I have a 44" w/span 450 sq.in. PH3D profile model powered with a GMS 47 with a APC 12x4 prop that weights 4.25 lbs and is a pretty nice flier. On the weekend our flying field grass was a bit too high for a take off run so I decided to do a first time hand launch of this particular model.

The model was launched head high at a fast forward trot at approx a 30 deg. angle. To my surprise the model lost a significant amount of altitude and ended up about two feet off the groung before flying on it's own. For all the flights we did the same thing happened every time even though the model was properly trimmed.

Doing hand launches are not new to me but this behaviour was and did give me some very anxious moments every time. The model has an excellent power to weight ratio and will literally fly out of one's hand if held vertical, so what could the problem be. Could it be the low pitch prop or what.

I would certaintly appreciate all and comments and suggestions.

Karol