Stabilize vs. FBWA in Heavy Quadplanes

ArduPlane VTOL Plane
1

Hi everyone,

I’m preparing to test flight modes on a heavy quadplane and I’m concerned about transitioning directly from Q-HOVER to FBWA, especially if the fixed-wing PID parameters aren’t well-tuned. To mitigate risk, I was considering Stabilize mode instead.

The issue is that while I’ve used FBWA successfully on smaller VTOLs, I’ve never relied on Stabilize mode, as the ArduPilot Wiki advises against it. However, I’m unsure if these limitations still apply in recent ArduPilot versions or if they’ve been resolved.

In SITL, Stabilize mode appears to work perfectly, but I’d appreciate insights from someone actively involved in ArduPilot’s development. Is there any ArduPilot developer who can provide an update on the current state of Stabilize mode for quadplanes?

Thanks in advance!

2

During the transition to fixed-wing mode the control loops will be in effect already. Assuming that all has been set up and tested before launch you should be okay going into FBWA as fixed wing tuning isn’t as sensitive as on multirotors. And by that I mean the defaults should fly most plane “well enough”. I can’t over emphasize though, the plane must be mechanically and aerodynamically sound first. The best flight controller in the world can’t fix physics.

Normally I would only suggest manual or stabilized if you are practiced and comfortable flying RC planes already (not just SITL)