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

[ZZY1977]

KJ-600 (at least I feel like it is important enough) =P
This feel like the happiest day of my life

this picture not take recently，but first public today

 

[plawolf]

The way I am reading into the images, the difference is not just with the canopy. Whole line of the back of the plane is now a tad less sloped. The top of the canopy itself is almost straight now. While the FC31 had a slight drop in the line starting pretty much right after the brace of canopy point. That line goes on further from the canopy glass as well.
Basically, the new plane has more of a hump behind the cockpit in volume, compared to the old one. Though the difference isn't great.

Still, that difference might amount to hundreds of liters of volume.

I'd wager there's a chance the change was there due to fuel requirements as well. It's plausible PLANAF wanted X amount of range under given conditions and that the design simply needed even more fuel (on top of whatever might have been achieved through allegedly larger wings and more advanced/pricier construction methods). One of the best places to put fuel inside a plane is that central point behind the cockpit. All fighters have their big internal fuel tanks there and when additional fuel is needed in novel variants, its often the first place where redesign is done - easiest to place additional fuel without having large impact on other characteristics.

Now, are wings and tails indeed larger - is still impossible to say. What other carrier planes teach us - that change is more than likely. But this image is simply not good enough yet to make proper measurements. I tried, but there's just too many uncertainties due to perspective and lacking FC31 images that are an EXACT match perspective wise.

What does seem to be likely is that the horizontal tails are slightly bigger in span than the wings at their folding point. Which is not strange.

The only difference is have is that I don’t think the changes to the back of the canopy is slight.

It almost look like someone took a twin seater dual canopy profile and deleted the second seat.

In light of the new J20S twin seater, I do wonder if the PLANAF also asked for a twin seater J35 and SAC just kinda decided to bake that into the design from the get go in terms of baseline airframe design.

 

[minusone]

I assume you mean WS-13E...

oh sh1t...my bad hahaha

 

[Blitzo]

The only difference is have is that I don’t think the changes to the back of the canopy is slight.

It almost look like someone took a twin seater dual canopy profile and deleted the second seat.

In light of the new J20S twin seater, I do wonder if the PLANAF also asked for a twin seater J35 and SAC just kinda decided to bake that into the design from the get go in terms of baseline airframe design.

I think benefits in having a larger hump in terms of volume (especially in terms of additional fuel), and any aerodynamic advantages as alluded to by the screenshots of studies, are a more than reasonable explanation for the modification of the canopy/fuselage part we are talking about.

 

[minusone]

The only difference is have is that I don’t think the changes to the back of the canopy is slight.

It almost look like someone took a twin seater dual canopy profile and deleted the second seat.

In light of the new J20S twin seater, I do wonder if the PLANAF also asked for a twin seater J35 and SAC just kinda decided to bake that into the design from the get go in terms of baseline airframe design.

i think they have j15D or j15T for dual seat variant?

 

[Gloire_bb]

Well, maybe a bit too early to say, but this is the case when a bit of weight actually did her good.
Aesthetically looks far more pleasing than the predecessor.

First impression:
-quite a lot of added fuel and/or equipment space in general, everywhere. Feels almost like YF-22 -> F-22 change;
-hump;
-seemingly new, wider canopy with more downwards visibility;
-nose radome is larger;
-Big gray below cockpit. Side arrays, or simply area around extendable ladder?
-Control surfaces are substantially larger. (low-speed control authority?;.
-New landing gear;
-visible wing fold.

 

[plawolf]

I think benefits in having a larger hump in terms of volume (especially in terms of additional fuel), and any aerodynamic advantages as alluded to by the screenshots of studies, are a more than reasonable explanation for the modification of the canopy/fuselage part we are talking about.

Well, let’s wait for clearer pictures to emerge, but if the changes are as significant as I think they are, then that would suggest to me that SAC went beyond what might be needed for such factors and also future proofed it for a future twin seater design. If they did that, we may see the twin seater a lot earlier in its development than we did for the J20S or many even J10S in their respective development cycles.

That would make a lot of sense given the expected rapid expansion of the PLAN carrier fleet and the low base PLANAF carrier aviation started from that they would have a very significant and front loaded training burden. Having a sizeable twin seater 5th gen carrier fighter fleet could potentially also allow the PLANAF to overcome the numerical disadvantage it faces against the USN in terms of VLO airframes by incorporating VLO lots wingman UCAVs in large numbers a lot earlier.

