Well, I did it!!! I launched her inverted, and it's definitely a way to go (at least for me).
Instead of a flight report, a friend of mine had a camera, and was so kind to place on his web site a short video clip (less than 300 Kb) of a first launch attempt. So please take look at:
Some important details you cannot see from the clip:
- Elevator down trim was about 30-40 % of a full recommended down throw. It was a bit over trimmed, 25 - 30% (2 - 3 mm) would be just enough, I guess.
- Throttle was at 50 - 70 % of a full throttle (OS-25 FX + APC 9x6).
And a bit of advice: if you have at least minimum positive rate of climb, just concentrate on ailerons and don't touch elevator or throttle commands until you reach a safe altitude. Of course, if she sinks or it is extremely over trimmed you'll have to correct it, but do it very gently.
I would also recommend practice of inverted flight before trying an inverted launch. The day before I took my electric powered Corsair (from Alfa Models) and made 6 successful inverted launches with that one, just for a practice.