Why stick the tanks after fueling

Yellowbird

Yellowbird

Pre-takeoff checklist
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Yellowbird
Inspired by the fuel thread in the Hangar Talk forum:

I went out to the airport on Saturday to fill the tanks on the plane. I wasn't planning on flying that day, but I did want to fill up in case I did so some evening after the FBO closed (we don't have self serve at KBJJ).

I pulled Yellowbird out of the hangar, the fuel truck drove up, the connections were made, and fuel started flowing. The lady on the pump noted that the hose didn't feel quite normal (no jokes please) but also noted that she wasn't that familiar with my type of plane (Cardinal with Monarch caps).

The fuel flowed, the gallons ticked by on the pump, and after she had put about 35 gallons into the right side (which only holds 30, and probably had about 10 to begin) we suspected something was amiss.

I took a look (fuel nowhere near the top of the port), tried a hand at the pump (fuel flowing, but not as energetically as normal), and after putting about 60 gallons in, we firmly concluded that something was wrong.

I sticked the tanks (just shy of 20 gallons in the right side, only 10 in the left which we had yet to fill) and she called another fellow over to check the truck. Although the truck's gauge had shown somewhere over 40 gallons on board, it was apparently below the level at which the pump would reliably draw. We had filled Yellowbird up with about 10 gallons of fuel and about 50 gallons of air.

If we had been inattentive, and if I had departed without checking the actual level in the tanks, this could have resulted in a shorter flight than planned.

And that's why you should always visually confirm the fuel level after refueling.
 
Yellowbird said:
And that's why you should always visually confirm the fuel level after refueling.
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...and is very easy to do on a low wing. :) Plus, it's very easy to see the fuel level.

I always do a visual check after fueling, even if the line guy puts all my caps back on.
 
I generally top the tanks off, or have them do it. So sticking the tanks isn't necessary, but I quite agree it's a good idea to double check.

Another reason to do it is to make sure the caps are on and tightened down.
 
Y'alls got no excuse high wing or low, you should see me climbing up the side of my plane like friggin King Kong sticking my tanks, I also always fuel myself when it comes to my personal plane.

It's such a easy thing and can prevent some major heartache, always do a visual on your fuel, fuel yourself, use a watch as a primary fuel gauge and your panel as a secondary.
 
azure said:
I generally top the tanks off, or have them do it. ....
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It's a good thing that I requested that they top it off. If I had requested a set quantity for each side, we could have missed this.
 
Yeah, I'll always either check it visually or actually stick the tank. (Full is pretty easy to see, less may need a stick.)

I'll note another item: dragging the last few gallons out of the truck's tank will often also pull in any crap at the bottom of the tank, too. Should be caught by the truck's filters, but I'm not super-trusting when it comes to avoiding falling out of the sky.
 
Yellowbird said:
It's a good thing that I requested that they top it off. If I had requested a set quantity for each side, we could have missed this.
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I ALWAYS check that.

I find that rampies told to "fill to the tabs" often overfill by quite a bit. Since some of the flights I fly are weight limited, getting the W&B wrong because the rampy put an extra 15 gallons in is not acceptable.

I stick the tanks, give the rampy a number of gallons for each tank, then stick them again afterward.

The next-to-use CAP guys in particular get kinda upset if the aircraft is overfilled because it can cause a mission to get canceled.
 
luvflyin said:
Not if you checked. Always check. Always.
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^ that

Also some planes don't work for the mission with full tanks.

I've yet to ever top the LR tanks in my plane.
 
I watch them run the gas over the wing, I know its full.

Or the gas coming out the vents, yep its been "topped"
 
cgrab said:
So did they charge you for all the air they pumped?
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Obviously! Along with the fuel load, they topped off his tanks with nitrogen-infused air; which actually gives him a weight savings over "standard" air...
 
vkhosid said:
Obviously! Along with the fuel load, they topped off his tanks with nitrogen-infused air; which actually gives him a weight savings over "standard" air...
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...and helps prevent leaks!
 
I've been tempted to make a fuel stick for my airplane, but I worry about sticking a plane with fuel bladders.
 
Put a rubber stopper on the bottom - or coat it in FlexSeal, for a soft yet durable finish!
 
steingar said:
I've been tempted to make a fuel stick for my airplane, but I worry about sticking a plane with fuel bladders.
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Make a T-shaped stick, kind of like a sword with a hand guard. Make it so it can't hit the bottom. Who cares if it has one or two gallons in it - if the stick comes up dry, you need fuel. -Skip
 
Skip Miller said:
Make a T-shaped stick, kind of like a sword with a hand guard. Make it so it can't hit the bottom. Who cares if it has one or two gallons in it - if the stick comes up dry, you need fuel. -Skip
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Thing is I can visually see the level of fuel in the tanks. If I can get a good stick going I can probably learn to tell how much gas is in the tanks just by the fuel level. I could do it in my Cherokee pretty well. I like Ed's idea except I've no rubber stoppers that fit what I'd like to use (a paint mixing stick. i even have directions on how to mark it). Does one obtain Flexseal from one's local purveyor of hardware?
 
arnoha said:
I'll note another item: dragging the last few gallons out of the truck's tank will often also pull in any crap at the bottom of the tank, too. Should be caught by the truck's filters, but I'm not super-trusting when it comes to avoiding falling out of the sky.
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Not sure why this is always mentioned regarding fuel tanks, trucks, or gas stations...


