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Chengdu J-20 5th Generation Aircraft News & Discussions

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Not sure if anyone here can judge the quality of such a display or its functionality correctly. ... and concerning the FC-31 could it be that You are a bit biased ????

I would prefer to wait and see how V2 evolves ... and then again, time will tell.

Deino

"Not sure if anyone here can judge the quality of such a display or its functionality correctly"
Other people might have a hard time to tell,but I could. My technical field is software is engineering, specialized in Interface Design. The reason that highway signs are mostly graphics with different shape and color is because our eyes can pick them out easily. There is a lot of differentiations and contexts to let our brain quickly judge the message. When there is a bunch of words on the same background. Our eyes have to read them in a hurry, and our minds must interpret them. Similarly, with this supposed JC-31 display, there is a bunch of white lines of the same width and color on a dark background. There is no differentiation at all. So our eyes have to squint hard to read them, and our mind have to work hard to interpret their meaning. Most HUD displays are like that, I really doubt how useful they are actually to the pilot who are fighting with their lives. Yes they save the pilot the trouble of look down on the instrument panel, but presentation of the informations have much to desire. IMO.

upload_2016-12-13_14-43-17.png
 
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"Not sure if anyone here can judge the quality of such a display or its functionality correctly"
Other people might have a hard time to tell,but I could. My technical field is software is engineering, specialized in Interface Design. The reason that highway signs are mostly graphics with different shape and color is because our eyes can pick them out easily. There is a lot of differentiations and contexts to let our brain quickly judge the message. When there is a bunch of words on the same background. Our eyes have to read them in a hurry, and our minds must interpret them. Similarly, with this supposed JC-31 display, there is a bunch of white lines of the same width and color on a dark background. There is no differentiation at all. So our eyes have to squint hard to read them, and our mind have to work hard to interpret their meaning. Most HUD displays are like that, I really doubt how useful they are actually to the pilot who are fighting with their lives. Yes they save the pilot the trouble of look down on the instrument panel, but presentation of the informations have much to desire. IMO.
I can tell that you have never been under stress in a cockpit. There are many things in your criticism that while correct in principles, are wrong in practice. I will let this subject go for a little longer. But for now, I suggest you look up the science of HUD symbology and its companion subject of semiotics.
 
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Some rumors about the on-going military exerise in Dingxin:

2 J-20 vs J-10/11 backed by AWACS, J-20 shot down the AWACS first, then dominate the J-10/11 in combat, it is said J-10/11's radar cannot detect J-20 even within visual range, several J-10/11 are shot down within visual combat range.

Next few days, PLA may try anti-stealth radar array to develop tactics to defeat J-20.

Not sure about the radar installed on J-10/11 since it is depend on block/version of the fighters, however since all China's AWACS are equiped with AESA radar, so its safe to say J-20's LO is robust to AESA radar's detection.

http://lt.cjdby.net/forum.php?mod=viewthread&tid=2329857&extra=page=1

So far I think China should stop all other fighter's prodcution and pull full speed on J-20's production.
If J10c/J11bs is that chicken even with AESA, it's a problem.

Maybe we didn't realize the power of stealthy fighter in a right way.

@gambit Do you think it's true?
 
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If J10c/J11bs is that chicken even with AESA, it's a problem.

Maybe we didn't realize the power of stealthy fighter in a right way.

@gambit Do you think it's true?

The problem is probably you don't know which direction the enemy is coming from, so you don't know which direction to turn the nose of your plane.

I can tell that you have never been under stress in a cockpit. There are many things in your criticism that while correct in principles, are wrong in practice. I will let this subject go for a little longer. But for now, I suggest you look up the science of HUD symbology and its companion subject of semiotics.

I do think HUD is a huge improvement from looking down at the instrument panel. I just think the HUD looks very busy with all the numbers display in one color and in small font would make them very hard to read under high stress. That's all.

Just like those tightly packed numbers and symbols in cameras, they are hard to read unless you're a real pro. working with the camera everyday.

Screen Shot 2016-12-13 at 8.46.39 PM.png
 
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The problem is probably you don't know which direction the enemy is coming from, so you don't know which direction to turn the nose of your plane.
Yankee can slaughter our airforce if we don't develop J20, God bless China.

If two stealthy fighter go nose to nose, highly likely there will be a dog fighter, cause both of them hard to lock each other at BVR. That's why I always emphasize the importance of maneuver ability of the stealthy fighter and the super cruise ability.
 
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Yankee can slaughter our airforce if we don't develop J20, God bless China.

