China's latest fighter jet, the J-20 has a power problem.
The new engines for the Chengdu J-20 are not reliable enough to handle the extreme heat generated by jet propulsion.
Because of unreliable performance with newer WS-15 engines, the J-20 has entered service as a combat-ready aircraft with older jet engines.
In order to rush the aircraft into service, China has outfitted the J-20 with WS-10B engines, found in the other J-10 and J-11 fighters.
