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Water landing |
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A Mute Swan performs a water landing
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A water landing is, in the broadest sense, any landing on a body of water. All waterfowl, those seabirds capable of flight, and some human-built vehicles are capable of landing in water as a matter of course.
The phrase "water landing" is also used as a euphemism for crash-landing into water in an aircraft not designed for the purpose. An intentional water landing during distress, but under controlled flight, is called ditching. Such water landings are somewhat common for small craft in general aviation and the military, but they are extremely rare for commercial passenger airlines.
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Seaplanes, flying boats, and amphibious aircraft are designed to take off and land on water. Landing can be supported by a hull-shaped fuselage and/or pontoons. The availability of a long effective runway was historically important on lifting size restrictions on aircraft, and their freedom from constructed strips remains useful for transportation to lakes and other remote areas. The ability to loiter on water is also important for marine rescue operations and fire fighting. One disadvantage of water landing is that it is dangerous in the presence of waves. Furthermore, the necessary equipment compromises the craft's aerodynamic efficiency and speed.
Early manned spacecraft launched by the United States were designed to land in water by the splashdown method. The craft would parachute into the water, which acted as a cushion to bring the craft to a stop; the impacts were violent but survivable. Landing over water rather than land made braking rockets unnecessary, but its disadvantages included difficult retrieval and the danger of drowning. The modern Space Shuttle lands on a runway instead.
Although extremely uncommon in commercial passenger travel, small aircraft ditchings are common occurrences. According to the United States Coast Guard, including helicopters and fixed-wing aircraft, between military, air carrier, corporate, and general aviation, there is one ditching every day in U.S. waters alone.1
General aviation includes all fields of aviation outside of military or scheduled (commercial) flights. This classification includes small aircraft (eg, training aircraft, airships, gliders, helicopters, and corporate aircraft (including business jets and other for-hire operations). General aviation has the highest accident and incident rate in aviation, with 16 deaths per million flight hours, compared to 0.74 deaths per million flight hours for commercial flights (North America and Europe) [1].
Australian pilot Ray Clamback has twice survived ditchings of small aircraft (he also ended up in the water on an earlier occasion when the hull of the flying boat he was in was breached)2. The first ditching was during a ferry flight from the United States to Australia on 20 November 1999. The Piper PA-28-181 Archer was forced to ditch between the US mainland and Hawaii after developing engine problems, and Clamback and his co-pilot were forced to tread water in mid-ocean for ten hours before being rescued by a cargo ship3. The second ditching took place on 4 October 2004; this time Ray was between Hawaii and Christmas Island in a Cessna 182 on another US-Australia ferry flight when it developed engine trouble. This time he was picked up by a cargo ship after six hours in the water3.
Commercial airliners almost never make water landings. The FAA does not require commercial pilots to train to ditch, regulating instead the distance a plane can stray from an airfield.1 Nevertheless, all commercial aircraft are equipped with flotation devices in case of water landings. According to FAA regulations, aircraft that travel no further than 50 nautical miles from shore are only required to be equipped with flotation seat cushions. Aircraft that travel no further than 162 nautical miles from shore are required to be equipped with life vests for all passengers. If an aircraft travels further than 162 nautical miles from shore it must be equipped with life vests for all passengers, and life rafts/raft evacuation slide. While there have been several 'successful' (survivable) water landings by narrow-body and propeller-driven airliners, there is still a good deal of popular controversy over the efficacy of such measures. For example, Ralph Nader's Aviation Consumer Action Project has been quoted as claiming (quite erroneously) that a wide body jet would “shatter like a raw egg dropped on pavement, killing most if not all passengers on impact, even in calm seas with well-trained pilots and good landing trajectories."1 In December 2002, The Economist quoted an expert as claiming that "No large airliner has ever made an emergency landing on water" in an article that goes on to charge, "So the life jackets ... have little purpose other than to make passengers feel better."45 This claim was repeated in The Economist in September 2006 in an article which claimed that "in the history of aviation the number of wide-bodied aircraft that have made successful landings on water is zero."6 This is correct, but incomplete (the one wide-bodied landing was a case of a 767 leaving a runway).
In all cases where a passenger plane has undergone an intentional water landing or ditching, some or all of the occupants have survived. Examples of water landings in which passengers survived are:
Aircraft also sometimes end up in water by running off the end of runways, or landing in water short of the end of a runway. While such incidents are not quite water landings, the passengers do find themselves swimming. Twice at LaGuardia Airport, aircraft have rolled into the East River; in 1989, USAir 5050, a Boeing 737-401 with 63 people aboard, sustained 2 deaths.13 In 1993 a China Airlines Boeing 747-409 ended up in water after it overran runway 13 at Kai Tak International Airport on landing during a typhoon with wind gusting to gale force. All of the 396 occupants donned life-vests, boarded the 8 slide/rafts and no fatalities resulted. The airframe remained above water even after the aircraft was evacuated.14In 1985, an American Airlines DC-10 taking off from Muñoz Marín to Dallas-Fort Worth International Airport in Texas overran the runway and nosedived into a nearby lake. Everybody avoided injury. Finally, on May 27, 1968, a Japan Air Lines DC-8-62 landed short of the runway in San Francisco Bay on approach to San Francisco International Airport. There were no fatalities, and the aircraft itself was in good enough condition to be removed from the water, rebuilt, and flown again.
There is a distinction between a controlled ditching and simply crashing (not even crash-landing) into the water; the latter is capable of killing everyone upon impact and disintegrating the plane. For example, Armavia Flight 967, Alaska Airlines Flight 261, EgyptAir Flight 990, SilkAir Flight 185 (which disintegrated in midair) and Swissair Flight 111 left no survivors when they crashed, while just 8 of 73 on board American Airlines Flight 320 and 10 of 179 on board Kenya Airways Flight 431 survived their crashes. On a smaller scale, John F. Kennedy, Jr. and his two passengers died in a water crash. As pilot and columnist Patrick Smith comments, these crashes tend to be more memorable than controlled water landings, perhaps fueling the public's suspicions of the survivability of aircraft that hit water.15