J-XY/J-35 carrier-borne fighter thread

[minusone]

Who scaled that image and on what basis did they use to scale it?

i stand corrected, cant wait for clearer images to emerge

 

[Mischa]

I posted a Google translation to English of the Chinese article on the J-XY optimisations.

Picking out the core points:

Modifications to the wing, simple flaps and scheduled use of rudder allowed it to meet lift requirements without needing slotted flaps which are bad for stealth.

The changes to the rear of the canopy, intakes and rear fuselage/tail area were made for drag reduction, overall drag reduced 10% which allowed the design to reach its acceleration requirement.

Redesign of the tail area reduced the negative load of the horizontal tail.

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Some say that this aircraft is actually a verifying aircraft, an X-series aircraft. Currently, PLAN has too many things to verify, especially the stealth coating against erosion and maintenance of a 5th generation aircraft on board. The current model is really hard to believe to be the main fleet for PLAN in the future, both the engines and the size are really unsuitable.

 

[Mischa]

Yes, when people say significantly smaller, they think of the difference in the size of the engines. In fact, carrier based aircraft have different requirements. What it will probably mean is that J-35 will have slower top speed or flight ceiling, but that is the same trade-off that F-35 made versus F-22. Especially for a naval variant, it is an acceptable trade-off.

But tbh, PLAN's CV should focus more on defending the fleet than working as a striking platform. China now has advanced hypersonic missiles, possibly they will put them on board, carried by giant destroyers, which seems to be a better anti-navy weapon than air2navy missiles carried by aircraft. On the other hand, PLAN needs to face attacks both from the US's CVs and bombers from their overseas airbases. Thus to effectively protect the fleet, what they need should be a bigger aircraft, instead of a smaller FC-31 size one. That's why I think the model we see here is still verifying aircraft, the same as the preceding FC-31 family. And don't forget, their current model is J-15, one of the biggest carrier fighters ever in the world.

The reason that the US turns to smaller F-35 and gives up NATF is definitely the collapse of USSR and sudden relief of air-defend stress to the CV. Also they quickly retire all the F-14 and AIM-54, and turn to multi-function FA18.

 

[Intrepid]

I think the Chinese aircraft carriers are needed when Chinese citizens are threatened overseas. In other words, rather smaller conflicts that can perhaps be resolved in advance through a demonstration of power and the simple availability of transport capacity for rapid evacuation before they actually arise.

Not so much an aggressive component as a retreating protective ability for one's own people.

 

[plawolf]

Ok, I don’t want to derail this thread, but just want to make a few quick, final points. I’ll leave you to have the final word if you want.

Actually I would say the same logic does not apply to 4th gen and 3rd gen fighters to the same degree.

Flight hour costs of 4th and 3rd generation fighters relative to trainers were not as exorbitant as flight hours costs of 5th generation fighters are relative to trainers.
Furthermore, when 4th and 3rd generation fighters emerged, the sophistication of simulators was significantly below what we have now.


"If you can afford them" -- IMO is the key here.

Sure, I agree that every air force with 5th generation jets would love to have twin seater combat capable trainers for 5th generation fighters.
But even if they were willing to develop them, the money to actually fly proper 5th generation fighters for the purpose of training, when a 5th generation fighter includes all of the bells and whistles like RAM, internal weapons bays, advanced full sensor suites, advanced networking capability -- is a waste of time of a 5th generation aircraft's flight hours.
There's a reason why 5th generation aircraft fleets around the world do not have dedicated 5th generation twin seaters for training purposes, and there is a reason why the idea of J-20S being used as a trainer is also immensely unlikely -- it's just a poor use of an air force's finite resources, and the training for 5th generation jets can be better done through a combination of modern simulators and LIFT.

Or, putting it another way -- I think that having 5th generation combat capable trainer aircraft would be an active detriment to an air force's 5th generation fleet.
I would truly question the rationale of the PLA if they developed J-20S for the purpose of training, and doubly so if they chose to do so for J-XY as well.

Well, firstly that’s a false comparison to compare twin seat fighters to dedicated trainers as if it is a this or that choice, since no one ever suggested to use twin seater combat trainers instead of actual dedicated trainers or simulators. They are different tools for different jobs and you can have both!

It is equally a false choice to suggest that having a second seat significantly detracts from the combat capabilities of a fighter. Because that is patently not so, as the Su30, J16, F15E etc will all serve as clear counterpoints to. Similarly it’s absurd to suggest that the twin seat J20S would be an ‘active detriment to China’s 5th gen fleet’. Just as it would be ridiculous to suggest that any of the 4th gen twin seaters would somehow detract from the combat capabilities of their respective fleets.

Sure, you might loose some theoretical agility due to the additional weight, but firstly, that’s just theoretical, in practice you can easily enter combat with many times more weight just due to the fuel and weapons load at the time. Secondly, you gain significantly in capabilities from having the second seat.

