China's V/STOL studies, concepts & considerations

[jnd85]

China’s research on STOVL propulsion systems began about 10 years ago, but progress was initially slow. It only accelerated significantly after 2020, as evidenced by the increase in the number of research papers and patents. The development is clearly led by the 606 Institute, likely under the requirements of the 14th Five-Year Plan. I believe they will complete engine testing during the 15FYP period and simultaneously begin the formal development of STOVL aircraft. We can expect to see the results of the next phase by the end of the 15FYP period (around 2030).

STOVL is frequently derided as being ineffective or a waste of money, but I see it as a technology and capability that has just not reached its inflection point yet. Just look at how long it took for electric cars or AI to mature and become commercially viable. Does that mean that all the effort that went into it before that point was wasted? Of course not. If people hadn't put the R&D effort into them, the tech would have never matured.

I for one am fully convinced that STOVL capabilties will become increasingly common over the comming decades, and every bit spent on building out their enabling infrastructure will pay huge dividends.

 

[Tomboy]

you know pretty well.. 606 also working on VCE/ACE and most likely is in advance stages of development even further ahead of that CAS next gen engine.

whether copy F-135B or not but the thing is, they also have XA100/XA102 equivalent engine in development.

and its too early to talk about STOVL WS-XX engine specifications.

Though what I don't understand is why they would need to reverse engineer a F135 then? Surely, they have far more advanced core designs by now as you said 606 should have atleast XA102/103 level of technology right now. Also, -400 from the F-35Cs that crashed in SCS contains no STOVL technology, which is apparently what people speculate what they got their hand on.

Given that they are in advanced stage of development with their 6th gen VCE why not just use the core and design from that considering this STOVL fighter is going to take till the 30s to enter service. Even if they were to just use WS-15's core, it should still be more advanced than F135 in almost all ways hence I just don't see really a reason for them to reverse engineer a F135.

 

[sunnymaxi]

Though what I don't understand is why they would need to reverse engineer a F135 then? Surely, they have far more advanced core designs by now as you said 606 should have atleast XA102/103 level of technology right now. Also, -400 from the F-35Cs that crashed in SCS contains no STOVL technology, which is apparently what people speculate what they got their hand on.

Given that they are in advanced stage of development with their 6th gen VCE why not just use the core and design from that considering this STOVL fighter is going to take till the 30s to enter service. Even if they were to just use WS-15's core, it should still be more advanced than F135 in almost all ways hence I just don't see really a reason for them to reverse engineer a F135.

they have used mature WS-15 core not VCE/ACE and build engine on this and as per the tender they reverse engineered some of parts not entire Engine.

and yeah you are right. if PLAN interested in it then they will proceed to next stage so most likely service in 2030's.. by the time this machine will further push in tech and material.. you know there is WS-15A as well.

we don't even know what core 606 institute used in this STOVL Engine. we can only guess. it might be WS-15 or it can be totally fresh core or some other gas turbine..

there are so many questions and i think we should wait for some research paper or authentic information about WS-XX. what kind of machine this is.

 

[another505]

STOVL is frequently derided as being ineffective or a waste of money, but I see it as a technology and capability that has just not reached its inflection point yet. Just look at how long it took for electric cars or AI to mature and become commercially viable. Does that mean that all the effort that went into it before that point was wasted? Of course not. If people hadn't put the R&D effort into them, the tech would have never matured.

I for one am fully convinced that STOVL capabilties will become increasingly common over the comming decades, and every bit spent on building out their enabling infrastructure will pay huge dividends.

I just don't see it. This very different than electric cars or AI which has much higher potential while the main selling point and the peak of VTOL is that your carriers don't require EMALS which isn't a problem for China.
It also compromises range which is a big thing for WESTPAC theater unlike F-35B and Harrier bombing some 3rd world country or terrorist off their coast.

Others argued that it ca land anywhere and provide air cover to beach head.
I don't see how attractive it is to able to land anywhere you like because it isn't simply true. VTOL require special heat resistant surfaces to land or else it will burn a hole on the ground, and then you still need the logistic train to go with it so it isn't that simple or flexible. I still don't see the use of it.

I am going to say a VTOL engine for a helicopter might be even more useful for PRC than a VTOL fixed wing. Rapid transportation and insertions of troops and vehicles. Though I doubt it require 2 or even 1 F-35B level powerplant. Now VTOL is actually beneficial to the platform, increasing range, payload and speed. While a VTOL fixed wing reduces range and payload.

 

[Gloire_bb]

XA100/101: Hello?
This is not even new technology as both companies already moved on from this design. Considering this engine is meant to be in service in the 2030s, similar design spec to these are the bare minimum to stay relevant. F-135 copy is just not good enough.

I don't even know what's there to learn even if they have a F-135 on hand, It's a two decade old engine based on a 3 decade old core. Chinese aeroengine technology should have advanced far beyond this by now in terms of both design and materials.

"Old technology" is something that was delivered for enough years to be counted mature.
X- series engine can not be old by default. F135 is at this point old technology, sure, but this is what they're trying to go from.
Same is true for China. Methods are methods, deliverables are deliverables.
China's benchmark right now is WS-10C, WS-20 and WS-19/21, all 3 very fresh and hot off production line.

We are not in a Huawei event, things move differently in aircraft industry.

