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, descent and landing.
Aircraft usually land at an airport on a firm runway or helicopter landing pad, generally constructed of asphalt concrete, concrete, gravel or grass. Aircraft equipped with pontoons (floatplane) or with a boat hull-shaped fuselage (a flying boat) 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 slow 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. 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. 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". This is known as flaring
In large transport category (airliner) aircraft, pilots land the aircraft by "flying the airplane on to the runway." The airspeed and attitude 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, spoilers (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 system, can take effect. Reverse thrust is used by many jet aircraft to help slow down just after touch-down, redirecting engine exhaust forward instead of back. Some propeller-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'.