which an engine failure is simulated and the pilot has to get the aircraft on the ground safely, by selecting a landing area and then gliding the aircraft at its best gliding speed. If there is a suitable landing spot within the aircraft's gliding or autorotation distance, an unplanned landing will often result in no injuries or significant damage to the aircraft, since 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); but medium and heavy aircraft generally require long, prepared runway surfaces because of their heavier weight and higher landing speeds. Glider pilots routinely land away from their base and so most cross-country pilots are in current practice. UAV forced landing research Since 2003, research has been conducted on enabling unmanned aerial vehicles to perform a forced landing autonomously. Notable examples Large airliners have multiple engines and redundant systems, so forced landings are extremely rare for them, but some notable ones have occurred. A 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. In June 1982, British Airways Flight 9, a Boeing 747 en route from Kuala Lumpur to Perth flew into a plume of volcanic ash and lost power in all four engines, three of which subsequently recovered, eventually diverting to Jakarta. On April 28, 1988, Aloha Airlines Flight 243 experienced an explosive decompression when approximately of aluminium skin separated from the fuselage. The flight was successfully diverted to Kahului Airport with only one casualty, flight attendant Clarabelle "C.B." Lansing who was sucked out when the cabin depressurized. Less than a month later, another 737, TACA Flight 110, lost both engines due to bad weather but was able to make a successful deadstick landing on a grass levee on the grounds of NASA's Michoud Assembly Facility outside New Orleans, with minor injuries to the passengers and minor damage to the aircraft. Investigations drove the engine manufacturer, CFM International, to modify the engine design to prevent future power loss. One year later, United Airlines Flight 811, a Boeing 747, suffered a cargo door failure in-flight, separating a section of fuselage with 9 passengers and resulted in cabin depressurization. The plane made a successful emergency