Russian investigators have indicated that the Antonov An-148 which crashed outside of Moscow was intact and was not on fire as it came down.
The Saratov Airlines twinjet crashed shortly after departing Domodedovo airport on 11 February.
Russia's federal Investigative Committee says it has established a team of 100 personnel to look into the circumstances of the accident.
It states that, at the time of the aircraft's descent, it was intact and there was no fire.
"[The] explosion occurred after the aircraft had come down," it adds.
Interstate Aviation Committee
Its findings would appear to set aside early concerns that, given the size of the debris field, the aircraft might have broken up in mid-air.
The Investigative Committee says two flight recorders have been located at the scene of the crash.
It says these will enable the air accident authority, the Interstate Aviation Committee, to reconstruct the flight in detail.
"All scenarios will be checked during the preliminary investigation, including the airline's activities, the aircraft's technical condition [and] the training level of the crew," it adds.
The documentation obtained so far by investigators includes maintenance information and crew medical details.
Fuel samples, radar surveillance data, and recordings of air-ground communications have also been collected.
The Interstate Aviation Committee has yet to confirm the initial findings from the Investigative Committee.
But it says it has secured both the cockpit-voice and flight-data recorders from the An-148 and has commenced work to open them and retrieve their information.