 

[Blitzo]

Well, let’s wait for clearer pictures to emerge, but if the changes are as significant as I think they are, then that would suggest to me that SAC went beyond what might be needed for such factors and also future proofed it for a future twin seater design. If they did that, we may see the twin seater a lot earlier in its development than we did for the J20S or many even J10S in their respective development cycles.

That would make a lot of sense given the expected rapid expansion of the PLAN carrier fleet and the low base PLANAF carrier aviation started from that they would have a very significant and front loaded training burden. Having a sizeable twin seater 5th gen carrier fighter fleet could potentially also allow the PLANAF to overcome the numerical disadvantage it faces against the USN in terms of VLO airframes by incorporating VLO lots wingman UCAVs in large numbers a lot earlier.

This would only make sense if we expect a twin seater J-XY to emerge in the first place, and I'm not sure I see the rationale for one.

The idea of using a twin seat 5th generation aircraft for flight training would be a waste of vital airframe hours for a 5th generation aircraft, and is better done through a combination of LIFT and simulator time.

A twin seat J-XY could certainly fulfill the same kind of battle management/control role that we expect J-20S to do, but let's remember that J-20 is a much larger airframe than J-XY to begin with and the enlargement of the cockpit and addition of a second human being would make up much less of its overall weight and structural difference.



That said, I agree with you -- I believe that the changes to the airframe certainly are significant.

.... but I think the changes to the airframe are also entirely consistent with what we'd expect out of a "bulked up" airframe derived from FC-31 that intends to increase its internal fuel capacity and to make various aerodynamic refinements.
Whether such benefits might be beneficial if they ever want to pursue a twin seater variant some time down the line, sure maybe.
However let's not miss the benefits and advantages of those structural changes staring us in the face as well.

 

[Totoro]

The only difference is have is that I don’t think the changes to the back of the canopy is slight.

It almost look like someone took a twin seater dual canopy profile and deleted the second seat.

In light of the new J20S twin seater, I do wonder if the PLANAF also asked for a twin seater J35 and SAC just kinda decided to bake that into the design from the get go in terms of baseline airframe design.

I agree the the change can also be referred to as not slight. It's just word choice and what different people perceive as the meaning of the term "slight". I like to be careful with wording so that's why I used it.

Given that there are likely hundreds of liters of added volume in the new shape, and given that there is less volume spent on clear view rear cockpit and more of same volume spent on possible added fuel - i'd say overall there's a fair likelihood there's nearly 500 pounds of added fuel between FC31 V2 and this plane.

 

[plawolf]

This would only make sense if we expect a twin seater J-XY to emerge in the first place, and I'm not sure I see the rationale for one.

The idea of using a twin seat 5th generation aircraft for flight training would be a waste of vital airframe hours for a 5th generation aircraft, and is better done through a combination of LIFT and simulator time.

Does the same logic not apply to 4th gen and 3rd gen etc? Yet twin seater trainers versions of principle frontline combat jets are a very important part of every serious modern Air Force.

LIFT, AJT and simulators are all essentially training tools, but they are still only ever approximations of the real thing.

Just because using 5th gens for such are more expensive doesn’t detract from the training value of having them if you can afford them. Indeed, the jump in capabilities from 4th gen to 5th gens would make the case for 5th gen twin seaters even more compelling.

One final point to consider is training time efficiency. 1 hour of LIFT/AJT/Simulator time < 1 flight hour in a frontline combat jet. If you are playing catch-up and want to close the gap against the leader in the least amount of time possible, then it makes sense to spend more money to save yourself time.

A twin seat J-XY could certainly fulfill the same kind of battle management/control role that we expect J-20S to do, but let's remember that J-20 is a much larger airframe than J-XY to begin with and the enlargement of the cockpit and addition of a second human being would make up much less of its overall weight and structural difference.

That might be the case if we are talking about making the J35 twin seater only, but that’s clearly not the case here. While putting in place the structural provisions to take a second seat will obviously add weight and carry an aerodynamic penalty, it’s not going to be anywhere close to as large as actually having the second seat in place if that volume is used instead for additional fuel, which can and almost certainly will be used first so by the time the plane might realistically need to enter a dogfight, the extra weight is going to be rather minimal.

The benefit is going to be cheaper production costs for the twin seaters and little to no production time delay in switching between the models. Hell, if they are really clever, then might even make the two easily convertible in the field to allow you to quickly adjust your mix of single and twin seaters as the needs demands. Now that would be a very interesting capability to have.