I just built a SPAD that is a conglomeration of a few different airplane designs I found on the web. I set up the CG for the plane that the wing, tail feathers, and fuse length were copied from, which figures out to be 25% from LE, right on the spar. My problem is that even though the plane becomes airborne very quickly and smoothly, at about 30-40 feet up it goes nose over and is impossible to recover. It acts like the elevator is not even working. On all 3 flights (you have to love SPAD) the elevator worked just fine when I checked it on the ground, after the crash. Do I need to change my CG? Increase elevator control surface? Throw it away? Any suggestions are greatly appreciated.