Full Service Fuel Quantity

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JOhnH

Touchdown! Greaser!
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Have any of you ever questioned the amount of fuel the FBO claims they pumped into your plane?

If I take off, fly about 2 hours and land I am pretty sure I am going to need about 18 gallons of fuel and adjust a little for altitude, leaning etc. If I go to self-service, I usually manage to pack in about 17 to 19 gallons. But it sure seems to me that more often than not, if I let the FBO guys fuel her up without me watching, they manage to pack in about 22, 23 or more gallons. For the longest time I always just gave them the benefit of the doubt because I usually like those guys. But for some reason, the amount of fuel purchased from full service never seems to be LESS than I expect.

I am usually a pretty big tipper, but now my tip is inversely proportional to the amount of fuel in excess of what I expect. And I keep track so that if I HAVE to buy fuel there again, I specify the minimum I need and stick the tanks before and after.
 
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JOhnH said:
Have any of you ever questioned the amount of fuel the FBO claims they pumped into your plane?

If I take off, fly about 2 hours and land I am pretty sure I am going to need about 18 gallons of fuel and adjust a little for altitude, leaning etc. If I go to self-service, I usually manage to pack in about 17 to 19 gallons. But it sure seems to me that more often than not, if I let the FBO guys fuel her up without me watching, they manage to pack in about 22, 23 or more gallons. For the longest time I always just gave them the benefit of the doubt because I usually like those guys. But for some reason, the amount of fuel purchased from full service never seems to be LESS than I expect.

I am usually a pretty big tipper, but now my tip is inversely proportional to the amount of fuel in excess of what I expect. And I keep track so that if I HAVE to buy fuel there again, I specify the minimum I need and stick the tanks before and after.
Click to expand...

When you fuel your plane, do you go to the collar? Or do you slow the pump down and let the fuel settle and bubble around? It's quite easy to put an extra 2-3 gallons per side into the plane if you're patient - And when I was a lineman I took "topped off" to mean TOPPED off. I didn't want to be the guy answering to the NTSB about whether I had really topped off a plane that ran out of fuel. I figured that if the pilot is planning on x gallons of usable fuel, I'm gonna be sure he's got it all.

One way to see if this is happening is to see if you end up putting less than you expect (or at the low end of your expectation) into the plane the next time you do self-serve. Better yet would be if you had a fuel flow system and could see exactly what you burned. Best would be to simply stand and watch as they fuel your plane and see how much they really put in it - The pumps on fuel trucks at the airport have to be calibrated the same way pumps at your local gas station do. Then you'd know - And maybe the linemen can show you how they pack that extra couple gallons in.
 
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I've found that folks fueling my AA-5B pretty much always pump almost exactly what I predict based on my totalizer and my watch. If the amount they pump ever differed significantly, I'd have them check the sheets. Frankly, my biggest concern is being underfueled (leaving me with less than I think I have) than overfueled (and overcharged). The only time a problem occurs is when I have them fuel to the tabs, and if the person fueling isn't familiar with AA-5A/B tanks/tabs, I supervise the fueling.
 
Or you could be like Kent and pump too fast, and spill a couple gallons on the wing :D
 
I once put another 9 gallons in after the lineman "topped" off the Cardinal. The fuel truck had a high pressure nozzle and without being careful it would overflow the tank without actually filling it.

On the IAR the fuel will just run out the tank vents if you fill it to the skin so I tell the lineman to leave an inch or so below, which is about 2 gallons per tank .
 
My fuel meters have to be calibrated yearly and have seals on any screws that would have to be removed to affect the calibration. There is also a sticker on them indicating the name of the company doing the calibration and the date of calibration. The calibration data sheets include as found data. To cheat a customer, the fuel would have to be being pumped somewhere else other that in the aircraft tanks.

If a customer is going cross country, we ask if he wants the tanks topped off or "stuffed". If he wants it stuffed, we squeeze in all we can. Most people want some expansion room so that they don't lose fuel out the vents. They will specify "bottom of the filler neck or "half inch below the filler neck - etc.".
 
