ORIGINAL: Dave Wilshere

No jet needs a bubble trap...but

Tank shape is everything...its how I decide on pick up type.

I generally add a hopper not as a bubble trap, but as a ''use all the capacity'' device. I use Felt clunks in 95% of my models, NEVER cleaned a filter yet.

My Airworld Cougar which started all of this with the first ever Lambert T32 #1 produced had no hopper, just an Stil/Orbit clunk. When I added the JetCat P-20SE in the summer of 2010 I still didn't add a hopper and it was fine. When I built my Habu 32 turbine I used a MAP Mini BT and in 139 flights it never flamed out. Felt clunk in the 20oz Kavan and the paper pick up MAP use. I could land with 6mm of fuel in the tank and hardly a bubble in the hopper.

To answer your question...depends on the fuel tank shape!

Dave