Russia’s stealth fighter jet program continues to move forward as the military prepares to put the fighter jet, known as the PAK FA or T-50, through state tests.

Responding to a question from journalists, Deputy Defense Minister Yuri Borisov confirmed on February 3, 2017 that serial production would be forthcoming soon.

“Most likely, this will be already the next state armament program, i.e. 2018-2025”, said Yuri Borisov.

The Russian Defense Ministry is expected to make an initial purchase of only a dozen operational T-50 aircraft. The Russian Aerospace Forces are expected to use those initial twelve production jets for operational testing before Moscow commits to buying more of the expensive new stealth fighters.

But Centre for Analysis of Strategies and Technologies reported, that Russia to get first mass-produced T-50 fighter jet by 2020 and perhaps even later in ’25.  The T-50 fighter jet the plane has multiple technological problems. Among these problems are the plane’s engine performance and the reliability of its AESA radar.

Currently, the Russian stealth fighter is powered by a derivative of the Saturn AL-41F1S engines that are installed on the Sukhoi Su-35S Flanker-E called the AL-41F1, which was formerly known as the izdeliye 117. Though the AL-41F1 produces roughly 33,000lbs of thrust with full afterburner, the engine is not powerful enough to realize the full potential of the PAK-FA airframe. Thus, the Russians are developing a new engine that is currently designated as the izdeliye 30 for eventual installation on the T-50. The engine will be deployed between 2018 and 2020 after it passes state tests in 2020.