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flyingcheesehead said:
Yeesh... Lesson learned! Do NOT fuel a DA40 fast. It does not work. :no:
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Oh you can fuel fast, you just have to get the right angle on the fueling nozzle and learn to anticipate when its going to kick back at you. Personally, I hated fueling any of the Kingair's, with the flap that likes to blow Jet-A back at you.
 
KSCessnaDriver said:
Oh you can fuel fast, you just have to get the right angle on the fueling nozzle and learn to anticipate when its going to kick back at you. Personally, I hated fueling any of the Kingair's, with the flap that likes to blow Jet-A back at you.
Click to expand...

Not the DA40 - Its problem isn't the nozzle angle, it's that there are 2 or 3 tanks but only 1 filler (on the farthest outboard tank) and the fuel doesn't flow from the outboard tank to the inboard tanks fast enough to catch up with the hose if you've got it on full blast.

EDIT: Hey, that looks like a DA40 in your avatar - Okay, I'll bite. What's the right angle? Because it was kicking ALL of the fuel back out at me after a few gallons. It was a really fast hose, though.
 
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flyingcheesehead said:
EDIT: Hey, that looks like a DA40 in your avatar - Okay, I'll bite. What's the right angle? Because it was kicking ALL of the fuel back out at me after a few gallons. It was a really fast hose, though.
Click to expand...

Every time I fueled a DA40 as a line guy, I'd angle the nozzle in towards the fuselage a little bit. Still couldn't get blast away, but I always thought that it would fuel a little bit quicker that way. But, everything I fueled had the extended range tanks, if that makes a difference or not.

Personally, I thought the DA-20 was worse, as it was really tough to tell when the tank was actually full, without filling the neck as well, by which point you will wear some gas.
 
JOhnH said:
Have any of you ever questioned the amount of fuel the FBO claims they pumped into your plane?

If I take off, fly about 2 hours and land I am pretty sure I am going to need about 18 gallons of fuel and adjust a little for altitude, leaning etc. If I go to self-service, I usually manage to pack in about 17 to 19 gallons. But it sure seems to me that more often than not, if I let the FBO guys fuel her up without me watching, they manage to pack in about 22, 23 or more gallons. For the longest time I always just gave them the benefit of the doubt because I usually like those guys. But for some reason, the amount of fuel purchased from full service never seems to be LESS than I expect.

I am usually a pretty big tipper, but now my tip is inversely proportional to the amount of fuel in excess of what I expect. And I keep track so that if I HAVE to buy fuel there again, I specify the minimum I need and stick the tanks before and after.
Click to expand...

I always stay with the airplane when it is being fueled. :thumbsup:
 
KSCessnaDriver said:
Every time I fueled a DA40 as a line guy, I'd angle the nozzle in towards the fuselage a little bit. Still couldn't get blast away, but I always thought that it would fuel a little bit quicker that way. But, everything I fueled had the extended range tanks, if that makes a difference or not.
Click to expand...

Ours has the extended range tanks, but I don't think that makes a difference. When I mentioned the "2 or 3" tanks, the standard range is 2 tanks, the long range is 3 tanks. Must have been some sort of structural thing - Each side has a 17-gallon tank, and then a 3-gallon tank. If you have long range tanks, they add a 3rd 5-gallon tank.

As is my habit, I angled inwards on both sides (easier to see the readout that way, too) - But that hose was just too fast. WAY too fast.
 
I make several trips to Nashville each year. On one trip they actually put in (charged for) 81 gallons. That would have left 3 gallons split between at least three tanks. I had never used more than 72 on any previous trip, and this one had no more time or problems than any other. I made them check their logs, but they just came out with the same readings as before, so either the line guy wrote down the wrong meter reading, or I was dangerously close to running out of fuel, which I should not have been, according to my calculations.
 
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