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Landing is the last part of a flight, where a flying animal, aircraft, or spacecraft returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing", "touchdown" or " splashdown" as well. A normal aircraft flight would include several parts of flight including taxi, takeoff, climb,
cruise A cruise is any travel on a cruise ship. Cruise or Cruises may also refer to: Tourism * Booze cruise * Music cruise * River cruise Aeronautics and aircraft * Cruise (aeronautics), a distinct stage of an aircraft's flight * Aviasouz Cruise, a R ...
,
descent Descent may refer to: As a noun Genealogy and inheritance * Common descent, concept in evolutionary biology * Kinship, one of the major concepts of cultural anthropology **Pedigree chart or family tree **Ancestry **Lineal descendant **Heritage (d ...
and landing.


Aircraft

Aircraft usually land at an airport on a firm runway or
helicopter landing pad A helipad is a landing area or platform for helicopters and powered lift aircraft. While helicopters and powered lift aircraft are able to operate on a variety of relatively flat surfaces, a fabricated helipad provides a clearly marked hard s ...
, generally constructed of
asphalt concrete Asphalt concrete (commonly called asphalt, blacktop, or pavement in North America, and tarmac, bitumen macadam, or rolled asphalt in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface roads, parkin ...
, concrete, gravel or grass. Aircraft equipped with pontoons (
floatplane A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, ...
) or with a boat hull-shaped fuselage (a
flying boat A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...
) are able to land on water. Aircraft also sometimes use skis to land on snow or ice. To land, the airspeed and the rate of descent are reduced such that the object descends at a low enough rate to allow for a gentle touch down. Landing is accomplished by slowing down and descending to the runway. This speed reduction is accomplished by reducing thrust and/or inducing a greater amount of drag using flaps, landing gear or
speed brakes In aeronautics, air brakes or speed brakes are a type of flight control surface used on an aircraft to increase the Drag (physics), drag on the aircraft. Air brakes differ from Spoiler (aeronautics), spoilers in that air brakes are designed ...
. When a fixed-wing aircraft approaches the ground, the pilot will move the control column back to execute a flare or round-out. This increases the
angle of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is m ...
. Progressive movement of the control column back will allow the aircraft to settle onto the runway at minimum speed, landing on its main wheels first in the case of a tricycle gear aircraft or on all three wheels simultaneously in the case of a conventional landing gear-equipped aircraft, commonly referred to as a "taildragger".Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 217. Aviation Supplies & Academics, 1997. Transport Canada: ''Aeroplane Flight Training Manual, 4th Edition'', pages 104-115. Gage Educational Publishing Company, 1994.


Light aircraft

In a light aircraft, with little crosswind, the ideal landing is when contact with the ground occurs as the forward speed is reduced to the point where there is no longer sufficient airspeed to remain aloft. The stall warning is often heard just before landing, indicating that this speed and altitude have been reached. The result is very light touch down. Light aircraft landing situations, and the pilot skills required, can be divided into four types: * Normal landings * Crosswind landings - where a significant wind not aligned with the landing area is a factor * Short field landings - where the length of the landing area is a limiting factor * Soft and unprepared field landings - where the landing area is wet, soft or has ground obstacles such as furrows or ruts to contend with


Large aircraft

In large
transport category Transport category is a category of airworthiness applicable to large civil airplanes and large civil helicopters. Any aircraft's airworthiness category is shown on its airworthiness certificate. The name "transport category" is used in the US, Ca ...
(airliner) aircraft, pilots land the aircraft by "flying the airplane on to the runway." The airspeed and
attitude Attitude may refer to: Philosophy and psychology * Attitude (psychology), an individual's predisposed state of mind regarding a value * Metaphysics of presence * Propositional attitude, a relational mental state connecting a person to a pro ...
of the plane are adjusted for landing. The airspeed is kept well above stall speed and at a constant rate of descent. A flare is performed just before landing, and the descent rate is significantly reduced, causing a light touch down. Upon touchdown,
spoiler Spoiler is a security vulnerability on modern computer central processing units that use speculative execution. It exploits side-effects of speculative execution to improve the efficiency of Rowhammer and other related memory and cache attacks. Ac ...
s (sometimes called "lift dumpers") are deployed to dramatically reduce the lift and transfer the aircraft's weight to its wheels, where mechanical braking, such as an
autobrake An autobrake is a type of automatic wheel-based hydraulic brake system for advanced airplanes. The autobrake is normally enabled during takeoff and landing procedures, when the aircraft's longitudinal deceleration system can be handled by the autom ...
system, can take effect. Reverse thrust is used by many
jet aircraft A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by jet engines. Whereas the engines in propeller-powered aircraft generally achieve their maximum efficiency at much lower speeds and altitudes, je ...
to help slow down just after touch-down, redirecting engine exhaust forward instead of back. Some
propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
-driven airplanes also have this feature, where the blades of the propeller are re-angled to push air forward instead of back using the 'beta range'.


