Aviation safety was called into question in 2013 as plane crashes dominated world headlines. Here are some of the tragic accidents that took place this year.
All 50 on board killed in Russian plane crash
On 17 November, Tatarstan Airlines Flight 363 crashed at Kazan International Airport in Russia during a go-around. All 50 people on board were killed.
Crash investigators said the pilot of the airliner had pushed the steering column to pitch it into a nosedive.
However, they did not explain why the pilot of the Boeing 737 jet might have performed the manoeuvre at a height of 700 metres after aborting a first attempt to land.
Asiana passenger jet crash in San Francisco kills 3
Asiana Airlines Flight 214 crashed short of the runway on landing at San Francisco International Airport on 6 July. It killed three of 307 on board and injured 182. The crash was the first fatal commercial airline crash in the United States since 2009.
The pilot of the South Korean airliner said during a testimony at a hearing at the US National Transportation Safety Board in mid-December that he was stressed about touching down because a system used to guide planes down to the runway had been turned off during a construction project.
Aerobatic pilot dies in air show crash
Aerobatic pilot Glen Dell died on 12 October when his light aircraft crashed during a show in Mpumalanga, South Africa.
The 51-year-old survived the initial impact when his plane plunged into the ground at the Secunda Air Show, but later died of his injuries. This video shows the moment that the plane plummeted to the ground.