We're not
talking here about a Mao-times air force that couldn't get anything else.
It's perhaps these two types of which only "80 front-line aircraft" are

Before 90s chinese RMA advocates were pretty weak but during 90, with changes
in chinese society they got a big boost and were able to develop their
ingenious concepts like Assains' Mace weapons.

Surely they have Brainpower to develop and design them (many of
scientists,cutting edge researchers here in US are imported from China)and they
have also industrial infrastructure to build them now.