I've had this happen 3 times now and I'm paranoid to use my Iris+ now and considering selling it for a different drone. The first dive was only the 2nd flight. It was clear skies and no interference. The drone was about 150 feet in the air 20 feet in front of me and it lost signal flipped upside down and crashed into the snow. Fortunately the snow broke the fall and save the copter from damage. 3DR helped troubleshoot and stated it was a compass failure. After 2 hours of working with 3DR we reset and recalibrate the copter and sent it up again. Within seconds the copter launched into the air uncontrollably and crashed into the ceiling and plummeted to the floor. Lesson learned never to turn it on indoors. I sent that entire machine back to 3DR and ordered a new one with the hopes that the first one was a lemon and I would have no issues with a new one. Months later and many flights later, with the new copter, I was filming the beginning of a community picnic. Already fearful with the memories that I may loose control and it might crash to the ground I steered clear of people and cautiously captured footage. It was doing great as it had many flights before. Then with only an unrecognizable beep from the remote it lost all power, blades stopped and down she came! Scared the SH*T out of me because people were in the area. I ran over, opened it up only to discover the batter had expanded so much that I could barely get it out! It was a warm day and the copter had been flying for about 15 minutes with the gimbal and GoPro. Now I am faced with the decision to continue working with 3DR or check out the Phantom Pro. After reading this forum I see many 3DR drones drop from the sky. This is so dangerous. What are the options? What are other doing?