J-20 5th Gen Fighter Thread VIII

[Deino]

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All of which is to say, in 2024, the status and rationale of a "PLAAF land based FC-31/J-31" is definitely in some doubt, and while it's a factor to keep in mind, we are at a stage where it probably has to justify its own existence somewhat to be brought into the conversation.

So @ChinaWatcher1 and his original question about "why even produce a land based J-31" is probably best answered at this stage with something like "at this stage the rationale for a land based J-31 is rather weak, and even what benefits it may have, pale in context of other current and future procurements we can observe and predict for the PLAAF".

Maybe an argument might be not the aircraft itself or its capabilities in comparison to the J-20 but other reasons?
Maybe China wants alone from an industrial-political point of view that SAC could remain in the fighter businesses and in order to raise the numbers of aircraft (as such SAC's share) and as such to bring down the unit cost of the J-35, a certain number of J-31 (?) could be an option worth to consider?

 

[CasualObserver]

Maybe an argument might be not the aircraft itself or its capabilities in comparison to the J-20 but other reasons?
Maybe China wants alone from an industrial-political point of view that SAC could remain in the fighter businesses and in order to raise the numbers of aircraft (as such SAC's share) and as such to bring down the unit cost of the J-35, a certain number of J-31 (?) could be an option worth to consider?

Then why don't order more J-35s for the Navy, similar to the Superbug programme?

 

[Index]

This is too oversimplified. We don't know enough about these planes and their capabilities, RCS, IR signatures, RAM coats, sensors, armaments, escorts, AWACS capabilities, strategies, tactics, etc., to come to these conclusions.

These "experts" are just guesstimating. Even if they solid modelled the planes like all these "studies" we see online, it still doesn't give the full picture. The solid models do not take into account tolerances and manufacturing imperfections. They don't take into account how clean and well taken care of the or even what type of RAM coat is applied or the quality of riveting. No one can tell what these planes are capable of without having a serial production variant on hand and a multi billion dollar lab to test them.

When you say the J-20 is bigger, and therefore, better, you are assuming both sides are equally capable, technologically speaking. The truth is the US has decades on China in that regard,

Nope, there is no evidence whatsoever that the current level of technology differs significantly. Truth would imply you could measure that one side has a lead. Having spent a long time having a lead in ancient times does not correlate with being at the forefront today. The UK navy has centuries on USA navy in that regard, which navy is mightier today? History means nothing.

so even if they are deindustrializing and China is rising fast, it does not constitute reasonable evidence for assuming the US is not capable of producing, or is not currently working on producing a new air superiority fighter that would rival or surpass the J-20 by a significant margin, and mass produce it well before 2030, provided their economy has not collapsed by then.

The F-22A can likely compete with the J-20 in all regards. The F-35 might be incapable of competing with the J-20, it still lays out the foundation for a next generation air superiority fighter to be produced in a relatively short amount of time. The sensors and tech are almost ready and their issues are being optimized, and so is the incredible F135 engine, and the new Adaptive Cycle engines are already being tested.

F135 is incredible by current standards but so is the WS15.

It is even possible for the US to pull the YF-23 off the shelf and and optimize it for today's tech. That alone would produce a phenomenal fighter with lower RCS and IR signatures than any fighter on the market, but chances are, they are working on something even better.

You can't just pull stuff that is only mockups and prototypes into active service just by saying "I'm taking it off the shelf!!", it's fanboy level thinking. Like J-31s to Pakistan can just be pulled off China's shelf lol

Or "just lengthen the J-20 to make it into the world's best strike fighter" lmao

"chances are, they are working on something even better" lmfao is this the US version of the J-25 hypersonic space fighter speculation?

We should stick to being realistic and evaluating according to current specs. While the J-20 has the advantage in a 1v1 air superiority scenario, it has other weaknesses such as a relatively low number deployed and not much anti ground capabilities. We should access the US threat realistically, and they are absolutely still a huge threat, mainly owing to a larger starting military and their intent to attack. Realistically assessing what the J-20 can do (out dogfight enemy 5th gens) is just 1 tiny piece in the whole puzzle of how to keep China safe from US threat.

 

[Ironhide]

Maybe an argument might be not the aircraft itself or its capabilities in comparison to the J-20 but other reasons?
Maybe China wants alone from an industrial-political point of view that SAC could remain in the fighter businesses and in order to raise the numbers of aircraft (as such SAC's share) and as such to bring down the unit cost of the J-35, a certain number of J-31 (?) could be an option worth to consider?

Also, Are they going to replace all the 400ish J-10s with heavy fighters (J-20/J-16)
I think No

 

[ACuriousPLAFan]

Then why don't order more J-35s for the Navy, similar to the Superbug programme?

Because there aren't a lot of carriers for the PLAN to field their fighters from?

Unlike the USN's 11 CVNs, China only has 2 CVs (soon to be 3), and the 4th one isn't expected until at least the late-2020s. Unless China kickstarts a CV-building spree immediately, the demand for new carrier-based fighters are going to be much smaller for the PLAN than it is for the USN.

