Unknow reason the plane did not fly as planned

2017-02-07 15-14-05.zip (2.7 MB)

hello everyone, i test my plane with firmware ArduPlane 3.7.1 when i takeoff the plane did not fly as planned, and i switch to mode RTL and the plane flew overhead is not according to the circle, I suspect there is something wrong with the sensor.
dose anyone help me to find out what is the problem. thank you!!!