V-tail

In aircraft, a V-tail or Vee-tail (sometimes called a Butterfly tail) is an unconventional arrangement of the tail control surfaces that replaces the traditional fin and horizontal surfaces with two surfaces set in a V-shaped configuration when viewed from the front or rear of the aircraft. The aft edge of each twin surface is a hinged control surface (sometimes called a ruddervator) which combines the functions of both elevators and rudder.

The V-tail, invented and patented in 1930 by Polish engineer Jerzy Rudlicki, has not been a popular choice for aircraft manufacturers.

The X-shaped tail surfaces of the experimental Lockheed XFV were essentially a V tail that extended both above and below the fuselage.

The most popular conventionally V-tailed aircraft that was mass-produced is the Beechcraft Bonanza Model 35, often known as the V-tail Bonanza or simply V-Tail. Other examples include the F-117 Nighthawk stealth fighter and the Fouga Magister trainer.

The Blohm & Voss P.213 Miniaturjäger was one of the first aircraft having an inverted v-tail. Unmanned aerial vehicles such as the Amber, GNAT and the MQ-1 Predator would later feature this type of tail. The Ultraflight Lazair ultralights, of which over 2000 were produced, also featured an inverted V-tail.

Ideally, with fewer surfaces than a conventional three-aerofoil tail or a T-tail, the V-tail is lighter, has less wetted surface area, so thus produces less induced and parasitic drag. However, NACA studies indicated that the V-tail surfaces must be larger than simple projection into the vertical & horizontal planes would suggest, such that total wetted area is roughly constant; reduction of intersection surfaces from three to two does, however, produce a net reduction in drag through elimination of some interference drag.

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Wikipedia