China on Friday announced its J-20 stealth fighter had entered into combat service — but military sources told the South China Morning Post that it had an “embarrassing” flaw.
Makeshift engines in the J-20 mean that it cannot fly or fight as a true fifth-generation jet and that its stealth has been compromised.

It looks as if China rushed the plane into service, and it’s unlikely to be fully operational for at least a year.

Chinese state media announced on Friday that the Chengdu J-20 stealth jet had officially entered into service as a combat-ready platform— but inside sources say it’s a long way from fighting fit and has an embarrassing flaw.

Citing military sources with knowledge of the J-20’s development, the South China Morning Post reported that the jets that entered service didn’t feature the engines China custom-built for the platform but used older ones instead.

The result is an underpowered, less stealthy jet that can’t cruise at supersonic speeds and is therefore not a true fifth-generation fighter.

The Posts’ sources pinned the jet’s troubles on a test in 2015 in which the custom-built engine, the WS-15, exploded — something they attributed to China’s inability to consistently build engines that can handle the extreme heat of jet propulsion.

http://www.businessinsider.com/china-j-20-stealth-jet-fighter-rushed-embarrassing-flaw-2018-2