The Irkutsk Aviation Plant, a branch of Irkut Corporation (a part of UAC), has completed systems diagnostics of the fourth MC-21-300 aircraft designed for flight tests. The results of first prototypes testing were taken into account in the aircraft production process. Three of them are undergoing flight tests, two of them are on static tests. On November 28, the new aircraft was transferred from final assembly shop to the plant's flight-test division.
On June 25, 2020, the MC-21-300 test aircraft, painted at Spektr-Avia, Ulyanovsk, returned to Ramenskoye airfield (Zhukovsky, Moscow region), where it will continue its flights under the certification test program.