Sorry for the title but I just bought the above yesterday. The dealer gave me this supplemental product info page that directed me to tighten the main grips if there was play. Sure enough there was, so I followed the recommeded proceedure.
Unfortunately tonight, barely into the second run, a blade flies off, though fortunately not in my face. It looks to me that Horizon Hobbies is having a bearing problem not an assembly one. I’m going to contact them about it so I’ve uploaded the pictures here. Apologies for the dust, the heli did a dance in my carpet, didn’t notice the mess until too late.

Here's an overall shot.

Closeup shot #1 w/ remaining pieces spaced apart.

Closeup #2 with bearing repositioned.

Main Grips with the parts that remained attached to it. Looks to me the outer race and ball cage.

Closeup #3 w/the pieces from the main grip to show their size.