Twin tail

A twin tail is a type of vertical tail arrangement found on the empennage of some aircraft. Two vertical tails—often smaller individually than a single conventional vertical tail would be—are mounted at the outside of the aircraft's horizontal stabilizer. This arrangement is also known as an H-tail, as it resembles a capital "H" when viewed from the rear.

The twin tail was particularly used on a wide variety of World War II multi-engine designs that saw mass production, especially on the American B-24 Liberator and B-25 Mitchell bombers, the British Avro Lancaster and Handley Page Halifax heavy bombers, and the Soviet Union's Petlyakov Pe-2 attack bomber.

It can be easily confused for the similarly named twin-boom (or "double tail") arrangement, which has two separate tail-booms (typically parallel, extending aft from the wing or wing-mounted engines), rather than a single tail with twin stabilizers (a singular "twin tail" vs. two identical tails).

One variation on the twin tail is the triple tail, but the twin-boom arrangement can also be considered a variation of the twin tail.