Chengdu next gen combat aircraft (?J-36) thread

drowingfish

Junior Member
Registered Member
Rick Joe wrote a bit about how the J-20S has served as a test-bed for the J-36 fighter. With that in mind, I really believe that the J-36 is a two seat fighter.

Other things China used the J-20s to help design the J-36

-acting as a drone command ship
-serve as suite for EW
-power generation of WS-15 for a command ship and this lead to the decision to have 3 engines
J36 being a two-seater is a given. same deal with J-20S, it takes in a lot of info, so obviously it will need to have another pilot to process all that data.
 

Patchwork_Chimera

New Member
Registered Member
are modern AAMs even designed to hit aircraft that high and fast and can still turn like a fighter?
For what it's worth, in air that thin, absolutely nothing turns like a fighter lol. Modern AAMs can indeed get up there and prosecute though. As a general rule of thumb, in practically all relevant flight regimes, modern AAMs are more kinematically capable than their target.

It's naturally already hard for any fighter jet to obtain weapon grade tracking on J-36. But it's even harder to do it in look up mode.
I'd note that the signature characteristics of J-36 remain very close to the PLA's chest, and that while I obviously understand where you're coming from, I would be hesitant to make the former claim quite so definitively. I mean nothing other than what I say by saying this, but advances in sensing have quite substantially outpaced advances in signature management over the past couple decades.

On the second point, look-up is actually the easier of the two when compared to look-down engagements, so the high elevation doesn't constitute a significant factor in ease of acquisition.

it is even harder for something like AAM to lock on to J-36 looking up and facing strong EW pressure and flying at > mach 2.5.
Regarding the speed, there are imo a couple of noteworthy considerations to address first.

For starters, while I have zero doubt that 36 has ample giddyup in its step, >M2.5 is a veeeery high bar. There may be envelopes wherein it achieves those speeds, but I strongly suspect that figure will be substantially beyond anything the aircraft sees during 99.999% of operational sorties (both peacetime and potential wartime).

For starters, maneuverability in high-supersonic regimes is best described as "lumbering," and one trait no pilot has ever desired during the inbound leg of his CAP orbit is a pull-off turn radius measured in eventually's. Thus, even at its face, the most desirable envelope during operational tasks is likely found in the high transonic to low supersonic (1.2-1.5, just after the worst of drag-divergence subsides) regime depending on a myriad of factors.

Secondly, an object's thermal signature at M2.5 - even at 20km altitude - is going to be quite substantial, which bodes poorly for a platform with a major/primary design focus on signature management. Coupled with this, the impact on airframe readiness and longevity from extended periods at this speed is easy to identify; thus, even should they be achievable at any given time, it's highly unlikely that the capability sees frequent or prolonged use - especially during an air to air engagement. A more likely use case, assuming there is one, would be in a scenario involving either a need to very expediently go from being "here" to "not here" (i.e. evading a launch from another platform) - a scenario I find largely dissonant with the role and environment I expect to see 36 find itself in; or in a uniquely rare instance where a specific sequence of events places the aircraft in position to accomplish some mission/task/goal if and only if it employs its absolute design top speed, despite the margins for such things seldom falling within such thresholds. At the end of the day, a few hundred m/s on top of ones' current airspeed is rarely meaningful when examined at larger scopes - stuff like chasing down an enemy aircraft or stretching an out of position aircraft's legs for a stray shot is pretty much always either a bad idea regardless of whether you eventually get there, or was already possible given the capabilities of the pursuing aircraft. There's a reason most jets have converged on pretty similar kinematic performance.

As far as EW pressure goes, this is imo a poor representation of how EA impacts signature dynamics. Funny enough, by virtue of the unique envelopes wherein 36 seems likely to operate, there will be relatively fewer opportunities for offboard electronic effects compared to aircraft flying more conventional profiles; and while there certainly are a lot of neat things jammers can do nowadays, modern phasers are really really reluctant to bite on onboard angle deception jamming, and most range deception techniques are quite a bit less effective than they were some 20+ years ago due to a variety of factors which lend themselves poorly to discussion in this setting. Of additional note, certain supplementary countermeasures - most obviously, towed decoys - would be put in rather a bind should the aircraft employ them while hanging out at M2.5+ (it will rapidly evolve into an un-towed decoy, and eventually into a land-based one).

