One of Russia's Sukhoi Su-57 stealth fighter jets crashed on Tuesday in the Far East, Russian news agencies reported, the first accident of its kind involving what is the country's most advanced warplane.
The RIA news agency cited Russia's United Aircraft Corporation (UAC), which makes the plane, as saying the incident took place during a training flight in the Khabarovsk Region and that the pilot ejected safely.
The Defence Ministry will set up a commission to investigate the accident, which looked like it was caused by a failure in the steering system, the TASS news agency cited two military sources as saying.
The lost plane was one of the first to be mass-produced and was due to be handed over to the Russian air force by the end of this year, the Interfax news agency reported, citing a source.
Russia has previously tested the Su-57 in Syria.
A prototype of the plane, conceived as a rival for the US F-22 Raptor, first took to the skies in January 2010. The Su-57 made its first appearance at Russia's annual Red Square parade in May last year when a pair of them roared over Moscow.