Handley Page Halifax in the context of "Electronic-warfare aircraft"

A twin tail is a type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers—often smaller on their own than a single conventional 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 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 from the same fuselage rather than a single tail with twin stabilizers (a singular "twin tail" vs. two identical tails).