Chengdu J-20 news and analysis Part III

[Blitzo]

Whether an aircraft is able to carry four or two EFTs or whatever I think should have no implication for what we estimate its internal fuel capacity is.

Ability to carry 4 fuel tanks requires additional complication of fuel system.
No one will do it without a proper reason. Even more so for a 5th generation fighter.

Simplest possible reason is a ferry range, of which they want really a lot(5500 was quoted by Xinhua).
Without these EFTs we just drop 8+t of fuel out of equation. Which basically is a full Raptor worth of fuel.

Yes, of course the engineering and testing to allow an aircraft to carry four or two EFTs needs time, and money and effort.

However, that merely means the Air Force would've believed that it would have been worthwhile for the aircraft to have that ability. It does not convey to us on what the aircraft's internal fuel capacity/range is, nor does it tell us what the aircraft's internal+EFT fuel capacity/fuel range is.


In other words, we know the Air Force definitely has fuel and range requirements, both with and without EFTs, but the fact that they decided to allow the aircraft to carry four EFTs doesn't tell us what those requirements are.

 

[overscan (PaulMM)]

It may just mean they are short on tankers.

 

[Ainen]

In other words, we know the Air Force definitely has fuel and range requirements, both with and without EFTs, but the fact that they decided to allow the aircraft to carry four EFTs doesn't tell us what those requirements are.

It's the most logical explanation. AndI believe design of aircraft to be logical more often than not.
There are too few reasons to do it on a stealth fighter this way apart from additional ferry range.
Otherwise internal fuel wins.

2Paul
You mean as a buddy tanker? While possible, sounds a bit wasteful on a non-naval 5th gen fighter.

 

[overscan (PaulMM)]

No - I mean, they may want it to be able to deploy long distances (China itself is kind of big) without relying on tanker support like the US does for its F-22s.

 

[VTOLicious]

No - I mean, they may want it to be able to deploy long distances (China itself is kind of big) without relying on tanker support like the US does for its F-22s.

And J-20 doesn't feature in flight refueling so far...
http://chinesemilitaryreview.blogspot.co.at/2013/02/boom-tanker-in-flight-refueling-chinese.html?m=0

 

[kaiserd]

No - I mean, they may want it to be able to deploy long distances (China itself is kind of big) without relying on tanker support like the US does for its F-22s.

And J-20 doesn't feature in flight refueling so far...
http://chinesemilitaryreview.blogspot.co.at/2013/02/boom-tanker-in-flight-refueling-chinese.html?m=0

I’ll let the real experts on the J-20 chip in on this but there are many more at least as reliable sources that the J-20 has a retractable refueling probe and it seems hardly credible that it would’t have this feature from the get-go.

 

[Deino]

No - I mean, they may want it to be able to deploy long distances (China itself is kind of big) without relying on tanker support like the US does for its F-22s.

And J-20 doesn't feature in flight refueling so far...
http://chinesemilitaryreview.blogspot.co.at/2013/02/boom-tanker-in-flight-refueling-chinese.html?m=0

Since when? We have not many but at least a few clear images of the probe already posed. So this report is quite unreliable and wrong.

 

[overscan (PaulMM)]

The article was from 2013 - cut it some slack

 

[kcran567]

The point is, with 4 large external drop tanks and full internal fuel wouldn't the J-20 be able to self deploy anywhere in the world without the need for aerial refueling? That would save assets and time, resources, and equipment to be used elsewhere.

 

[totoro]

stealthy planes are voluminous and heavy. they consume a lot of fuel, compared to their previous gen brethren of the same class. Just compare f-22 range with its fuel load and F-15 range with its. Adding some tanks on f35 (or j20) does not equate to same benefits as adding them to f-16. The example of the famous norwegian sales brochure for f-35: addition of two 480 gallon tanks increased range by only 15% or so, even though weight wise they added 35% more fuel. So even though J-20 may carry over 10 tons of fuel internally and 7 more tons externally, overall ferry range may still be around 4000 km, even with all that fuel. If so, that'd be comparable to F-15c without cft.

