It’s a system of systems. Not only would there be other roles for 4.5 gens, there’s nothing wrong with homeland air patrols. Totally agree about the bomb truck role though.
They would fill roles, in the absence / agnostic of air superiority, where it doesn’t matter that you’re radar observable. Obviously without running them too close to or over their airframe lives, there’d be no need.
E.g.:
- Homeland air patrol: you’re backed by your entire infrastructure (ground radar, AEW&Cs) and you’re basically a tripwire — If you’re blown up, you’re being invaded, otherwise they can all other aspects of the role sufficiently.
- Anti-drone / UAV ops deep behind your lines. If you don’t have air superiority at your rear, then you’ve got bigger problems. However, drones would still be a nuisance and you want something with cheaper maintenance hours and/or airframe life per hour to help with the job.
- AEW&Cs escort and long range missileer. The AEW&Cs is already visible and frequently blasting out EM emissions, and would be operating in a system of systems that includes 5th and 6th gens in more forward positions, so it would be suitable for escorting something further back, that also happens to sport your best detection capabilities. Plus, no PLAAF fighter has a radar with a detection range exceeding the PL-17’s max purported range, and I think it’s more than a safe assumption to say that the PLA is looking into even longer range AAMs, including air-breathing scramjets (especially if those CJ-1000 and other rumours have any truth to them).
I appreciate that everything is of course a system of systems, but we are talking about a period of time in which the PRC:
- can afford replacement of 4.5th gens with 5th gens (or newer) aircraft
- have the industrial capacity to replace 4.5th gens with 5th gens (or newer) aircraft
- are still paying personnel (maintenance crew, pilots) to be active anyway, regardless of whether they are operating 4.5th gen aircraft in the certain remaining units or whether they are operating 5th gen aircraft in those units
- will have had produced the last 4.5th gen aircraft for the air force about a decade into the past
The problem is that people are trying to come up with ways to justify the continuing role of 4.5th gen aircraft into the future, which sure, I can agree there are certain missions it can do like homeland air patrol, escorting AEWC, anti-drone operations.
However, continuing to operate 4.5th generation aircraft comes with an opportunity cost:
- 5th generation aircraft will be able to do all of those aforementioned 4.5th gen roles (5th gen can carry external weapons or fuel tanks after all in missions where RCS is less important),
and still also be relevant in a high end fight; heck if you're 5th gen you can even jettison stores and EFTs in your homeland patrol/drone defense/AEW&C escort role and then transition to a more "forward" position as needed in a single sortie.
- in a system of systems battle, the PLA will of course be more formidable with an even greater fleet of 5th generation aircraft, rather than retaining a fraction of their fleet as 4.5th gen.
- 5th generation aircraft will have been produced in far larger numbers by the era we're talking about (2035) and likely have a far more robust logistics and spare parts lineup, such that it is very possible that 5th gen aircraft of that era may have
greater availability and maintainability than 4.5th generation aircraft.
- you are still paying for the same air crew and pilots and other personnel and basing, regardless of whether your unit operates 4.5th gen or 5th gen aircraft, so why pay your crew and pilots to operate a far inferior aircraft?
The only reasons I could see in which it would make sense to keep 4.5th generation aircraft in service circa 2035 would be:
- if they did not have the funds or industrial capacity to procure or produce 5th gen (or better) aircraft to replace them
- if there were far more pressing needs in the air domain which would bring forth even higher yield capability gains
- if they want to actively expand their manned fighter fleet and are using 4.5th gen aircraft as placeholders to keep units active while increasing the total size of the fighter force
But if the above criteria are not relevant, then it doesn't make sense to retain 4.5th gens by 2035.
Just because there are certain roles that 4.5th gens can hold onto to remain partially relevant, and just because warfare is a system of systems fight, doesn't mean that keeping 4.5th gens around is the correct decision if they have means to replace them with 5th gens.
Because you would far prefer to have assets that can be relevant for the high end roles as well as lower end roles, and to augment the overall robustness and durability of your system of systems by improving the average capability and quality of your individual systems (manned fighter aircraft) as well.
I also want to recommend people remember that in the contest for air superiority, if you have the means to attain an imbalance of capability in your favour, then it is important to exercise it.
Air superiority is one of the heights of warfighting -- it is probably one of the few domains where if you can afford laughable, vastly gratuitous overkill, then it is criminal negligence to not procure it, as air superiority will be the factor which enables so many other key capabilities and warfighting pursuits.