Definition
An aircraft empennage configuration consisting of two surfaces arranged in a V-shape that combine the functions of a conventional vertical fin and horizontal stabilizer. The movable portions, called ruddervators, work together to provide both pitch and yaw control: when deflected in the same direction they act as elevators, and when deflected in opposite directions they act as a rudder. Also called a V-tail.
Plain English
A tail design that uses two angled surfaces forming a V instead of the usual upright fin plus a flat horizontal stabilizer. The control surfaces on these two panels work together to steer the aircraft up and down, and left and right.
Context Anchor
Seen in aircraft design descriptions, aircraft recognition, and discussions of V-tail airplanes.
Derivation
Called a butterfly tail because the two surfaces, when viewed from behind, splay outward like the open wings of a butterfly. Also widely known as a V-tail because of the V-shape it forms.
Why Pilots Care
Fewer surfaces reduce weight and drag, yet the combined controls require pilots to anticipate coupled pitch and yaw responses during maneuvers.
Analogy
Think of two fins forming a wide V, each doing part of the job that separate rudder and elevator surfaces would normally share.
Intuition Check
Do not read “butterfly” as a separate moving part or a decorative feature. Here it describes the V-shaped tail layout.
Example Sentence 1
The Beechcraft Bonanza V35 is well known for its distinctive butterfly tail.
Example Sentence 2
In turbulence the pilot used small inputs on the control yoke to keep the butterfly tail stable without overcorrecting.