Russian Emergency Situations Minister Vladimir Puchkov says the "technological systems" on board the firefighting plane that crashed in the Irkutsk region of Siberia, killing all 10 crewmembers, was "functioning properly" before the accident.
The finding increases suspicions that the pilot might have lost orientation in thick smoke from the blaze the Il-76 and its crew were battling at the time on July 1.
Rescue teams have now located the bodies of all the crewmembers, and decoded the aircraft's flight-data recorders.
The wreckage of the plane was found 4 kilometers south of the Rybny Uyan settlement.
Based on reporting by Interfax and TASS