I'm facing a problem last month, on the ground, the elevons are not aligned - the left elevon is up while the right elevon is aligned(mid position) in auto mode or the elevons is moving all the time with airplane on the ground.
If I select manual mode the elevons are perfectly aligned but in auto or FWB the left elevon is always up.
I recalibrate accel, compass, level and I detected only when I enable the airspeed this behavior are happening.
I already know before having 3d fix, there is an oscilation on the elevons, but then 3dfix are achieved this behavior disappear, but in my case the elevons still moving.
I'm suspecting there are something wrong with my airspeed, but the airspeed is measuring the airflow so I don't know what problem or how can I detect a problem with airspeed.
This is a sample log - the airplane was on the ground, inside a room with no wind, and the elevons are moving all the time. https://drive.google.com/open?id=0B1omx8hPUswTM0stZXpfQzVNeUk
Thanks for any help.