The pilot of a Russian passenger plane that erupted in a ball of fire on the runway of Moscow's busiest airport, killing 41 people, said lightning led to the emergency landing.
Investigators were on Monday working to understand the causes of the blaze after the Sukhoi Superjet-100 had to return to Sheremetyevo airport shortly after take-off Sunday evening.
But pilot Denis Yevdokimov told Russian media the craft lost communication and needed to switch to emergency control mode "because of lightning" on the Aeroflot flight to the Arctic city of Murmansk.
He did not specify if the plane was struck directly.
"We managed to restore communication through the emergency frequency on our radio connection. But the link was only for a short time and kept cutting out… it was possible to say only a few words," he told the Komsomolskaya Pravda newspaper.
Videos on social media showed the plane crash-landing and then speeding along the runway with flames pouring from its fuselage.
Passengers could be seen leaping onto an inflatable slide at the front and running from the blazing plane as columns of black smoke billowed into the sky.
Another video shot inside the cabin showed roaring flames outside the window and passengers crying out in panic.
Evdokimov said he believed the plane burst into flames on landing, most likely because of full fuel tanks.
At least two children were among the 41 dead and nine more people were in hospital, three of them seriously injured, authorities said.
Aeroflot, today is a safe, modernised airline, used to suffer a tremendous number of crashes. In 1973 alone, it was involved in 27 accidents in which a total of 780 people lost their lives, according to the Aviation Safety Network, making up nearly half of all worldwide air crash deaths for the year.