Emergency landing
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Image:JetBlue292Landing.jpg An emergency landing is a non-planned landing made by an aircraft in response to a crisis. There are two general types of emergency landing for powered aircraft:
- a forced landing, where the aircraft is gliding and no power is available to attempt a second approach and landing; and
- a precautionary landing, where partial or full power is still available but some other crisis requires an unplanned landing.
The difference lies in the options available to the pilot — during a forced landing, the pilot has a limited selection of landing spots (since the aircraft is gliding and constantly descending), and cannot usually reject a landing after beginning the approach (since there is no power for an overshoot and second approach).
Student pilots in most countries practice simulated forced and precautionary landings intensively during their training, and air transport pilots practice them routinely on flight simulators.
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[edit] Forced landing
A forced landing is the result of a complete loss of power to all engines (or loss of the burner in a hot air balloon), normally through fuel exhaustion (no fuel remaining), fuel starvation (fuel system blocked), or mechanical failure. A pilot may also voluntarily shut down engines in response to an onboard fire or other crisis. In an aircraft with multiple engines, the mechanical failure of a single engine does not normally lead to a forced landing, though fuel exhaustion or starvation still will. During a forced landing, a fixed-wing aircraft glides, while a rotorcraft autorotates to the ground.
If there is a suitable landing spot within the aircraft's gliding or autorotation distance, a forced landing will often result in no injuries or damage to the aircraft, since even powered aircraft generally use little or no power when they are landing. Light aircraft can often land safely on fields, roads, or gravel river banks (or on the water, if they are float-equipped); medium and heavy aircraft generally require long, prepared runway surfaces because of their higher landing speeds.
[edit] Famous forced landings
Large airliners have multiple engines and redundant systems, so forced landings are extremely rare for them, but some notable ones have occurred. The most famous example is the Gimli Glider, an Air Canada Boeing 767 that ran out of fuel and glided to a safe landing in Gimli, Manitoba, Canada on July 23, 1983. More recently, Air Transat Flight 236 ran out of fuel over the Atlantic Ocean on August 4, 2001 and made a successful forced landing in the Azores.
A less successful forced landing involved Southern Airways Flight 242 on April 4, 1977. The DC-9 lost both of its engines due to hail and heavy rain in a thunderstorm and, unable to glide to an airport, made a forced landing on a highway near New Hope, Georgia, United States. The plane made a hard landing and was still carrying a large amount of fuel, so it burst into flames, killing the majority of the passengers and several people on the ground.
[edit] Precautionary landing
A precautionary landing is an unplanned landing made with power still available, usually in response to a crisis inside or outside the aircraft. For example, after the September 11, 2001 attacks, all non-military aircraft flying in Canada and the United States were ordered to land immediately at the nearest usable airport, resulting in thousands of precautionary landings in a single day. Normally, however, the crisis is local to a single plane, such as weather problems, system or instrument failures, structural damage, an onboard fire, a security threat, or a seriously-ill passenger.
[edit] Famous precautionary landings
Airliners frequently make precautionary landings, and almost all of them are uneventful. Some notable exceptions include Swissair Flight 111, which crashed near Halifax, Nova Scotia, Canada on September 2, 1998 while dumping fuel in preparation for a precautionary landing due to fire; United Airlines Flight 232, which broke up while landing at Sioux City, Iowa, U.S.A. on July 19, 1989; and Air Canada Flight 797, which burned after landing at Cincinnati/Northern Kentucky International Airport on June 2, 1983 after a fire started in the cabin.de:Landung#Landung eines Luftfahrzeuges es:Aterrizaje de emergencia hu:Kényszerleszállás sl:Zasilni pristanek
