Chinese Engine Development


taxiya

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It’s not producing 20% of WS-15, but 20% of supply for specific parts used on the WS-15. The supply of the part is not the same thing as the production output of the engine. Those don’t always scale linearly. Furthermore, as I said earlier, the marketshare figure may have nothing to do with the total production output for the engine. Perhaps the output is fixed, and the share refers to how much of specific parts procured for the 5 engines the supplier anticipates they will cover.
Yes, that is correct. The (serial) production output (after the 2020-2026 phase) is estimated being 300 per year according to the same report.
 

Bltizo

Lieutenant General
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The reducing is the XWS-15 and XWS-19, not serial production of WS-15 and WS-19. I use X to designate the test-production variant. These engines from 2020 to 2026 are NOT production articles, every batch of them are slightly different with later batches being closer to the final articles for mass productions. It is natural to expect that the divination being reduced, so the number of test articles being reduced in total. At the end of the phase, only the last batch (say 5 in 2026) would be identical to the version in mass production. Most early makes of these engines are not going to be used by J-20.

Let me illustrate in total numbers. In 2020 the total is 15, if 5 as a batch, there will be 3 batches. I will make 3 batches in sequence. The first batch results to deviation that only 2 is up to spec, I will improve my process and make 2nd batch which results 3 good, so by the 3rd batch I may get 4 good. That means out of 15 in 2020, I have improved my process to make a batch (5) of quality 80%. That is not good enough, so I start another batch of 5 in 2021. Do I still need 15? Probably not because now I have a much higher baseline. If everything goes smoothly, I may only need 2 batches to reach 5/5 where I can settle my process.

This is to illustrate how pre-production development are planned. How they spread out these numbers (size of batches and number of batches) are dependent on their R&D methodology, but the overall trend is gradual reduction of total articles until the last batch.

Assuming that the engines described here are not "production" and that they are "test production" -- I still do not believe it would be reasonable to expect the total number of test-production articles to reduce year by year.

You would expect the number of test articles per year to either increase, or at least to stay static, as development and testing of the type continues and as it approaches production.


Unless there is some kind of factor we are missing, like the "XWS-15s" being produced by this company each year are all slightly different test articles (e.g.: different variants), and that another company is actually spooling up an increasing batch of production WS-15s.
 

Bltizo

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It’s not producing 20% of WS-15, but 20% of supply for specific parts used on the WS-15. The supply of the part is not the same thing as the production output of the engine. Those don’t always scale linearly. Furthermore, as I said earlier, the marketshare figure may have nothing to do with the total production output for the engine. Perhaps the output is fixed, and the share refers to how much of specific parts procured for the 5 engines the supplier anticipates they will cover.

Right, so you're saying that the "market share" may instead mean "share of value of each product". That is plausible, if we take it to mean that this company projects it is able to capture more of the value/work for each engine produced as time goes on.

However the kicker in all this still comes back to the projected yearly engine production rate. Considering where we know WS-15 is at in its development, it is very strange if not suspicious for the type to see no change in yearly production rate for six whole years. Even during testing and development, it would be normal if not expected for the production of test articles per year to increase as it progresses through its development phase and edges towards production.


The possible explanation of course is that WS-15 development and projected production is just that much more difficult than previously projected, but seeing it fixed for six whole years still doesn't quite jive.
 

taxiya

Brigadier
Registered Member
Unless there is some kind of factor we are missing, like the "XWS-15s" being produced by this company each year are all slightly different test articles (e.g.: different variants), and that another company is actually spooling up an increasing batch of production WS-15s.
I believe every single article to be slightly different, not that they want to (so not different variants by design), but because they have not figured out every detail of mass producing. Every batch is a incremental improvement closer to the final.

If that "another company" is the other 50%, that would still indicate an overall decrease.

I don't believe the "other company" is producing something outside these test-production. There is no reason to produce in big number while the production specification is being ironed out, it is just waste.
 

ZeEa5KPul

Senior Member
Registered Member
The possible explanation of course is that WS-15 development and projected production is just that much more difficult than previously projected, but seeing it fixed for six whole years still doesn't quite jive.
I think a principle of this PLA watching thing of ours is that no news is good news. If the WS-15 were in that kind of trouble then that information should have percolated through the grapevine to reach us.
 

Bltizo

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I think a principle of this PLA watching thing of ours is that no news is good news. If the WS-15 were in that kind of trouble then that information should have percolated through the grapevine to reach us.

