A very nice flying plane. A guy in my club has one, I've seen it flown with everything from a Fox .40, to a ST-45. It did fly better with the larger of the two. It will fly fine with the Saito .56, but as Bodman said you would want a bigger engine for hover and other extreme flight. No major problems with this plane, and he has been flying it for several years now. The landing gear could be stronger Alum, it tends to pancake out if you have a "not so good" landing. Good luck.