Backgrounder: World's mysterious airplane crashes

EgyptAir Flight 990, all 217 on board dead

Mystery surrounds the crash of EgyptAir Flight 990, which left John F. Kennedy International Airport in New York on Oct 31, 1999 bound for Cairo.

The Boeing 767 crashed into the Atlantic south of Massachusetts killing all 217 passengers and crew.

The Egyptian report suggested different control failure scenarios as possible causes of the crash, focusing on a possible failure of one of the right elevator's power control units.

While the report of the NTSB, the American investigatory body, did not determine a specific reason for the co-pilot's actions, the primary theory is that he committed suicide.