It depends on wether or not you have them setup proportional to the elevator or just on a up or down switch. I have my flaperons set on a 3 position switch, where up is spoilerons, middle is nuetral, and down is flaperons. I use my flaperons for really slow flybys. The best time to apply them is when you have washed of some speed, as when you apply flaps models tend to balloon. You may also have to mix in some elevator correction to stop this even at low speeds. Then do your manouever, throttle up and gain speed, then flick them off. Simple as that!!!! If that makes sense.