The BBC's current take on the matter....
Russian aviation experts say the pilots of a Boeing 737 jet which crashed in Kazan on Sunday carried out a manoeuvre that put the plane into a dive.
During a second attempt to land, the pilots switched to manual control and made a correction when the plane lost speed, the investigators said.
But the jet then nose-dived and crashed on to the tarmac, killing all 50 people on board.
According to the initial findings, the jet did not have any technical faults.
Presume the last sentence means that no faults were reported: can't see much information coming from that debris field just yet.