MOSCOW: With recovery of main flight recorder of ageing Tupolev or Tu-154 airliner that came down in Black Sea with the loss of all 92 passengers on Sunday has revealed that faulty flaps were reason behind crash, Russian media say. As per the sources close to the investigation team, the flaps, panels on the wings that help lift an aircraft, were not moving together and as result of that, pilots lost control as the plane was at a "critical angle". The plane was heading to Russia's air force base in Syria where the choir was due to perform at a New Year's concert. The plane crashed soon after take-off from an airport near the city of Sochi, where it had landed for refuelling. It disappeared from radar two minutes after taking off from Adler airport at 05:23 (02:23 GMT) on Sunday. The military airliner was commanded by experienced pilot Maj Roman Volkov and his co-pilot was Capt Alexander Rovensky, who had 10 years of aviation service. About Tupolev-154 Tupolev-154 three engines, narrow-bodied and medium range plane considered as Russian workhorse and the backbone of Soviet and Russian airlines for decades. Designed in the mid-60s, came into service in 1972 and was modernised in 1986 with new engines and equipment Before Sunday’s incident, 39 fatal accidents has seen, 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. ALSO READ: “All 92 die” as Russian military plane comes down in Black Sea