Ask anything Thread (Air Force)

[IpWoman]

Sorry for the stupid question, when is J-35 expected to enter service? And the aircraft carrier variant?

 

[Michaelsinodef]

Sorry for the stupid question, when is J-35 expected to enter service? And the aircraft carrier variant?

The aircraft carrier variant is gonna enter before land based, and we're actually not 100% sure a landbased variant will be adopted.

As for when, likely around when 003 enters service?

 

[gelgoog]

If you use the J-20's development as a yardstick it took Chengdu 6 years from first prototype flight to entry into service.
That was comparatively much faster than US 5th generation programs. It took the F-35 like a decade from first flight to entry into service.

The J-35 first flew in its carrier configuration in 2021. If we use prior 5th generation programs as a yardstick we could say it will enter service between 2027-2031. But a lot of people think J-35 will enter service roughly at the same time the 003 carrier does in 2025.

The FC-31 flew much earlier, in 2012, but that is more comparable to the X-35 first flight than the F-35 first flight. FC-31 is more like an US X-plane than a prototype of a fighter aircraft meant for production.

J-35 development has been a lot more iterative than any of the prior stealth aircraft programs. They have had several prototypes with major design changes between them. If you compare the FC-31 with the J-35 in its current iteration, it does not use the same engines, the same tail, or the same canopy design.

 

[minime]

J-35 development has been a lot more iterative than any of the prior stealth aircraft programs. They have had several prototypes with major design changes between them. If you compare the FC-31 with the J-35 in its current iteration, it does not use the same engines, the same tail, or the same canopy design.

Is WS-19(TW ratio 9.5-10, Wet Trust 10 tons) suppose be the target engine for J-35?

If WS-19 is the same size as WS-13/RD-93, do you think Pakistan JF-17 will adopt?

 

[ACuriousPLAFan]

Posted moved here from the J-XY/J-35 Carrier-borne fighter thread due to the risk of derailing the thread completely.

Possible improve variant ws15 with higher thrust beyond 20ton plus thrust in the future.for single engine fighter.

Same thoughts with @Deino.

