ZHUKOVSKY (Moscow Region), July 19. /TASS/. The pre-production batch of T-50 fifth-generation fighter jets will equal 12 planes, United Aircraft Corporation (UAC) Head Yuri Slyusar said at the MAKS-2017 international airshow on Wednesday.

"From the very outset, we proceeded from the fact that the final decision had been made on 12 planes," he said.

The T-50 (PAK FA) is Russia’s fifth-generation fighter, which took to the skies for the first time in 2010. It was earlier reported that the serial production of T-50 fighters would begin in 2017 and it would enter service with the Russian Aerospace Force.

According to new data, the first stage of the aircraft’s trials is expected to be completed in 2018.

It was reported earlier that the T-50 with the advanced (main) engine would perform its debut flight in the fourth quarter of 2017.

Currently, the so-called first stage engine 117S is mounted on the Russian fighter. A new engine has not yet received its name and is conventionally designated as the second stage engine.