Investigators have ruled out a terror act as the cause of the crash of Tatarstan Airlines flight No. 363 that killed 50 people on Sunday night in Kazan, suggesting the accident was instead the result of combined human error and technical deficiencies.
Russia's Transportation Minister Maxim Sokolov outlined five possible causes of the crash — pilot error, technical failure of the aircraft, the use of low-quality fuel, improper ground services work and weather conditions — at a press conference at the Kazan International Airport, RIA Novosti reported.
"Until the Investigative Committee has finished its work, all five theories may be valid," Sokolov said. "At this point, the investigation has not shown that an act of terror could be among the possible causes of the crash."
Meanwhile, Moscow's Transregional Transportation Prosecutor opened a probe into Domodedovo Airport in connection with the crash.
The 23-year-old Boeing 737-500 jet, operated by Tatarstan Airlines since 2008, was flying to Kazan, a city of 1.1 million located 720 kilometers east of Moscow, from Domodedovo Airport. Upon landing, the plane crashed into the ground and burst into flames between the runway and a taxi strip of the Kazan Airport at 7:25 p.m. Moscow time, regional investigators said.
Several witnesses reported in Russian media that the plane fell vertically from the sky. A video of the crash shown on NTV corroborated that claim.
The air traffic controller on duty at the time of the crash said there was nothing to indicate an impending calamity.
"The pilot informed me that he was going to make a second landing approach," said Kirill Kornishin, the air traffic controller in charge of the aircraft's landing, in an interview on Rossia 24. "Literally 10 to 15 seconds later, the plane crashed."
The pilot and co-pilot, Rustem Salikhov and Viktor Gutsul, had a combined 44 years of in-flight experience.
Weather conditions were normal at the time of the crash, according to Kornishin.
The Emergency Situations Ministry said the aircraft's black boxes, both of which were reportedly badly damaged, had been sent to Moscow for analysis. The fuel used to refuel the aircraft will also be analyzed in Moscow, the Investigative Committee said.
The U.S. National Transportation Safety Board announced on its website that it would be sending a team of three investigators to Kazan to assist Russian authorities with the investigation.
"We will be assisting the investigation as technical advisers because the incident involved a Boeing, an American-made aircraft," said Eric Weiss, a spokesman for the U.S. National Transportation Safety Board, in a telephone interview. "But this will be a Russian-led investigation," he said.
Prior to being used by Tatarstan Airlines, the aircraft had been in service with at least eight other airlines, including Air France and Uganda Airlines, according to aviation industry websites.
The last full maintenance check the aircraft underwent was in March 2012, the Federal Air Transportation Ministry told RIA Novosti. But the aircraft's last monthly maintenance check, conducted two days prior to the crash, did not reveal any abnormalities.
Tatarstan Airlines confirmed that that the aircraft was technically sound, having made a return flight from Kazan to Yerevan, Armenia, earlier on Sunday, before heading to Moscow.
Alexander Sidyakin, a State Duma deputy from Tatarstan, said in comments to Kommersant, however, that the airline was known for having planes that "left something to be desired."
"Many of my colleagues avoided taking flights on that airline. … All the plastic panels were always shaking, vibrating. It was unpleasant," Sidyakin said.
The Tatarstan division of Russia's Emergency Situations Ministry released the list of the 44 passengers and six crew members that perished in the crash. There were no survivors.
Among the victims were Irek Minnikhanov, the son of the President of Tatarstan, Rustam Minnikhanov, and Lieutenant General Alexander Antonov, the regional chief of Russia's Federal Security Service. A 53-year-old British woman, Donna Bull, who worked as an education consultant for Russian schools, was also aboard the flight.
The Kazan city administration is spearheading efforts to assist the victims' families.
Sergei Lobov, press secretary of Kazan City Hall, said by phone that the city was "currently assisting in the process of identifying the remains of the victims of the crash."
"We will also be helping families organize the transportation of bodies to cemeteries, given that not all the victims were residents of Kazan."
Two foreigners, 29 residents of Tatarstan and 19 residents of other Russian regions were aboard the flight.
The recovered remains of the victims will only be released to the relatives following DNA testing, which could take up to one month, Nail Nigmatulin, the head of the Tatarstan Bureau of Forensic Medical Examination, said in an interview with Interfax.
Russian authorities and the airline's insurance company will compensate the victims' families with up to 2 million rubles ($61,500) each.
The Kazan airport remained closed until 6 p.m. Moscow time on Monday as investigators scoured the crash site. A number of scheduled flights were redirected to nearby airports in the cities of Nizhny Novgorod, Izhevsk, Nizhnekamsk and Cheboksary. The Kazan International Airport began operating normally on Monday evening.
The Kazan crash is one of many airline tragedies to tarnish Russia's air transportation record in recent years.
In September 2011, in response to a plane crash that killed the Yaroslavl Lokomotiv hockey team, then-President Dmitry Medvedev instructed his government to ban airline carriers that did not meet Russia's flight safety standards by Nov. 15, 2011.
Despite its stated willingness to improve civil aviation safety throughout the country, the Russian government's initiatives have been more reactive than proactive, however.
In 2012, Russia held the world record for the number of plane crashes of aircrafts seating more than 13 passengers, according to AviaSafety, a Russian organization specializing in airline safety. A total of 93 people died in the four crashes that occurred on Russian territory last year.