MOSCOW, Dec. 29 (UPI) -- Investigators in the crash of a Russian military transport plane into the Black Sea on Sunday have ruled out an explosion as causing the plane to go down but they do not have enough evidence to say a terrorist attack of some sort was at fault.
Enough pieces of a Syria-bound Russian plane that went down in the Black Sea have been recovered to decipher some kind of mechanical malfunction caused the crash -- possibly a problem with the Tu-154's wing flaps -- if a partial analysis of black box recorders is correct.
"We arrived at the conclusion that there was no explosion aboard," Sergei Bainetov, head of the Russian armed forces' flight safety service, said during a press conference Thursday. "However, a terror attack does not have to be an explosion. Other causes are possible. Hence, we have not ruled out this theory for now."
The defense ministry airliner was traveling from Sochi to Syria, crashing into the sea barely more than a minute after takeoff and hit the water with so much force it destroyed the plane and killed all 92 people on board.
In addition to recovering 19 bodies and more than 200 body parts, investigators have lifted 13 large pieces of the plane out of the sea and collected nearly 2,000 smaller ones. Included among the pieces found are the flights' black box recorders.
The last words on one of the recordings before the crash includes the words "the flaps, damn it," suggesting a problem with the flaps that could have played a role in the plane's quick descent after takeoff.
Evidence collected thus far suggests an explosion didn't occur on the flight, including what Bainetov called an "emergency situation" on the aircraft though few details were made available.
"It is apparent that the equipment didn't work as intended," Russian Transport Minister Maksim Sokolov, who is heading the investigation into the crash, told reporters during a press conference. "What caused this is for the experts to establish. A technical commission has been created to do this work. Preliminary results may be available in January 2017."