Pixhawk installed
conventtional fixed wing aircraft
If mode stabilize is on and the control services work as they should [ nose down = elevater up ] can it be assumed that the servo directions are also correct for RTL or Auto modes as well? Thx
Hi,
I think your [ nose down = elevator up ] is incorrect. If the elevator is pulled up, that will decrease lift and make the nose go up. If you push the elevator down that gives a larger upper surface and more lift forcing the nose down. I would not make any assumption with this stuff. Understand and check everything. 
Best way I’ve found to test the auto pilot control is to switch to stabilise or fbwa, then hold the plane in your hands (all powered up but 0% throttle obviously) and move the plane into different pitch and bank angles.
As you move the plane you should see the relevant surfaces moving to try and make the plane go level. Rudder takes a bit more effort but if you stand holding the plane and spin on the spot you should see the rudder try to deflect to straighten the plane.
If that work’s as it should then your auto modes should be fine, if any control surface goes the wrong way then it has to be reversed in mission planner. If the surfaces go the wrong way in manual mode then you need to change the direction on the transmitter.
[quote=“MarkM”]
If that work’s as it should then your auto modes should be fine[/quote]
Thanks Mark that’s what I needed to know! I took out an amp 2.5 and put in a pixhawk. So far I’ve only had one flight but when I tested RTL it immediately made a sharp decline. I tried to figure out why. The throws in stabilize etc were correct checking on the ground so it didn’t make sense. I did discover I have ‘use airspeed sensor’ enabled but I didn’t have an airspeed sensor. So It seems it went into a nose dive not because of reverse throws but because of the airspeed sensor… it would see no airspeed and try too dive to avert a stall. At least that’s what I’m thinking at this point. Unfortunately I have not been able to try it again. But I agree if the throws in stabilize seem okay on the ground it sure seems like it would react the same in auto!
Thanks for the reply!