Overall, I would just encourage commenters to take note of the fact that altitude is not at all the hard part in these engagements. Launch platforms are in quite thin air to begin with (taking the hardest part out of the equation), and while a higher altitude target is challenging in its own ways, the even more rarified atmosphere at those altitudes will - if anything - probably amount to similar or superior cross-range performance in plenty of profiles. The way to shave range off a missile is to get down into the thick and soupy air, not to hang out as a functionally straight-line speedster in the land of minimal drag.
 

leibowitz

Junior Member
For what it's worth, in air that thin, absolutely nothing turns like a fighter lol. Modern AAMs can indeed get up there and prosecute though. As a general rule of thumb, in practically all relevant flight regimes, modern AAMs are more kinematically capable than their target.


I'd note that the signature characteristics of J-36 remain very close to the PLA's chest, and that while I obviously understand where you're coming from, I would be hesitant to make the former claim quite so definitively. I mean nothing other than what I say by saying this, but advances in sensing have quite substantially outpaced advances in signature management over the past couple decades.

On the second point, look-up is actually the easier of the two when compared to look-down engagements, so the high elevation doesn't constitute a significant factor in ease of acquisition.


Regarding the speed, there are imo a couple of noteworthy considerations to address first.

For starters, while I have zero doubt that 36 has ample giddyup in its step, >M2.5 is a veeeery high bar. There may be envelopes wherein it achieves those speeds, but I strongly suspect that figure will be substantially beyond anything the aircraft sees during 99.999% of operational sorties (both peacetime and potential wartime).

For starters, maneuverability in high-supersonic regimes is best described as "lumbering," and one trait no pilot has ever desired during the inbound leg of his CAP orbit is a pull-off turn radius measured in eventually's. Thus, even at its face, the most desirable envelope during operational tasks is likely found in the high transonic to low supersonic (1.2-1.5, just after the worst of drag-divergence subsides) regime depending on a myriad of factors.

Secondly, an object's thermal signature at M2.5 - even at 20km altitude - is going to be quite substantial, which bodes poorly for a platform with a major/primary design focus on signature management. Coupled with this, the impact on airframe readiness and longevity from extended periods at this speed is easy to identify; thus, even should they be achievable at any given time, it's highly unlikely that the capability sees frequent or prolonged use - especially during an air to air engagement. A more likely use case, assuming there is one, would be in a scenario involving either a need to very expediently go from being "here" to "not here" (i.e. evading a launch from another platform) - a scenario I find largely dissonant with the role and environment I expect to see 36 find itself in; or in a uniquely rare instance where a specific sequence of events places the aircraft in position to accomplish some mission/task/goal if and only if it employs its absolute design top speed, despite the margins for such things seldom falling within such thresholds. At the end of the day, a few hundred m/s on top of ones' current airspeed is rarely meaningful when examined at larger scopes - stuff like chasing down an enemy aircraft or stretching an out of position aircraft's legs for a stray shot is pretty much always either a bad idea regardless of whether you eventually get there, or was already possible given the capabilities of the pursuing aircraft. There's a reason most jets have converged on pretty similar kinematic performance.

As far as EW pressure goes, this is imo a poor representation of how EA impacts signature dynamics. Funny enough, by virtue of the unique envelopes wherein 36 seems likely to operate, there will be relatively fewer opportunities for offboard electronic effects compared to aircraft flying more conventional profiles; and while there certainly are a lot of neat things jammers can do nowadays, modern phasers are really really reluctant to bite on onboard angle deception jamming, and most range deception techniques are quite a bit less effective than they were some 20+ years ago due to a variety of factors which lend themselves poorly to discussion in this setting. Of additional note, certain supplementary countermeasures - most obviously, towed decoys - would be put in rather a bind should the aircraft employ them while hanging out at M2.5+ (it will rapidly evolve into an un-towed decoy, and eventually into a land-based one).

Overall, I would just encourage commenters to take note of the fact that altitude is not at all the hard part in these engagements. Launch platforms are in quite thin air to begin with (taking the hardest part out of the equation), and while a higher altitude target is challenging in its own ways, the even more rarified atmosphere at those altitudes will - if anything - probably amount to similar or superior cross-range performance in plenty of profiles. The way to shave range off a missile is to get down into the thick and soupy air, not to hang out as a functionally straight-line speedster in the land of minimal drag.
Welcome back. Side question, is DEW more effective, watt for watt, at higher altitudes, and if so, how much more effective?
 

