Yesterday my 520 stopped responding to commands from the remote and eventually the inevitable happeden,. It ran out of power and gravity did the rest. The worst part was I was surveying a fishing beat on the river Tay north of Perth. The mission was to use two batteries and it was time to change as it was at 24% left and not too far out to bring it in. I paused the mission and it stopped as requested. That was the last command it acted on. The craft was above the fastest and deepest stretch of the river so it went under instantly and was carried away down stream. The whole time it was unresponsive the E90 was still streaming images to the st16. Even when the software was saying returning to land there was no response. Remote has been sent to Yuneec so they can determine the issue and hopefully replace the craft and camera as it is still under warranty.