Hi. I am using APM 2.0 for arduplane. During autopilot function, the thrust was sometimes increased and sometimes decreased by APM. Actually I could not understand why and how the APM increases (or decreases) the thrust. Is there any nominal airspeed coded in APM? I am also looking for a way to control this thrust control function with ground testing. I will be glad if someone helps me. Note: I am using airspeed sensor.