Not so simple. Remember we got rockets that can obliterate the airfields around China? and we got anti-stealth radars. I think stealth is overrated if that plane don't also have strong supersonic maneuverability.

Yankee can slaughter our airforce if we don't develop J20, God bless China.

If two stealthy fighter go nose to nose, highly likely there will be a dog fighter, cause both of them hard to lock each other at BVR. That's why I always emphasize the importance of maneuver ability of the stealthy fighter and the super cruise ability.

When dog fights happen, a good missile with flares-proof infrared imaging that can fire with Helmet mounted sighting is super important.

I think the advantage of able to not using your afterburner in a dogfighting is underestimated. Afterburner runs at a super hot temperature, your chance of dodging a very sensitive and agile missile is zero, if you have a very hot jet stream.
 
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When it comes to your Flight Control Computer having a voice, I think its more important that all warnings should be Voiced instead of simply having a blinking light. It's easy to miss a blinking light or a loud beeping sound. At least one Eurofighter was lost, when the pilot didn't noticed his landing gear malfunction during landing. He missed the flashing light warning.
 
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Months before I was told by some AF guy that the subsonic sustained turn rate of the previous J-20 prototype is pretty much equivalent to that of a F-16A or 16C blk32, even with such a low thrust-to-weight ratio. That's pretty much out of my expectation.
 
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High commands(CMC and HQ PLAAF) are said to be extremely satisfied with J-20. :D:D

They should be. They didn't cut any corners and aim to be cheap and simply copy. They did serious amount of deep thinking on how to beat F-22 in aerial combat. That was their aim. I think China has achieved it.

Months before I was told by some AF guy that the subsonic sustained turn rate of the previous J-20 prototype is pretty much equivalent to that of a F-16A or 16C blk32, even with such a low thrust-to-weight ratio. That's pretty much out of my expectation.

"even with such a low thrust-to-weight ratio" LOL. Very funny. :omghaha:. After seeing the flight videos of J-20, only a fool could still believe J-20 is "underpowered".
 
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"even with such a low thrust-to-weight ratio" LOL. Very funny. :omghaha:. After seeing the flight videos of J-20, only a fool could still believe J-20 is "underpowered".

The guy also told me the clean weight to be around 19~20 tons, funny or not. If he's right about the sustained turn rate, I think it's safe to assume that the thrust-to-weight ratio is lower than the F-16, which in parallel means higher Lift-Drag ratio.
 
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The guy also told me the clean weight to be around 19~20 tons, funny or not. If he's right about the sustained turn rate, I think it's safe to assume that the thrust-to-weight ratio is lower than the F-16, which in parallel means higher Lift-Drag ratio.

F-16's empty weight is 20, 300lb or 10.15 ton, Engine Max. Trust, 29,500lb or 14.75 ton, Internal fuel, 7000lb or 3.5 ton, external fuel tank is 3000lb or 1.5 ton.

Total weight not including weapons is 15.15 ton. Trust to weight ratio = 14.75/15.15 = 0.97

J-10 empty weight is 20 ton, internal fuel appr. 12 ton, Engine Max. Trust >18ton, times two is 36 tons.

Total weight, not including weapons = 32 tons. Trust to weight ratio = 32/36 = 1.15

Don't believe the nonsense that J-20 is using WS-10A,B, or AL-31FN. IMO, J-20's WS-15 engine's maximum trust is >20 ton.

That's why it is able to fly those tight turns that is similar to F-16 without using the afterburner. This is very significant. During dog-fighting, fighters usually launch their heat seeking infrared imaging missiles. If you use afterburner, your plane will have a super hot jet stream, that is very easy to track. In visual range combat, infrared stealth is even more important than radar stealth.

In all the video clips, I have seen, J-20 rarely have to use it's afterburner to do those amazing maneuvers. This indicates it has two very powerful engines.
 
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I do think HUD is a huge improvement from looking down at the instrument panel. I just think the HUD looks very busy with all the numbers display in one color and in small font would make them very hard to read under high stress. That's all.

Just like those tightly packed numbers and symbols in cameras, they are hard to read unless you're a real pro. working with the camera everyday.
I can tell from this response that you have not done what I suggested.

So let us begin your education...

"Not sure if anyone here can judge the quality of such a display or its functionality correctly"

Other people might have a hard time to tell,but I could.
No, you cannot, because...

My technical field is software is engineering, specialized in Interface Design.
...Unless you are an end-user, like a pilot that uses a HUD, even a civilian HUD, and THEN you uses different HUD designs for different missions, you are in no position to judge the quality of displays and functionalities.