It is most peculiar that as soon as one even mentions the word ‘training’ or ‘trainer’ and suddenly otherwise reasonable and rational people seem to just flip and switch and think that means whatever it is has to be massively nerfed. Just like how people were hang up on the Liaoning being referenced as a ‘training’ carrier, as if the name alone means it cannot possibly perform actual frontline combat operations! Combat trainers are called trainers, but are fully combat capable, and always have been!

I absolutely expect the PLAAF to make full use of its twin seat J20S once they become operational to perform niche training duties, just like how J20 units also use J16s for training. Would that magically make them any less capable in combat roles?

The very fact that J20 units tend to also use J16s is a good illumination in point in the massive training value of having fully fledged fighters with a second seat.

AJTs and simulators are good, but none can 100% replicate what it’s like to fly a top of the line combat jet to the limits of its capabilities. While they might be able to effectively simulate 90% of the flight envelope, that last 10% of capability is also the most important, hardest to learn and most dangerous to master since you will be pushing both the plane and pilot to the very edge of their physical limits.

This is also where twin seaters are most important and valuable, as you can have a seasoned pilot fly the manoeuvre with the trainee in the back getting a first hand feel of what it’s like to get it right, and also have the seasoned instructor on hand to save the day when the trainee tries his hand at it in case they mess up. With only single seaters, each pilot must slowly build up to those advanced manoeuvres bit by bit.

That sort of experience and safety net allows you to massive cut down on your training time while vastly improving training effectiveness and quality, which is why air forces around the world pays the massive costs of having twin seaters frontline combat gets.

The much higher flight hours costs of 5th gens actually makes twin seaters more valuable, not less because of this increased training efficiency

Before you get too invested on the whole cost-benefit not working for 5th gens argument, maybe it’s worth remembering that there were twin seat trainer versions planned for the F22 before it got canned, and twin seater trainer 5th gens would absolutely have happened had the F22 had its full planned production run.

The F35 not having a twin seater is more down to how much trouble that programme has already run into thanks to its three-version-in-one-airframe approach that no sane person would dare suggest doubling the versions to include twin seaters to that mess. But the specific problems with that programme does not automatically translates to the entire generation.

The structural provisions for a second seat are not there, however.

The canopy/hump that we see externally is an external aerodynamic shape that internally likely carries fuel, but even if they wanted to potentially make it a two seater in the future, they would have to make substantial structural changes below the airframe's surface to accommodate a cockpit and the requisite life support system and enlarged canopy etc.

This isn't even starting to think about just how big (long especially) a second cockpit would make the canopy, which, even on cursory glance at the aircraft, would actually require an even more outward displacing and longer hump than what we see now.



All of this is to say -- I'm not ruling out the idea that maybe we might one day see a twin seater J-XY (with the caveat that if we see a twin seater, it would almost certainly be for the battle management/control role rather than for training).

However, I am saying that the nature of the airframe modifications -- including the canopy/fuselage hump -- we see on this J-XY prototype relative to the FC-31 airframes, can be best attributed to the requirement for greater internal fuel and any possible aerodynamic benefits as well.
Whether those modifications might make developing a twin seater variant of J-XY slightly easier in the future if they chose to do so -- maybe, it does. But the primary and most upfront benefits for them would be greater internal fuel + aerodynamic refinement.

Well, I guess we have to agree to disagree here until clearer pictures emerge, because to my eyes, the changes to the hump seems way too big to just be for more fuel.

 

[AndrewS]

But tbh, PLAN's CV should focus more on defending the fleet than working as a striking platform. China now has advanced hypersonic missiles, possibly they will put them on board, carried by giant destroyers, which seems to be a better anti-navy weapon than air2navy missiles carried by aircraft. On the other hand, PLAN needs to face attacks both from the US's CVs and bombers from their overseas airbases. Thus to effectively protect the fleet, what they need should be a bigger aircraft, instead of a smaller FC-31 size one. That's why I think the model we see here is still verifying aircraft, the same as the preceding FC-31 family. And don't forget, their current model is J-15, one of the biggest carrier fighters ever in the world.

The reason that the US turns to smaller F-35 and gives up NATF is definitely the collapse of USSR and sudden relief of air-defend stress to the CV. Also they quickly retire all the F-14 and AIM-54, and turn to multi-function FA18.

Yes, aircraft are inherently inefficient at carrying long-range anti-ship missiles

The last CBSA planning reports had carrier aircraft providing long range ISR and air superiority, rather than focusing on strike.

