Russia’s upgraded Tupolev Tu-160 (NATO reporting name: Blackjack) strategic missile-carrying bomber with Factory No. 0804 produced at the Kazan Aircraft Enterprise started flight trials last week, a source in the Russian defense sector told TASS on Wednesday.

"The 804th plane made using Soviet aircraft breakthroughs took to the skies for the first time last week and has been performing evaluation flights since then. The missile-carrying aircraft will be delivered to the Aerospace Force until the end of this year," the source said.

Commenting on various media reports, the source said the new plane was not a modernized bomber prototype.

"The plane underwent only small-scale upgrade while its airframe and the engines have remained the same. Fully digitalized documentation on the new missile-carrying aircraft will be issued no sooner than the middle of this year and the work on building the Tu-160M is impossible without it," the source noted.

TASS has not yet received an official confirmation of this information.

As was reported earlier, a ceremony was held at the Kazan Aircraft Enterprise on November 16, 2017 to roll out the upgraded Tu-160 missile-carrying bomber. On the same day, Deputy Prime Minister Dmitry Rogozin overseeing the defense sector in the Russian government told Russia’s President Vladimir Putin that the debut flight of the upgraded strategic missile-carrying bomber was scheduled for February 2018.