Hi, I’m testing my own JSBSim model in PX4 and QGroundControl, as a SITL.
JSBSIM version: 124.dev1
Px4 version: v1.15.3
QGroundControl: v5.0.6
My model is not super flexible at the moment, hence the JSB aerodynamic tables are spanning AoA 0–7 degrees and Beta (±)0–3 degrees etc. I would like to verify my model with flying with PX4 autopilot. The JSBSim model is confirmed stable at cruising speed, and is not suitable for takeoff/landing at the moment.
Hence, I would like to test the plane during cruising mode at an altitude. PX4 arms the plane successfully at zero speed, but when I start with a speed, the aircraft won’t arm, even if I force it to arm as commander arm -f. Before I tested to do the same with the Rascal model, but likewise I was unable to arm it whilst having an initial speed. Im using mission mode and position mode, with a fixed wing airframe.
So, if I start JSBSim with other conditions than, on ground and still, it cannot be armed.
Has someone successfully solved this? How? 
Would you recommend be able to do manual control first?
JSBSIM and PX4 run in wsl, talking UDP to QGroundControl.
I have started with the custom params that was from the Rascal model, and then I configured them a little bit to be more relaxed for the arming conditions.
all_px4_params.pdf (120.5 KB)