Indonesian authorities have asserted their right to lead the inquiry into the fatal Sukhoi Superjet 100 accident, confirming they will head the analysis of the cockpit-voice recorder.
After the device had been located on 15 May, six days after the crash on Mount Salak, there were indications it would be transferred to Russian investigators for decoding.
However, the National Transportation Safety Committee has exercised its right to treat the inquiry as an Indonesian affair, although it will rely heavily on Russian assistance in case of "constraints", such as the need to interpret cockpit conversation. The flight-data recorder will similarly be examined by the NTSC.
While the cockpit-voice recorder had been subjected to fire, and sustained damage to its housing, it remained in an "acceptable" state, says the Indonesian transport ministry.
The ministry says the Russian authorities have demonstrated "seriousness" in aiding the inquiry, providing specialised equipment with which to examine flight-recorder contents.
Russia's ministry of industry says it will be "actively involved" in the transfer, interpretation and analysis of information.
Deputy industry minister Yuri Slusar said putting a timeframe on obtaining the information would be "premature", but added: "We will try to work as quickly as possible."
The ministry says the Russian representatives will look carefully at data received from the Indonesian side, particularly the aircraft's trajectory, the traffic situation in the area, air traffic controller workload and weather conditions.
Search teams have located several major components of the aircraft, including both PowerJet SaM146 engines.
Few confirmed details have emerged regarding the circumstances of the 9 May accident, beyond the request by the Superjet's crew to descend to 6,000ft (1,830m) shortly before contact was lost.
Loss of the aircraft has not held up deliveries. Russian flag carrier Aeroflot formally accepted the eighth production airframe, serial number 95014, on 17 May ahead of a delivery flight to Moscow scheduled for 23 May.