Aileron reflex is raising both ailerons. These extremely short coupled combat planes often act half-way between a flying wing and a conventional plane. By raising the ailerons, you change the pitching moment of the airfoil and at the same time change the incidence of the wing compared to the stab and engine.

This has a couple of effects in the air. For one thing, a plane that is "pitchy" and often suddenly pops the nose up or down can often be made to fly more smootly by increasing reflex. Many designs just won't fly right with out some raising of the ailerons. I suspect that was part of what you describe from your first plane.

It also affects the power-off glide, so one way to test reflex is to fly level at full power and then quickly yank back on the throttle, best is to go deadstick. Watch the glide you get with no elevator input. You should transition into a smooth glide at a reasonable descent rate, no sudden darting up or down, and the glide should be stable, not so flat as to lead to a stall, and not into an increasing dive.


(One of these days I'm going to re-do my airfoil design by running the XFoil plots with the ailerons raised and see if that changes things. Lazyness has prevented me from doing it though).