Flight Modes Auto Pilot - arthurbenemann/ardupilot GitHub Wiki

In this mode, the aircraft travels to pre-programmed GPS waypoints. The waypoints are set before flight with the configuration utility.

You can also "nudge" the aircraft manually in this mode. Throttle "nudging" occurs if the throttle stick is in the top 1/2 of the range and moves the airspeed or throttle setpoint up towards the upper limit proportional to the stick's position in the top 1/2 of the range. Normally you should have the throttle stick in the lower 1/2 of its range when using any "auto" mode.