Pixhawk worked good for a few flights then

I flew my quad with a Pixhawk flight controller a couple times this morning and everything was working good. I was testing different flight modes, arming in loiter, etc. A few hours later I went back out to do some more testing. After letting the quad sit for a few minuets to acquire satellites, and the barometer to settle down, I set the flight mode to loiter and armed. I started raising the throttle and it took off like a bullet and ended up hitting a tree. It broke a prop and knocked the top cover off the external mag/GPS. I put everything back together (except the top cover of the mag/GPS, which I haven’t found yet) and tested again. I started out in stabilize, but when I put it in loiter it shot off again. This time I was ready and quickly flipped it back into stabilize.

The log and kmz files for the flight that went awry are attached. I would appreciate any insights.

I noticed on the Mission Flight Data screen my quad is depicted as + mode, but I have it set up as X mode.