 

[Blitzo]

In other words, we know the Air Force definitely has fuel and range requirements, both with and without EFTs, but the fact that they decided to allow the aircraft to carry four EFTs doesn't tell us what those requirements are.

It's the most logical explanation. AndI believe design of aircraft to be logical more often than not.
There are too few reasons to do it on a stealth fighter this way apart from additional ferry range.
Otherwise internal fuel wins.

I agree aircraft design is logical. But I think additional ferry range is a perfectly sensible reason to develop this capability to carry four EFTs.

The ability to rapidly redeploy within the comparative safety of Chinese airspace using EFTs alone without relying on tankers to get from one end of the country to the other, in fast moving crises, and to immediately enter the combat area by ditching EFTs with full internal fuel in a stealthy configuration can be invaluable.


Not to mention the general benefits of increased flexibility of greater ferry range for things like global or regional self deployment if that ever becomes a necessity.

 

[Blitzo]

...
J-20 can carry four EFTs and I would be surprised if it ever carries them outside of Chinese airspace defended by IADS during a high end conflict.


In any case, I think between the YF-22 and YF-23, the latter's greater size and longer range would've made it more suitable for the pacific theatre that we see now.
...

To be fair, I am not even sure if unrefueled range of J-20 is that large to call it especially long-legged, heavy usage of EFTs for clearly non-frontline configuration sujests it can be actually not that large.
Otherwise, why so many? Addition of this capability doesn't come for free.


The further, the more it seems what J-20 is quite pure air superiority bird with only secondary a2g or anything else.

Just circling back to this point, specifically the underlined part...

I think I would agree with you that J-20 is itself not "long legged," in the modern context and in the theatre it is expected to operate in, because the future of air power in APAC will likely be one where air superiority fighters have increasingly greater range and persistence. In that context, J-20's internal fuel range and endurance is probably average.

However, what that means is that F-22's internal fuel would comparatively have to be called "short legged" in the same sort of context.



But otherwise, even with a large or larger internal fuel capacity for J-20, it would still make sense to have a non-stealthy "ferry" configuration with more internal fuel tanks for certain mission profiles or deployments where it may be useful.
As far as designing and testing the aircraft for four EFTs go, I think the treasure and time spent on that is fairly small compared to what the rest of the aircraft's design and development would be, yet spending that small amount of time and money opens up substantial flexibility. Just because the F-22 only carries two EFTs rather than four doesn't necessarily mean it is not worth doing in other aircraft. If anything I wonder if the USAF might be kicking themselves a little for not spending the cash to allow the Raptor to carry four EFTs, in hindsight.

 

[Deino]

 

[Ainen]

However, what that means is that F-22's internal fuel would comparatively have to be called "short legged" in the same sort of context.

Well, it is. Her combat persistence is probably it's weakest point.

ATF studies began with some truly long endurance/high speed concepts.
Soviets also played with them, and drawn precisely something most experts expect from J-20.(Article 70.1, or MDP ).
Only difference, it had to be literally twice as heavy, and forget about any serious maneuvering capability.

 

[Blitzo]

However, what that means is that F-22's internal fuel would comparatively have to be called "short legged" in the same sort of context.

Well, it is. Her combat persistence is probably it's weakest point.

ATF studies began with some truly long endurance/high speed concepts.
Soviets also played with them, and drawn precisely something most experts expect from J-20.(Article 70.1, or MDP ).
Only difference, it had to be literally twice as heavy, and forget about any serious maneuvering capability.

Well, my point was that if J-20 is not called "long legged" but rather merely having "average" range/endurance, then it must be in the context of comparing it with other fighters of its generation and category and role, primarily the F-22.

