Shenyang FC-31 / J-31 Fighter Demonstrator

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vesicles

Colonel
This weight thing is more and more like a discussion on alien visitation... I say “I saw aliens!” You say “no you didn’t!”

This is what I call an untestable hypothesis. No one can provide any solid evidence. This is also why this sort of discussion is always dragged on and on. No one can convince anyone else because of lack of solid evidence.

In cases like this, my suggestion is to present your argument, while at the same time, respect the other side. Without actual solid evidence, your argument is as good as others. There is absolutely no need to argue. There is nothing to argue (a possibility of something is not evidence). No evidence to support you whatsoever. Everyone presents your case and moves on.

We can actually dedicate a special thread (maybe even a special category, in addition to strategic defense, army, navy, AF, etc) and name it “technical predictions for new Chinese weapons systems”.

Under this special category, we can have a thread like “data prediction for the J-20 weight”. Everyone presents their position and their support. No need to argue and no need to attack others. Simply state your case and move on. We will come back to the same thread when some members feel that they have gotten solid enough evidence to convince most people. When things are settled, we close the thread. No need to go back and forth.

Of course, the actual format can be different. I guess my goal is to maximize our strength as a forum specializing professional opinion on Chinese weapons. Let’s keep things as professional as we can.

Another good thing is that we have a special place to collect all the technical data. If anyone wants to look up things, they can simply to go this category and look up different weapon systems and get all the numbers.

These threads would have no photos, only numbers, charts and tables. Show your numbers and your support, and that’s it. No argument and no attacks. It’s like a special place for data. When we get access to actual data and someone got it right, they got the bragging rights. And we can easily keep track of everyone’s predictions.

If you visit those professional academic or research forums, you will see that everyone simply states their own opinions and presents evidence. If no one can settle the argument, you will see things like “we will wait for more evidence”. And everyone moves on.

It is difficult to keep personal feelings in check when you are passionately arguing about things. I know that I have lost control many times. However, if we can create a professional environment, things will be easier for all of us. Being professional is what separates men from boys.
 
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kwaigonegin

Colonel
Agreed with vesicles. Speculations are fine even w/o hard evidence that's why they are call speculation.. not too dissimilar to the theory vs law notion in the hard sciences.
If someone 'claims' it's in the 15T range then the burden of proof is on him to show actual hard based facts.
If someone is merely 'suggesting' as oppose to 'claiming' it is so, then he also has to show some sort of inclination or some sort of research which aligns with his speculation.
In my mind both are fine as long as they follow proper argumentative etiquette.
 

Tirdent

Junior Member
Registered Member
The largest product they made using this method is 2.2 meters long and 1.8x1.4x0.02 meter, max weight 260kg.

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Report on August 28, 2017 on acceptance delivery to "an international" aircraft manufacture (Airbus) of 3d printed products (1st picture). It was stated that "the quality exceeded Airbus's expectation". It is delivered unpolished as requested. It is of titanium.

You can see other things they made for airbus in the link.

So, at this moment, I would say the notion "3D printing is weaker than traditional method" is already outdated.

Depends on what Airbus' expectations were (those parts look like the kind of moderately stressed stuff that could be made using previous 3D printing processes), and they specifically say a forging pass is part of the solution (shades of Arconic's Ampliforge). So a crucial element of the traditional method is actually still present :)

Furthermore, to be applicable to the J-20, the process would need to have been tested and mature by early 2013 (in time to manufacture the second batch of prototypes) and capable of handling parts considerably larger than 2.2m. On the F-22, the bulkheads are up to 4.9m wide and while the maximum width of the J-20 fuselage is slightly lower than the Raptor's, we're still looking at about 4.5m.

Speaking of F-22 bulkheads...

The only way for traditional method is to cast separate pieces, forge them, mill them, then weld them together, then mill the welding joints again. That is very time consuming and costly.

With 3d printing, you do only two steps. First, print one final piece in what ever shape, then polish the surface if necessary.

Besides 3d printing can make complicated shapes that traditional method can not do without huge cost and time, even something traditional method seemingly should be good at is better to be done by 3d printing.

For example, welding is very difficult to do to titanium alloy. F-22's bulkhead were cast/forged into three pieces then welded together. While forging is known to guarantee strength, welding does not. This creates two weak lines in the bulkhead. While F-31's bulkhead is printed in one piece. So long as the 3d printing method is reliable, there is no weak points or lines.

