J-35A fighter (PLAAF) + FC-31 thread

lgnxz

Junior Member
Registered Member
Illustrations from academic papers which likely indicates the longitudinal cross-sectional diagram of the internal weapons bay (IWB) of the J-35A (for the PLAAF) and the J-35 (for the PLAN).

Posted by @Captain小潇 on Weibo.

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Assuming the lengths of IWBs on both the J-20/As and J-35/As are similar, if not exactly the same:

Through comparison, the IWBs of the J-35/A seems to considerably differ from the IWB of the J-20, such that the J-35/A's IWB actually has a deeper depth towards the front than the J-20's IWB, mainly due to the differences in the placement of the IWBs and the designs of the engine inlets on both the J-20 and J-35/A.

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This has likely resulted in the J-35/As being actually capable of carrying larger-dimension payloads inside her IWB than the J-20.

The upper four diagrams should refer to the J-35/As, whereas the lower four diagrams should refer to the J-20.

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Honestly, didn't realise the the IWB of the J-20 actually doesn't have a uniform depth across the entire length until today.

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Such features could also explain why the J-20/As and J-35As are given different mission sets by the PLAAF.
Interesting find, but still isn't completely certain, given that we have many other papers on J-20 and J-35A (such as a supposed gun installed on the left-side of J-35A) that didn't materialize into the actual aircraft.

Also regarding the IRST comparison, what does LTD mean on the supposedly J-35A's, does anyone know about this abbreviation?
 

Alfa_Particle

Junior Member
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Interesting find, but still isn't completely certain, given that we have many other papers on J-20 and J-35A (such as a supposed gun installed on the left-side of J-35A) that didn't materialize into the actual aircraft.

Also regarding the IRST comparison, what does LTD mean on the supposedly J-35A's, does anyone know about this abbreviation?
The gun looks to be present on the J-35. The A might have it, we'll see. Could just be that some prototypes don't.

LTD: Laser Target Designator.
 

lgnxz

Junior Member
Registered Member
The gun looks to be present on the J-35. The A might have it, we'll see. Could just be that some prototypes don't.

LTD: Laser Target Designator.
Let's see indeed. It would be very counterintuitive to me for them to still have a gun on the naval variant but not the airforce one, given the latter should have better (yet albeit small) utilization on the gun.

Talking about small utilization, if the gun is going to be installed it would be quite a reversal from almost a decade long doctrine and understanding established by the gun-less J-20. I'm still in the opinion that guns are pretty useless for 5th gen aircrafts and onwards, but this topic probably has been discussed during the first revelation of the research paper about gun for J-35. Surely those working at AVIC are more knowledgeable and have their reasons and the reasonings will trickle down to us from the usual sources anyway (of course only if the rumor about the gun is going to materialize instead of mere rumor).
 

LuzinskiJ

Junior Member
Registered Member
Let's see indeed. It would be very counterintuitive to me for them to still have a gun on the naval variant but not the airforce one, given the latter should have better (yet albeit small) utilization on the gun.

Talking about small utilization, if the gun is going to be installed it would be quite a reversal from almost a decade long doctrine and understanding established by the gun-less J-20. I'm still in the opinion that guns are pretty useless for 5th gen aircrafts and onwards, but this topic probably has been discussed during the first revelation of the research paper about gun for J-35. Surely those working at AVIC are more knowledgeable and have their reasons and the reasonings will trickle down to us from the usual sources anyway (of course only if the rumor about the gun is going to materialize instead of mere rumor).
Mostly I agree with futility of guns in a FifthGen-on-Any-other-Fighter scenario, but what about in cases of chasing down cruise missiles and drones? A F15 crew just got medals for doing just that, even if they may have missed.
 

Gloire_bb

Captain
Registered Member
In the case of J-35A, the point can be the same with F-35A - it doesn't have WVR bays, and BVR between LO jets isn't an exactly an unlikely scenario. It is not a good option for WVR, but it's an option these aircraft are stuck with.
Many point out to Ukrainian conflict being almost WVR-less, but it became so only when frontlines became static and VKS stopped flying over Ukrainian territory to manage loss rate.

The only place where China can (unlikely, but perhaps) encounter such a scenario is Korea. Which is just not a primary concern.
 

Index

Senior Member
Registered Member
Mostly I agree with futility of guns in a FifthGen-on-Any-other-Fighter scenario, but what about in cases of chasing down cruise missiles and drones? A F15 crew just got medals for doing just that, even if they may have missed.
The "missed" clues you into how useful that is.

I think that's a nail in the coffin of the whole gun idea since the argument was that it would let fighters shoot down "many" drones/cruise missiles. And it was now shown to be pretty bad at even that.

The issue is apparently that a jet is too fast to do it reliably. Guns do work well against drones, but only when you're slow enough like with a prop plane or another drone.
 

LuzinskiJ

Junior Member
Registered Member
The "missed" clues you into how useful that is.

I think that's a nail in the coffin of the whole gun idea since the argument was that it would let fighters shoot down "many" drones/cruise missiles. And it was now shown to be pretty bad at even that.

The issue is apparently that a jet is too fast to do it reliably. Guns do work well against drones, but only when you're slow enough like with a prop plane or another drone.
Maybe the current gun aiming systems on board fighters are bad at shooting down slow speed flyer. However, perhaps software can be programmed to recognize them as such and create specific shooting funnel/profile just for them.
 

taxiya

Brigadier
Registered Member
It is interesting that J35a sports a HUD while F35 eschew it altogether. My guess is that F35 uses the HMD for almost everything visual including HUD functions, whereas we seldom see j20 pilots wearing HMD, so HUD still needed. I wonder what reasons China has to go the traditional route for pilot plane visual interface instead of relying on advanced HMDS
I'd say high G in maneuver makes HMD less useful to useless. HMD is heavier than conventional helmet because it moves lots of electronic circuit from the dashboard to the head. 100 grams is nothing when you expereince no extra G, but would be 600 grams if you are pulling a 6G turn which is quite frequent, it would be near a kilogram if you pull a 9G. This is enough to pin your head on the head-rest with only eyeballs movable. Since the advantage of HMD is the ability to sync the display with your head movement, without head moving HMD becomes meaningless. A HUD on the other hand has all information on the screen to see, you can just move your eye balls. A good example is rollercoaster raid, you should have experienced moments when you can not move your head, that is still low G compared to fighter jet.

HMD will always be heavier than conventional setup, the only thing one can do is to reduce that weight to a tolerable level under a limited G load (less intense combat).
 
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Gloire_bb

Captain
Registered Member
Maybe the current gun aiming systems on board fighters are bad at shooting down slow speed flyer. However, perhaps software can be programmed to recognize them as such and create specific shooting funnel/profile just for them.
Problem is not accuracy, problem is length of attack cycle - and relative trouble to make a repeat approach if attack run failed. On top of that there are of course risks of collision etc, which makes pilots more reluctant=even less efficient.
Slight stand off removes all trouble.

Also, remember that current drones are often literally tinkered Alibaba drones.
Imagine that someone serious will put some rnd into it, and produce, say, stealthily-shaped flying wing with electric jets.
You missed it once - you just won't reacquire it.

Gun is really... knight's stiletto at this point. Mounted knight's stiletto.
 
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