Apparent nose up flight


Ive been working on attempting to tune my pixhawk and plane for best performance. (Stable image platform but can turn quickly)

By big issue that I cant seem to easily fix is its straight line “level” it wants to fly with the left wing down 3 to 5 deg and and the nose up 5 deg.

When the plane is level on the ground the the hud on mission planner is very close to level in both roll and pitch.

The plane tracks well and trims well in manual flight there is no apparent nose up issue

I have use “Trim_Auto” to set trim limits to zero and confirmed them in parameter list as being equal to the Tx PWM.

If it were an AHRS Trim issue wouldn’t I see this on the ground with the plane level?

Im really hoping for a solution to this because I get uneven turn radius and less that set limit climb because its using 5 deg to fly level and if my max climb is 10 I really only get 5 deg.

I dont know why it would seem to fly level in manual mode with wings and nose level but not in auto mode.

Any ideas or subject to explore would be great


I was able to solve this by using AHRS trim for the roll error

a graph of nav roll vs nav pitch showed nav pitch -2deg off of zero while nav roll was on zero. I used trim to center nav pitch graph to zero then mechanically adjusted the elevator for level flight.

This got the nose on the horizon and wings level

One odd thing I noticed was after reboot nav pitch was again back at -2 deg but it appears the plane still tracked horizon well.