FX3 Wing Fuel Tank Recommendation?

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Chuck,

So that was 1 of the 22 gallon tanks and you ran it dry and it took 20.8 to refill so that was 1.2 unusable with THE FUEL SELECTOR ON 1 Side? Correct?

This is pretty much exactly what I found on Bluebird when I tested it on 1 side only. There was 1-1/2 gallon unusable on that side (3 total both sides for 41 gallons usable). My question on my was that it was static and we (Mitch & I) theorized that in flight, with pressure into the fuel cap vent, it would pressurize and make more useable and that seems the case as you were better by about 1/4 gallon.

On Grizzly with the fuel selector on BOTH there was only 3/4 of a gallon unusable per side or 1-1/2 gallons total unusable. Strange. Current EX3 I’m building I’m going to test it each way and see if that is repei atable.

thanks for jumping in with that.

Dave
Yea then I actually stepped on the rudder and pushed all the fuel inboard switched back to that tank it ran for maybe 1 min ran out again. Almost had to make a emergency landing cause It didn’t want to come back to life.

[Andy]

Chuck,

So that was 1 of the 22 gallon tanks and you ran it dry and it took 20.8 to refill so that was 1.2 unusable with THE FUEL SELECTOR ON 1 Side? Correct?

The test, as specified, tells us nothing about the unusable fuel quantity. It does tell us something about the usable fuel in one tank for this particular airplane. I believe it was you that said there is some variation in fuel tank capacity.