares the crap out of me. When I was in high school one of my friends was in a plane crash with her dad flying when the engine quit right after takeoff.

I think this was due to rain and he did sump some of the water out but I don't think he got it all. I like to mitigate any risk of fuel contamination.

http://www.asias.faa.gov/pls/apex/f?p=100:17:0::NO::AP_BRIEF_RPT_VAR:MIA03LA119
 
jaymark6655 said:
Refueling makes sense to me from a keeping moisture out of the tanks stand point,
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Condensation is VERY rare in my experience. I have never seen water in the tanks that wasn't a result of leaking gas caps in rain.
 
Greg Bockelman said:
Condensation is VERY rare in my experience. I have never seen water in the tanks that wasn't a result of leaking gas caps in rain.
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I'd imagine its more likely if the plane has been left alone in changing weather for extended periods of time. But I'm just guessing here.
 
I fill up after every flight, but it's for the benefit of the Other Guy, not because I'm worried about condensation. Likewise he tops the plane off as well after he uses it.
 
I have 75 gallon tanks. My norm is to land with 10 remaining and add to that prior to the next flight according to what I need for that flight to get me back home with 10. Always done it that way. I occasionally sump a pea sized blob of water from condensation but nothing more than that. If you really want to track water in your sumped fuel add Marvel Mystery Oil to your gas. The red dye is attracted to water and really makes a drop or two show up in your tester.
 
I used to top off after every flight, but gas prices the way they are, I'll probably never do that again.

Gas at my home field is like $6.00 a gallon. I can take a short 10-15 minute flight to a grass strip north of me and fill up for about half that price and if that field is wet or soggy, I'll go about 20 minutes south for a tad more money.

I'll run the tanks down to about an hour of fuel remaining then go top off and come back. Sure it means I start any flights at slightly less than max fuel, but it's never been a problem.

Also, I've never gotten water in the fuel, even with all the rain we've been having here in FL. I'm not in a hangar, the plane is tied down on the field.

I do own my plane and no one else fly's it so..I have that luxury.

When I rented, it was customary to fill out a fuel ticket upon return (which some people forgot to do as well..<sigh>). If I was sharing the plane, I might top it off or fill up on my way back just to be courteous.
 
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Somedudeintn said:
I'd imagine its more likely if the plane has been left alone in changing weather for extended periods of time. But I'm just guessing here.
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I submit that there isn't enough movement through the vent system to be a factor.
 
Greg Bockelman said:
Condensation is VERY rare in my experience. I have never seen water in the tanks that wasn't a result of leaking gas caps in rain.
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This. I was told the story about fueling after every flight by my first CFI, while it may be possible, I have never seen it. Only leaking fuel caps.
 
Never. It's usually late and the wife and baby are cranky and we just want to get home. My 182 holds nearly 6 hours of fuel so it's not unusual to return home with 3-4 hours or more of fuel.

Additionally, my hangar is on a slight incline. I can feel the difference between pushing back a topped off plane, versus one that's 250lbs lighter.

When I leave, fueling the plane is part of my departure ritual, which includes stopping by the potty and calling ATC for my squawk code. This also gives me the ability to plan my fueling if we're going to be loaded up heavy.

The reasons I've heard for keeping tanks filled is:
1) condensation
2) keeping the rubber bladder wet so it doesn't dry out.
3) courtesy of partner, club, FBO, etc.

I'm not buying the condensation argument. Those smarter than me did the math and figured out that the maximum possible water in the tanks is incredibly small. That concurs with my findings; I've never found water in my tanks (I'm hangared too)

My solution to the bladder issue is to fly on a regular basis. Besides, I'm not sure I buy this argument either, as the bladder point that leaks first (the fuel line drain) is the lowest point of the tank and always wet.

The last issue isn't one for me. The joys of sole ownership; the plane is always* as I left it :)

*except for MX personnel, trespassers, etc., which is why I always conduct a thorough preflight.
 
