I thank everybody.
Olefart: I thank you. I seen the training kit thanks the link you posted.
This kit seems simple to mount on helicopter and it's cheap.
Looking for on the web, I found some video where there are Helicopters with these kits mounted. The helicopter is free to take off and can do
every motion. Maybe again, I think the helicopter would be in danger to crash with a wrong command of a beginner as me.
In fact I found several movies where this kit doesn't works very well. Please, Can you look at them ?
http://www.youtube.com/watch?v=Sld6ThHLhCk
http://www.youtube.com/watch?v=EOcXN6jRF-o
http://www.youtube.com/watch?v=rpFFp2A9saU
Maybe, the Heliwalker device, found on altervista seems to be more safe, in fact in the movie at minute 4:06,
it impacts against a wall but it doen't break itself and saves the model.
What do you think about this issue?