MOSCOW - A Russian serviceman was killed and five others injured Tuesday when their transport plane crash landed and caught fire after a training flight near the central city of Saratov, authorities said. Russia's defence ministry said the incident, which took place at around 6:00 am (0300 GMT), could have been caused by failure of one of the engines of the plane, an Antonov AN-26. There were six people onboard the aircraft when it made a hard landing at Saratov's Balashov aerodrome, the defence ministry said in a statement quoted by Interfax news agency.