Greg Bockelman said:
I submit that there isn't enough movement through the vent system to be a factor.
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You are probably right, but IF it is a factor, each cycle of changing temperatures could condense a little more water out of the air. I'm sure a plane left for 5 years would condense more water than left for one month.

Obviously there are other issues to deal with if the fuel sits that long and the engine doesn't run.
 
For me it depends on the airplane. If the airplane has bladder-type fuel tanks, then yes, I will almost always top off after every flight, unless I know I am going to fly it again with a reduced fuel load in the near future. Leaving bladder tanks empty or partially full is a good way to reduce their usable life and once you've replaced bladders in a Baron or Bo, you won't want to do that again ($$$).

If it doesn't have bladders, I'll either leave it or fuel it with whatever I need for the next flight.

If my tanks are full and I need to lighten the load, I will go up the day before and log some flight time.
 
Somedudeintn said:
You are probably right, but IF it is a factor, each cycle of changing temperatures could condense a little more water out of the air. I'm sure a plane left for 5 years would condense more water than left for one month.
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True, but regardless, you need to sump the tanks before you fly it and IF you get water collected from condensation, it is going to be a rather small amount.

In short, if you want to fill it up before putting it away, there's nothing wrong with that. I just wouldn't do it simply because you are trying to avoid condensation.
 
We try to top off in winter for "bladder longevity" (the airplane, not the old guys flying it!) and in the summer we go by the stick and shoot for 40-50 gallons left on board for the next guy... hot and high limits what we'll fill up to with the long-range tanks in summer... don't want to stick someone who wants to take more than two people aloft with a problem of needing to fly around for a couple of hours to get down to weight and performance numbers that are reasonable.
 
I will say one time on the ramp I was doing a pre-flight on a Cessna with a CFI who was gonna get me checked out in the plane and I saw something I've never seen before.

The plane next to us (I believe it was a twin, don't know the make/model) just started spraying fuel on the Tarmac. It was summer and it was frickin' hot...

I was surprised but the CFI told me that I guess someone had topped it off TOO much and since there was no room to vent air it just spewed it out of the vents.

I watched in horror as what must have been at least 3-5 gallons of avgas just continued to pour out of the plane, it was probably more.
 
Brad Z said:
My solution to the bladder issue is to fly on a regular basis. Besides, I'm not sure I buy this argument either, as the bladder point that leaks first (the fuel line drain) is the lowest point of the tank and always wet.
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I can tell you from first hand experience that it IS true.

The bladder will start to degrade and break down internally usually before it starts to leak externally at the low point. The first sign is that you start getting sediment in your fuel samples - little bits of greasy sludge and residue coming out when you sump the tanks. That is the bladder starting to break down and if you empty the tank and borescope it will confirm that the bladder is breaking down. When you first start seeing the sediment, you can delay the bladder replacement by keeping the tanks full, but eventually, you will have to replace.
 
denverpilot said:
We try to top off in winter for "bladder longevity" (the airplane, not the old guys flying it!) and in the summer we go by the stick and shoot for 40-50 gallons left on board for the next guy... hot and high limits what we'll fill up to with the long-range tanks in summer... don't want to stick someone who wants to take more than two people aloft with a problem of needing to fly around for a couple of hours to get down to weight and performance numbers that are reasonable.
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Nate, do you have a reference for that 40-50 gallon number? I have read that bladders need to be topped off, is that an OWT?

edited to add:
http://www.eaglefuelcells.com/ga/tech_tips.html
 
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Caramon13 said:
I will say one time on the ramp I was doing a pre-flight on a Cessna with a CFI who was gonna get me checked out in the plane and I saw something I've never seen before.

The plane next to us (I believe it was a twin, don't know the make/model) just started spraying fuel on the Tarmac. It was summer and it was frickin' hot...

I was surprised but the CFI told me that I guess someone had topped it off TOO much and since there was no room to vent air it just spewed it out of the vents.

I watched in horror as what must have been at least 10 gallons of avgas just continued to pour out of the plane.
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The underwing vents I assume? Can happen to a number of types, depending on the vent config.

