Glassair II FT Wing Heavy situation

[martymayes]

I would not fly it either. Need to find out the how it’s plumbed bring it up to factory specs

[CHICAGORANDY]

The emptying tank and its cross-over plumbing would need to be higher than the fill point of the other tank for it to over-run it. Also it would seem that there is no fuel tank selector on the airplane? Sounds like both tanks are joined with a "T" going to the engine or a 3rd 'header' tank under the cowling?

[vaflier]

The vent line on the tank that is emptying is plugged. Mud dauber would be my guess. Check the tank vents. If the caps have vents check those as well or just replace the tank caps. Problem solved. Reasoning is as follows, tank with plugged vent is warming up in the sun and building pressure since the vent is plugged and forcing the fuel over into the other tank.

[cub builder]

If you only have the main and header tank, the GlasAir only has one main tank that spans across the wings. Whichever wing is downhill is going to want to overflow. Leave the caps on and check it again on a level surface. The tanks should level out again and should also equalize once you taxi onto the runway to take off.

If you have the tip tanks installed, they have some rather complicated antisiphon and anti-overflow plumbing between the tips and the main tank. If the tip tank is overflowing, the valving that controls that is mounted just under the seam where the tip tank attaches to the wing. The tip tanks should feed into the mains during flight automatically if the valving is all working correctly.

However, since I don't know your specific plane's configuration, please put the plane on level ground and check that the fuel tanks level out again.

[Bill Berson]

If the landing gear is low on the pilot side it won't matter how many ways you position it on the ramp.

[kazansky22]

If you only have the main and header tank, the GlasAir only has one main tank that spans across the wings. Whichever wing is downhill is going to want to overflow. Leave the caps on and check it again on a level surface. The tanks should level out again and should also equalize once you taxi onto the runway to take off.

If you have the tip tanks installed, they have some rather complicated antisiphon and anti-overflow plumbing between the tips and the main tank. If the tip tank is overflowing, the valving that controls that is mounted just under the seam where the tip tank attaches to the wing. The tip tanks should feed into the mains during flight automatically if the valving is all working correctly.

However, since I don't know your specific plane's configuration, please put the plane on level ground and check that the fuel tanks level out again.

I have parked the plane in various locations on the airfield to see if it was just the spot I was in, and then I went into the same spot points in different direction to see if it would alter the pilot side of the wing tank being more full but it didn't seem to make any difference. I also left it there with the fill caps off to vent in case the vents were clogged and it also didn't seem to make any difference.

If the landing gear is low on the pilot side it won't matter how many ways you position it on the ramp.

I thought maybe the left main tire might have been low but I checked both mains and the nose tire while I was at it and they are all about the same.

[Marc Zeitlin]

I thought maybe the left main tire might have been low but I checked both mains and the nose tire while I was at it and they are all about the same.

When parked on known flat ground, measure the height of the left wingtip and the right wingtip off the ground. There's not a lot of geometric dihedral in a II FT and if one wingtip is only a few inches below the other, there can be substantial fuel transfer from one side to the other.

This is just ONE of the many reasons that having a "BOTH" setting on a fuel valve on a low wing airplane is generally (although not always) a bad idea.

You may want to take a look at CFR 14 Part 23.2430 (the new version of Part 23) - although EAB aircraft are not required to comply with Part 23, generally the rules are written for good safety reasons. Your fuel system would not meet the requirements of 23.2430.

I am not familiar with the II FT fuel system, and couldn't find a specification on-line. To those who know - what connects the left and right tanks in the wings? (and then connects them both to the fuel valve, which apparently is a "Header", "Both", "Off" setup)? Knowing this might help debug this problem.

Just out of curiosity, how long have you been flying this plane for before noticing this issue (which can be a serious safety issue, depending on the answer to the above questions, since draining ONE tank dry may [again, depending upon configuration], lead to an inability to draw fuel from the other wing tank). And did you have a complete Pre-Buy Examination performed on the plane? If so, what was their report on the fuel system?