Goldberg Tiger 2 ?? !!!

I assume by "high RPMs" you mean high airspeed.

How much elevator travel do you have? What do you consider a "normal" loop?

A little 1 - 2 degrees right thrust MIGHT help. However, some planes simply won't loop tightly, like in "bite your own tail". I suspect you're trying to loop to tightly with too much elevator travel. This is causing a high-speed stall, and the plane snaps out.

Ease off the elevator travel until the plane will loop with full stick input at full throttle and not snap out. Dr.1 Driver "There's a Hun in the sun!"

be aware that you can stall the wing at any airspeed!!! I agree with Gerald. I've had the same thing happen to several of my planes. To much elevator at any speed will snap a plane. Keep reducing the travel until at full stick it won't snap. Then you will have as tight a loop as you can get from your plane. Eddie Fulmer

Sounds right to me.

You are correct in that I meant airspeed not RPM. But it is not an overcontrol problem. The plane snaps over whenever it gets above 60 degrees A of A or so even with moderate up elevator input. I can't even get vertical without it snapping. I'm going to try a couple of degrees of right and maybe one degree or so of down thrust just for curiosity's sake. I've been flying R/C for nearly 20 yrs. and have never had a plane act this way for no apparent reason. I need to get this thing straightened out since it is my

12yo's first low wing and was picked because it was supposed to be gentle and predictable. I let you know after this coming weekend if the thrust change helped. FDW

Let us all know what you find out. Very interesting. Eddie Fulmer

One of the other things you may want to check is the wing and tail feathers for warp. You could be introducing more lift one one side than the other. I fly a Tiger 60 and while bigger, is supposed to have similiar flight characteristics. It is one of my favorite take it and fly it planes, like a Chevy, always performs reliably and can always do more than I know how to ask of it. Let us all know what you come up with. Did you make any mods to the kit as you built it? Andy

We can make a box of wood.....FLY!!

Tail heavy

Tail heavy? I say NOSE heavy! A forward CG will encourage a snap roll. A nose-heavy airplane flies with excessive up-trim (i.e., decalage) and a resulting higher angle of attack, in order to compensate for the nose-down tendency of the forward CG. As a result, since a nose-heavy airplane flies with too much decalage in normal flight (i.e., up-trim), adding some more 'up' elevator to do a loop will effectively increase the angle of attack to the stalling angle. This results in a pronounced snap roll.

BUT, the original poster said the Tiger 2 balances correctly, so I remain mystified. A stumper, indeed.

Don Bailey

jeboba wrote:

Has the washout been checked?