I am new here. My friend and I make our first quadcopter which is 550mm and includes pixhawk 2.4.8. We tried the first flight at the weekend. I started in loiter mode. Drone lifted about 50 cm and hang in the air for 5-6 seconds. Then, suddenly it started to rise. Rc transmitter can not control the quadcopter. It rose fast and turn yaw axis slowly. I swicthed the flight mode as stabilizer and took control again. But it rose about 30 meters. Then, I did panic and couldn’t control it, it crashed.
We wonder that what the reason of that is. I think that it can be because of transmitter connection but when I changed the mode, it continued. In addition, quadcopter can not switch failsafe because of a problem before the flight. So failsafe is disabled.
I upload the log file, can you help us to understand the reason?
Flight video: https://youtu.be/Al1ImMF-OJQ