Hooray, got to the point where I've got APM set up and in a plane (Hawk Sky). Now I need a bit of help diagnosing a flight problem.
I took off and got some altitude, and then flipped into stabilize mode. As you can see from the video, as soon as I did this, the plane started spiraling down and to the right.
I brought the plane back in and recalibrated gyros, but still couldn't get it to work.