I hope someone could please help me, I bought a used nexus 30 and and a indoor hoverfly to train on, after some hover practice on the hoverfly I decided to take the nexus for a first take-off I fitted the training gear started her up and applied some throttle, I got about half way on the collective stick and i thought she was ready to take-off, I was just preparing to leave the ground and pushed up on the stick a little further at that point the the the engine throttled down and I didn't get off the ground. What I want to know is how could this happen is it somthing to do with the fuel air mix or could it be that the radio is not set up right or could it be that I just bought a duff helicopter. I hope someone can help as I've really enjoyed geting into this hobby so far but it would be nice to get of the ground!