title_body: Kk2.1.6 falling in mid air and losing control
upvoted_answer: The loose nuts that you hear may be the prop nuts. If this is the case, the props are not held down with enough force and so will be slipping, not providing the torque or the RPM to be able to lift the drone.
  
  I would suggest tightening all of the prop nuts and all of the frame fixings and seeing if the issue persists.