Mine flies great, just like it is on a railroad track. Landings are easy, and maneuvers are so smooth it makes me look like I know what I am doing. I really noticed the difference in elevator trim from a full tank to a low fuel situation. I moved the tank back to the CG. My forward fuselage was empty anyway as I mounted the reciever and 2000mah 6 volt battery all the way back in the radio area. I just cut the forward floor off a bit and moved the throttle servo over a bit so the tube and rod were next to the tank. I used the tank provided, several feet of hose and a Perry Pump. My OS 120AX had a neat boss in the backplate that I drilled and tapped. Now it runs even smoother than it did and runs cleanly in all attitudes. Great plane, great engine.