Gday,
after flying my Viper today I noticed that my UAT (Hanson UAT) was only 2/3 full. The main tanks had about 1/3 remaining.

It is 2 main tanks feeding into the UAT via a Festo Y to the UAT. Engine is a Spark T12 120 nm .

I think it's the first time Ive noticed this. It should no be this way.
What would cause it? I thought a restriction in the Y, but both tanks seem to be emptying ok and flowing ok.

I pumped fuel both in and out with refuel line and it stayed full.

Just some simple advice is being sought, before I pull the fuel system out for a close inspection.

Cheers

Matt