The reason that highway signs are mostly graphics with different shape and color is because our eyes can pick them out easily. There is a lot of differentiations and contexts to let our brain quickly judge the message. When there is a bunch of words on the same background. Our eyes have to read them in a hurry, and our minds must interpret them.
I understand that you are on a zealot's mission to denigrate the F-35 as much as possible, but here is where you have gone beyond your expertise of software engineering and you made yourself look foolish.

Do you wonder why the HUD real estate, despite decades of use and continuous development, remains relatively the same, meaning the glass dimensions ?

MalKvy1.jpg


In the above illustration, there are four fields of views (FOV)...

- Left monocular
- Right monocular
- Combined binocular
- Intersect binocular

Left and right monocular are obvious enough.

Combined binocular is the total of both monocular views, from extreme left all the way to extreme right.

Intersect binocular is that overlapping area and THAT is the reason why HUD real estate have remained the same all these decades.

Basic research have determined that while there are variations among pilots regarding how capable is a pilot in processing data in their eyes' FOVs, there is a commonality that in all humans, we can only process FOV data in very limited quantity restricted by biology -- the iris. HUD real estates have varied from design to design, but no real changes have been made.

Inside the Int-FOV are two more factors that limits HUD real estate: Design Eye Reference Point (DERP) and Alert Eye Reference Point (AERP).

https://en.wikipedia.org/wiki/Design_Eye_Position

For most people, not just pilots, the AERP is physically higher than the DERP, meaning we focused on a region that is higher in the HUD than what the HUD's designer's intended because he/they wanted to accommodate the variations of end-users.

Do you wonder why HUD symbology is that green, some call it 'alien', color ?

Because research consistently found that this 'alien green' color contrasts well against background colors, from blue sky to Earth.

When we put the two questions together, we get the high level answer on why the HUD is the way it is all these decades.

If we put different colors into the HUD, as you wanted with your street signs argument, there is a high risk of having vital information get masked by background colors, leading to something that every pilot will experienced to some degrees in their flying careers -- HUD induced spatial disorientation (SOD).

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040065771.pdf
The concerns about conformality of the HUD were not the only issues discovered during the early development of HUD technology. The AFIFC found evidence for inadequate symbol dynamics, lack of standardization with symbology and operational use, inadequate field-of- view (FOV), intensity/contrast problems, night visibility issues, and an increase in HUD-induced spatial disorientation (Newman, 1980; 1995).
Another issue with your street signs argument is that as the driver changes direction or just move straight ahead, those visual information cues eventually disappears from his FOV.

For the HUD, vital flight and target information must remain inside that Int-FOV at all times, creating the necessity that HUD symbols must be as simple as possible. This simplicity need is so important that symbol sizes are measured in MILLIRADIANS. Every pixel that a symbol demands must be justified, in both information necessity and size to convey that critical information, or the symbol is not designed in at all.

Another issue is symbol clutter that says all symbols must be as simple as possible. In contrast to popular belief, HUD symbol clutter does not mean the quantity of symbols, but SYMBOL CONFLICTS, in other words, even if there are only two symbols in view, if they collide and overlap, vital information could be lost. That constitutes clutter.

In the event that symbols cannot help but overlap, we have to determine which symbol representing which information should be suppressed. We have to create a table listing information priority which further demands that symbols be as simple as possible to minimize memory allocation. A symbol is suppressed then re-init in a few milliseconds. It should be as simple as possible for that re-initialization.

Another issue that demands HUD symbols to be as simple as possible is called the 'accommodation trap' or 'attention trap'.

http://www.mvs.net/pdf/Human_Factors_of_HUDs.pdf
In effect, the HUD acts as an attentional ‘trap’ that draws information processing resources to the HUD and slows/degrades processing of external events.

The implication is that the edges of the HUD combiner will tend to draw accommodation (termed “convergence-accommodation traps“ by Weintraub and Ensing, 1992, p. 98).
What happens when a viewer, car driver or aircraft pilot, switches from non-HUD to HUD focus, it is found that the viewer processes information best at very close distance despite the HUD symbol being collimated to optical infinity. This switching action occurs constantly so to minimize the odds of HUD-induced SOD, all the more reasons why HUD symbols should be simple to the point of being little more than short lines.

...I really doubt how useful they are actually to the pilot who are fighting with their lives. Yes they save the pilot the trouble of look down on the instrument panel, but presentation of the informations have much to desire. IMO.
Sorry, but your opinion is worthless, and I say that kindly.