Extremely doubtful that China would ever need a single-engine 5th-gen fighter in the future, especially when the current focus of the PLA moves on towards developing and fieldinh 6th-gen fighters that are only to get even bigger and heavier (and thus, also going to require two engines per airframe rather than one).

~~~~~

BUT, just for a little food-for-thought discussion - If there is really a demand and incentive for it, then China can absolutely develop a single-engine 5th-gen fighter.

Firstly, to set the stage - As both Chengdu and Shenyang are already very busy with heavy hitters that are actually needed by the PLAAF and PLANAF, the best candidate for the development and manufacturing of this fighter that I could think of would be Hongdu. This is considering that Hongdu is primarily responsible for the production of the JL-8 & the JL-10 jet-powered trainers, alongside the GJ-11 jet-powered UCAV. Secondary candidate would be Guizhou, as they have produced JL-9 jet-powered trainer and the WZ-7 jet-powered UCAV.

The single-engine 5th-gen fighter would be using either the WS-10B/C/G (non-TVC variant), or the WS-15 as its powerplant.

In the meantime, there is no need to develop a 20+ ton variant of the WS-15 just for this fighter. A WS-15 variant with a max thrust of over 20 tons would be more suitable for newer J-20 variants in the future, and/or becoming the interim engines for China's upcoming 6th-gen fighters.

Now, back to the discussion.

With the engine choice set, that single-engine 5th-gen fighter would be:
1. First-&-foremost, a 5th-gen light fighter, which is in the same category as the Su-75 and the cancelled LMFS. Which means that this fighter is never meant to go toe-to-toe against medium-weight and heavy-weight 5th-gen fighters, such as Su-57, F-22, F-35, Kaan, and KF-21;
2. Solely focused on the export market, since there is literally zero market in China for fighters of this size and type;
3. Targeted at countries that have to find underneath and in between their couch for spare coins for their military, as this fighter should be considerably cheaper than the medium-weight and heavy-weight ones; and
4. Offering a direct competitor to Russia's Su-75 Checkmate.

However, it should be understood that since this fighter is expected to see negligible to zero usage inside China, so it is extremely doubtful for the Chinese government to fund the development of this fighter. Therefore, the developmental cost would have to be fully bore by Hongdu/Guizhou itself - Which further brings the question of necessity for developing single-engine 5th-gen fighter into light.

 

[Heresy]

However, it should be understood that since this fighter is expected to see negligible to zero usage inside China, so it is extremely doubtful for the Chinese government to fund the development of this fighter. Therefore, the developmental cost would have to be fully bore by Hongdu/Guizhou itself - Which further brings the question of necessity for developing single-engine 5th-gen fighter into light.

What about as a 5th-Gen replacement for the J-10? Something relatively cheap for mainland defense and maybe potential future action against Korea, Vietnam, or India?

I could see use of the WS-15 as further cost savings and easing maintenance.

 

[99PLAAFBalloons]

What about as a 5th-Gen replacement for the J-10? Something relatively cheap for mainland defense and maybe potential future action against Korea, Vietnam, or India?

I could see use of the WS-15 as further cost savings and easing maintenance.

I've found what @Blitzo has previously written on this to be compelling. Essentially that there isn't likely to be enough WS-15s to spare for them, that loyal wingmen UCAVs are likely more competitive at most levels including cost and that China has other projects that the efforts and resources are better spent on (This probably needs more appreciation, see Northrop Grumman knowingly forgoing the USAF NGAD bid to concentrate their efforts into specific programs). I'd probably just throw in the pilot element - China might not have the pilot shortage issues that the USAF has at present but that doesn't mean their training should be considered cheap or attritable. If they don't need to be put into something a UCAV can do, it gives China a larger pilot pool for the heavyweight fighters that probably remain the imperative for the foreseeable future

This thread and the other one has had fruitful discussions over this topic before, and in the time since then, to be honest I have only just become even more convinced that I think a single engine, land based 5th generation aircraft may not be desirable for the PLA.

I'm going to call it "SEFA" for short (Single Engine Fifth-gen Aircraft), to describe a 5th gen fighter of medium weight, that can for all intents and purposes be considered as J-XY/FC-31 but powered by one large thrust engine rather than two medium thrust engines.

===

Now that we are in late 2021, I think there are a few contextual realities that any prospective PLA SEFA needs to be considered in:

1: Any SEFA that enters service would require an engine of WS-15 class to be viable. IMO this is important, because going into the next 10-20 years, WS-15 production will be prioritized for other aircraft first -- specifically J-20 for the next decade or so, but also as we approach 2030, I can see a variable cycle variant of WS-15 being prioritized for the PLA 6th gen effort, as we all expect 6th gen fighters to use VCEs, and WS-15 is really the only plausible basis for a 6th gen viable VCE.
That is to say, I expect the production of any prospective SEFA to be dependent on the availability of WS-15 production, and I do not expect WS-15 production into the next 20 years to be able to meet the production of J-20s, PLA 6th gen, and a SEFA itself, when the SEFA would be third/last in line for WS-15 priority.
If a JH-XX does emerge, then it is possible that any prospective SEFA might even be fourth in line for WS-15 priority, as WS-15 would obviously also be the powerplant of choice for a modern stealthy theater bomber as well.
Meanwhile, J-XY will use WS-19, an engine of a similar generation to WS-15, but a medium thrust rather than large thrust engine and whose production and commitment is already guaranteed and whose production may well be easier to achieve in the immediate to near term future given for various reasons not least the size of the blades.

2: J-XY/FC-31 is simply so much further ahead of any prospective SEFA in development and testing, and the aerospace resources of the industry is finite.
Developing and producing an entirely new fighter -- which SEFA will be, i.e.: a clean sheet aircraft -- takes up the time and energy of designers, computing power, engineers, subsuppliers, factories, all of which could be spent doing other things.
J-XY has already flown and is guaranteed to be developed and produced for the PLAN, and we expect a land based variant to be developed that will likely share massive overlap in subsystems and logistics -- that is to say, the aerospace resources for J-XY is already "committed". Furthermore, we expect at least a reasonable sized order of the J-XY (in both carrier based and land based forms), meaning the production and tooling and expertise will all be there by the time they become familiar with producing it.
