Broken UAT
 

Hi,
I went to fly my Picaro for the first time. It was a previoiulsy owned airplane. I seen it fly a few times.
As I put fuel in, I immedately noticed the fuel was flooding in the fuselage. I caught it quickly but it still made a mess.
Turns out the clear tube of the UAT was cracked and split in two. I have no idea why this happened. Has anybody else experienced this?
https://cimg8.ibsrv.net/gimg/www.rcu...48236085ae.jpg

I honestly now avoid this style UAT now, To many issues related to them. I know use BVM type and they are flawless. Similar to MAP brand but IMHO a bit better due to the construction materials inside.

I have been using that type of UAT (250ml) for 6 years now on two different jets flying F3S Jet aerobatics. I think they work very well. From experience, your issue possibly came from tightening down on the "grub screws" that hold both ends of the stands. By tightening down on them, they bite into the brittle plexi-glass material and disrupt the O ring seal and may have broken the clear plexi-glass material.
Other than that, you should not have any other issues with the UAT. A replacement for the broken part should be available. Try Elite AeroSport to see if they have them https://www.eliteaerosports.com/prod...43417070272726
Hope that helps,
Wayne

This 100ml model has no grub screws. It was held on the 3D printed mount with nylon tie straps. The caps screw on the central part and tighten against o-rings on each end. I never messed with it. The model was fully built by the Lighter Side of RC and was a good flying aircraft when I got it.
It some how cracked on the way from my house to the field. It was perfect before I left. No fuel was leaking. Just so weird.
I used this brand of air trap before with good success. I don't want to knock it.
I order a replacement barrel from Aero Panda. I was worried about taking it apart but it was not tight at all, perhaps because it was broken.
I'm sticking with it, because its way less work to install the same and the inside of the airplane is so nice. A MAP UAT may be better, but way uglier - LOL.

This is the screw I was referring to. It is located on the very top of the front and back pieces. If you tighten anywhere tighter than finger tight it will create issues on the plexi-glass.
Wayne
https://cimg8.ibsrv.net/gimg/www.rcu...b7e47cf44.jpeg

Wayne - you are 100% correct. I have that one too, but its not the same one that broke.
Thanks for the good safety tip!

MAP is 1000% the best UAT. The pleated pick up is a fuel reservoir. CARF changed to it a few years ago on my recommendation, they had too many flame outs on the Red type similar to yours.

MAP dominates the U.K. jet scene…

I agree with switching to MAP/BVM style. I won't use the "glass" one's anymore. I have one left in my Ultra Flash and everything else has MAP/BVM.

I believe I discovered what happened. The fuel vent was closed and it is a really good seal. The airplane got warm inside my car, before I left for the field. The fuel system develops a surprising amount of pressure under these conditions. The pressure must have cracked the plastic tube.
So, vents should be left open.