So, I was helping someone fly their dii vision 2. It wasn't the gimbal model. I told the operator to make sure his transmitter was fully charged, which unfortunately never got charged to fully green. So, Im always flying phantom mode. I don't bother with naza, just keeping it simple. We got it up in the air, extremely windy day. Had 10 satellites, I calibrated it to its spot and waited for the green lights. We had it up, brought it down. He brought it up and back down again and then wanted to fly one more time. He took it up to about 150 feet, when all of a sudden I saw two red and two yellow lights on bottom. The unit started drifting away from us. I took over control and tried to get it back. It came slightly back, but i couldn't get it to come down when all of a sudden it took off away from us. When i looked at the phone and android it said going home. This thing flew across the river from queens to manhattan and we never saw it again. I just feel bad cause this was the maiden voyage it had never been flown before. What could have happened. These flyways scare me. Im just glad it wasn't mine, but felt extremely sad that the unit had malfunctioned and owner was out over 1000 bucks.