An arrangement in which the tailplane is used as a primary control surface in looping the plane. This arrangement increases the effectiveness of controls at high Mach numbers when the effectiveness of the elevator is somewhat reduced. In some aircraft, the elevator is retained and is linked to the tailplane in such a way that movement of the tailplane causes the elevator, by virtue of its linkages, to move in the usual direction and to assist the action of the tailplane. On some aircraft, where no elevator is used, the arrangement is known as a slab tailplane. Also known as a flying tail * or an all-moving slab.