Not true at all. The F-22 uses welded titanium tail booms (the structures flanking the outside of the engines which carry the horizontal stabilizers) but the bulkheads are single pice.
 

taxiya

Brigadier
Registered Member
Depends on what Airbus' expectations were (those parts look like the kind of moderately stressed stuff that could be made using previous 3D printing processes), and they specifically say a forging pass is part of the solution (shades of Arconic's Ampliforge). So a crucial element of the traditional method is actually still present :)

Furthermore, to be applicable to the J-20, the process would need to have been tested and mature by early 2013 (in time to manufacture the second batch of prototypes) and capable of handling parts considerably larger than 2.2m. On the F-22, the bulkheads are up to 4.9m wide and while the maximum width of the J-20 fuselage is slightly lower than the Raptor's, we're still looking at about 4.5m.
The first picture (the unpolished)looks like load bearing stuff to me, and I am sure it use "micro-cast/forge 3d printing" method as that is the business of this company.

The others may be or may be not using the method but that is not my point.

Also regarding stressed stuff and airbus expectation. You may know that the wing-root beam of C-919 at 4?meters long is printed? That is a serious stressed thing. And C-919 is flying already. So maybe Airbus did not expect much from this printing, but COMAC is confident in it already. The whole reason that I brought up this report is because some people here would only believe it if it is verified by western customers than Chinese customers.

I don't know how you think I excluded the forging (traditional) part in the picture. The very central outstanding point of this company's method is combining forging during the printing. This is my whole point of 3D printing is able to match traditional method.

And to emphasize, there is not just ONE forging pass, there are numerous "micro-forging" passes embedded in the printing. One print one layer, micro-forge it, print another layer and so on. You can see from the first picture those layers, very different from other printing method (before polished).

Nobody, at least not me is talking about J-20 utilize (or not) this method. J-31 is the subject which is not what my post is about. I am only talking about (answering another poster's) doubt of 3D printing.

Speaking of F-22 bulkheads...



Not true at all. The F-22 uses welded titanium tail booms (the structures flanking the outside of the engines which carry the horizontal stabilizers) but the bulkheads are single pice.
You probably know better than me.
 
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MastanKhan

Junior Member
This weight thing is more and more like a discussion on alien visitation... I say “I saw aliens!” You say “no you didn’t!”

This is what I call an untestable hypothesis. No one can provide any solid evidence. This is also why this sort of discussion is always dragged on and on. No one can convince anyone else because of lack of solid evidence.

In cases like this, my suggestion is to present your argument, while at the same time, respect the other side. Without actual solid evidence, your argument is as good as others. There is absolutely no need to argue. There is nothing to argue (a possibility of something is not evidence). No evidence to support you whatsoever. Everyone presents your case and moves on.

We can actually dedicate a special thread (maybe even a special category, in addition to strategic defense, army, navy, AF, etc) and name it “technical predictions for new Chinese weapons systems”.

Under this special category, we can have a thread like “data prediction for the J-20 weight”. Everyone presents their position and their support. No need to argue and no need to attack others. Simply state your case and move on. We will come back to the same thread when some members feel that they have gotten solid enough evidence to convince most people. When things are settled, we close the thread. No need to go back and forth.

Of course, the actual format can be different. I guess my goal is to maximize our strength as a forum specializing professional opinion on Chinese weapons. Let’s keep things as professional as we can.

Another good thing is that we have a special place to collect all the technical data. If anyone wants to look up things, they can simply to go this category and look up different weapon systems and get all the numbers.

These threads would have no photos, only numbers, charts and tables. Show your numbers and your support, and that’s it. No argument and no attacks. It’s like a special place for data. When we get access to actual data and someone got it right, they got the bragging rights. And we can easily keep track of everyone’s predictions.

If you visit those professional academic or research forums, you will see that everyone simply states their own opinions and presents evidence. If no one can settle the argument, you will see things like “we will wait for more evidence”. And everyone moves on.

It is difficult to keep personal feelings in check when you are passionately arguing about things. I know that I have lost control many times. However, if we can create a professional environment, things will be easier for all of us. Being professional is what separates men from boys.

Hi,

You forgot to mention the REWARD for the guy who comes closest to the truth---.

I think that he should get the title of " Grand Poobah "---and everyone bows to him one time at least.
 

Klon

Junior Member
Registered Member
Why did it take (or is still taking) the PLAN so long to decide on it's next generation carrier-based fighter? For example, had a project started in 2013 they could have had a new plane in about ten years, in time for the first catapult-equipped carrier. It could have been given directly to Shenyang (as Chengdu had the J-20) or decided by a competition. What was the point of making a FC-31 that is not based on any PLAN or PLAAF requirements (as far as I know) when there was definitely a need for a new fighter?
 

Air Force Brat

Brigadier
Super Moderator
Why did it take (or is still taking) the PLAN so long to decide on it's next generation carrier-based fighter? For example, had a project started in 2013 they could have had a new plane in about ten years, in time for the first catapult-equipped carrier. It could have been given directly to Shenyang (as Chengdu had the J-20) or decided by a competition. What was the point of making a FC-31 that is not based on any PLAN or PLAAF requirements (as far as I know) when there was definitely a need for a new fighter?

