Russia seeks answers over deadly crash Russia has sought answers for the latest deadly plane crash to raise concerns about the safety of its civil aviation, with investigators focusing on a fault with the 23-year-old plane or pilot error as the likely cause. The Tatarstan Airlines Boeing 737-500 crashed on landing at the airport in the Volga city of Kazan after a flight from Moscow's Domodedovo airport on Sunday night, killing all 44 passengers and six crew on board, the emergencies ministry said. "The main versions of what happened are an error in piloting and technical factors, including a technical failure," the head of the transport Investigative Committee for the Volga region, Alexander Poltinin, was quoted on Monday as saying by Russian news agencies. He confirmed that the crash occurred while the aircraft was making a second attempt at landing and said the investigation would have to consider why the pilot had not managed to land the first time. The disaster claimed the lives of the son of the leader of the Tatarstan region, Irek Minnikhanov, and the head of Russia's FSB security service in Tatarstan, Alexander Antonov. Also among the dead was a Briton, Donna Carolina Bull, 53, and a Ukrainian national, the emergencies ministry said. The rest of the victims are believed to be Russian citizens. The plane owned by Tatarstan Airlines, the regional carrier of the Tatarstan region in central Russia, was 23 years old and had seven owners during its life, Russian media and specialised websites said. It went into service in 1990 and was used first by now-defunct French airline Euralair Horizons and then by Air France. Before being acquired by Tatarstan Airlines, it was operated by Uganda Airlines, Brazil's Rio Sul, Romania's Blue Air and then Bulgaria Air. While being operated by Rio Sul, it had a serious accident on landing in Brazil in 2001, which, although it claimed no lives, meant the plane had to have serious repairs. Russia has experienced a string of deadly air crashes, usually involving small and poorly regulated regional airlines that sprang up across Russia after the break-up of the Soviet Union. The most recent major accident before Sunday's disaster was in April 2012, when a passenger plane crashed shortly after take-off from Tyumen airport in Siberia, killing 33 people.