Besides, at present, only the Liaoning and Fujian are qualified for J-35 operations. Shandong will have to wait for at least a couple years before she can have her MLU to receive J-35s.

 

[gelgoog]

Maybe an argument might be not the aircraft itself or its capabilities in comparison to the J-20 but other reasons?
Maybe China wants alone from an industrial-political point of view that SAC could remain in the fighter businesses and in order to raise the numbers of aircraft (as such SAC's share) and as such to bring down the unit cost of the J-35, a certain number of J-31 (?) could be an option worth to consider?

I think one big question is how long will J-16 production continue. For comparison China built less than 300 JH-7 aircraft.
I expect Shenyang to fully switch to production of the J-31 and J-35 aircraft in the near term as J-16 production winds down. By that point J-16 production is over it is likely that the PLAAF orders for the stealth will come. It just makes little sense to develop a whole new engine and airframe for an aircraft that would at best be used in like three carriers in the near term. Only roughly a hundred aircraft would be required for the carriers.

But if the J-31 does get ordered it will likely be used to replace the existing J-10 aircraft. I still expect the J-20 to replace all the PLAAF Flankers like the J-11.

 

[Blitzo]

Maybe an argument might be not the aircraft itself or its capabilities in comparison to the J-20 but other reasons?
Maybe China wants alone from an industrial-political point of view that SAC could remain in the fighter businesses and in order to raise the numbers of aircraft (as such SAC's share) and as such to bring down the unit cost of the J-35, a certain number of J-31 (?) could be an option worth to consider?

Even that is far from an obvious answer given SAC will still be producing plentiful J-35/XYs into the future and will likely have a big workshore in GJ-11 and other future CCAs/UCAVs.

Ultimately there are lots of ways we can reason it out for the idea of pursuing a "PLAAF land based J-31/FC-31" to make sense, but either way we are at a stage where it is not an intuitive accepted baseline assumption right now

 

[CasualObserver]

Because there aren't a lot of carriers for the PLAN to field their fighters from?

Unlike the USN's 11 CVNs, China only has 2 CVs (soon to be 3), and the 4th one isn't expected until at least the late-2020s. Unless China kickstarts a CV-building spree immediately, the demand for new carrier-based fighters are going to be much smaller for the PLAN than it is for the USN.

Besides, at present, only the Liaoning and Fujian are qualified for J-35 operations. Shandong will have to wait for at least a couple years before she can have her MLU to receive J-35s.

They could operate as land based aircraft until the demand for carrier fighters increases; and mind you not all naval aircraft are carrier-based at all times.

PLA still needs hundreds of more fighters in a 2030 contingency, regardless of how many carriers they actually have.

 

[Totoro]

I see j20 and j31 to be roughly similar to SU27 and mig29 combo. Not in all areas, but when it comes to range and partially payload and role.
J20 is the long legged plane to operate close to japan mainland and similarly distant areas.
J31 is to operate close to China's coastline, which includes being able to operate over Taiwan.
J20 will also benefit from a bit more payload.

Other than that, and the fact j31 development is partially payed by j35 and possibly by exported planes, both planes seem to be multirole.

It's possible j31 trails a bit behind in certain other charactersitics, though far less than, for example j10c trailing j20.

Then there is always the political factor. Part of j31 mission set is to keep shenyang relevant, its expertise alive and its interest groups happy.

 

[tphuang]

Come on now.

I've clearly, explicitly, specified some areas that are different;


Range, although a major advantage, is not everything. What about cost?

When I said roughly equal capabilities, I also consider stealth, internal payload, radar and avionics, etc. Then I addressed parts that may not fit as well.

I thought I clearly expressed that, but judging from your reaction, apparently not. So allow me to reiterate it.

The J-31 is rumored to be significantly cheaper than the J-20 to procure, while having similar capabilities in stealth, internal payload (minus the bays for close range AAMs), avionics, radar, etc. However, it being a medium-sized fighter, it's limited in areas such as fuel capacity, maximum payload (no. of external pylons and how heavy they can carry, etc.), etc.

So you get a J-20 with less range but significantly cheaper. It's great for replacing aged aircrafts.

Hopefully this clears it up!

That's fine, but earlier you said

Apparently, rumors from the grapevine said that the J-31/35 is much cheaper with roughly equal capabilities

and I think range is clearly a significant consideration in the capability of an aircraft

I think it's important when we talk about similar capabilities in avionics and radar, we again should consider the inherent advantages in a larger aircraft.
If you cannot install as much high power computation and sensors in J-31/35 due to having smaller interior space for electric generators, battery and thermal management system, then how can it have roughly equal capability to J-20?

When we consider having J-20A or J-20S controlling a bunch of UCAVs in the future, it needs to have long patrol time, long range and large amount of processing to manage the data input from UCAVs and give them appropriate command.

historically speaking, we have never had such a situation where computation power is so important to a fighter jet. Manned aircraft are no longer flying computers, they could be flying servers. An ever larger % of engine power will be devoted to powering computers and sensors.

So it's really becoming not so logical to have smaller aircraft.

I can't emphasize enough how big of an advantage J-20 has over F-35 at this point.

Why do you want to blow that advantage with a smaller J-31?