At some FBOs in Arizona and Nevada, they'll only top off their airplanes the night before you depart and never *quite* all the way, expecting the fuel to expand a bit as the sun comes up.

They warned me to stick tanks and make sure I had the fuel level I wanted at Henderson in Vegas one time for that reason... "We'll fill it pretty full when it's cool tonight, but we don't want aircraft leaking all over the ramp, so when you come out to depart, if you need more fuel, just let us know."
 
GeorgeC said:
I have read that bladders need to be topped off, is that an OWT?
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Read my comment above - it is not an OWT.

Now, I don't know how big of a job it is to replace bladders in a Cessna, but for a Baron/Bo it is a real pain - and a whole lot of labor involved because it is so tight in there. It is roughly a $7-8000 job (per side) to replace bladders on a Baron.

*Now, that doesn't mean that you must at all costs, top off the bladders every single time you fly.......just don't leave them empty or partially full on a regular basis.
 
Caramon13 said:
I will say one time on the ramp I was doing a pre-flight on a Cessna with a CFI who was gonna get me checked out in the plane and I saw something I've never seen before.

The plane next to us (I believe it was a twin, don't know the make/model) just started spraying fuel on the Tarmac. It was summer and it was frickin' hot...

I was surprised but the CFI told me that I guess someone had topped it off TOO much and since there was no room to vent air it just spewed it out of the vents.

I watched in horror as what must have been at least 3-5 gallons of avgas just continued to pour out of the plane, it was probably more.
Click to expand...

I've seen that happen before when I was flying from Arizona to North Carolina in my DA-20 with three other DA-20s, the fuel cell is right behind you. So when the FBO topped off the plane without using the fuel stick to confirm the fuel quantity they way over filled it. As soon as our friend hopped into the plane you saw it ****ing out a significant amount of fuel.

Although it isn't out of the ordinary for me, racing formula cars I've seen people top off their cars and then hop in, as soon as they hop in the fuel tank overflow ****es out a bit of fuel.
 
I think it's situation-dependent. I learned at sea level, where the school always wanted us to leave the tanks topped. Then I moved to Denver where, for obvious reasons, some airplanes would not be able to depart with full tanks, depending on how they were loaded. Then there's the expansion problem if the airplane is fueled with cool fuel then it heats up in the sun. It will come out the vents as a previous poster mentioned.
 
Fearless Tower said:
Read my comment above - it is not an OWT.

Now, I don't know how big of a job it is to replace bladders in a Cessna, but for a Baron/Bo it is a real pain - and a whole lot of labor involved because it is so tight in there. It is roughly a $7-8000 job (per side) to replace bladders on a Baron.

*Now, that doesn't mean that you must at all costs, top off the bladders every single time you fly.......just don't leave them empty or partially full on a regular basis.
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Standard tanks are a huge PITA, and LR tanks are worse.

If the shop has a kid with ape arms that are about two inches around but hang to his knees, he gets the job of clicking that outboard hanger in place.

I don't think I've heard our mechanics complain louder about ANY other job on our airplane, ever. And we only did one. :)
 
I refuel after every flight. My mooney is a glorified 2 seater in my mind, anyway. There have been a few times where I've had to carry a 3rd person. I keep two 5 gallon gas cans and a manual siphon in my hangar just in case I need to defuel.
 
I've always defaulted my plane to 1/4 tanks, not too concerned about water in the hangar, and you never know what your next flight will bring, adding some fuel before a flight doesn't take any time or effort really, off loading fuel however, that's a pain in the arse.
 
When I had rubber bladders ,I always topped the aircraft ,to keep the bladders wet. Now I usually top off ,due to the small size of my tank.
 
James331 said:
adding some fuel before a flight doesn't take any time or effort really
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I used to think that way......and then I bought a Twin Beech with 6 fuel tanks holding 318 gallons. Last time I filled up at a self-serve pump, I had to swipe my card 3 times....:mad2:
 
Keeping rubber bladders "wet"? Where did that come from? I don't recall any manufacturer's instructions that advised maintaining full tanks to preserve fuel bladders. I never have.
 
