"I informed the pilot that he has reached a point where he should go down," Bikbov said in an audio recording broadcast on TV. "He confirmed he was going down but kept climbing."
Bikbov then ordered the pilot to make a second run, but instead of making the right turn he turned left.
When he asked the pilot whether things were normal on board, the pilot answered positively but his voice was strained as if under stress, Bikbov said.
"He was behaving in a strange manner and wasn't following my orders," Bikbov said. The last thing controllers heard was a scream in the cockpit seconds before the plane crashed."