On October 31, 1999, EgyptAir flight 990, a Boeing 767-366ER crashed into the Atlantic Ocean 60 miles south of Nantucket, Massachusetts. All 217 people on board were killed, and the airplane was destroyed. According to the NTSB the impact with the Atlantic Ocean was a result of the relief first officer's flight control inputs. The National Transportation Safety Board determines that the accident is a result of the relief first officer's flight control inputs. The reason for the relief first officer's actions was not determined.

On October 31, 1999, EgyptAir flight 990, a Boeing 767-366ER, crashed into the Atlantic Ocean 60 miles south of Nantucket, Massachusetts. All 217 people on board were killed, and the airplane was destroyed. According to the Egyptian Investigation Team a mechanical defect is the most likely cause of the accident, there is no credible evidence to support a conclusion that the First Officer intentionally dove the airplane into the ocean in fact.