 

[Deino]

Heureka ... I was right with my conclusion yesterday: As expected the first operational unit is the 172nd Air Brigade assigned to the Flight Test & Training Base (FTTB) based at Cangzhou/Cangxian.

https://twitter.com/RupprechtDeino/status/972889584873951233
https://www.facebook.com/pg/Modern-Chinese-Warplanes-611223845748378/posts/

 

[Hood]

An interview in China Daily with an air force test centre head, seems to indicate that further multi-role developments of the J-20 are likely and confirms that the type will not be exported, but no details were given.
Also Flight quotes an interesting part from the interview, "In the past, we had to follow others' paths when it came to designing military aircraft because our research and development capabilities were primitive in this regard, but now we have become capable of designing and making what we want to have." This may be confirmation that the J-20 did not rely on imported designs/expertise, though perhaps a bit disingenuous given number of programmes undertaken since the 1980s (Super-7, JF-17, Xian JH-7, J-10 etc.) which must have helped the learning curve somewhat.

https://www.flightglobal.com/news/articles/chengdu-j-20-to-become-multi-role-platform-446703/

 

[Blitzo]

An interview in China Daily with an air force test centre head, seems to indicate that further multi-role developments of the J-20 are likely and confirms that the type will not be exported, but no details were given.
Also Flight quotes an interesting part from the interview, "In the past, we had to follow others' paths when it came to designing military aircraft because our research and development capabilities were primitive in this regard, but now we have become capable of designing and making what we want to have." This may be confirmation that the J-20 did not rely on imported designs/expertise, though perhaps a bit disingenuous given number of programmes undertaken since the 1980s (Super-7, JF-17, Xian JH-7, J-10 etc.) which must have helped the learning curve somewhat.

https://www.flightglobal.com/news/articles/chengdu-j-20-to-become-multi-role-platform-446703/

I don't see how that is disingenuous considering the first part of that quote is "In the past, we had to follow others' paths when it came to designing military aircraft".

In any case, I am more interested in whether it is referring merely to adding the strike capability to J-20 (which would be a simple enough thing to add on to the aircraft as it is), or if they are thinking about other more dedicated roles in cyber, EW, ISR, UAV/UCAV control.

 

[bobbymike]

http://www.defenseworld.net/news/22133/China_to_Commence_Research_on_Sixth_gen_Jet_Based_on_J_20_Stealth_Fighter#.WqsYkXwh02y

China is preparing to commence research on a sixth-generation fighter aircraft from experience gained in the developing the fifth-generation J-20 stealth jet, its most modern fighter to date.

The J-20 stealth fighter jet will be given more capabilities than merely penetrating an enemy's air defense networks, according to its chief designer, Yang Wei, a deputy director at Aviation Industry Corp of China and an academician of the Chinese Academy of Sciences.

Yang Wei told China Daily that designers will develop variants of the radar-evading J-20 and will open research on its successor, a sixth-generation fighter jet, Global Times reported.

 

[Deino]

Allegedly a new J-20 prototype spotted ... ???

 

[sferrin]

Don't know if this has been posted or not yet. . .

 

[litzj]

http://idrw.org/did-indias-su-30s-were-able-to-see-chinese-j-20-stealth-aircraft/

Indian said their Su-30 could detect J-20, and they thought J-20 could not change regional balance of air-power.

 

[sferrin]

http://idrw.org/did-indias-su-30s-were-able-to-see-chinese-j-20-stealth-aircraft/

Indian said their Su-30 could detect J-20, and they thought J-20 could not change regional balance of air-power.

The J-20 could have been fitted with RCS enhancement devices like US stealth aircraft. They have been photographed with them.

 

[Airplane]

http://idrw.org/did-indias-su-30s-were-able-to-see-chinese-j-20-stealth-aircraft/

Indian said their Su-30 could detect J-20, and they thought J-20 could not change regional balance of air-power.

The J-20 could have been fitted with RCS enhancement devices like US stealth aircraft. They have been photographed with them.

