Two questions about my flight

Hi,

I’m a newbie in analyzing flight logs and fairly so with APM in general. I’ve been experimenting with the auto modes and had my longest RTL flight just now. There were two questions which I couldn’t answer myself:

  1. At one point the plane had a fairly steep roll (from the camera angle it looks almost 90 degrees) while transitioning from flight mode to another (from FBWB to CIRCLE if I’m right). My max roll (LIM_ROLL_CD) was at 50 degrees. I’ve been flying with default PIDs and the CG might be off a bit too (not much though), but are these factors the full explanation? (there is a second steep roll later in the log)

Video of the roll: youtube.com/watch?v=lVXjQkV6WXs

  1. The RTL didn’t take the shortest route back home, as seen from the attachment (the flight back after the last 90 degree turn is RTL). Is this normal or should I do something about it?
    https://www.dropbox.com/s/zucj2y13ega6vja/2015-06-13%2020-46-08.tlog.jpg?dl=1

If anyone with more experience could share tips they’d be greatly appreciated, that roll had me scared for a moment!

The plane is Skywalker Revolution 1720mm (hobbyking.com/hobbyking/store/__ … ARF.html). Wind was mild (~ 3m/s). Autopilot is Pixhawk with Plane 3.3.0 firmware.

.BIN log file: dropbox.com/s/mksy4ua9s0jlnz9/225.BIN?dl=1