Divers have found one of the black boxes of the crashed Russian Defense Ministry's Tu-154 aircraft in the Black Sea, a source in law enforcement agencies said.
"During search operations, one of the black boxes was found under the aircraft's cabin. It will be taken out of the water soon," TASS cited the source as saying.
The condition of the black box is yet unknown, the source added. "Two other two boxes were in the tail section of the aircraft. They have not been found yet," the source added.
According to the source, one of the priority causes of the Tu-154 plane crash now is the penetration of foreign objects in the engine. But the investigators were considering four main possible causes of the crash - penetration of foreign objects in the engine, substandard fuel that caused the loss of thrust, pilot error and technical malfunction of the plane.
