Tailplane

[
Boeing 737]

A tailplane, also known as horizontal stabilizer, is a small lifting surface located behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes. However, not all fixed-wing aircraft have tailplanes, such as those configured with canards (where the "tail-plane" is located in front), flying-wing aircraft, where there is no tail, and v-tail aircraft where the fin/rudder and tail-plane are combined to form two diagonal surfaces in a V layout. The tailplane serves three purposes:

Equilibrium

An aeroplane must be in balance longitudinally in order to fly. This means that the net effect of all the forces acting on the aeroplane produces no overall pitching moment about the centre of gravity. Without a tailplane there would be only one combination of speed and center of gravity position for which this requirement was met. The tailplane provides a balancing force to maintain equilibrium for different speeds and center of gravity positions. Because the tailplane is located some distance from the center of gravity, even the small amount of lift it produces can generate a large pitching moment at the centre of gravity.

tability

An aeroplane with a wing only is normally unstable in pitch (longitudinal stability). This means that any disturbance (such as a gust) which raises the nose produces a nose-up pitching moment which tends to raise the nose further. With the same disturbance, the presence of a tailplane produces a restoring nose-down pitching moment which counteracts the natural instability of the wing and make the aircraft longitudinally stable. A stable aeroplane can be flown "hands-off" and will not depart significantly from its airspeed and pitch attitude.

Control

Elevator

A tailplane has a hinged flap called an elevator, which allows the pilot to control the amount of lift produced by the tailplane. This in turn causes a nose-up or nose-down pitching moment on the aircraft, which is used to control the aircraft in pitch.

All moving tail

In transonic flight, however, shockwaves generated by the tailplane render the elevator unusable. This was first discovered in the Bell X-1;Fact|date=September 2008 fortunately, although the tailplane was conventional in design, Bell Aircraft Corporation had included an elevator trim device that could alter the angle of attack of the entire tailplane. This saved the program from a costly and time-consuming rebuild of the aircraft. Transonic and supersonic aircraft now have all-moving tailplanes to counteract the Mach tuck and maintain maneuverability when flying faster than the Critical Mach number. While technically called a stabilator, this configuration is often referred to as an "all-moving" or "all-flying" tailplane.

ee also

* Aircraft flight control systems
* Elevator (aircraft)
* Flight control surfaces
* T-tail


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • tailplane — ► NOUN Brit. ▪ a horizontal aerofoil at the tail of an aircraft …   English terms dictionary

  • tailplane — UK [ˈteɪlˌpleɪn] / US noun [countable] Word forms tailplane : singular tailplane plural tailplanes either of the parts at the back of a plane that look like small wings …   English dictionary

  • tailplane — i. A nearly horizontal airfoil at the tail of an airplane that provides stability in pitching. It has an elevator hinged to its trailing edge. The tailplane can be trimmed from the cockpit. ii. A pivoted airfoil at the tail of an airplane whose… …   Aviation dictionary

  • tailplane — noun Date: 1909 the horizontal tail surfaces of an airplane including the stabilizer and the elevator …   New Collegiate Dictionary

  • tailplane — noun A horizontal airfoil, at the rear of an aircraft, to which the elevator is attached; usually associated with the tailfin …   Wiktionary

  • tailplane — tail|plane [ teıl,pleın ] noun count either of the parts at the back of an airplane that look like small wings …   Usage of the words and phrases in modern English

  • tailplane — n. horizontal part of a plane s tail intended to give equilibrium and stability …   English contemporary dictionary

  • tailplane — noun Brit. a horizontal aerofoil at the tail of an aircraft …   English new terms dictionary

  • tailplane — /ˈteɪlpleɪn / (say taylplayn) noun a horizontal surface at the rear end of an aircraft providing longitudinal stability; horizontal stabiliser. {tail1 + plane1} …   Australian English dictionary

  • tailplane — n. a horizontal aerofoil at the tail of an aircraft …   Useful english dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.