I am willing to bet India is smart enough to know if they are reading returns on a radar reflector or an aircraft. The world has grown up. Detected with what wavelength of radar is the question.... THE question. If they can't target it with said radar wavelength, it doesn't really matter as we all know. Or maybe China left off a lot of ram in order to make the detection intentional but more plausible than a radar reflector which reflects all wavelengths. There are easy methods of determining whether or not a return is from a reflector!

 

[overscan (PaulMM)]

Indian Air Force generals may be politically savvy enough not to say "our Su-30s are completely useless now China has J-20s", too.

Air Chief Marshal B.S. Dhanoa, while addressing the media at Halwara on Thursday, said that signals from the J-20s can be picked up easily by existing radar from several kilometers away against the currently held belief. Air Chief Marshal Dhanoa also said that the IAF is better equipped and prepared to tackle any threat from China.

"The Sukhoi's radar can see them. The new Chinese jets are not so invisible after all. No special technology is required to detect the J-20, as it can be detected by ordinary radar stations," Indian Air Force commander Arup Shaha said.

 

[Deino]

Indian Air Force generals may be politically savvy enough not to say "our Su-30s are completely useless now China has J-20s", too.

Air Chief Marshal B.S. Dhanoa, while addressing the media at Halwara on Thursday, said that signals from the J-20s can be picked up easily by existing radar from several kilometers away against the currently held belief. Air Chief Marshal Dhanoa also said that the IAF is better equipped and prepared to tackle any threat from China.

"The Sukhoi's radar can see them. The new Chinese jets are not so invisible after all. No special technology is required to detect the J-20, as it can be detected by ordinary radar stations," Indian Air Force commander Arup Shaha said.

I would even go a bit further... My point is that so far no J-20A ever deployed to that area, so from what event should the IAF get these radar emissions and should have had an option to track a J-20 with an MKI or a ground station?? IMO these reports are as faked as this alleged super-secret spy mission purported in some media a J-20 was flying already missions over Korea.
Second so far all J-20s seen outside were equipped with Luneburg lenses in order to track and follow them ..

And finally – but that’s a personal opinion – the media is hyping that report and none of them is in a position to say anything that matters. We know that the Indian media and IAF have the tendency to brag about their capabilities. IMO it is a purely internal effort to convince the Indian public that their leaders and the IAF has everything under control. In return if you take a look at where are PLAAF bases in the Western TC related to India, there is barely anything. India is completely irrelevant and surely the Chinese side have much more serious issues in the Eastern and Southern TCs against Taiwan and the SCS Islands. These are the area, that matters for China, … but by the Indian self-perception it could not be that China does not care about them.

So better forget this report.

 

[SOC]

It's entirely likely that they are making these claims for public consumption, in order to play down the cancellation of the Russian-Indian FGFA.

 

[VH]

"I would even go a bit further... My point is that so far no J-20A ever deployed to that area, so from what event should the IAF get these radar emissions and should have had an option to track a J-20 with an MKI or a ground station?? "

It is very likely that J-20 has been detected by IAF assets: The PLA has deployed the J-20 to Tibet for testing. Tibet is located such that J-20s flying their test program from Daocheng Yading Airport (DCY)could easily be located by Indian AWACs and maybe even Su-27's patrolling along the border. Further, it should be recalled that J-20 does not offer all aspect stealth and from certain quarters the J-20 is very detectable.

"China is apparently in the process of testing out the Chengdu J-20, the country’s first ever fifth-generation stealth fighter, in the Tibetan mountains"

https://tacairnet.com/2016/09/08/china-has-been-secretly-testing-its-j-20-stealth-fighter-in-tibet/

 

[VH]

"The J-20 has been characterized as having medium stealth with its best performance from the front and the worst from the rear. Business Insider quotes a senior scientist at Lockheed Martin as saying, “It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”
https://www.usni.org/magazines/proceedings/2017-10/professional-notes-us-f-35-versus-prc-j-20

So given how the J-20 presented itself if is quite possible that the Indians detected it during its test program in Tibet

 

[sferrin]

“It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”

Yep. It's easy to copy the answer off somebody else's paper, but when you have to solve a new problem that strategy has. . .limitations.

