Russian investigators have determined that the flight-recorder tapes from the IrAero Antonov An-24 badly damaged in an overrun at Blagoveshchensk are in good condition.
The Interstate Aviation Committee said it was conducting a laboratory examination of the recorder media following the 8 August accident, which badly damaged the twin-turboprop and injured its crew and several passengers.
Both recorders suffered mechanical damage in the accident, it added, but the tapes from both the flight-data recorder and the cockpit voice recorder are "not affected" and are in "good condition".
"The mechanisms were not exposed to fire or fire extinguishing agents," it added. "All the information is being copied and studied to determine its quality and completeness."
Both were functioning at the time of the accident, the Interstate Aviation Committee said.
The investigation agency has already carried out aerial surveys of the crash site using helicopters, to detail the spread of wreckage.