Faulty brakes may be to blame for the Red Wings airliner sliding off the runway and crashing onto a highway near Moscow, killing five people, a member of the crash investigation team said.
Investigators said they were examining the black boxes to try to determine the cause of Saturday's crash, which cracked the wings off the Tupolev-204 plane and split the fuselage into three pieces.
If they find bad brakes were at fault, it would match a warning issued to the state-owned Tupolev by Russia's aviation authority to fix problems with the brakes that may have caused a Tu-204 with 70 people onboard to go off a Siberian runway on December 21.
Any sign that the catastrophe during peak holiday travel could have been avoided will worsen concerns over the country's poor air-safety record, despite President Vladimir Putin's calls to improve controls.
"After landing the pilot uses all the available brake systems on the plane, but for some reason the machine did not stop," a member of the investigation team told the Interfax news agency. "Most likely it was faulty reverse engines or brakes."
A fifth crew member of the Red Wings plane, which was flying without passengers, died of her injuries in hospital on Sunday, the company said.
Despite icy weather conditions, the plane had been piloted by an experienced crew with many hours of flight time, according to Russia's aviation safety body.
Television footage showed the jet with smoke billowing from the tail end and the cockpit broken clean off after the crash.
A photo showed a crew member, still strapped to a seat, sprawled on the pavement after apparently being hurled far from the plane during its impact with the highway barrier.
Red Wings, whose fleet includes nine of the Soviet-designed Tu-204 jets, said on Sunday it would not retire them from use. The Russian-built Tu-204 is comparable in size to an Airbus A321 or Boeing 757.
Russia and other former Soviet republics had some of the world's worst air-traffic safety records last year, with a total accident rate almost three times the world average, IATA said.