Make sure that you have the plane perfectly balanced. I prefer to be a little nose heavy. The plane loved to climb so I added 2 washers to the top of the mount(against the firewall). I have yet to find any bad tendancies. My 30 size yellow 300s has about 150 flights on it and no dammage from some very hard landings! The stall speed is pretty slow. Powered by a 40La the plane moves pretty fast. Good luck!