Try rolling circles - you use the elevator when the plane is in knife- edge to steer the plane in a circle while at the same time using rudder and elevator to keep the nose up.Also, try a blender because you don'tnecessarily need a 3D plane to do this manuver.have as much throw on the controls as you can get .While going straight down suddenly apply full down elevator, full left aileron, full right rudder and have the throttle at idle.Do this at height so You don't get caught out!