Precise Fuel Mass Measurement in GA

[mirkoni]

Originally Posted by ahramin

With modern fuel flow instruments it is easy to be brutally accurate in your fuel quantity on board. Several aircraft I fly have these systems and landing with just over 30 minutes fuel (in other words less than 1/10th of a tank remaining) is a regular occurrence. Failing that, you can be fairly accurate starting from full tanks and using a stopwatch for fuel burn but it takes some practice. Otherwise you just overestimate for W&B and underestimate for FOB and hope you aren't too far off.

Thanks for the answer.
The common practice is to fill the tanks right up, but with two of us in the cockpit and full tanks Seneca IV goes overweight. So I need to find a way to fill it to an amount that will not make it overweight, say around 200 lbs (mass) below full tank. The bowser has a totalizer in litres, and there is always some fuel left in the tanks, when we start refuelling ... obvuously if the tanks were empty at beginning of refuelling, we could calculate litres to fill it to desired lbs value, but with some fuel still there...