Patchwork_Chimera

New Member
Registered Member
Welcome back. Side question, is DEW more effective, watt for watt, at higher altitudes, and if so, how much more effective?
Thanks, glad to once again be in a .mil role that isn't a package deal with infinite demotivation and getting yelled at for posting unclass retorts on the internet.

Firstly, I suppose it depends on the variety of DEW being discussed; and secondly, I suppose it depends on whether your "higher altitudes" is shorthand for "higher altitudes within standard fixed wing air breathing vehicle flight regimes" or literally "higher altitudes."

I assume we're going to consider all external variables as being equal, since there are an absolute crapload, and you can get very different results out of fairly minor circumstantial changes. For ye fabled laser, generally yeah higher altitude is preferable. Less attenuation due to scattering and other atmospheric effects, dulled gradients in atmospheric conditions, the thinner air makes it a little harder for a target to dump heat via convection, though this goes both ways and can have impacts on duty cycle. For stuff in the microwave world, some of this technically holds true, but there's just a lot less attenuation with those long ass wavelengths compared to laser realm. Plus, HPM works with pretty strictly EM-derived effects as opposed to the sheerly thermal "fuck you, melt" stuff HELs bring to the table, and as such, even the minor but technically still there stuff like a little more convective cooling capacity becomes a straight up no-factor when your 12V RC quadcopter motor suddenly eats 90 trillion billion volts and goes to heaven.

The reason I ask if you mean literally "higher altitudes" is because teeeechnicallyyy there's the ionosphere if you go high enough, and yeah I bet living and operating there would make HPM systems a lot less effective, or at least a lot less predictable. But that's mostly just a fun edge case, and I kinda don't know for sure - never really thought about it tbh lol.
 

GTI

Junior Member
Registered Member
For what it's worth, in air that thin, absolutely nothing turns like a fighter lol. Modern AAMs can indeed get up there and prosecute though. As a general rule of thumb, in practically all relevant flight regimes, modern AAMs are more kinematically capable than their target.


I'd note that the signature characteristics of J-36 remain very close to the PLA's chest, and that while I obviously understand where you're coming from, I would be hesitant to make the former claim quite so definitively. I mean nothing other than what I say by saying this, but advances in sensing have quite substantially outpaced advances in signature management over the past couple decades.

On the second point, look-up is actually the easier of the two when compared to look-down engagements, so the high elevation doesn't constitute a significant factor in ease of acquisition.


Regarding the speed, there are imo a couple of noteworthy considerations to address first.

For starters, while I have zero doubt that 36 has ample giddyup in its step, >M2.5 is a veeeery high bar. There may be envelopes wherein it achieves those speeds, but I strongly suspect that figure will be substantially beyond anything the aircraft sees during 99.999% of operational sorties (both peacetime and potential wartime).

For starters, maneuverability in high-supersonic regimes is best described as "lumbering," and one trait no pilot has ever desired during the inbound leg of his CAP orbit is a pull-off turn radius measured in eventually's. Thus, even at its face, the most desirable envelope during operational tasks is likely found in the high transonic to low supersonic (1.2-1.5, just after the worst of drag-divergence subsides) regime depending on a myriad of factors.

Secondly, an object's thermal signature at M2.5 - even at 20km altitude - is going to be quite substantial, which bodes poorly for a platform with a major/primary design focus on signature management. Coupled with this, the impact on airframe readiness and longevity from extended periods at this speed is easy to identify; thus, even should they be achievable at any given time, it's highly unlikely that the capability sees frequent or prolonged use - especially during an air to air engagement. A more likely use case, assuming there is one, would be in a scenario involving either a need to very expediently go from being "here" to "not here" (i.e. evading a launch from another platform) - a scenario I find largely dissonant with the role and environment I expect to see 36 find itself in; or in a uniquely rare instance where a specific sequence of events places the aircraft in position to accomplish some mission/task/goal if and only if it employs its absolute design top speed, despite the margins for such things seldom falling within such thresholds. At the end of the day, a few hundred m/s on top of ones' current airspeed is rarely meaningful when examined at larger scopes - stuff like chasing down an enemy aircraft or stretching an out of position aircraft's legs for a stray shot is pretty much always either a bad idea regardless of whether you eventually get there, or was already possible given the capabilities of the pursuing aircraft. There's a reason most jets have converged on pretty similar kinematic performance.

