South African French-origin Mirages flew with Russian-origin engines. Atleast in Ukraine's case, the engine vendor and aircraft manufacturer would closely collaborate - for the South Africans, integrating the Russian engine was harder.
F-14s, F-15s, F-16s all have had different types of engines powering seperate fleets of these aircraft. The US has a fleet of F-16s powered with P&W F-100 engines, and another fleet powered by GE F-110. The question is whether the Ukrainian engine makes sense for Pakistan - can it deliver more performance than the WS-13A/B, what's it's reliability like, etc. Ukraine has been making reliable aero-engines for decades, but China can invest alot more money. But reliability has been a problem atleast for earlier models of Chinese WS-10 and WS-13 engines.
It would be interesting if some senior members could share info about Ukraine's contribution in RD-33's development. I remember reading that Ivchenko-Progress had collaborated with Klimov on the development of certain components. I also remember Nabil_05 also mentioning that we're already getting some RD-93 engine maintainance assistance from Ukraine.
