The tailplane is usually at the bottom of the fin, but some aircraft have theirs fitted halfway up the fin. This type of tail is called a cruciform tail. The word “cruciform” means cross-shaped, and a cruciform tail forms a cross shape when viewed from the front or back.
The tailplane also can be at the top of the fin. This type of tail is called a T-tail because the tail fin and tailplane form a T shape. Cruciform tails and T-tails are common in business jets, which often have their engines mounted on each side of the tail. Mounting the tailplane higher up the tail fin places it out of the way of the engines.
A few aircraft have been built with a V-tail. This has two fins at an angle, forming a V shape. Each fin has a moving part at the back, which is called a ruddervator because it works as both a rudder and an elevator. The F-117 Nighthawk attack plane has a V-tail. The V-tail causes less drag than other designs because it has fewer surfaces, but the aircraft’s tail has to be made stronger, and its control system is more complicated.