I fly in auto mode without an airspeed sensor on my Pixhawk with cruise throttle at 47% in Mission Planner which works very well.
The plane’s speed varies between about 19 and 27 m/s depending on wind direction and battery voltage.
Is it possible to make the plane maintain a steady 24m/s GPS ground speed irrespective of these factors and adjust the throttle accordingly?
There will be no stall risk as I don’t fly in winds above about 5m/s.
Try changing the settings below to both 24m/s
ARSPD_FBW_MIN
ARSPD_FBW_MAX