Guys,

Ive heard multiple reports of the Brio's going in due to a uncontrollable stalled spin or snap.

I've experienced this stalled snap twice on my brio. Im pretty sure I know what the problem is now. At first I thought it may have been just a dumb thumbs, or the elevator flexing based on the reports. I dont think so now. After experiencing it myself, its a very unique situation. No warning or anything. It will be flying along fine, and all of a sudden WHAM...into the stalled condition. It normally happens when your in a turn or pulling up into a vertical position on a downwind leg.

The manual recommends a CG at 110mm...its too far back.

During a smooth turn, the plane may suddenly roll out (like its going into a snap roll), the surfaces will all stall, and the plane will begin a uncontrollable spin. If you have enough altitude you can relax everything, pour on the power and hopefully regain control, but its very difficult. If at low altitude...its toast.

I would recommend moving the CG farther forward. I havent yet determined exactly where yet, but I would cut it down to about 97mm or so to start.

At 110mm it doesnt feel tail heavy, and will seem to fly fine. The symptoms are as follows.

1. In a shallow smooth turn, the wings will rock rapidly opposite the turn like its rolling out of the turn. LET GO of everything, and go to full throttle. Allow the plane to build up airspeed before you try to "fly" it.

2. If you try to continue the turn by correcting with ailerons, the nose will drop. You will lose aileron authority, and it will spin to the ground.

I now have to replace one of the plastic wingtips on mine due to this. It cartwheeled. Luckily, not much damage other than replacing that wingtip and it scuffed up the cowl a little.
Its the weirdest thing Ive ever seen any plane do. Normally when a plane is tail heavy, you know it the first time you lift off. But this thing will fly fine...until you get it to that point...then it goes nuts. Literally. If youve got your CG at 110mm...be careful. Eventually it will stallout, and you'd better be ready for it. Its really hard to pull out of. The first time it did it to me was on a downwind pull to to vertical. It started flying into the vertical, and then it rolled suddenly out of control. The second time I was in a normal smooth turn to downwind, and it rolled out of the turn like a snap. I hit the throttle and attempted to regain control. I just about had it when I ran out of altitude and it cartwheeled on the runway.

I KNOW my elevator isnt flexing, Ive already corrected any possiblity of that happening. We had a long talk about this out at the field after my little mishap. The general concensus was that the CG was too far back. I agree. I think that 110mm CG is right on the borderline of stability and crash. Im gonna replace the wingtip, move the cg up to about 97mm and try again, and keep moving it forward until it will no longer stall like that. Flying around just shy of a crash is not the correct way to set it up.

If I cant fix this problem, Im gonna sell it and replace it with a Fliton QuietStorm. I plan on flying pattern competition with one of these in the Sportsman class. If I cant rely on it not to go nuts in the middle of my sequence, its not reliable enough to fly in competition. I wont compete with inferior equipment or set-up ever again. I learned that lesson already.