J-31 aims at F-35 market

hornetfinn · by **hornetfinn** » 30 Oct 2017, 10:14

charlielima223 wrote:
XanderCrews wrote:

I'll admit to thinking only the B had a lift fan bulge as well

Because the F-35 was/is advertised as a common airframe (or as common as they could design and engineer it...)

(still more commonality between the 3 variants than an F-16, F/A-18 or Harrier...)

people will always assume that all 3 variants have all the same physical features and dimensions. My favorite one (that is still being thrown around) is when they blames the STOVL version for all giving the other variants a wide fuselage body

I never understood why people are so fixated on airframe commonality when the real issue is commonality in avionics, engine and software. Of course there are some differences in engines, especially the B version, but they still have very much in common. Avionics and software are basically all the very same and that's where majority of the work has been done. Having differing airframe is not a problem in this day and age of robotics and automated production lines.

SpudmanWP · by **SpudmanWP** » 30 Oct 2017, 15:49

hornetfinn wrote:I never understood why people are so fixated on airframe commonality when the real issue is commonality in avionics, engine and software.

^^This

sferrin · by **sferrin** » 30 Oct 2017, 18:05

twistedneck wrote:
sferrin wrote:The "bulges" are for fuel as I recall.

I thought the gun was housed in the bulge in the A model.. the the B/C get gun pods? Or is he talking about the B lift fan bulge?

It's the "bulge" (more like a hump) for additional fuel. BF-1 does not have this. Was added after.

SpudmanWP · by **SpudmanWP** » 30 Oct 2017, 18:24

The "bulge" on the F-35B is to accommodate the opening of the lift fan.

rheonomic · by **rheonomic** » 31 Oct 2017, 04:12

hornetfinn wrote:I never understood why people are so fixated on airframe commonality when the real issue is commonality in avionics, engine and software.

Because people are stupid and ignorant.

Corsair1963 · by **Corsair1963** » 31 Oct 2017, 06:18

disconnectedradical wrote:
Corsair1963 wrote:
disconnectedradical wrote:The last I heard, Chengdu actually rained on the J-31's parade since their navalized J-20 proposal was judged to be better.

Honestly, I have my doubts about the J-20 being better than the J-31. Sounds like internal politics to me or even disinformation aimed at the West.....

The J-31 will be critical to the future of PLAAF. Just as the F-35 is to the USAF!

???

What are you basing this on? Based on reports from reputable PLAAF sources like Andreas Rupprecht (the guy who wrote THE western book on modern PLAAF), the J-31 has so far not impressed the PLAAF. The J-31 is pretty much entirely funded by Shenyang rather than the PLAAF, which is investing in the J-20.

First, I have a bridge to sell you. If, you think Shenyang is solely funding the J-31 without assistance from Beijing. :doh:

Second, the J-20 is a large Air Superiority Type Fighter similar to the F-22 and PAK-FA in general. It will not be produced in "vast" numbers. While, the J-31 is a Medium Sized Strike Fighter. In the same class as the US F-35. In short the J-31 would be the "workhorse" of both the PLAAF and PLAN!

In my opinion the J-31 is just as critical to China. As the F-35 is to the US and her Allies. :wink:

popcorn · by **popcorn** » 31 Oct 2017, 06:51

Back to the topic, what country in their right mind that can afford a F-35 and pass US vetting would even consider buying a J-31?

Corsair1963 · by **Corsair1963** » 31 Oct 2017, 07:08

popcorn wrote:Back to the topic, what country in their right mind that can afford a F-35 and pass US vetting would even consider buying a J-31?

Is that an "oxymoron" :shock:

Yet, to answer the obvious "NONE".

arian · by **arian** » 17 Dec 2017, 03:35

hornetfinn wrote: Having differing airframe is not a problem in this day and age of robotics and automated production lines.

There's very little "robotics and automated production lines" in aircraft manufacturing. The components are all assembled by hand, with the aid of various technologies in the F-35 to fit them to better tolerances etc.,. But it's still all put there by hand. The parts themselves are still produced the same way as they were in previous fighters: CNC machines or composite laying machines. Of course these are more sophisticated than what they were 30 or 40 years ago; more axis of movement for CNC machines and much more advanced composite construction.

The commonality saves in the design phase so that you don't have to design different structures for the planes. In as much as that is an issue. And to a certain degree in the jigs needed for assembly and for not duplicating assembly/manufacturing lines. All of these: design, manufacturing and assembly, do matter to some degree when you have commonality.

Even if it were more automated as is the case for the 787 where entire fuselage skin sections can be manufactured in one piece by giant robots, having commonality helps in not needed additional jigs and additional programs for doing all that work. But F-35 is nowhere near as automated as 787 because it is a lot more complex in shape than a simple tube.

madrat · by **madrat** » 17 Dec 2017, 03:56

I'm not sure J-31 won't be costlier lifetime costs versus Su-50. Could even be comparable operational costs for less capabilities.

popcorn · by **popcorn** » 18 Jan 2018, 09:21

separated at birth... :mrgreen:

kimjongnumbaun · by **kimjongnumbaun** » 18 Jan 2018, 10:11

popcorn wrote:separated at birth...

