"In
2009, Western media reported that the WS-10A approached the performance of the AL-31, but took much longer than the AL-31 to develop thrust.
[12] Furthermore, the engine reportedly only generated 110–125 kilonewtons (25,000–28,000 lbf) of thrust.
[6] In April
2009,
Lin Zuoming [
zh], head of AVIC, reported that the engine's quality was unsatisfactory.
[13] In
2010, it was reported that reliability was also poor; the WS-10A lasted only 30 hours, while the AL-31 needed refurbishing after 400 hours".