Russian investigators say the pilot and the co-pilot of an airliner that crashed near the Russian city of Kazan last month, killing 50 people, received their training from aviation centers that were later closed on suspicion of operating illegally.
The November 17 crash -- a near-vertical dive -- killed all 44 passengers and six crew.
Aleksander Neradko, a spokesman for the Federal Air Transport Agency (Rosaviatsiya), said the pilot had passed training at the Kaluga training center, while the co-pilot had graduated from a training course at the North-Western center.
Both schools were subsequently closed.
Meanwhile, Investigative Committee spokesman Vladimir Markin said there was reason to believe that many pilots working for smaller Russian airlines have effectively "received fake commercial licenses" as they have not undergone proper training.
Based on reporting by Reuters, Interfax, and ITAR-TASS