This is one area China will have to wait a long time to catch up. GE/RR/PW have a huge technology lead over rest of the world. Just think about the $billion orders they receive every year and all that CAPEX they need to spend to eke out additional thrust, lower noise level or improve fuel burn. Until the past decade, China has really never been able to invest anywhere close to the same level of money on its aeroengine industry. Frankly, that money was always better spent on other projects.
In the 5 years I was gone, the most curious development I saw is the vastly proliferation of aeroengine for aircraft and helicopters. I remember back in the days, so many projects were held back or produced more slowly due to reliance on Russian engines or not having engines. Remember, PLAN only saw the massive build group start up after they got domestic production ramped up on QC-280 for 052C/D, diesel engines for 054A and also the engines for Yuan class.
As such, now that they have this full lineup of engines available, they can finally ramp up their production. I mean they are building probably 80 to 100 large helicopters a year. They never would've been able to do this before they could mass produce WZ-9/10 or even newer WZ-6 variants. It's only with the complete development of WS-10 that they are now able to mass produce everything. The entire process is cyclical in nature.
Better engine performance reliability -> higher order count from more planes -> more revenue -> more investment in people and R&D -> even better engine performance. That's how you get quicker development cycle and faster improvement. That type of investment flows down all through the supply chain.
The point is now that we've reached this point, I expect the improvements to come more quickly. They never would've been able to mass produce J-20 if they are still relying on the Russians for engines. Just look at how much the Russians struggle with their own aircraft production.
Having said all of this, one must still be realistic about where they are. Currently, WS-10C has wet thrust 142 kN according to reports whereas F-119 is at 156 kN. I'm not sure what the weight of each engine is, but F-119 should have a slight advantage over WS-10C in T/W ratio also (9 vs 8.5 to 8.7?) While that makes it sound like WS-10C is 90% of the engine F-119 is, one should also keep in mind that the top line numbers are confidential, since neither J-20/F-22 are being exported. I've heard F-119 thrust to be a lot higher than that. WS-10C might also actually be at 150 kN for all I know. But the greatest advantage F-119 has is in its dry thrust. Even when American and Russian engines have similar thrust with afterburners, the dry thrust were higher for American engines. I'd guess there is a similar gap in dry thrust between China and America if we think of WS-10C as having slightly better characteristics. Aside from this, Western engines also have really high standard for MTBO and fuel burn. China does have higher expectations here than Russians, but still lower than Western counterpart. Keep in mind, we are comparing an engine (F-119) that was used on F-22 by early 2000s vs WS-10C, which only went on production machines in 2019. We are looking a gap of about 20 years if China continued to improve WS-10 series to reach over 150 kN in thrust. The gap would be at most 25 years if we assume that WS-15 will exceed F-119's performance and be production certified in the 2025 to 2027 time frame.
Now, moving on to WS-15. The best comparison for its is probably F-135. From what we know, WS-15 will have a T/W ratio of around 10. We know F-135 is at around 11.5. If we just look at when the flight testing with J-20/W-15 started (let's say 2021) vs when F-35/F-135 started (let's say late 2000s), we are still looking at about a 15 year gap and a more advanced engine with F-135. If WS-15 reaches mass production in 5 years, it would be 15 years after non-prototype F-35s started to fly with F-135. It's hard to compare more deeply than this, since American fighter jet generally don't have to wait for engines.
So, when I look at China's aeroengine industry vs GE or Pratt, I just don't see the gap shrinking as fast as other areas. These Western companies have to throw so much capex every year to push the boundaries of engine performance that China's military related investment can't compare to it. I do expect China to blow past Russia here though.
