The search for missing Malaysia Airlines flight MH370 is ongoing. The circumstances surrounding the disappearance are unusual, with no distress signal sent and no sign of the aircraft in an ever-expanding search area.
It is not, though, the first time an aircraft has vanished.
1937: American aviation pioneer Amelia Earhart disappeared on July 2. The first female aviator to fly solo across the Atlantic Ocean, she vanished over the Pacific Ocean, near Howland Island, while attempting to circumnavigate the globe.
1945: On December 5, five TBM Avengers, known collectively as Flight 19, took off from a military base in Fort Lauderdale for a routine exercise never to return . Later, a 13-man PBM mariner sent to search for them also vanished, starting a search that covered the Atlantic Ocean and the Gulf of Mexico. No trace was ever discovered.
1948-49: Two aircraft operated by British South American Airways were lost without a trace almost a year apart in what is popularly known as the Bermuda Triangle. Star Tiger was flying from England to Bermuda in January 1948 when it stopped for fuel in the Azores before disappearing en route to its final destination. In January 1949, Star Ariel departed Bermuda, bound for Kingston, Jamaica and was never seen again, despite a search involving more than 70 aircraft.
1957: American Airways Flight 7 vanished from radar screens on November 9 while on the first leg of a round-the-world journey. It sent no distress signal before it disappeared and about a week later debris and bodies were discovered in the ocean, off course, and northeast of Honolulu. The cause of the crash remains a mystery, particularly as toxicology reports showed higher than normal levels of carbon monoxide in the bodies of those passengers who were recovered.
1963: While transporting troops to Saigon from a US airforce base in California, the Flying Tiger Line Flight 739 disappeared. All 107 people on board were declared missing presumed dead . The ensuing search covered more than 520,000 sq km in eight days, but no wreckage was ever recovered.
2003: In a case that has stumped the FBI, CIA and the US Department of Homeland Security, a Boeing 727 was stolen from Angola , never to be found. Its theft prompted a worldwide search, fuelled by fears it could be used in some sort of an attack. There has never been any trace of the plane or its pilot, Ben Charles Padilla, whose family think may have been kidnapped.
(Compiled by Philippa Stewart)