It's happened several times before. As NBC News reports, despite advances in technology, every plane that ventures more than 120 miles from land disappears from radar. (Intercontinental flights rely on satellites to keep air traffic controllers up to date on their position.)
If Malaysia Airlines Flight 370 did crash in the waters off of Southeast Asia as suspected, even finding the wreckage would be a tall task: Unsure of its exact location, authorities have thousands of miles of ocean to check.
Flight 370 is only the most recent aircraft to vanish without a trace. Below, a look at other famous air mysteries.
2009: Air France Flight 447
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The Angola 727In 2003, a Boeing 727 took off from the runway of Angola's Quatro de Fevereiro International Airport – a normal occurrence, except for the fact that the plane had sat unused at the airport for more than a year, awaiting repairs. There were only two people onboard: a flight engineer named Ben Charles Padilla and his assistant, John Mikel Mutantu. Neither of them had the experience to pilot the plane, and, a 727 normally requires three crew members to fly. No one knows why the plane took off, or where it went – neither it nor Padilla or Mutantu was ever seen again.
Ian Mackintosh was a veteran of the Royal Navy, creator of the acclaimed British television show Sandbaggers and, his friends and family suspected, a spy. In 1979, Mackintosh, his girlfriend and his pilot friend disappeared while flying a small aircraft around the coast of Alaska and were never seen again. In a blog post, Mackintosh's brother expressed suspicion over the official story and accused the U.S. and U.K. governments of stonewalling over Ian's disappearance.
The Two Congressmen
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Flying Tiger Flight 739In 1962, the early stages of the Vietnam War, a military-chartered plane flying from California to Vietnam disappeared off the coast of Guam while carrying 93 Army Rangers. Witnesses on a nearby tanker ship reported seeing an explosion in the air, opening up the possibility the plane was sabotaged; with no wreckage found, the exact cause of the plane's disappearance has remained unknown. Despite this, loved ones of the men aboard have petitioned to get the names of the missing added to the Vietnam Veterans Memorial Wall.
The United States Navy denies the supernatural qualities of the Bermuda Triangle on its FAQ page; the 1945 disappearance of five Navy bombers during a training exercise off the coast of Florida was probably due to a navigational error. (The planes, the Navy says plainly, "ran out of fuel and crashed into the ocean.") But that logical answer hasn't stopped fevered speculation that the pilots were doomed by the Triangle's mystic spells or, as Close Encounters of the Third Kind implied, captured by aliens.