Guys

I have used a UAT in both a vertical and 45o position without any problems. For those of us who don't like to throw money away at £50 per model for UAT's I now use a Graupner 6oz hopper tank with an Orbit clunk centralised in the tank on a piece of stiff tubing. The tank comes wirh good quality fittings which fit tygone perfectly. 15 minutes work and you have a reliable hopper , I am currently using three of them, cost about £16 each.I always check the fuel in the hopper on landing and it has always been full with only a small amount of air at the top of the tank. I have run the main tank empty and the hopper down to half full on one occassion when the gear would not come down and I had to fly some hard extra turns to release it.

I mount the tanks both horizontally and at 45o and it doesn't seem to make any difference. The original idea came from David Gladwin who does seem to know a bit about fuel systems and he is not a man to skimp on anything.

John