BVM U.A.T. Question? Picture Uploaded
 

Now I know the instructions tell you to mount the UAT in a certain position. However due to space and lack off. The only place that I have sufficient room it needs to lay flat. Will I get away with this? Suggestions please.

I am getting so close I can smell the KERO:D

RE: BVM U.A.T. Question?
 

When the U.A.T. first came out. There were quite a few flame outs on take off.
The fix was to put it at a 45 degree angle or upright.(really the fix was to saturate the U.A.T. properly.

I had a BVM F-86 and it was laid on it's side. After getting the sack soak with fuel and running it on the ground to further get the air out of the bag. I picked it up and turn it every way bust loose.

The biggest thing is to saturate the U.A.T. I've never seen one laid flat but mine on it's side is close.

The flame out will occur at take off after you rotate, but this is only if the bag wasn't properly bled.

I'm no expert but I have had no bad luck with the U.A.T.

My best advice would be to call BVM They test their products to the fullest!!!

RE: BVM U.A.T. Question?
 

The UAT in my Phantom has been laid flat on it side like you have pictured for around 150 flights. One flameout when I ran out of fuel. (Having too much fun!) Make sure and purge it throughly, I typically fill at least the UAT and let it with fuel in it for a while, then fuel the airplane all the way up. Start the engine and shake the airplane. I usually do this at mid throttle settings then run the throttle all the way up and shake the model again, usually on the ground. Make sure and flivk your fuel filters with your finger while at full throttle to dislodge any air bubbles there as well. If you don't pull all the fuel out of it you will likely never need to purge it again.

RE: BVM U.A.T. Question?
 

???? :D:D:D


I've never seen one laid flat..you might consider going with the Rich Fong method as an alternative...

RE: BVM U.A.T. Question?
 

"DavidR" I like your method on fueling the UAT first and allowing it to sit for a little while before you fuel your mains.

In looking over the directions again and thinking about the principles behind the UAT. It would seem that as long as you have it saturated and never allow it to run empty you should be OK.

RE: BVM U.A.T. Question? Picture Uploaded
 

The key to success with the UAT is not just total saturation but total and complete PURGING. Dont do this with the engine running (potentially hazardous, time wasting, and uneccessary) do it by using the engine fuel pump with the engine fuel line diverted to a fuel container to receive the diverted fuel. Then, with the model orientated so that the UAT is VERTICAL, delivery line uppermost, (or just by holding the UAT vertical) run the pump via the GSU prime mode (or just connect a battery direct to the pump) until clear totally bubble fuel -free comes out of the fuel line even when the model (ie UAT) is shaken quite violently. Then connect the fuel line to the engine and fly and you will not have a problem regardless of tank orientation. REPEAT the procedure if you drain the UAT.
Regards,
David Gladwin.

RE: BVM U.A.T. Question?
 

I always make sure not to run the UAT empty. If it is mounted vertically, the UAT can't be drained by defueling either because the fill line is at the top of the tank. When the main tanks empty out, the defueling pump will start sucking air, leaving the UAT full.

RE: BVM U.A.T. Question? Picture Uploaded
 

Agree with DavidR. I've seen them laid flat in several installations with no issues.

I've run one dry before too having too much fun. Just fill'er up and go again ;)

Sean

RE: BVM U.A.T. Question? Picture Uploaded
 

Yeah, two different airplanes set up like the picture and around 300 flights that way. It's going to end up that way inflight during the maneuvers anyway.

RE: BVM U.A.T. Question? Picture Uploaded
 

Well guys, thank you I ran the engine today and did as recommended. No problems and no visible air in the UAT or the lines.

Now to finish up this bird and get it ready for it's maiden flight this weekend.