I started flying mine with a .25 fx. Then I got the bright idea to bolt a .32 sx on it, two flights later and the .25 went back on. The .32 was too fast. It spun an apc 8-10 pylon prop like it was'nt there. Best guess on speed had to be around 115 to 120mph. It would'nt sustain full throttle flight for very long with out getting alittle flutter.

I really wish I could come up with the larger size bird.