A pilot onboard a plane flying from Bangkok to Novosibirsk in western Siberia died in the cockpit after suffering a heart attack.
Sergei Golev, 44, suffered the attack in the cockpit and died despite all attempts to resuscitate him.
The captain attempted an emergency landing in the Chinese city of Chengdu, but abandoned it when Golev died before the jet could touch down.
The Daily Mail reports that the 239 passengers onboard the UTair Boeing 757 landed safely in Novosibirsk despite his death.
Senior investigator Anastasia Utochkina told Life News: "The co-pilot died at 12.25am, Novosbirsk time (5.25pm GMT), three hours after takeoff.
"The captain made a decision to descend, while the crew called over the tannoy for a female physician who appeared to be among the passengers. However her attempts to revive the man, who was lying on the cockpit floor, failed."
Officials insist that the co-pilot was only travelling as a passenger and was at no time in control of the aircraft.
He was employed as a reserve pilot, tasked with replacing a crew member in case they fall ill.
Irina Levit, a press officer at Novosibirsk airport, said: "The deceased pilot was travelling as an ordinary passenger.
"The aircraft belongs to UTair airline, where Sergei Golev was employed. There was no threat to passengers."
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