Hiya,
I am new to this, but anyway..I have the BCX also, the only time I had this happen was just yesterday, I got too confident and gave it the juice to turn right and come back nose in and from what I saw the top blade hit the flybar then hit the botton rotor all in the blink of an eye, so course don't know if that is the order it really happened but one bottom blade was broke, one top blade was broke and the flybar was bent.

I have a lot of flights by now, can't count them all anymore, but that is first time I tried to really do an aggressive move, and in that I mean tried to do something really, really quick. I don't know if you mean it happens all the time or what but what I think is, this heli cannot do any type of aggressive or really quick movements, being intended for training a newb like me. I probably am mistaken, just trying to help.
Now, if it happening just trying to give it power to lift I would think that the outer shaft might be loose and causing the blades to get too close or wobble?
You prolly know about "Tracking"? spinning the blades up and getting eyeball lvl with them and seeing if they are spinning perfectly flat/straight. Either raise it to eye lvl or get down to its' lvl to make sure.
Wish I could help more,
Hope you get a better answer if mine doesn't work, just learning the basics myself.
good luck and don't get discourged,
Blue