The tests of the Russian Sukhoi T-50 (PAK FA) fifth-generation fighters using operational engines should begin in late 2017, the head of the United Engine Corporation said Thursday.

PAK FA, equipped with advanced avionics and all-digital flight systems, is set to become the first operational stealth aircraft of the Russian Aerospace Forces.

“The [operational engine] for PAK FA should [begin tests] in the end of 2017, to begin a series of tests as part of the plane in the fourth quarter,” Alexander Artyukhov told reporters.

The PAK FA fighter was first seen in January 2010 when it was presented at the air show MAKS-2011. The fighter jet is expected to join the Air Force of the Russian Federation in 2016. Mass production of Russia’s Sukhoi T-50 fifth-generation fighter jets will begin in 2017.