The question is whether it makes sense to commit additional aerospace resources to build a whole new clean sheet SEFA, when J-XY is already there, and when (imo this is important) the aerospace resources could be used doing other things.
Does it make sense to develop a brand new SEFA when the aerospace resources could be used to develop a couple of new UCAVs instead, or maybe if they could be used to develop the PLAAF's 6th generation fighter in a faster manner, or if they could be applied onto a notional JH-XX theater bomber instead? Is it maybe more wise to just buy additional land based J-XYs whose development, subsystems, logistics, are already mature and paid for, and just accept that at the national and industry and strategic level, that the economical/maintenance benefits of a single engine for SEFA is not actually worth it?

3: UAVs/UCAVs. This is another big factor imo, that we can start to describe with more confidence.
Everyone is focused on wanting a capable yet affordable fleet of modern combat aircraft. Part of the rationale for a SEFA is wanting to operate an aircraft that's cheaper than a twin engine aircraft by virtue of having one powerplant versus two powerplants.
But IMO, the role of cheaper UAVs/UCAVs and loyal wingmen systems may greatly change what is considered "capable yet affordable".
A SEFA will have to be a medium weight fighter powered by a WS-15, yet still be relatively high end enough to have 5th gen or 5.5th gen capabilities.
However, emerging UAVs/UCAVs and loyal wingmen have the potential to be significantly lower in cost than a SEFA, and also require less strenuous powerplants to be effective. For example, a loyal wingman UCAV of the near future may only require a single WS-10 variant or even a single WS-13 variant engine to be effective.
UAVs and UCAVs and loyal wingmen drones are not a choice -- regardless of whether the PLA gets a SEFA or not, a robust unmanned capability and fleet is basically guaranteed to be a significant part of their fleet makeup into the 2030s, and likely to be a determining capability that we use to describe 6th gen and maybe 5.5th gen fighters.
So the question is whether a slightly more affordable (but still manned, relatively high performance, 5th gen fighter airframe) SEFA is worthwhile in context of the large scale emergence of UAVs/UCAVs in the near future that are likely to be much more affordable than a SEFA will be -- and in context of both premises 1 and 2.


Now, on paper, if everything were held equal, then yes it goes without saying that a SEFA would be more economical than a twin engine fighter of the same class/type/weight, by virtue of having one powerplant rather than two.
The logic of it, is very very reasonable.

But for the PLA and for China's aerospace industry, I think as of our current time in late 2021 the combination of contextual factors:
1. in terms of powerplant availability and higher priority projects that will require powerplants that SEFA depends on, and
2. the much greater maturity of the existing J-XY/FC-31 solution for a land based medium weight 5th generation fighter relative to a notional SEFA, plus the priorities of other aerospace projects where resources are better used on, and
3. the emergence of UAVs/UCAVs/loyal wingmen as a credible, capable and affordable makeup of tactical air fleets in a way that is far more affordable than a SEFA would be.....

..... all of that makes me strongly believe that at this point in time, developing and producing a SEFA doesn't make sense for the PLA, and is better spent on other things.

(The other factor of course, which I don't describe but which is obvious enough to go without saying, is that any new SEFA will introduce a whole new line of logistics and maintenance that is separate from J-20 family and the J-XY (carrier and land based) variants, introducing a third manned 5th generation aircraft type).


If some of the above factors change, then I think I would revise my assessment.
- For example, if they were able to produce something like 200 WS-15s a year from 2025 rising to 300+ WS-15s a year in 2030 and beyond, then in that case I could certainly believe a strong case for a SEFA could be made because the powerplant would no longer be a bottleneck.
- If they are able to develop a SEFA that uses far less aerospace resources than they would traditionally (either through new methods or design technologies etc) and be produced with greater speed and less retooling as well, then it might be reasonable to argue for a SEFA.


As it stands though, I don't think the logic of "single engine fighter is more economical than twin engine" is enough for them to actually develop and buy a new clean sheet SEFA.

 

[Mekconyov]

What about as a 5th-Gen replacement for the J-10? Something relatively cheap for mainland defense and maybe potential future action against Korea, Vietnam, or India?

I could see use of the WS-15 as further cost savings and easing maintenance.

This has been complicated by Ukrainian Russian war. China needs the alternate engine for its trainer. One option is twin engine trainer lift version to be further developed into J-10 category stealth version with uprated engine.
Second option is J31/J35 as secondary medium load stealth fighter.
An other option is stealth UAVs. China can use twin small engine as stealth aircraft as well as UAV also.
Main concern is to develop the engine. Not sure if China would divert the resources to this direction.

 

[gelgoog]

I already made the case for the single engine WS-15 powered fighter here before. I think it makes sense. And just like the Su-75 could come in both piloted and non-piloted versions.

 

[Andy1974]

We just saw a new production J-10 alongside new production J-20’s, I’d like to think it shares a lot of systems with the latest J-20’s, and that it might become a proper lead-in aircraft and support for the J-20s.

In other words, that new J-10 might be basically a fifth gen fighter in a fourth gen body.

Let’s just say WS-15 is not available, instead they can design a new stealth airframe based on the J-10 which would probably be more aerodynamic than the current body. There was recent breakthroughs in canopy and nose cone aerodynamics for example, even if the weapons are all still carried externally.

WS-10’s are still improving, and if certain WS-15 alloys or parts can be incorporated while maintaining production volumes then maybe the combination of..

1. Upgraded J-10, using latest J-20 technology as much as possible.
2. V-tailed, lighter, more aerodynamic airframe with stealth shaping and coating.
3. New more powerful WS-10 engines, maybe from circa 2025..

could be useful for the actual PLA as a J-20 trainer, an optionally manned J-20 wingman, and a genuine improvement over existing J-10’s, potentially increasing the fleet size.

If we want to be really resourceful then the new airframe could incorporate all the learnings made from the UCAV programs, so a new stealthy J-10 could be a validation and application and training for technology from both upcoming J-20A’s and their wingmen.

I think this addresses many of the concerns for not making it.