I have a RTF Y6 that has been glitchy when flying lately. When it is on a flight plan in auto mode it starts zipping to the side and all around and actually flips over and upside down. When I switch to RTF it tries to return and then just goes out of control, and when it’s in loiter it is hard to control sometimes. At other times everything works fine, I can have a few great flights in a row and then some bad ones. I’m wondering if you could tell me what is going on? If it could be a hardware issue or calibration issue? This has been somewhat of an ongoing problem and I've done so many calibrations, which makes me think it could be a hardware issue. I attached the log files of the latest issue which resulted in me just trying to bring it down to the ground after I realized it might not return to launch site. 251.BIN should be that log.