EgyptAir Flight 990

EgyptAir Flight 990 (MS990/MSR990) was a scheduled flight from Los Angeles International Airport to Cairo International Airport, with a stop at John F. Kennedy International Airport, New York City. On October 31, 1999, the Boeing 767-300ER operating the route crashed into the Atlantic Ocean about south of Nantucket Island, Massachusetts, killing all 217 passengers and crew on board, making it the deadliest aviation disaster for EgyptAir, and also the second-deadliest aviation accident involving a Boeing 767 aircraft, behind Lauda Air Flight 004.

Since the crash occurred in international waters, it was investigated by the Ministry of Civil Aviation's Egyptian Civil Aviation Agency (ECAA) and the National Transportation Safety Board (NTSB) under International Civil Aviation Organization rules. As the ECAA lacked the resources of the NTSB, the Egyptian government asked the American government to have the NTSB handle the investigation.

Two weeks after the crash, the NTSB proposed that they hand the investigation over to the United States Federal Bureau of Investigation (FBI), as all of the evidence that they had collected up until that point suggested that a criminal act had taken place, and that the crash was the result of an intentional act, rather than an accident.

The Egyptian authorities refused to accept this idea, and repeatedly declined the proposal to hand the investigation over to the FBI. As a result the NTSB was forced to continue the investigation alone, despite it falling outside of their investigative purview.

The NTSB found that the cause of the accident was the airplane's departure from normal cruise flight and subsequent impact with the Atlantic Ocean "as a result of the relief first officer's flight control inputs". However they were ultimately unable to determine any specific reason for his alleged actions. The ECAA independently concluded that the incident was caused by mechanical failure of the aircraft's elevator control system. The Egyptian report suggested several possibilities for the cause of the accident, focusing on the possible failure of one of the right elevator's power control units.

However the NTSB continues to dispute the findings of the ECAA report, claiming that there is no possible explanation for the flight’s final movements, other than an intentional human act. Provided by Wikipedia