Investigators believe the co-pilot of a German airliner deliberately crashed the plane into the French Alps earlier this week, killing all 150 people aboard.
While rare, there have been previous such incidents in which a pilot or co-pilot have brought down an aircraft.
- Mozambique Airlines -
November 29, 2013: Mozambique Airlines (LAM) flight TM 470 flying from Maputo to Luanda goes down in northeastern Namibia killing 33.
Investigators said the captain had a "clear intention" to crash the plane. They said flight recorders showed the Embraer 190 went down while Captain Herminio dos Santos Fernandes manipulated its autopilot in a way which "denotes a clear intention" to bring the plane down.
- EgyptAir -
October 31, 1999: EgyptAir flight 990, a Boeing 767 en route from New York to Cairo crashes into the Atlantic Ocean shortly after take off, killing all 217 on board.
An analysis of the black boxes showed that the pilot caused the accident and declared shortly before the crash: "I have just taken my decision. I put my faith in God's hands".
Egyptian authorities, however, rejected the explanation of pilot suicide, disputing among other things the interpretation of what he said in the black box recording.
- SilkAir -
December 19, 1997: A Singaporean SilkAir Boeing 737 plunges into a river in Indonesia on route from Jakarta to Singapore. All 104 passengers and crew aboard were killed.
US investigators say the captain probably crashed the plane on purpose, while the main investigation led by Indonesia was inconclusive, though it did say pilot suicide was a "plausible hypothesis".
A report by Singaporean accident investigators at the time said there were indications the flight had been deliberately downed and that the pilot had been in financial difficulties.
However Singaporean police investigated the claims and found that no member of the crew had any financial problems, and "no evidence that the pilot, co-pilot or any crew member had suicidal tendencies or a motive to deliberately cause the crash".
- Royal Air Maroc -
August 21, 1994: The pilot of a Royal Air Maroc jet crashes the plane into the Atlas mountains shortly after taking off from Agadir for Casablanca. All 44 aboard are killed. The probe, based on the last words of the co-pilot, quickly concluded it was suicide.
- Japan Airlines -
February 9, 1982: A Japan Airlines DC-8 crashes into Tokyo Bay on approach to Haneda Airport. Twenty four people are killed.
A probe concluded that the pilot, who survived, was mentally unstable.
Pilot suicide is also among the various hypotheses considered in last year's disappearance of Malaysia Airlines Flight MH370 with 239 people aboard. The communications system was deliberately deactivated and the flight changed course.