I recently downloaded Stephens' F86.  The appearance was excellent - cockpit, model, texture.  But the a/c doesn't fly.  On the takeoff roll, the tail drops to the runway, and as soon as I lift off (with full DOWN on the elevetors and elev trim), the nose rotates to near vertical.  Has anyone else had this problem, or did I miss something on install?  I'm hoping I just missed something, as the Sabre is one of the a/c I've been looking forward to flying.