From my time on the F-16, I know what 9-g feels like and as my vision narrows due to blood losses under g, I do not want complex symbols representing target information, and if I am under 9-g, that target is definitely hostile.

Support China all you want, but stay out of areas you know nothing about.
 
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I can tell from this response that you have not done what I suggested.

So let us begin your education...


No, you cannot, because...


...Unless you are an end-user, like a pilot that uses a HUD, even a civilian HUD, and THEN you uses different HUD designs for different missions, you are in no position to judge the quality of displays and functionalities.


I understand that you are on a zealot's mission to denigrate the F-35 as much as possible, but here is where you have gone beyond your expertise of software engineering and you made yourself look foolish.

Do you wonder why the HUD real estate, despite decades of use and continuous development, remains relatively the same, meaning the glass dimensions ?

MalKvy1.jpg


In the above illustration, there are four fields of views (FOV)...

- Left monocular
- Right monocular
- Combined binocular
- Intersect binocular

Left and right monocular are obvious enough.

Combined binocular is the total of both monocular views, from extreme left all the way to extreme right.

Intersect binocular is that overlapping area and THAT is the reason why HUD real estate have remained the same all these decades.

Basic research have determined that while there are variations among pilots regarding how capable is a pilot in processing data in their eyes' FOVs, there is a commonality that in all humans, we can only process FOV data in very limited quantity restricted by biology -- the iris. HUD real estates have varied from design to design, but no real changes have been made.

Inside the Int-FOV are two more factors that limits HUD real estate: Design Eye Reference Point (DERP) and Alert Eye Reference Point (AERP).

https://en.wikipedia.org/wiki/Design_Eye_Position

For most people, not just pilots, the AERP is physically higher than the DERP, meaning we focused on a region that is higher in the HUD than what the HUD's designer's intended because he/they wanted to accommodate the variations of end-users.

Do you wonder why HUD symbology is that green, some call it 'alien', color ?

Because research consistently found that this 'alien green' color contrasts well against background colors, from blue sky to Earth.

When we put the two questions together, we get the high level answer on why the HUD is the way it is all these decades.

If we put different colors into the HUD, as you wanted with your street signs argument, there is a high risk of having vital information get masked by background colors, leading to something that every pilot will experienced to some degrees in their flying careers -- HUD induced spatial disorientation (SOD).

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040065771.pdf

Another issue with your street signs argument is that as the driver changes direction or just move straight ahead, those visual information cues eventually disappears from his FOV.

For the HUD, vital flight and target information must remain inside that Int-FOV at all times, creating the necessity that HUD symbols must be as simple as possible. This simplicity need is so important that symbol sizes are measured in MILLIRADIANS. Every pixel that a symbol demands must be justified, in both information necessity and size to convey that critical information, or the symbol is not designed in at all.

Another issue is symbol clutter that says all symbols must be as simple as possible. In contrast to popular belief, HUD symbol clutter does not mean the quantity of symbols, but SYMBOL CONFLICTS, in other words, even if there are only two symbols in view, if they collide and overlap, vital information could be lost. That constitutes clutter.

In the event that symbols cannot help but overlap, we have to determine which symbol representing which information should be suppressed. We have to create a table listing information priority which further demands that symbols be as simple as possible to minimize memory allocation. A symbol is suppressed then re-init in a few milliseconds. It should be as simple as possible for that re-initialization.

Another issue that demands HUD symbols to be as simple as possible is called the 'accommodation trap' or 'attention trap'.

http://www.mvs.net/pdf/Human_Factors_of_HUDs.pdf

What happens when a viewer, car driver or aircraft pilot, switches from non-HUD to HUD focus, it is found that the viewer processes information best at very close distance despite the HUD symbol being collimated to optical infinity. This switching action occurs constantly so to minimize the odds of HUD-induced SOD, all the more reasons why HUD symbols should be simple to the point of being little more than short lines.


Sorry, but your opinion is worthless, and I say that kindly.

From my time on the F-16, I know what 9-g feels like and as my vision narrows due to blood losses under g, I do not want complex symbols representing target information, and if I am under 9-g, that target is definitely hostile.

Support China all you want, but stay out of areas you know nothing about.

May be you are right, when taking into account of how our eyes and brains works when under strain. I have no experience with HUD design, no I don't know what is the optimum design. Just my belief that way the informations presented in the HUD is extremely "packed". I can't believe the format can't be further improved after 4 decades of development.

Anyway, we were talking about the Chinese version of the F-35 like display. Hope the J-20's display is nowhere looking like it. Thanks for your education on HUD.
 
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