# horizontal stabilizer

Tailplane or horizontal stabilizer of a 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 centre of gravity position for which this requirement was met. The tailplane provides a balancing force to maintain equilibrium for different speeds and centre of gravity positions. Because the tailplane is located some distance from the centre of gravity, even the small amount of lift it produces can generate a large pitching moment at the centre of gravity.

## Stability

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 maintain the same altitude and pitch attitude and keeps the balance of the plane

## Control

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. In supersonic flight, however, shockwaves generated by the tailplane render the elevator unusable (this was first discovered in the Bell X-1; 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. The origin of this device is controversial, as the British had disclosed all of their research regarding the Miles M.52 prototype on the promise that US information would be shared the other way. The US failed to disclose any information in return and completed the rocket-powered Bell X-1. Supersonic aircraft now have all-moving tailplanes to counteract the Mach tuck when breaking the sound barrier and maintain maneuverability above the speed of sound. While technically called a stabilator, this configuration is often referred to as an "all-moving" or "all-flying" tailplane.

horizontal and vertical stabilizer]]

For aircraft, the horizontal stabilizer or tailplane is a fixed or adjustable surface from which an elevator may be hinged.
The lift force, lifting force or simply lift is a mechanical force generated by solid objects as they move through a fluid.[1]

While many types of objects can generate lift, the most common and familiar object in this category is the airfoil, a
fixed-wing aircraft is a heavier-than-air craft where movement of the wings in relation to the aircraft is not used to generate lift. The term is used to distinguish from rotary-wing aircraft, or ornithopters, where the movement of the wing surfaces relative to the aircraft
helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors, each rotor consisting of two or more rotor blades. Helicopters are classified as rotorcraft or rotary-wing aircraft to distinguish them from fixed-wing aircraft because the helicopter derives
autogyro is a type of rotorcraft invented by Juan de la Cierva in 1919, making its first successful flight on January 9, 1923 at Cuatro Vientos Airfield in Madrid, Spain.[1] The lift for an autogyro is provided by a rotor, similar to that of a helicopter.
canard (French for duck) is an airframe configuration of fixed-wing aircraft in which the tailplane is ahead of the main lifting surfaces, rather than behind them as in conventional aircraft, or when there is an additional small set of wings in front of the main lifting surface.
V-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.
In physics, force is an action or agency that causes a body of mass m to accelerate. It may be experienced as a lift, a push, or a pull. The acceleration of the body is proportional to the vector sum of all forces acting on it (known as net force or resultant force).
pitching moment of an airfoil, in aerodynamics, is a moment produced by a vertical force applied at a distance forward or aft from the aerodynamic center of the airfoil, causing the aircraft to pitch up or down[1].
center of mass of a system of particles is a specific point at which, for many purposes, the system's mass behaves as if it were concentrated. The center of mass is a function only of the positions and masses of the particles that comprise the system.
pitching moment of an airfoil, in aerodynamics, is a moment produced by a vertical force applied at a distance forward or aft from the aerodynamic center of the airfoil, causing the aircraft to pitch up or down[1].
Elevators are control surfaces, usually at the rear of an aircraft, which control the aircraft's orientation by changing the pitch of the aircraft, and so also the angle of attack of the wing.
supersonic. Speeds greater than 5 times the speed of sound are sometimes referred to as hypersonic. Speeds where only some parts of the air around an object (such as the ends of rotor blades) reach supersonic speeds are labelled transonic (typically somewhere between Mach 0.
shock wave (or simply "shock") is a type of propagating disturbance. Like an ordinary wave, a shock wave carries energy and can propagate through a medium (solid, liquid or gas), or, in special cases, through a field such as the electromagnetic field in the absence of a
Type rocket plane
Manufacturer Bell Aircraft Corporation
Maiden flight 19 January 1946
Status Retired
Primary users USAF
NACA

The Bell X-1, originally designated XS-1, was a joint NACA-U.S.
Bell Aircraft Corporation was an aircraft manufacturer of the United States, a builder of several types of fighter aircraft for World War II but most famous for the Bell X-1, the first supersonic aircraft, and for the development and production of many important civilian and
Angle of attack (AOA, , Greek letter alpha) is a term used in aerodynamics to describe the angle between the airfoil's chord line and the relative airflow, wind, effectively the direction in which the aircraft is currently moving.
Type Experimental supersonic aircraft
Manufacturer Miles Aircraft
Designed by Don L. Brown
Maiden flight 8 October 1947
Retired 1947
Status Cancelled
Primary user Royal Air Force
Number built 1

The
Type rocket plane
Manufacturer Bell Aircraft Corporation
Maiden flight 19 January 1946
Status Retired
Primary users USAF
NACA

The Bell X-1, originally designated XS-1, was a joint NACA-U.S.
Mach tuck is an aerodynamic effect, whereby the nose of an aircraft tends to pitch downwards as the airflow around the wing reaches supersonic speeds. Note that the aircraft is subsonic, and traveling significantly below Mach 1.0, when it experiences this effect.