Elevators are

flight control surfaces Aircraft flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. Development of an effective set of flight control surfaces was a critical advance in the development of aircraft. Ea ...

, usually at the rear of an

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engine ...

, which control the aircraft's pitch, and therefore the angle of attack and the lift of the wing. The elevators are usually hinged to the

tailplane A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyropla ...

or horizontal stabilizer. They may be the only pitch control surface present, and are sometimes located at the front of the aircraft (early airplanes) or integrated into a rear "all-moving tailplane", also called a slab elevator or stabilator.

Elevator control effectiveness

The elevator is a usable up and down system that controls the plane, horizontal stabilizer usually creates a ''downward'' force which balances the nose down moment created by the wing lift force, which typically applies at a point (the wing center of lift) situated aft of the airplane's

center of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...

. The effects of drag and changing the engine

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...

may also result in pitch moments that need to be compensated with the horizontal stabilizer. Both the horizontal stabilizer and the elevator contribute to pitch stability, but only the elevators provide pitch control. They do so by decreasing or increasing the downward force created by the stabilizer: * an increased downward force, produced by ''up'' elevator, forces the tail down and the nose up. At constant speed, the wing's increased angle of attack causes a greater

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobil ...

to be produced by the wing, accelerating the aircraft upwards. The drag and power demand also increase; * a decreased downward force at the tail, produced by ''down'' elevator, causes the tail to rise and the nose to lower. At constant speed, the decrease in angle of attack reduces the lift, accelerating the aircraft downwards. On many low-speed aircraft, a

trim tab Trim tabs are small surfaces connected to the trailing edge of a larger control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the boat or aircraft in a pa ...

is present at the rear of the elevator, which the pilot can adjust to eliminate forces on the

control column A yoke, alternatively known as a control wheel or a control column, is a device used for piloting some fixed-wing aircraft.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 563. Aviation Supplies & Academics, 1997. ...

at the desired attitude and airspeed. Supersonic aircraft usually have all-moving tailplanes ( stabilators), because shock waves generated on the horizontal stabilizer greatly reduce the effectiveness of hinged elevators during supersonic flight. Delta winged aircraft combine ailerons and elevators –and their respective control inputs– into one control surface called an

elevon Elevons or tailerons are aircraft control surfaces that combine the functions of the elevator (used for pitch control) and the aileron (used for roll control), hence the name. They are frequently used on tailless aircraft such as flying wings. A ...

Elevators' location

Elevators are usually part of the tail, at the rear of an aircraft. In some aircraft, pitch-control surfaces are in the front, ahead of the wing. In a two-surface aircraft this type of configuration is called a canard (the French word for

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

) or a

tandem wing QAC Quickie Q2 A tandem wing is a wing configuration in which a flying craft or animal has two or more sets of wings set one behind another. All the wings contribute to lift. The tandem wing is distinct from the biplane in which the wings are ...

. The Wright Brothers' early aircraft were of the canard type;

Mignet Pou-du-Ciel The Flying Flea (french: Pou du Ciel, lit=Louse of the Sky) is a large family of light homebuilt aircraft first flown in 1933. The odd name comes from the French nickname for the Ford Model T automobile: ''Pou de la Route'', or "Louse of the Ro ...

and

Rutan Quickie The Rutan Quickie is a lightweight single-seat taildragger aircraft of composite construction, configured with tandem wings. The Quickie was primarily designed by Burt Rutan as a low-powered, highly efficient kit-plane. Its tandem wing desig ...

are of tandem type. Some early

three surface aircraft A three-surface aircraft or sometimes three-lifting-surface aircraft has a foreplane, a central wing and a tailplane. The central wing surface always provides lift and is usually the largest, while the functions of the fore and aft planes may ...

had front elevators ( Curtiss/AEA June Bug); modern

may have both front (canard) and rear elevators (

Grumman X-29 The Grumman X-29 was an American experimental aircraft that tested a forward-swept wing, canard control surfaces, and other novel aircraft technologies. The X-29 was developed by Grumman, and the two built were flown by NASA and the United St ...

Research

Several technology research and development efforts exist to integrate the functions of

aircraft flight control system A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft ...

s such as ailerons, elevators,

flap Flap may refer to: Arts, entertainment, and media * ''Flap'' (film), a 1970 American film * Flap, a boss character in the arcade game ''Gaiapolis'' * Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland'' Biology and he ...

s and

flaperon A flaperon (a portmanteau of flap and aileron) on an aircraft's wing is a type of control surface that combines the functions of both flaps and ailerons. Some smaller kitplanes have flaperons for reasons of simplicity of manufacture, while ...

s into wings to perform the aerodynamic purpose with the advantages of less: mass, cost, drag,

inertia Inertia is the idea that an object will continue its current motion until some force causes its speed or direction to change. The term is properly understood as shorthand for "the principle of inertia" as described by Newton in his first law ...

(for faster, stronger control response), complexity (mechanically simpler, fewer moving parts or surfaces, less maintenance), and

radar cross section Radar cross-section (RCS), also called radar signature, is a measure of how detectable an object is by radar. A larger RCS indicates that an object is more easily detected. An object reflects a limited amount of radar energy back to the source. ...

for stealth. These may be used in many

unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...

s (UAVs) and 6th generation fighter aircraft. Two promising approaches are flexible wings, and fluidics. In flexible wings, much or all of a wing surface can change shape in flight to deflect air flow. The

X-53 Active Aeroelastic Wing The X-53 Active Aeroelastic Wing (AAW) development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory (AFRL), Boeing Phantom Works and NASA's Dryden Flight Research Center, where t ...

is a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

effort. The

Adaptive Compliant Wing An adaptive compliant wing is a wing which is flexible enough for aspects of its shape to be changed in flight. Flexible wings have a number of benefits. Conventional flight control mechanisms operate using hinges, resulting in disruptions to the ...

is a military and commercial effort. In

fluidics Fluidics, or fluidic logic, is the use of a fluid to perform analog or digital operations similar to those performed with electronics. The physical basis of fluidics is pneumatics and hydraulics, based on the theoretical foundation of fluid dyna ...

, forces in vehicles occur via circulation control, in which larger more complex mechanical parts are replaced by smaller simpler fluidic systems (slots which emit air flows) where larger forces in fluids are diverted by smaller jets or flows of fluid intermittently, to change the direction of vehicles. In this use, fluidics promises lower mass, costs (up to 50% less), and very low

and response times, and simplicity.

Gallery

Image:elevator.curriewot.arp.750pix.jpg, A drooped ''elevator'', nearly touching the grass, on the horizontal stabilizer of this Currie Wot biplane . File:Tail of a conventional aircraft.svg, The tail of an Airbus A380, showing the ''elevators'' at the rear of the horizontal stabilizer Image:Airbus-Höhenruder.jpg, Pre-installed elevators for a small

Airbus Airbus SE (; ; ; ) is a European multinational aerospace corporation. Airbus designs, manufactures and sells civil and military aerospace products worldwide and manufactures aircraft throughout the world. The company has three divisions: ' ...

. The elevator is the silver surface on the right hand side of the picture, immediately below the red pipes on the factory wall

References

External links

Aircraft Pitch Motion
(elevator function explanation,