Vertical stabilizer
From Wikipedia, the free encyclopedia
The vertical stabilizer or fin of an aircraft is typically found on its tail, generally pointing straight upward. It is also known as the vertical tail, and is part of an aircraft's empennage. The trailing end of the stabilizer is typically movable, and called the rudder; this allows the aircraft pilot to control yaw.
Often navigational radio or airband transceiver antennas are placed on or inside the vertical tail. In some aircraft, the vertical stabilizer houses an engine, or engine inlet duct, as in the Lockheed L-1011, McDonnell Douglas DC-10, McDonnell Douglas MD-11, Boeing 727, Tupolev Tu-154, and the Yakovlev Yak-40.
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[edit] Types of vertical stabilizers
[edit] Single
[edit] Conventional tail
The tail is configured vertically, and the horizontal stabilizer is directly mounted to the empennage. The Lockheed L-188 Electra is a typical example of this configuration.
[edit] T-tail
A T-tail has the horizontal stabilizer mounted at the top of the vertical stabilizer. It is commonly seen on rear-engine aircraft, such as the Boeing 727 or Douglas DC-9, as well as the Piper Arrow small airplane, and most high performance sailplanes.
T-tails are often incorporated on configurations with fuselage mounted engines to keep the tail away from the engine exhaust plume.
T-tail aircraft are more susceptible to pitch-up at high angles of attack. This pitch-up results from a reduction in the horizontal tail's lifting capability as it passes through the wake of the wing at moderate angles of attack.
T-tails present additional structural challenges since the horizontal tail loads must be transmitted through the vertical tail.
[edit] Cruciform tail
The Cruciform tail is arranged like a cross, the horizontal stabilizer intersects the vertical tail somewhere near the middle. The PBY Catalina uses this configuration.
[edit] Multiple
[edit] Twin tail
Rather than a single vertical stabilizer, a Twin tail has two. These are vertically arranged, and intersect or are mounted to the ends of the horizontal stabilizer. The Beechcraft Model 18 and many modern military aircraft use this configuration.
[edit] Triple tail
A variation on the twin tail, it has three vertical stabilizers. The best example of this configuration is the Lockheed Constellation. On the Constellation it was done to give the airplane maximum vertical stabilizer area, but keep the overall height low enough so that it could fit into maintenance hangars.
[edit] V-tail
A V-tail has no distinct vertical or horizontal stabilizers. Rather, they are merged into control surfaces known as ruddervators which control both pitch and yaw. The arrangement looks like the letter V, and is also known as a butterfly tail. The Beechcraft Bonanza Model 35 uses this configuration, as does the F-117 Nighthawk, and many of Richard Schreder's HP series of homebuilt gliders.
[edit] Winglet
Winglets served double duty on Burt Rutan's rear wing forward canard pusher configuration VariEze and Long-EZ, acting as both a wingtip device and a vertical stabilizer. Several other derivatives of these and other similar aircraft use this design element.