 

[Triton]

Overall, the J-20 is likely to be a serious threat to U.S. aircraft, ships, and bases for the foreseeable future. While the F-35 has better stealth and sensor capability and the J-20 may not be a matchup one-on-one, the Chinese may be able to put more of them in the sky. In 2017, General Herbert Carlisle, Commander Air Combat Command, stated that in the South China Sea the threat may be “10 squadrons of J-20s, plus Su-35s…and Su-30s and J-10s and J-11s.” So, while not as good as the F-35, the J-20 does not have to be as stealthy or have sensor parity to have an impact on the Far East military balance.

Source:
https://www.usni.org/magazines/proceedings/2017-10/professional-notes-us-f-35-versus-prc-j-20

 

[overscan (PaulMM)]

“It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”

Yep. It's easy to copy the answer off somebody else's paper, but when you have to solve a new problem that strategy has. . .limitations.

Its also possible they understand the concepts fine but chose not to implement them all. For example, if the requirement was for head-on stealth only, then it would be stupid of Chengdu to implement full-aspect stealth.

 

[Triton]

“It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”

Yep. It's easy to copy the answer off somebody else's paper, but when you have to solve a new problem that strategy has. . .limitations.

Its also possible they understand the concepts fine but chose not to implement them all. For example, if the requirement was for head-on stealth only, then it would be stupid of Chengdu to implement full-aspect stealth.

Whatever its capabilities, the J-20 still makes us wish that the United States Air Force had more than 187 combat coded F-22 Raptor fighters. The espionage and the reverse engineering saved time, but in the end the J-20 is also limited to the manufacturing capabilities of the Chinese aerospace industry.

 

[Airplane]

“It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”

Yep. It's easy to copy the answer off somebody else's paper, but when you have to solve a new problem that strategy has. . .limitations.

Its also possible they understand the concepts fine but chose not to implement them all. For example, if the requirement was for head-on stealth only, then it would be stupid of Chengdu to implement full-aspect stealth.

Whatever its capabilities, the J-20 still makes us wish that the United States Air Force had more than 187 combat coded F-22 Raptor fighters. The espionage and the reverse engineering saved time, but in the end the J-20 is also limited to the manufacturing capabilities of the Chinese aerospace industry.

Chinese manufacturing is very, very good. We the USA have literally speaking, trained them. The majority of ALL tooling for automotive components is now made in china and then said tooling is shipped to places like Mexico where the tools are turned on and parts are molded. This is a fact.

The Chinese mandate by law that if something is built in china, like a jeep (which is now a reality) that the majority of all the components must be built in china.

The great god of greed to squeeze every penny of profit possible out of everything sold in the USA has lead the USA to handing the Chinese the keys to the kingdom.

Chinese manufacturing is extremely good. I would rank it better than Russian.

I work with Chinese engineers in China... While they are getting better the US is losing its skills. This is very frightening and no one cares. You have to look to fringe news and opinion sources to even learn these things which is also frightening.

 

[Blitzo]

“It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”

Yep. It's easy to copy the answer off somebody else's paper, but when you have to solve a new problem that strategy has. . .limitations.

Its also possible they understand the concepts fine but chose not to implement them all. For example, if the requirement was for head-on stealth only, then it would be stupid of Chengdu to implement full-aspect stealth.

I wonder how much of the whole "all aspect stealth" idea comes from round vs flat engine nozzles. For most stealth aircraft, the least stealthy aspect is the rear aspect, and even aircraft with flat engine nozzles from the six o'clock aspect will have the innards of their turbofans exposed to radar.

 

[sferrin]

“It’s apparent from looking at many pictures of the aircraft that the designers don’t fully understand all the concepts of LO [low observable] design.”

Yep. It's easy to copy the answer off somebody else's paper, but when you have to solve a new problem that strategy has. . .limitations.

