Investigators examining the Aeroflot-Nord Boeing 737-500 crash have found no evidence of engine fire, and say both powerplants were operating before the jet struck the ground.
Russia's Interstate Aviation Committee (MAK) is still assessing information from the aircraft's cockpit-voice and flight-data recorders.
But information decoded so far, and evidence from wreckage at the crash site in Perm, shows no indication of fire in the CFM International CFM56 engines.
"Both engines were working before the impact of the aircraft with the ground," it adds.
MAK has also concluded that the aircraft did not break up in the air.
None of the 88 passengers and crew on board survived when the 737 came down during approach to Perm after arriving from Moscow Sheremetyevo on 14 September.