Moscow: Russian investigators said on Wednesday they were analysing the black boxes from the jet that crashed in Moscow this week, killing the chief executive of France`s Total oil company.
The latest step in the probe came as speculation focused on the role of the driver of a snowplough that collided with the plane late Monday and the air traffic controllers, one of whom may have been an intern.
The Interstate Aviation Committee, or MAK, which probes every air crash in Russia, said it had opened up the plane`s black boxes, which record the flight history and conversations in the cockpit.
MAK deputy head Sergei Zaiko told Rossiya 24 television that the plane was equipped with "modern and well protected black boxes".
"We hope the quality of the information we have copied will be enough to carry out a thorough investigation," the official said.
The boxes were opened in the presence of a Russian investigator and specialists from France`s accident investigation bureau known as BEA, MAK said.
Russian media reported that an intern at the air traffic control centre may have been in charge of the plane when it crashed just before midnight Monday, killing Total boss Christophe de Margerie and three other people.
Izvestia newspaper quoted a source at Vnukovo airport as saying that a female intern who had qualified at the civil aviation college in the provincial city of Ulyanovsk was put in charge of the flight.
There has been no official confirmation from investigators or the airport.
RIA Novosti state news agency also quoted a source at the airport saying an intern had been put in charge of the flight.
An air traffic controller told RIA Novosti however that such interns would always be supervised by a more experienced colleague.
"An intern air traffic controller always controls the movement (of planes) only under the supervision of an experienced air traffic controller who is an instructor. Such responsible work is always monitored."
Investigators said Tuesday that mistakes by air traffic controllers and by the snowplough driver were considered the most likely scenario.
They also accused the airport senior management of "criminal negligence," saying they failed coordinate staff`s actions and bore ultimate responsibility for their mistakes.
The snowplough driver has been detained for 48 hours. Russian television showed him being questioned by investigators, saying that he drove on to the runway by accident after losing his bearings.
Investigators said he was drunk at the time of the accident, allegations denied by his lawyer.
The Vnukovo 3 terminal is used for business travel and frequented by VIPs including Moscow`s mayor and Patriarch Kirill of the Russian Orthodox Church, Komsomsolskaya Pravda daily reported.