 

[AndrewS]

@plawolf @Bltizo

If the future carrier airwing is envisioned with lots of drones, then I could see them going with a 2 seater command/EW version as the default
But we'll have to see

---

Also here are the rough costings I've got for various aircraft

Given that even a single F-35 costs $481M over a 30 year lifetime, that could train a lot of pilots
I've seen a figure of a million being mentioned previously as the cost of training a military pilot
So it seems dedicated training aircraft would be inefficient when compared to the alternatives such as ground-based simulators or converting an older 2-seater training aircraft with updated back-seat avionics

F-22: $150M procurement + $660M operating/maintenance over 30 years
F-35: $80M procurement + $401M operating/maintenance over 30 years

F-15: $80M procurement + $330M operating/maintenance over 30 years
F-16: $60M procurement + $166M operating/maintenance over 30 years

 

[zayid]

J-XY X=2 Y=1

 

[Blitzo]

Ok, I don’t want to derail this thread, but just want to make a few quick, final points. I’ll leave you to have the final word if you want.



Well, firstly that’s a false comparison to compare twin seat fighters to dedicated trainers as if it is a this or that choice, since no one ever suggested to use twin seater combat trainers instead of actual dedicated trainers or simulators. They are different tools for different jobs and you can have both!

It is equally a false choice to suggest that having a second seat significantly detracts from the combat capabilities of a fighter. Because that is patently not so, as the Su30, J16, F15E etc will all serve as clear counterpoints to. Similarly it’s absurd to suggest that the twin seat J20S would be an ‘active detriment to China’s 5th gen fleet’. Just as it would be ridiculous to suggest that any of the 4th gen twin seaters would somehow detract from the combat capabilities of their respective fleets.

Sure, you might loose some theoretical agility due to the additional weight, but firstly, that’s just theoretical, in practice you can easily enter combat with many times more weight just due to the fuel and weapons load at the time. Secondly, you gain significantly in capabilities from having the second seat.

It is most peculiar that as soon as one even mentions the word ‘training’ or ‘trainer’ and suddenly otherwise reasonable and rational people seem to just flip and switch and think that means whatever it is has to be massively nerfed. Just like how people were hang up on the Liaoning being referenced as a ‘training’ carrier, as if the name alone means it cannot possibly perform actual frontline combat operations! Combat trainers are called trainers, but are fully combat capable, and always have been!

I absolutely expect the PLAAF to make full use of its twin seat J20S once they become operational to perform niche training duties, just like how J20 units also use J16s for training. Would that magically make them any less capable in combat roles?

The very fact that J20 units tend to also use J16s is a good illumination in point in the massive training value of having fully fledged fighters with a second seat.

AJTs and simulators are good, but none can 100% replicate what it’s like to fly a top of the line combat jet to the limits of its capabilities. While they might be able to effectively simulate 90% of the flight envelope, that last 10% of capability is also the most important, hardest to learn and most dangerous to master since you will be pushing both the plane and pilot to the very edge of their physical limits.

This is also where twin seaters are most important and valuable, as you can have a seasoned pilot fly the manoeuvre with the trainee in the back getting a first hand feel of what it’s like to get it right, and also have the seasoned instructor on hand to save the day when the trainee tries his hand at it in case they mess up. With only single seaters, each pilot must slowly build up to those advanced manoeuvres bit by bit.

That sort of experience and safety net allows you to massive cut down on your training time while vastly improving training effectiveness and quality, which is why air forces around the world pays the massive costs of having twin seaters frontline combat gets.

The much higher flight hours costs of 5th gens actually makes twin seaters more valuable, not less because of this increased training efficiency

Before you get too invested on the whole cost-benefit not working for 5th gens argument, maybe it’s worth remembering that there were twin seat trainer versions planned for the F22 before it got canned, and twin seater trainer 5th gens would absolutely have happened had the F22 had its full planned production run.

The F35 not having a twin seater is more down to how much trouble that programme has already run into thanks to its three-version-in-one-airframe approach that no sane person would dare suggest doubling the versions to include twin seaters to that mess. But the specific problems with that programme does not automatically translates to the entire generation.

What I said was that using twin seater 5th generation aircraft as trainers would be an active detriment, not that having twin seater 5th generation aircraft itself a detriment.

I have said for a long time why J-20S as a twin seater variant for the PLA makes sense and offers significant capability -- however I believe it has nothing to do with any trainer role that it is meant to offer, instead it is because of its enhanced capability to do battle management and command/control relative to the single seater.



As for the benefits of having twin seaters as trainers, again, the issue is "is it worth it".
The exorbitant coats of operating a proper 5th generation airframe in the training role means air forces all around the world are looking at enhancing the use of dedicated trainers, LIFT, and simulators so that they can save the airframe hours of their proper 5th gen airframes for more valuable duties and exercises.

On older aircraft like 3rd gen and 4th gen aircraft, having dedicated combat capable trainers that operate as trainers made a fair amount of sense.
For 5th generation aircraft, with the emergence of more capable trainers, more capable simulators, and the exorbitant cost of 5th gen planes, I do not believe that same rationale exists

 

[Maikeru]

Short and not very informative review.

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