As far as EW pressure goes, this is imo a poor representation of how EA impacts signature dynamics. Funny enough, by virtue of the unique envelopes wherein 36 seems likely to operate, there will be relatively fewer opportunities for offboard electronic effects compared to aircraft flying more conventional profiles; and while there certainly are a lot of neat things jammers can do nowadays, modern phasers are really really reluctant to bite on onboard angle deception jamming, and most range deception techniques are quite a bit less effective than they were some 20+ years ago due to a variety of factors which lend themselves poorly to discussion in this setting. Of additional note, certain supplementary countermeasures - most obviously, towed decoys - would be put in rather a bind should the aircraft employ them while hanging out at M2.5+ (it will rapidly evolve into an un-towed decoy, and eventually into a land-based one).

Overall, I would just encourage commenters to take note of the fact that altitude is not at all the hard part in these engagements. Launch platforms are in quite thin air to begin with (taking the hardest part out of the equation), and while a higher altitude target is challenging in its own ways, the even more rarified atmosphere at those altitudes will - if anything - probably amount to similar or superior cross-range performance in plenty of profiles. The way to shave range off a missile is to get down into the thick and soupy air, not to hang out as a functionally straight-line speedster in the land of minimal drag.
Nice to see you…

A lot’s happened, there’s probably a lot of conjecture you could sanity check or elucidate in broad directional strokes - across a few threads too… just saying, like if you happen to have a smidgen of time.
 

Patchwork_Chimera

New Member
Registered Member
Welcome back, Patch.

How is the US military & related think tankies reacting to J-36 and J-XX behind closed doors?
On the .mil side, there's not a lot that hasn't already been going on for a while. I'm not personally super tapped in on emerging threat systems stuff; but to the folks who focus on that domain, this wasn't much of a surprise.

Can't say know much about the think tankies' internal reactions though. Late last year I was subjected to a long APAC trip wherein I had to interact with many such creatures, as well as a few p*liticians and senior leadership figures. While I was promised that it would be the last time I had to do anything of the sort (I am now back to blissfully working in my lab), the experience was still deeply distressing to me, and I have no intentions of absorbing further psychic damage from the oxygen thief demographic. As a countermeasure against further interaction, I have begun directly insulting the entities and mocking their intelligence whenever one enters my attack range. It has been very successful.
 

tygyg1111

Captain
Registered Member
On the .mil side, there's not a lot that hasn't already been going on for a while. I'm not personally super tapped in on emerging threat systems stuff; but to the folks who focus on that domain, this wasn't much of a surprise.

Can't say know much about the think tankies' internal reactions though. Late last year I was subjected to a long APAC trip wherein I had to interact with many such creatures, as well as a few p*liticians and senior leadership figures. While I was promised that it would be the last time I had to do anything of the sort (I am now back to blissfully working in my lab), the experience was still deeply distressing to me, and I have no intentions of absorbing further psychic damage from the oxygen thief demographic. As a countermeasure against further interaction, I have begun directly insulting the entities and mocking their intelligence whenever one enters my attack range. It has been very successful.

For what its worth, I've heard this artifact grants +5 psy protection

1738467221111.png
 

another505

New Member
Registered Member
On the .mil side, there's not a lot that hasn't already been going on for a while. I'm not personally super tapped in on emerging threat systems stuff; but to the folks who focus on that domain, this wasn't much of a surprise.

Can't say know much about the think tankies' internal reactions though. Late last year I was subjected to a long APAC trip wherein I had to interact with many such creatures, as well as a few p*liticians and senior leadership figures. While I was promised that it would be the last time I had to do anything of the sort (I am now back to blissfully working in my lab), the experience was still deeply distressing to me, and I have no intentions of absorbing further psychic damage from the oxygen thief demographic. As a countermeasure against further interaction, I have begun directly insulting the entities and mocking their intelligence whenever one enters my attack range. It has been very successful.
What roles do you see in J-36?
 
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