It appears the Russians have ruled out any foul play in the Christmas Day aircraft accident in the Black Sea.<br /><br /> The search continues for the Tupolev 154’s black box, but the authorities are now concentrating their inquiry into either a technical fault, or human error as the cause of the crash.<br /><br /> Today is a national day of mourning for the victims, who were on their way to play a Christmas concert in Aleppo for Russian service personnel in Syria. All 92 people on board were killed, and while 11 bodies have been recovered more have yet to be found.<br />Some 3500 people are involved in the huge search operation.<br /><br /> Transport Minister Maxim Sokolov confirmed the plane, built in 1983, had a good service record, was renovated in 2014, and serviced only in September. But a euronews correspondent who used the plane four times recently found it ageing and dilapidated. <br /><br /> I took Russia’s Defence Ministry Tu-154 to Latakia and back 4 times in 2015 and 2016. Felt like flying in an old bus pic.twitter.com/VHOdBN1TNC— Denis Loctier (@loctier) 25 December 2016<br /> <br /><br /> Victims included leading charity activist Elizaveta Glinka and a media crew of nine journalists sent to cover the concert, along with dozens of Russian army Alexandrov song and dance band singers, dancers and musicians.<br /><br /> Flags are being flown at half-mast around the country and well-wishers have been bringing floral tributes to the airport in Sochi, from where the place made its final brief flight.<br />