Russian medics began Sunday identifying the bodies of four crew killed when a passenger jet careened off the runway of a Moscow international airport and smashed into a highway.
Rescue workers recovered the flight recorders from the four-year-old Tu-204 of tycoon Alexander Lebedev's Red Wings airlines late Saturday as Russia began mourning its latest post-Soviet crash.
"The plane touched down in the proper landing area but for some reason was unable to stop on the strip," Federal Air Transport Agency chief Alexander Neradko said in televised remarks.
A bigger loss of life was only averted because the 210-seat liner was empty except for eight crew on their return from a charter flight to the Czech Republic.
Cell phone footage of the accident posted on the Internet showed large chunks of debris hurtling over the highway and smashing into cars speeding on the highway whose drivers had to make sudden emergency stops,
The jet split into three pieces and required the temporary shutdown of both the Kiev Highway and Vnukovo -- Moscow's third largest airport and the site of a special terminal for Kremlin officials.
A security source said investigators had brushed aside poor weather conditions or pilot error and were focusing on technical problems with the Tupolev as the most likely cause.
"According to preliminary information, the Vnukovo catastrophe may have been caused by problems with the plane, which became exposed in difficult weather conditions," the unnamed official told the Interfax news agency.
Witnesses said heavy gusts accompanying a light snowfall were swirling over the airport at the time the plane came in for landing on Saturday at 4:45 pm (1245 GMT).
Red Wings owner Lebedev -- a billionaire famous for his critical view of the Kremlin and his ownership of the London Evening Standard and The Independent in Britain -- said the jet had recently passed a meticulous check.
"Plane number 47 had accumulated 8,500 flight hours and underwent its last serious check on November 23," Lebedev tweeted.
He also suggested that traffic controllers' initial refusal to authorise landing -- requiring the plane to complete several circles over Vnukovo -- may have been a contributing factor.
"All machinery has its limits, even when it is new," Lebedev wrote.