Fearless Tower said:
I used to think that way......and then I bought a Twin Beech with 6 fuel tanks holding 318 gallons. Last time I filled up at a self-serve pump, I had to swipe my card 3 times....:mad2:
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Stop by Llano TX. I refuel there on El Paso Austin flights and gas has been 3.10 a gallon for awhile. Rest of the nation needs to catch up on low fuel prices. At my field, it's still 4.70.

With those 300 gallon tanks, you might make it to Texas:goofy:
 
I always keep some fuel in the aircraft to make the bladders happy, but I don't want full fuel all the time. Supposed to be hard on the landing gear (more specifically on the rubber doughnuts that comprise the suspension).
 
Stewartb said:
Keeping rubber bladders "wet"? Where did that come from? I don't recall any manufacturer's instructions that advised maintaining full tanks to preserve fuel bladders. I never have.
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It's been a thing everywhere that has bladders.

206 I used to work we always kept some fuel in each tank to keep the bladders flat and from drying out.

I keep at least 10G per wing in my 185 for the sake of the bladders. I've also been meaning to get 3-4 15.5G beer kegs to keep some 100LL at the house.
 
Fearless Tower said:
I used to think that way......and then I bought a Twin Beech with 6 fuel tanks holding 318 gallons. Last time I filled up at a self-serve pump, I had to swipe my card 3 times....:mad2:
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Twin beech, with 318G, you got a 18??

I hope you added a new column in your logbook for badass hours!

Very cool!
 
Stewartb said:
Keeping rubber bladders "wet"? Where did that come from? I don't recall any manufacturer's instructions that advised maintaining full tanks to preserve fuel bladders. I never have.
Click to expand...

I'm not convinced it wasn't dreamed up by Aviation Consumer or Cessna Pilot's Association to create more paranoia content. Between fuel sloshing around and the containment of vapors, I'm not sure how a bladder with fuel in it wouldn't be "wet".
 
James331 said:
Twin beech, with 318G, you got a 18??

I hope you added a new column in your logbook for badass hours!

Very cool!
Click to expand...
Yes, a 1960 G18S. Just brought it home a couple weeks ago. Still doing the insurance checkout thing, but it is fun - hadn't thought about a separate column....just happy to be simultaneously logging ME and TW at the same time!
 
Stewartb said:
Keeping rubber bladders "wet"? Where did that come from? I don't recall any manufacturer's instructions that advised maintaining full tanks to preserve fuel bladders. I never have.
Click to expand...

I'm not convinced that it isn't an old wives tale. Someone told me that the fuel acts as a buffer to keep the tanks cooler on hot days when the plane is sitting out in the sun. I don't know if they thought heat would deteriorate the bladders over time.
 
Brad Z said:
I'm not convinced it wasn't dreamed up by Aviation Consumer or Cessna Pilot's Association to create more paranoia content.
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And I've never read anything from Aviation Consumer or CPA. I just know what I've seen from borescoping bladders that have been sitting and like I posted earlier, they weren't cracked and leaking at the drain points.
 
I almost always top the mains after the flight.
I usually top the baggage aux tank. While this means that the baggage area weight allowed is less, usually our stuff just goes in the back seat.
I rarely top the wing tip auxes. They only get filled when I anticipate needing them (more than three hours of flying).

That's a good balance of being ready for most flights and keeping the weight and other configuration issues in check.
 
Croomrider said:
I don't. I will do 3-4 flights before refueling. So far, I have never seen a drop of water in the fuel.
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ditto here.....I've never had an issue with condensation or water in the tanks with both the Six or the Bonanza.

I keep maybe 30-40 gallons in a 80 gallon system.....bladders are fine. :rolleyes2:

the thought of keeping my bladder wet....makes me want to pee.:goofy: :rofl:
 
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