I have an F-5A Tiger that I love to fly. It's a beautiful aircraft and flies great except for one thing. At about 620-630 knots, I completely loose the ability to roll. Pitch still works fine but about 600 knots roll starts to fade and then disappears completely. The owner of the company I work for is a retired USAF Colonel. He has flown everything from A-10s to C-141s, including T-38s. He told me that if anything the roll rate would increase at that speed but certainly wouldn't decrease and disappear. So my question is, what setting in the air file or cfg file would keep it from doing that? It has an airwrench entry in the cfg file. Is there something in there that tells it to stop rolling at high speeds?