A few thoughts on what constitutes a 6gen and why for the purpose of this project and commentary on tphuangs suggestions - didn't fit in a single post so as an exception I wrote a double. I think that will be it for Christmas so I wish you a happy holiday season as well.
If CAC's 6th gen project has a planform that looks like GCAP, then it would be a disappointment.
Just saying it can control a bunch of UCAVs & has AI doesn't mean much. There are AI and loyal wingman support in J-20S, does that make it a 6th gen aircraft? There are levels in AI and ability to do sensor fusion.
Yes it does.
In theory J-20 may be upgraded to sufficient capabilities that it will be a "de facto" 6gen. Everything that concerns AI and sensor fusion and UCAV control can be retrofitted into a J-20S airframe without much difficulty. It may not be very efficient wiring but it can be done in the same way that MiG-21 can be retrofitted to 4gen standards only with lower range of radar due to aperture size.
Upgrade of J-20S will likely result in degraded performance of such aircraft vs a J-20A but that is not relevant. 6gen performance doesn't need to match 5gen performance because the tactics will be entirely different in the same way that 5gen tactics differ from 4gen tactics and 4gen tactics differ from 3gen etc etc.
This is one major aspect of differentiating between generations that is almost always ignored - tactics. If a weapon system is an instrument of war and its specs are its range then tactics are what it excels at.
A baseline MiG-21 (2gen) can't perform the same tactics as F-16A Block 15 (4gen) but the same MiG-21 upgraded to 4gen standards will be able to engage in the same
tactics even if the effectiveness against F-16A will be lower for objective reasons.
As follows if an upgraded 5gen can engage a 6gen aircraft with 6gen tactics it makes it de facto 6gen.
You can try a counter-argument but I doubt you will get anywhere with it.I know because I tried it once and failed which is why I rethought my position.
Further proof:
Note that when J-20 started it didn't match all of the informal 5gen traits lacking appropriate radar, engines and sensor fusion. It was de facto 4gen VLO. But because it had the
defining trait of 5gen which is VLO airframe it could be upgraded over time to become a proper or "de jure" 5gen.
Therefore J-20 won't be a full 6gen
if and only if the defining trait of next generation is an airframe requirement. Which it won't be because every generation so far had a single defining trait - and that single trait was directly responsible for the available tactics.
The first 5gen ATF had the following fundamental requirements:
- VLO airframe,
- supercruise,
- AESA radar,
- sensor fusion.
Everything else was added at a later stage, so those are the "original 5gen characteristics".
Of those
only VLO airframe is something that can't be retrofitted to another aircraft type thus it defines the "sine qua non" of 5gen. The sine qua non trait is what we would describe in evolutionary dynamics as point of
speciation.
Generations of fighters follow the same rules of evolution, gradual adaptation and punctuated equilibrium as species in biology. This is why speaking of "generations" is really misleading because F-16 and F-35 are a different "species" of fighter. Block 10, Block 15, Block 25, Block 30, Block 50 are "generations". And we know that because the defining characteristic of a species is that it individuals of two different species can't interbreed. In other words you can upgrade or downgrade a F-16 between blocks but you will never turn an F-16 into a F-35 and vice versa.
You are essentially projecting your own preferences for what a 6gen should be onto aircraft which are the result of work of actual specialists in the relevant fields - including air tactics. You are not a specialist in relevant fields. Therefore it stands to reason that they know what they are doing and you don't. So you should be asking why those aircraft differ from your expectations and where you may be making a errors,
not where and why they fail to meet your expectations. Your logic is backwards and your decision to consider something 5.5gen instead of 6gen (because it's a marketing term) is just a cop out.
Consider:
The US was able to design a concept for a VLO fighter that remains in active use today in late 1980s when medium-range ARH missiles weren't in service yet and when the digital workstation had less computing power than a smartphone a decade ago. Designing a contemporary VLO airframe (different than F-117) was
not the challenge in ATF as the program resulted in two VLO airframes of which the selected one was
inferior. At exactly the same time Northrop developed a VLO bomber that remains in active use today. F-22 also has greater RCS in rear aspect compared to an older F-117 because it was deemed not necessary. F-35 has also (at least superficially) greater RCS in rear aspect compared to F-22 and most 5gens have an even greater rear RCS. Is it because designers in 2020s don't know how to solve what Lockheed could do in 1991?
This is not rational. The answer is that tactics - which needed extensive practical use of a VLO airframe - proved the limiting factor. If viable tactics don't need low rear RCS then it won't be necessary.
The planform for F-22 is the same general planform that is being used in both FCAS and GCAP. This doesn't indicate that any of these fighters are outdated but rather that
F-22 achieved sufficient parameters for whatever its intended role which is tactics. If that intended role and the resulting tactical capabilities match the intended role and tactical capabilities for FCAS or GCAP then there is no need to complicate the design for the sake of higher performance. Nobody needs an additional problem to solve, especially not at war.
Furthermore:
There are fundamental differences in how the US or China will be using their 6gen fighters compared to how Britain or France or Japan will use them. US and China having greater resources at their disposal will be able to devote some of those resources for high-risk/high-payoff missions like penetration of enemy-controlled airspace. France or Japan will not and their strategy and tactics will be more conservative. If you know that your doctrine will be conservative then expending resources on developing a non-conservative design is wasteful. It's better to have more airframes with lower performance than fewer with higher performance if lower performance is what is sufficient for you to reach a necessary capability.
But even between China and the US there will be a fundamental difference in how they will use their fighters. China can in its current situation fall on its geographical advantage and choose a more conservative strategy. US can't. Therefore the US must procure the most advanced system in terms of VLO or give up the field of battle. China doesn't. It can follow the development strategy of smaller countries because it can capitalise on its production capability to generate much higher numbers of less capable systems. It's dialectical materialism in warfare - quantity has an inherent quality of its own.
There is also a famous saying about Pentagon procurement that bottom 90% of capability consumes bottom 10% of budget and top 10% of capability consumes top 90% of budget. The changes to design that for you seem trivial may not be a trivial position on the budget side. What you think is disappointing may be a relief to anyone handling the resources behind the project. Budget problems can shoot down fighters so well that they won't even leave the factory.
Alternatively, ask yourself the question: does China need 100% capability when 90% or 80% buys 150% the number?
War is not a beauty contest.
