Drozdenko told Sputnik that the J-20 he saw at the air show appears similar to a Russian prototype fifth-generation jet fighter, the MiG 1.44, which was finally displayed last year.
"In my opinion, the machine is based on the Russian MiG 1.44. That plane was created to compete with the PAK FA at the preliminary design stage, and made its maiden flight in 2000. The Chinese plane is very similar. Although it hasn't been announced officially, the J-20 uses our AL-31F engine, developed by Salut, which the Chinese bought for half a billion dollars," he revealed.
The MiG aircraft corporation began to design a fifth-generation Multirole Tactical Fighter in 1983, in response to US efforts to develop an Advanced Tactical Fighter, which eventually materialized as the F-22.
In 2000 MiG flew a secret prototype of the fifth-generation fighter, but the project was eventually dropped in favor of the PAK FA. The 1.44 prototype remained under wraps until last year, when it was unveiled at the MAKS 2015 International Air Show in Moscow.
The design of the MiG 1.44 had some stealth aspects, and it was planned that the aircraft would be coated with "radar absorbing material" to improve stealth. The twin AL-41F engines gave the aircraft a "supersonic cruise" capability, and were fitted with thrust-vectoring nozzles.
Comparing the two fifth-generation prototypes, Defense Aviation spotted "startling similarities between the Chinese J-20 and the canceled Russian MiG-1.44."
As a stealth fighter, the J-20 is not as optimized for combat as the MiG 1.44, but both planes "have similarly styled delta wing canard configurations and a V-Shaped tail section with closely mounted engines," analyst Cavin Dsouza wrote.