Upon closer inspection of each air frame, they aren't exactly alike in lot of subtle ways. But despite being subtle, they actually would affect the performance significantly. Take a look at the intakes. The J-21 is a lot more open and would reflect a lot more radar waves. The chines are significantly different as well, where the F-35's are longer and would produce more thrust.

I wonder if the plans that were "stolen" were actually a planted honey pot to screw up the Chinese stealth fighter program.

weasel1962 · by **weasel1962** » 18 Jan 2018, 10:31

The J-31 is probably what anyone would get when they try to adopt the same external shaping and couple that with the "Russian" (opps, Chinese) jet engines that are fitted to it. This means vents all have to be designed to ensure optimal airflow and aerodynamics. The avionics are entirely different and hence so would its capabilities.

Chinese saying: 1 cent money, 1 cent goods.

tphuang · by **tphuang** » 26 Aug 2018, 03:09

Corsair1963 wrote:
First, I have a bridge to sell you. If, you think Shenyang is solely funding the J-31 without assistance from Beijing. Second, the J-20 is a large Air Superiority Type Fighter similar to the F-22 and PAK-FA in general. It will not be produced in "vast" numbers. While, the J-31 is a Medium Sized Strike Fighter. In the same class as the US F-35. In short the J-31 would be the "workhorse" of both the PLAAF and PLAN!

In my opinion the J-31 is just as critical to China. As the F-35 is to the US and her Allies.

I think there might be a little misunderstanding on this topic. I was actually one of the people that mentioned J-31 (or project 310 as I used to call it) was not an official PLAAF project. I'm not convinced it has officially received a J series numbers. Anyhow, it's definitely still receiving PLAAF funding. As of now, it hasn't been able to impress PLAAF enough to be officially established as a PLAAF program. But it's very important for PLA to keep the 2 factory workflow going between CAC and SAC. If CAC receives all the projects, it will be very bad for competition in China. I am under the impression PLAN has picked a design based on J-20 for the next generation naval fighter jet. At the time, it was a little surprising for me.

So my guess is that they will keep the program going and you will see more prototypes with incremental updates. They are not in a huge rush to get this into service like J-20. During the testing phase, it will probably use WS-13E at some point instead of RD-93. But the goal is to use WS-19, which is in development, for the production copy. Although I could see it entering service a little underpowered with WS-13E. Bottom line, there is not a lot of option out there for PLAAF, so I do see this as the LO fighter at some point, but PLAAF isn't going to just hand the money to SAC. They have to meet the requirements. You can see that they only produced one demonstrator + one flying prototype so far vs 2 demonstrators and many flying prototypes with J-20. SAC isn't getting the same level of funding CAC got for J-20.

I would imagine this is aimed at countries in middle east and ASEAN that would've otherwise went for Su-57. Outside of PAF, can't imagine any of China's traditional clients being able to afford this.

steve2267 · by **steve2267** » 26 Aug 2018, 03:15

tphuang wrote:
I think there might be a little misunderstanding on this topic. I was actually one of the people that mentioned J-31 (or project 310 as I used to call it) was not an official PLAAF project. I'm not convinced it has officially received a J series numbers. Anyhow, it's definitely still receiving PLAAF funding. As of now, it hasn't been able to impress PLAAF enough to be officially established as a PLAAF program. But it's very important for PLA to keep the 2 factory workflow going between CAC and SAC. If CAC receives all the projects, it will be very bad for competition in China. I am under the impression PLAN has picked a design based on J-20 for the next generation naval fighter jet. At the time, it was a little surprising for me.

So my guess is that they will keep the program going and you will see more prototypes with incremental updates. They are not in a huge rush to get this into service like J-20. During the testing phase, it will probably use WS-13E at some point instead of RD-93. But the goal is to use WS-19, which is in development, for the production copy. Although I could see it entering service a little underpowered with WS-13E. Bottom line, there is not a lot of option out there for PLAAF, so I do see this as the LO fighter at some point, but PLAAF isn't going to just hand the money to SAC. They have to meet the requirements. You can see that they only produced one demonstrator + one flying prototype so far vs 2 demonstrators and many flying prototypes with J-20. SAC isn't getting the same level of funding CAC got for J-20.

I would imagine this is aimed at countries in middle east and ASEAN that would've otherwise went for Su-57. Outside of PAF, can't imagine any of China's traditional clients being able to afford this.

Meeting requirements is always a good idea when designing an aircraft.

BUT... if J-31 doesn't really have a "J-number" and is NOT an official PLAAF project, then what are these requirements it must meet?