For example, the wings were interchangeable as were the fin and horizontal tail. Incidence angles can also be added to the wing and horizontal tail. The fins and horizontal tail consoles are attached to tail beams. It was bipedal, the horizontal torso being balanced by a long horizontal tail. The horizontal tail units were increased in span. The "No.21" was a wire-braced monoplane with bat-like wings and triangular horizontal tail. It was bipedal, walking on stout hindlimbs, its horizontal torso balanced by a horizontal tail. These surfaces were actually the horizontal tail surfaces from the F-16A. There, he placed a flashlight on the horizontal tail and climbed into the cockpit. Larger horizontal tail surfaces were adopted, with larger elevator horn balances. The horizontal tail is a stabilator with an antiservo tab (sometimes termed an antibalance tab). There are no moveable horizontal tail surfaces, only the vertical fin with rudder.