Its also possible they understand the concepts fine but chose not to implement them all. For example, if the requirement was for head-on stealth only, then it would be stupid of Chengdu to implement full-aspect stealth.

Agreed. On the other hand I'd think the Lockheed people would recognize that pretty easily. I don't think they're saying, "they didn't put all aspect stealth on their jet therefore they don't understand stealth". I think they're saying, "they've got these areas they obviously tried to make stealthy, and they might look stealthy to the casual observer but because of X, Y, & Z they're really not".

 

[Mat Parry]

Chinese manufacturing is very, very good. We the USA have literally speaking, trained them. The majority of ALL tooling for automotive components is now made in china and then said tooling is shipped to places like Mexico where the tools are turned on and parts are molded. This is a fact.

The Chinese mandate by law that if something is built in china, like a jeep (which is now a reality) that the majority of all the components must be built in china.

The great god of greed to squeeze every penny of profit possible out of everything sold in the USA has lead the USA to handing the Chinese the keys to the kingdom.

Chinese manufacturing is extremely good. I would rank it better than Russian.

I work with Chinese engineers in China... While they are getting better the US is losing its skills. This is very frightening and no one cares. You have to look to fringe news and opinion sources to even learn these things which is also frightening.

Transparency can be an issue with 'made in China'

Before my Father retired from Airbus the A320 plant in China had never produced an aircraft with even a single concession recorded... the joke was that the paint on these 'perfectly manufactured' airliners was suspiciously thick

 

[sferrin]

I work with Chinese engineers in China... While they are getting better the US is losing its skills. This is very frightening and no one cares. You have to look to fringe news and opinion sources to even learn these things which is also frightening.

That's the problem with business in the West. They'll sell their Golden Goose for a buck if that dollar will make it onto this quarters report. Planning for the future is a foreign concept. (And too often "the future" is anything beyond the end of the current budget cycle.)

 

[totoro]

At the end of the day, learning to achieve low radar cross section is a matter of trial and error. They have their plane, they measure the RCS from various angles, using various radars. While they may not know how to achieve certain things as well as Lockheed Martin, they do know when something is good enough. Evidently J-20, as it is, was deemed good enough to invest all that money in developing a plane with all those LO features. Had the state of tech been so low that designers told PLAAF "We can't achieve what you're asking for, not even close" then PLAAF wouldn't have invested in futile development effort, preferring to spend its budget on more stuff that actually worked as requested.

 

[Deino]

"I would even go a bit further... My point is that so far no J-20A ever deployed to that area, so from what event should the IAF get these radar emissions and should have had an option to track a J-20 with an MKI or a ground station?? "

It is very likely that J-20 has been detected by IAF assets: The PLA has deployed the J-20 to Tibet for testing. Tibet is located such that J-20s flying their test program from Daocheng Yading Airport (DCY)could easily be located by Indian AWACs and maybe even Su-27's patrolling along the border. Further, it should be recalled that J-20 does not offer all aspect stealth and from certain quarters the J-20 is very detectable.

"China is apparently in the process of testing out the Chengdu J-20, the country’s first ever fifth-generation stealth fighter, in the Tibetan mountains"

https://tacairnet.com/2016/09/08/china-has-been-secretly-testing-its-j-20-stealth-fighter-in-tibet/

Just tow points to consider:

1. You know that was a prototype briefly deployed during high altitude and cold weather testing at Daocheng Yading Airport and so they most likely were fitted with Luneburg-lenses as we've seen them most often esp. when operating from civilian bases.

2. Even if officially located in the Garzê Tibetan Autonomous Prefecture of Sichuan province, China, it is not what most Indians rate as Tibet... Therefore I'm not sure - and the report itself is more than vague too - what Indian radar assets were right that moment close enough to monitor: The report itself only claims: could probably ... but surely not there was !

IMO again that report hypes things that are most unlikely ever happened ... the whole report is a piece of BS.