FYI:
The Hyper Viper was to have the KillerBee .049 engine and in that combination if flew pretty good, it would fly the complete pattern although a bit larger. “The power that be” killed the KillerBee (cost way too much) and used the production engine. Because of that it was limited to basic stunts and maneuvers.
The foam and balsa prototype flew the pattern with ease and a lot of fun to fly. The wing I cut out from blue foam no sheeting but covered with Fast-cal, the fuse was a built up from 1/16” balsa sheet with built up cowl and Tuttle deck. But it still flew way better than than most most or/all the models ever produced there. Yes I flew the TD1 and it didn’t fly too bad but that was lacking engine power like the production engine. The aluminum wings we pretty fragile and easy to deform at the slightest bump.
Later,
Mikey Pratt