Big shame if this plane is just a crappy F-35B copy, the darn thing is 20 years old and it doesn't help with the 'China can only copy"" narrative. Just when I thought we were beyond the catching up and copying phase and into the innovation phase...

Well, often China still plays things very safe.
Which is a shame, as lack of 3-service requirement allows to build something to a national and service requirement.

I stood and will stay on the hill that USN requirement was that pushed F-35B in a wrong direction. And F135 is part of the problem here, it's way too much aircraft for PLA MC needs.
But I'm only an observer, so who cares what I think

 

[latenlazy]

Though what I don't understand is why they would need to reverse engineer a F135 then?

It’s very unlikely they would reverse engineer the whole engine given the risk of invisible technical debt for designs that you didn’t develop ground up. But it’s quite normal for engineering teams to copy aspects of other designs for study on their path to developing their own. You’d be shocked at how prevalent copy as launch pad approaches to R&D are in the product engineering world.

 

[Gloire_bb]

Though what I don't understand is why they would need to reverse engineer a F135 then?

As it it's a single most advanced deployed (mature) mil engine in the world. Especially in jet VTOL field, where China is an absolute newcomer.
F135s, for all their shortcomings, fly and power over a thousand aircraft.

Surely, they have far more advanced core designs by now as you said 606 should have atleast XA102/103 level of technology right now.

Designs/technology are curse worse at this point.
Right now China, in production, is at WS-10C.

In American terms this is mid 1990s, which is 30 years ago. F135 is two 10-year cycles and full generation ahead of that. Maybe WS-15 is just around the corner (it is for many years), which will still put the situation in the same general spot, as through 1990s, F119s powered F-22 prototypes without major issues.

What's the point of "designs" - I'd guess any seriously competent engineering professor in this field from university in Tehran or Pyongyang will come up with a reasonable design. What matters is not that, what matters is deployment. And here F135 is solid ahead, as a finished step.
Of China, of Europe(yes, even with RR F136 in mind, which wasn't deployed), of Russia, of everyone.

You can't take a flight in an aircraft powered with forum/substack technologies. You need an article.

 

[Tomboy]

What happened to becoming a first rate engine maker by 2030? You don't do that by making decades old technology and being proud of it.

What's the point of "designs" - I'd guess any seriously competent engineering professor in this field from university in Tehran or Pyongyang will come up with a reasonable design. What matters is not that, what matters is deployment. And here F135 is solid ahead, as a finished step.
Of China, of Europe(yes, even with RR F136 in mind, which wasn't deployed), of Russia, of everyone.

You can't take a flight in an aircraft powered with forum/substack technologies. You need an article.

The claim is that it is already in advanced stages of development and also considering China is the claimed to be the leading technological superpower and to be ahead of the US in fighter technology by many here, I don't see what's wrong with expecting the absolute best in arguably the most critical field for aircraft design like aeroengine. US and China should be absolutely toe to toe. Also, you do realize by the time this is fielded, US would likely be mass producing their next generation VCEs using largely improved technology derived from XA100/101s which are already a generational step above F135.

 

[Wrought]

What happened to becoming a first rate engine maker by 2030? You don't do that by making decades old technology and being proud of it.

The claim is that it is already in advanced stages of development and also considering China is the claimed to be the leading technological superpower and to be ahead of the US in fighter technology by many here, I don't see what's wrong with expecting the absolute best in arguably the most critical field for aircraft design like aeroengine. US and China should be absolutely toe to toe. Also, you do realize by the time this is fielded, US would likely be mass producing their next generation VCEs using largely improved technology derived from XA100/101s which are already a generational step above F135.

"Fighter technology" is not some kind of homogenous stat in a videogame. There are specific domains where Chinese technology has the edge, like BVRAAMs. And there are others where US technology has the edge, like VTOLs. They are not in any way interchangeable.

 

[Gloire_bb]

The claim is that it is already in advanced stages of development and also considering China is the claimed to be the leading technological superpower and to be ahead of the US in fighter technology by many here, I don't see what's wrong with expecting the absolute best in arguably the most critical field for aircraft design like aeroengine.

What is advanced stages of development?
Like, for instance, first time ru 5th gen engine flew is late 1980s, and they were sure enough to fly 1.44 on two of them in late 1990s. That's "advanced stages of development", but engines had like 50 hrs of time in them at that point, and soon after whole thing was abandoned.
They have "technology". But 3 decades later, no Ru aircraft can actually enjoy results. Do these decades matter? Who knows, for pilots in the air - they don't.
Same is applicable here for Chinese engine development. We're pitching experiments versus deployed level, which is ahead of current chinese deployed level, and it was deployed way earlier than current Chinese deployed level. If i remember correctly, F135-equipped fighters achieved IOC before J-10Cs with WS-10B engines were finally accepted into service.

Wrought summed it up well here. Especially because in "technologies" i will be rather surprised if US rocket fuel mixtures and electronics - "technologies" - from mid-2010s didn't allow them to create missile equal or better than PL-15.
But did they? They did not. Which is why not only for 10 years PL-15 has an edge in engine, seeker on top of just size - next weapon can capitalize on what was achieved back then, better. And US, as of 12.2025, will still go into combat with AIM-120D-3.
Which stretches everything from its 7" booster-sustainer package and seeker from 1990s. But no amount of laboratory technologies can help when those aren't deployed.