This is assuming of course, that to the insiders the idea of "5 engines per year for six years" would've been considered as bad news to begin with lol. It's very possible that this was within their projected estimates.
 

ZeEa5KPul

Senior Member
Registered Member
This is assuming of course, that to the insiders the idea of "5 engines per year for six years" would've been considered as bad news to begin with lol. It's very possible that this was within their projected estimates.
But it's from these insiders that we have the mass production around ~2025 estimate. If production is still at 5 engines in 2026 then there would certainly have been problems. We should have seen them revising their estimates.

I wonder something else: how can this company know what the total production figure next year - much less in 2026? Only the PLAAF and AECC would know, not some contractor buried deep in the supply chain. All they would know is what they've been contracted to build.

If we want to go with the assumption that they'd know, then information about the WS-15 would be far more widespread than it currently is, which means we'd know a lot more about it than we do. That's a lot of mouths that could be blabbing some subcontractor's subcontractor knows the production schedule out to 2026.
 

Bltizo

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I believe every single article to be slightly different, not that they want to (so not different variants by design), but because they have not figured out every detail of mass producing. Every batch is a incremental improvement closer to the final.

If that "another company" is the other 50%, that would still indicate an overall decrease.

I don't believe the "other company" is producing something outside these test-production. There is no reason to produce in big number while the production specification is being ironed out, it is just waste.

So, there are two different arguments I am seeing from yourself and latenlazy to explain this, both of which are relatively plausible.

Your argument, as I understand it, is that year by year the number of test production engines built per year is reducing as they incrementally approach final production spec engines -- i.e.: that the yearly produced "XWS-15s" is reducing and that this company is projecting the number of "XWS-15s" it will build, of the ones that other companies will also build.

Latenlazy's argument, is that year by year the number of overall engines built is fixed, but that the percentages represent the proportion of value/work of each engine that the company expects to contribute to, which would explain why the engines per year is not increasing but the percentage is.


To me, both seem reasonable explanations, but what is still confusing is that of annual engine production being fixed for the whole six years of both types. Considering where we know WS-15 (and also WS-19) are in their development, it would be somewhat surprising for the number of WS-15s projected to be fixed or even to reduce going forwards for six whole years. Given both of these engines will likely be in development and testing in this phase, I wonder if the projected number of WS-15s to be built later on in those 6 years may be subject to change depending on the results of tests and development in the early 2020s.
 

Bltizo

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But it's from these insiders that we have the mass production around ~2025 estimate. If production is still at 5 engines in 2026 then there would certainly have been problems. We should have seen them revising their estimates.

I wonder something else: how can this company know what the total production figure next year - much less in 2026? Only the PLAAF and AECC would know, not some contractor buried deep in the supply chain. All they would know is what they've been contracted to build.

If we want to go with the assumption that they'd know, then information about the WS-15 would be far more widespread than it currently is, which means we'd know a lot more about it than we do. That's a lot of mouths that could be blabbing some subcontractor's subcontractor knows the production schedule out to 2026.

I actually wonder what the original wording with the 2025 date was written as; whether it was more associated with mass production or entry into service. It's a date that's been thrown around so much now that I think the original context might have been last.

After all, the two mean very different things and you can enter service with a pair of WS-15 powered J-20s in the first year for PLAAF testing and evaluation, and then a slightly larger number the next year, and then gradually increase as production ramps up.
 

ZeEa5KPul

Senior Member
Registered Member
I actually wonder what the original wording with the 2025 date was written as; whether it was more associated with mass production or entry into service. It's a date that's been thrown around so much now that I think the original context might have been last.

After all, the two mean very different things and you can enter service with a pair of WS-15 powered J-20s in the first year for PLAAF testing and evaluation, and then a slightly larger number the next year, and then gradually increase as production ramps up.
I dug this up from the beginning of the year
https://www.sinodefenceforum.com/chinese-engine-development.t252/page-497#post-540974
Going by the post date we can say that Dr. Liu Daxiang predicted design certification within 3 to 5 years from mid-2018, i.e., mid-2021 to mid-2023. I believe there's another certification (production certification?) that takes about 2 years - so we can put mass production starting from mid-2023 to mid-2025. If we squint and look to the side we might say the document jives with the most pessimistic estimate. Still, I expect production numbers to be a lot higher than 5 engines per year (or 12.5 you calculated or 10) even before mass production. There should be closer to 10 times that many engines even in LRIP.
 

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