The flight data recorder of the Russian military airliner which crashed in the Black Sea on Sunday has been recovered, Russian officials say.
It is the first “black box” to be retrieved from the Tu-154 jet, which came down with the loss of all 92 passengers and crew.
The plane crashed soon after take-off from an airport near the city of Sochi.
It was carrying artistes due to give a concert for Russian troops in Syria, along with journalists and military.
The plane disappeared from radar two minutes after taking off from Sochi’s Adler airport at 05:25 (02:25 GMT) on Sunday, heading for Latakia in Syria, the defence ministry said.
The flight had originated in Moscow and landed in Sochi for refuelling.
It was carrying 64 members of the famed Alexandrov military music ensemble, as well as one of Russia’s best-known humanitarian figures, Yelizaveta Glinka, known as Dr Liza, executive director of the Fair Aid charity.
The Alexandrov Ensemble had been scheduled to perform a New Year’s concert at Russia’s Hmeimim air base near Latakia.
Russia has been carrying out air strikes in support of Syrian government forces who are battling rebels opposed to Syrian President Bashar al-Assad.
There have been few clues as to the cause of the crash although Transport Minister Maxim Sokolov has played down the possibility of a bomb attack.
He reiterated that investigators were looking into whether pilot error or a technical fault might have brought down the aircraft.
A source close to the investigation told Russia’s Interfax news agency that the plane may have been overloaded.
“Witness accounts and other objective data obtained during the investigation suggest the plane was unable to gain height and for some reason – possibly overloading or a technical fault – crashed into the sea,” the unnamed source said.
An audio recording played on Russian media and said to be of the final conversation between air traffic controllers and the plane reveals no sign of any difficulties.
Voices remain calm until the plane disappears and the controllers try in vain to re-establish contact.
The Tupolev airliner involved in the crash was an old model no longer flown by air lines in Russia but still used by the military.
Tupolev-154: Russian workhorse
The backbone of Soviet and Russian airlines for decades
Three engines, narrow-bodied and medium range
Designed in the mid-60s, came into service in 1972 and was modernised in 1986 with new engines and equipment
Has seen 39 fatal accidents, although few were due to technical problems. Many were as a result of difficult weather conditions and poor air traffic control.
A few were lost in conflicts including in Lebanon, Georgia and Afghanistan
Not used in Russia’s civil aviation since 2009, but is still used by the military. Only about 50 in service worldwide.