As conceived by Chinese specialists, the domestic WS-15 engines were supposed to solve the problem associated with the Russian engines on the J-20. Earlier, the Chinese military complained that fighters with Al-31FM2 engines “experienced difficulties with stealth.” In addition, Russian products allegedly “seriously affected the performance of maneuverability.”
At the same time, the WS-15 was also not smooth. Experts said that the main problem with Chinese engines is excessive fuel consumption. In general, the timing of the presentation of the installations has been shifted several times.
According to Voennoye Obozreniye, by the second half of November, the J-20 were supposed to start receiving the WS-15 with reduced fuel consumption and at the same time increased thrust. However, this did not happen, from which the journalists conclude that the Chinese “did not master” the task and the problems with aircraft engines were not solved.