I launched the large Colonial Viper again last Saturday on a G40. As I recall I think the Viper wanted to arc over early, so I had to give a little bit of correction to keep it going straight up. As soon as the upward movement was over, I flipped the D-switch (flap) from "0" (boost) to my glide setting "1". The Viper started to deviate a little after turning on the first flap setting. I intervened with the stick, but then I was stuck for most of the remaining flight trying to control with the stick, which I am not very good at. I am now wondering if instead of using the stick if I should try using the trim control first. It was a beautiful day. Using the Club rails on the HPR rack is convenient. The downside for me is that I don't make much progress on glide path bringing it back to me, so I have a little bit of a walk. I did better on Orbital Transport.