The FC-31 is a "tech demonstrator", and they do hope to interest the PLANAF/PLAAF enough to nail down a future requirement, in the mean time, it is available for export, the Saudi's or someone else in the Middle East? or Pakistan for example, who may not be eligible or able to buy F-35??
 

kurutoga

Junior Member
Registered Member
Why did it take (or is still taking) the PLAN so long to decide on it's next generation carrier-based fighter? For example, had a project started in 2013 they could have had a new plane in about ten years, in time for the first catapult-equipped carrier. It could have been given directly to Shenyang (as Chengdu had the J-20) or decided by a competition. What was the point of making a FC-31 that is not based on any PLAN or PLAAF requirements (as far as I know) when there was definitely a need for a new fighter?

There are bases on both mainland and SCS islands for the air force and navy's land based fighters/attackers. In the hypothetical event of US invading China, it is not carrier vs carrier.

So no pressing need exists for PLAN to have fifth-gen fighters on carriers, before they have an enemy far away for China to have reasons to invade. At this time it's hard to see the Chinese invasion of Japan or India have any credibility, both are markets for China goods and trade partners. Maybe attacking Australia to grab some resources? Very unlikely, because China can just buy what they want in the market.

That is my speculation, PLAN's pressing needs are ships, then subs, carriers+J15+AEWC platform.
 

Air Force Brat

Brigadier
Super Moderator
There are bases on both mainland and SCS islands for the air force and navy's land based fighters/attackers. In the hypothetical event of US invading China, it is not carrier vs carrier.

So no pressing need exists for PLAN to have fifth-gen fighters on carriers, before they have an enemy far away for China to have reasons to invade. At this time it's hard to see the Chinese invasion of Japan or India have any credibility, both are markets for China goods and trade partners. Maybe attacking Australia to grab some resources? Very unlikely, because China can just buy what they want in the market.

That is my speculation, PLAN's pressing needs are ships, then subs, carriers+J15+AEWC platform.

Agreed, nice sound logic and reasoning, A+ on what may well be our SDF "post of the day",, doesn't mean these transient thoughts may not float back through my empty skull?? LOL Merry Christmas Bub!

you're right about those islands, I think of them as stationary "aircraft carriers", and they are really not only a "trip wire", but a "hard asset" for China!

LOL! that's why we don't like em much, we meaning Westerner's,, have a great week-end, I'm done for the year, well, I'm working on the brakes on our old van, seized piston in the brake caliper,,,,,
 

Klon

Junior Member
Registered Member
The FC-31 is a "tech demonstrator", and they do hope to interest the PLANAF/PLAAF enough to nail down a future requirement, in the mean time, it is available for export, the Saudi's or someone else in the Middle East? or Pakistan for example, who may not be eligible or able to buy F-35??
There are bases on both mainland and SCS islands for the air force and navy's land based fighters/attackers. In the hypothetical event of US invading China, it is not carrier vs carrier.

So no pressing need exists for PLAN to have fifth-gen fighters on carriers, before they have an enemy far away for China to have reasons to invade. At this time it's hard to see the Chinese invasion of Japan or India have any credibility, both are markets for China goods and trade partners. Maybe attacking Australia to grab some resources? Very unlikely, because China can just buy what they want in the market.

That is my speculation, PLAN's pressing needs are ships, then subs, carriers+J15+AEWC platform.

My basic question was, why go with an export project when there is a requirement inside the country? Why isn't Shenyang working on a plane specifically based on PLAN requirements for a carrier-based fighter? Not that using a modified J-20 or FC-31 is bad, but I think there were better possibilities.

First, having two fifth-generation planes makes sense. I see it similarly to the American situation (except that J-20 should see much larger numbers than F-22). The second plane would incorporate lessons learned from the first and itself serve as a platform for further R&D, be optimized for carrier operation and offer a lower cost alternative for the air force (if possible). It would also keep Shenyang in the game.

Second are timelines. As far as I know, the US will be getting sixth-generation planes starting around 2030. I hope China will be there, let's say, not more than five years later. This is what makes 2017 pretty late to start a fifth-generation project, since it would be running in parallel (or close) to an American one which is a generation ahead. Although it can still be done, particularly if you make it "5.5 generation" or something similar.

For example, after J-20 first flew in 2011 PLAN (and PLAAF, if it's to be a joint program) could have come up with the requirements. Target for first flight between 2014 and 2016 and for service entry between 2020 and 2023. Instead there's an export project (with a total two planes made five years since first flight) hoping to be selected.
 
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