If it will roll forward (even the slightest) I will fly!!! Given that it is fairly steady. I had been flying for about 2 months when I finally told my dad that I had gotten into rc airplanes. I was eager to show him my skills. the first day I decided it was too windy and the second day I said what the heck. It was a steady wind and I had a .46 trainer. I place the plane on the runway and pointed it into the wind. I gave it gas and it rolled about 6 inches and was in the air. the wings were level but climbed straight up. the landing was the trickiest part. I got it over the runway, pointed the nose straight down, dove at the runway and about 15 feet alt. I pulled up adjusted the throttle and set it down. As soon as the wheels were on the ground I cut the engine. the plane actually rolled backwards.