Environmental factors

Factors such as crosswind where the pilot will use a crab landing or a
slip landing In aviation, a crosswind landing is a landing maneuver in which a significant component of the prevailing wind is perpendicular to the runway center line. Significance Aircraft in flight are subject to the direction of the winds in which the a ...
will cause pilots to land slightly faster and sometimes with different aircraft attitude to ensure a safe landing. Other factors affecting a particular landing might include: the plane size, wind, weight, runway length, obstacles, ground effects, weather, runway altitude, air temperature, air pressure, air traffic control, visibility, avionics and the overall situation. For example, landing a multi-engine turboprop military such as a
C-130 Hercules The Lockheed C-130 Hercules is an American four-engine turboprop military transport aircraft designed and built by Lockheed Corporation, Lockheed (now Lockheed Martin). Capable of using unprepared runways for takeoffs and landings, the C-130 ...
, under fire in a grass field in a war zone, requires different skills and precautions than landing a single engine plane such as a Cessna 150 on a paved runway in uncontrolled airspace, which is different from landing an airliner such as an Airbus A380 at a major airport with air traffic control. Required Navigation Performance (RNP) is being used more and more. Rather than using radio beacons, the airplane uses GPS-navigation for landing using this technique. This translates into a much more fluid ascent, which results in decreased noise, and decreased fuel consumption.


Parachutes

The term "landing" is also applied to people or objects descending to the ground using a
parachute A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, who ...
. Some consider these objects to be in a controlled descent instead of actually flying. Most parachutes work by capturing air, inducing enough drag that the falling object hits the ground at a relatively slow speed. There are many examples of parachutes in nature, including the seeds of a dandelion. On the other hand, modern ram-air parachutes are essentially inflatable wings that operate in a gliding flight mode. Parachutists execute a flare at landing, reducing or eliminating both downward and forward speed at touchdown, in order to avoid injury.


Spacecraft

Sometimes, a safe landing is accomplished by using multiple forms of lift, thrust (''propulsive landing'') and dampening systems. Both the
Surveyor Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ca ...
uncrewed lunar probe craft and the
Apollo Lunar Module The Apollo Lunar Module (LM ), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed ...
used a rocket deceleration system and landing gear to soft-land on the moon. Several Soviet rockets including the
Soyuz spacecraft Soyuz () is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau (now Energia). The Soyuz succeeded the Voskhod spacecraf ...
have used parachutes and airbag landing systems to dampen the landing on earth. In November 2015,
Blue Origin Blue Origin, LLC is an American private spaceflight, privately funded aerospace manufacturer and sub-orbital spaceflight services company headquartered in Kent, Washington. Founded in 2000 by Jeff Bezos, the founder and executive chairman of Am ...
's New Shepard became the first rocket to cross the
Kármán line The Kármán line (or von Kármán line ) is an attempt to define a boundary between Earth's atmosphere and outer space, and offers a specific definition set by the Fédération aéronautique internationale (FAI), an international record-keeping ...
and land vertically back on Earth. In December 2015,
SpaceX Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...
's Falcon 9 became the first launch vehicle on an orbital trajectory to successfully vertically-land and recover its first stage, although the landed first stage was on a sub-orbital trajectory.


See also

* Arresting gear *
Hard landing A hard landing occurs when an aircraft or spacecraft hits the ground with a greater vertical speed and force than in a normal landing. Landing is the final phase in flight, in which the aircraft returns to the ground. The average vertical sp ...
* Landing performance *
Visual approach A visual approach is an approach to a runway at an airport conducted under instrument flight rules (IFR) but where the pilot proceeds by visual reference and clear of clouds to the airport. The pilot must at all times have either the airport or t ...
* Instrument approach * Instrument landing system (ILS) * Instrument flight rules (IFR) * Visual flight rules (VFR)


Notes

* touchdown: tango delta, TD


References


External links

{{Flight phases * * Flight phases Articles containing video clips Aircraft performance