The pickup for the pump suction should be at the bottom already and it won't matter if it's the first or last gallon pumped, it will pull in any crap that has sunk near the pickup.

Maybe you'd get some additional junk that was floating in the tank but otherwise it doesn't matter.
 
hockeyrcks9901 said:
Not sure why this is always mentioned regarding fuel tanks, trucks, or gas stations...


The pickup for the pump suction should be at the bottom already and it won't matter if it's the first or last gallon pumped, it will pull in any crap that has sunk near the pickup.

Maybe you'd get some additional junk that was floating in the tank but otherwise it doesn't matter.
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The pickup is near the bottom, yeah, but the bottom is usually pretty flat. That means that you'll get whatever is on the pickup, but there will be a large amount of sediment laying on the bottom away from the pickup. Usually, the fluid dynamics of the low pickup mean that these parts of the tank floor don't actually get much fluid flow. You can usually think about the fluid as coming from an expanding cone up from the pickup. The stuff on the floor away from the pickup just doesn't move and gravity isn't generally enough to make it slide down the very slight angle.

However, once you are down to a very low level, finally this fluid starts to move. The accelerating fluid picks up the sediment and draws it toward the pickup.

You can see this if you fill up a flat-bottom sink, like most kitchen sinks. Wash some dishes and there'll be some junk at the bottom. Open the drain and see when the stuff near the perimeter finally moves. You'll find that it's when the sink is almost empty. In a fuel tank, it's even worse. The flow rate out the pump is relatively low compared to the tank size and the size of the sediment is relatively much smaller.
 
steingar said:
I've been tempted to make a fuel stick for my airplane, but I worry about sticking a plane with fuel bladders.
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Mine has bladders, lots of other planes with bladders use fuel sticks.

I just got a 1" wide by 14" long dowel from Home Depot, got a tank empty, added 2 gal at a time and marked it with a razor, once I was done I went over that with the engraving bit for the dremel, worked great and it's too big to loose in a tank.

As long as you don't go all norman bates with the fuel stick I can't see how you could hurt the bladders.
 
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arnoha said:
The pickup is near the bottom, yeah, but the bottom is usually pretty flat. That means that you'll get whatever is on the pickup, but there will be a large amount of sediment laying on the bottom away from the pickup. Usually, the fluid dynamics of the low pickup mean that these parts of the tank floor don't actually get much fluid flow. You can usually think about the fluid as coming from an expanding cone up from the pickup. The stuff on the floor away from the pickup just doesn't move and gravity isn't generally enough to make it slide down the very slight angle.

However, once you are down to a very low level, finally this fluid starts to move. The accelerating fluid picks up the sediment and draws it toward the pickup.

You can see this if you fill up a flat-bottom sink, like most kitchen sinks. Wash some dishes and there'll be some junk at the bottom. Open the drain and see when the stuff near the perimeter finally moves. You'll find that it's when the sink is almost empty. In a fuel tank, it's even worse. The flow rate out the pump is relatively low compared to the tank size and the size of the sediment is relatively much smaller.
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True. I still would wager that between the filling of the truck, driving to the plane, and multiple filters at each point that there is nearly a 0% chance of getting debris in the tanks of the plane.
 
One of the first things during the pre-flight check is fuel. Gauges are 90% inaccurate at best, so checking visually is a must.
 
I wouldn't use a rubber foot on a stick. Fuel can attack the wrong sort of polymers and you end up with bits coming off the stick into the fuel.

The T-shape is best for all tanks. Bladders don't appreciate being poked, and light aluminum tanks gradually get abraded below the filler by dipsticks. I make a banana-shaped T-stick for customers who run 180s or 185s. The fuel is well back in the tanks when in the three-point attitude and a straight stick is useless unless the tank is nearly full.

Calibrating from a dry tank gives you total fuel, not useable fuel. Best to start with useable and call that zero. It won't show up on the stick in many tanks, of course, but the rest of the readings are more accurate when starting from unusable.

An aluminum stick becomes very readable if it's finished with green epoxy primer. The epoxy is fuel-proof and the matte finish makes the fuel level show up nicely. I once used high heat barbecue flat black and baked it on after it dried. Held up OK.
 
James331 said:
Mine has bladders, lots of other planes with bladders use fuel sticks.

I just got a 1" wide by 14" long dowel from Home Depot, got a tank empty, added 2 gal at a time and marked it with a razor, once I was done I went over that with the engraving bit for the dremel, worked great and it's too big to loose in a tank.

As long as you don't go all norman bates with the fuel stick I can't see how you could hurt the bladders.
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HAHA! Exactly this. If you are worried, round off the edges a bit, but a wood dowel shouldn't be anything to worry about if you aren't digging at the bottom of the bladder with it.
 
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