Twin tail
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. Variations on the twin tail include the triple tail, twin boom tail and double tail. Design Separating the control surfaces allows for additional rudder area or vertical surface without requiring a massive single tail. On multi-engine propeller designs twin fin and rudders operating in the propeller slipstream give greater rudder authority and improved control at low airspeeds, and when taxiing. A twin tail can also simplify hangar requirements, give dorsal gunners enhanced firing area, and in some cases reduce the aircraft's weight. It also affords a degree of redundancy: if one tail is damaged,