Hi.
I have 450 X quad with APM 3.1 mini and ublox neo 6M. The firmware is 3.2.1 I think (newest 2 months ago).
I had a crash lately. I have some trouble with my GPS, it looses fix for some reason. I believe the crash happened right after I tried to switch RTL which I have setup under channel 7. I switched it once, but it didn’t react as the GPS had no fix. I switched it of and on again, and it did couple of roll rotations (3-5) straight to the ground. I tried to switch modes when it was falling but it didn’t react anyhow. The rotations were consistent, fast with the axis of rotation right in the middle of the quadcopter from left to right, it looked like it was doing what the ecu wanted it to do. It didn’t look like ESC/motor failure. After crash I mounted new props and it flies just fine now. In logs it shows desired roll of 230 degrees so it looks like some ECU error.
I’m glad I didn’t mount camera gimbal yet, but now I’m afraid to do so. How can I avoid another crash?