Hey everyone...I just finished a FuntanaX 50 electric conversion; running a E-Flight 60. It flys great except when doing loops...it wants to twist to one direction (can't recall which right now). This is particularly true the tighter the loop is. A big loose loop is usually pretty straight but I may be compensating with out realizing it.

So my question is what might be going on and how do I fix it?

I was considering a tip stall, but doesn't seem to apply because it is always the same direction and usually at a pretty good speed.

My final thought is it is related to the firewall angle/offset for a glow engine. So I tried to compensate for it with my mount, but the trial and error factor is a real pain in the butt. My mount is pretty simple, 1 1/2" PVC pipe as a spacer with 4 x 3" screws running through the firewall to surround the PVC and keep everything tight.

Can anyone tell me what the angle is on the firewall on this plane?

If I compensate for it to make the electric engine square to the thrust line will it solve the problem or create another?

Can I compensate for the issue with my radio (Spectrum7) to mix the alleron to the elevator?

Thanks for your help!!

Remember that this is pretty "usual" behaviour for most planes assuming that lateral balance, or other factors are at play.

I don't know how many times I've seen this asked about Ultimate Biplanes...

You may have the elevator adjusted at the moment, to the point that you are getting one wing to stall before the other during the tight loop.

There are two ways to cure this

1. Lessen the loop or throw so that the wings do not stall

2. INCREASE the throws so that both wings stall at the same time.

I usually will adjust the throws so that at low rates I get a nice round loop, and at high rates I get a tight loop with both wings stalling eveningly.

Both adjustments result in round loops.

My Funtana did the same thing as yours until I adjusted it, because of it's large high deflection elevator.