Originally posted by SOC
Which sub was that?

Project091 Han Class SSN and Project 092 Xia Class SSBN.

Then at what boundary do we define something as indigenous or not? In the broadest sense, all planes fly because they utilised the same principle of air flowing under the wing cause pressure differences. Does that mean all planes are not indigenous because their designers didnt use another way of keeping it airborne? Where does one make the difference between a modifiacation of a certain idea and a different idea with similar properties?

Like arthur said, these are all prototype stage designations, like how all chinese fighters designed by Sheng Yang have prototype stage designation of DF-xxx.
Also to arthur: I rather remember it is PJ-1 (Peng Jiao -1 as in jet trainer 1), not JJ-1, or is my memory playing tricks with me?

There is no Chinese official designation of J-2, J-4 or CJ-3 . Those are all made up by people who dont know how designation naming worked. ALL chinese plane’s starts from “5”. IE: J-5, H-5, Y-5,Q-5,CJ-5…and the list goes on. I alsways chuckle when I see people say things like PLAAF J-4, because they dont exist. They all start from 5 because 5 is the same sound as ÎÞ(nothing) pronounced WU. This is suggested by Mao himself to show chinese aviation industries developed from ÎÞ (nothing) to what it had achieved £¨´ÓÎÞµ½ÓУ©.
P.S. Another chinese plane that is quite succesful and is still in service today: SH-5 seaboats
EDIT: P.P.S: Another chinese development I had nearly forgotten: Y-12 light transports.:D