Go Go Bird Eagle test flight, the first flight with successful launch and safe landing. But It dropped in the second flight, because of the screw off, causing the wings to stop flapping in the air and drop, fortunately, in the landing area.

It seems to be an oversight in design. The screw should be locked. It looks to be a big hidden danger and must be checked regularly before flying.

Reinstall the screw. Hope the coming flight will be okay.