Egypt Air Flight 990

Egypt Air Flight 990

EgyptAir Flight 990 (MS990/MSR990) was a regularly scheduled flight from Los Angeles International Airport, United States to Cairo International Airport, Egypt, with a stop at John F. Kennedy International Airport, New York City. On 31 October 1999, the Boeing 767-300ER operating the route crashed into the Atlantic Ocean about 60 miles (97 km) south of Nantucket Island, Massachusetts, killing all 217 people on board. The disaster was the third-deadliest aviation incident to have occurred in the Atlantic Ocean, after Air India Flight 182 and Air France Flight 447, and the second-deadliest involving a Boeing 767, after Lauda Air Flight 004.

As the crash occurred in international waters, the responsibility for investigating the accident fell to the Egyptian Civil Aviation Authority per International Civil Aviation Organization Annex 13. As the ECAA lacked the resources of the much larger American National Transportation Safety Board, the Egyptian government asked the NTSB to handle the investigation. Two weeks after the crash, the NTSB proposed handing the investigation over to the Federal Bureau of Investigation, as the evidence they had gathered suggested a criminal act had taken place and that the crash was intentional rather than accidental. This proposal was unacceptable to the Egyptian authorities, and as such the NTSB continued to lead the investigation. As the evidence of a deliberate crash mounted, the Egyptian government reversed their earlier decision, and the ECAA launched their own investigation. The two investigations came to very different conclusions: the NTSB found the crash was caused by deliberate action of the Relief First Officer Gameel Al-Batouti; the ECAA found the crash was caused by mechanical failure of the airplane's elevator control system.

The Egyptian report suggested several 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 NTSB's report did not determine a specific reason for the Relief First Officer's actions, the primary theory is that he committed suicide. Supporting their deliberate-act conclusion, the NTSB report determined that no mechanical failure scenario could result in airplane movements that matched those recorded by the flight data recorder, and that even had any of the failure scenarios forwarded by the Egyptian authorities occurred, the aircraft would still have been recoverable because of the 767's redundant elevator control system.