i'm a new user, but took it very easy to get to know the drone, a few very short flights, some images, some videos, all was going so well. It must have been my 7th outing, battery showed 60% charge, up it went and within 3mins the controller shook with a critical level warning. I immediately started to return and when the drone was about 75' away motors stopped and it fell from 30' up in the air. No one hurt and surprisingly the drone only broke a few peripheral parts, a landing leg, battery door, and the propellors. Total flight time around 4mins. Not sure if the battery worked loose, or just died in flight. I did have some trouble with the battery door locking, and saw it land with the door open so thinking it may have been that. I wrote to yuneec 24 hr ago and am surprised not to already have had a reply. I chose the brand as saw posts raving about the customer service!!! Anyway posting as a warning for others. Double check the battery is firmly in, double check the door is locked. If you land and see the door opens during the flight maybe tape it up, use velcro, anything to be extra safe.