Ragwing airplanes have the option of mounting spoilers over ailerons. This can save weight and help someone try to meet Part 103 Ultralight regulations. My plane is being built with normal ‘barn door’ style ailerons.

In general spoilers are slow acting. Nothing you can really do to get around that. Likely has something to do with being placed where most of the lift is generated on the airfoil. But don’t quote me.

In other Ultralights with spoilers the response is slow acting, but it does help induce the turn. This was good and bad. Good because the turn is more coordinated. Bad because you are basically dragging the wing and killing the lift on one wing. Early Ultralights with very little margin between stall speed and cruise speed with this type of setup could get themselves into trouble by stalling the wing in a tight turn with not enough airspeed. You can imagine what happens next.

I’ve thought about spoilers before myself. You would need to increase your dihedral more than 2 deg. to make it more stable and more likely to return to neutral. I would experiment between 3-5 deg. You will fly more like a quicksilver, but then that’s point isn’t it?

I always liked the old Quicksilver MX that was 2 axis, or technically 3-axis with the spoilers. They were deployed by the foot pedals (can’t call them rudder pedals). The spoiler controls were individual from each other so you could press both feet and deploy both spoilers at once. Instead of turning the plane just lost a good amount of lift, but not enough to stop flying.This was actually quite effective in dumping the lift and allowing you to get down into tight spots fast. Also helped if it seemed like you were coming in too hot and needed to bleed off airspeed and lift quickly. They gave you more control in your landings, with the exception of cross winds of course. This is where spoilers are less than useful.

Lots of Ultralights have used spoilers effectively. If “I” were to use them, I would change the rigging and have the control stick linked to the rudder and the spoilers linked to the foot pedals, then you could dump both spoilers at once.

Sounds like fun!