Chengdu J-20 5th Generation Aircraft News & Discussions

[marshall]

why are you guys comparing 2 aircraft at prototype stage

Both Pak fa and J-20 will never face each other nor we dnt knw about the mass produced variant..

The PAK FA follow-on variant will be sold to India, who is financing PAK FA development. Once India gets its hands on a few regiments of this, given the Indian government's belligerent behavior against China, it wouldn't be surprising if India's government concocts a crisis, gets their population into a frenzy through "Times of India", etc, before launching an unprovoked attack against China. The Indian government knows it will win the propaganda war even though it will be the aggressor. It happened before in 1962 and Indian leadership is far more xenophobic today then it was then.

 

[marshall]

You just made up some nonsense about the canard locking into place (I want a source).

I've never seen a quote about this but depending on the situation, it makes sense. Last year I speculated that the FBW probably has this sort of flight mode in mind. It would probably allow a few degrees movement and not strictly lock the canards but it would definitely improve the stealth.

 

[marshall]

[video]http://www.56.com/u12/v_NjY1NDE4MTc.html[/video]
The latest video of J-20, absolutely a state of art. USA never image we could build this kind of thing now, which is 10 year faster than they think! Martian2, just ingnore what gambit said, Uncle Sam never want to play fair with China in their guts and bone.

Solid progress, but it hasn't been pushed yet. If it's pulling 8+ Gs, I want to see a 360 in under 20 seconds. I don't think it's been fully loaded or conducted supersonic flights yet.

 

[DARKY]

your moronic logic is amazing!!!!

According to your logic, F-22's round Bubble canopy must be un-stealth as well.

lol

Not according to me... But your fellow Martin2's logic.

 

[gambit]

Haha, yes. They learned that with canard, it makes the plane much more manuvarable and thus a better fighter. Especially at super sonic speed, the double delta wing and canard makes it ultra agile, thus comes super manuverbility!!


As for the new plane SAC is developing, it is a stike plane like F-35, thus need less agility!

And apparently you did not learned or know that the US have had far more extensive research and knowledge than China on canards. The F-16 set the standard for agility -- without canards.

 

[amalakas]

I've never seen a quote about this but depending on the situation, it makes sense. Last year I speculated that the FBW probably has this sort of flight mode in mind. It would probably allow a few degrees movement and not strictly lock the canards but it would definitely improve the stealth.

I don't think so, the canards on the J-20 are the primary control surfaces. They can't be locked into place. At least I don't see the way

---------- Post added at 12:47 AM ---------- Previous post was at 12:44 AM ----------

And apparently you did not learned or know that the US have had far more extensive research and knowledge than China on canards. The F-16 set the standard for agility -- without canards.

Or perhaps even with this....

because others have discovered the wheel too

 

[gambit]

because other have discovered the wheel too

What is this 'wheel' thing you speak of?

But seriously...

I have a friend who was on F-16/AFTI program, specifically flight testing, and it was absolutely mind-boggling what that F-16 can do -- 20 yrs ago.

NASA Dryden AFTI/F-16 Photo Collection

The AFTI F-16 phase I tests began following its arrival at Dryden on July 15, 1982. The initial flights checked out the airplane's stability and control systems.These included a triplex digital flight control computer system, and the two triangular "chin" canards mounted under the aircraft's intake, which form an inverted "V"-shape. These canards allow the AFTI F-16 to make flat turns. By late December 1982, tests began of the Voice Command System. This allowed the pilot to change switch positions, display formats, and modes simply by saying the correct word. The initial tests were of the system's ability to recognize words.

I wonder if this is where Apple lifted the technology to develop Siri.

Anyway, we are talking about as much as 20 deg nose off angle gun solution while the entire aircraft was still moving/heading 'forward'. The flight control laws written for it was twice as large as the standard F-16's and is still secret, as far as I know, and I might give my left nut to take a gander at it. My friend passed away years ago. Its maneuverability was radical enough to make experienced test pilots physically ill at times.

 

[marshall]

...speculated that the FBW probably has this sort of flight mode in mind. It would probably allow a few degrees movement and not strictly lock the canards but it would definitely improve the stealth.

I don't think so, the canards on the J-20 are the primary control surfaces. They can't be locked into place. At least I don't see the way

Never said it should lock in place. The FBW would compensate with the other control surfaces so that the canard would essentially be a big LERX, albeit able to move a few degrees when necessary. The goal is to minimize canard movement, especially larger angles. Not having this sort of FBW flight mode would validate the main criticisms people have about canards in a threat environment, not that I ever agreed with canards to begin with. Unbeatable for maneuverability though, if done right.

 

[gambit]

Never said it should lock in place. The FBW would compensate with the other control surfaces so that the canard would essentially be a big LERX, albeit able to move a few degrees when necessary. The goal is to minimize canard movement, especially larger angles. Not having this sort of FBW flight mode would validate the main criticisms people have about canards in a threat environment, not that I ever agreed with canards to begin with. Unbeatable for maneuverability though, if done right.

This reveals you do not know what you are talking about but can only patch together words to put on a pretense of knowledge. Just like the Chinese boys here.

Anyway, computer assisted/augmented or completely FBW-FLCS flight control surfaces deflections are governed by calculations from these sources:

- Gyroscopes

- Accelerometers or rate of changes in any axis

- Commands (stick)

- Pitot/Static inputs: Altitude and Airspeed

- Angle of attack

The pilot have no control over their calculations. If the J-20 canards are active flight control elements, and signs are likely that they are, then they are constantly in motion. Their deflection angles and rate of deflections are necessary to maintain stable flight in all regimes, from TO-L to supersonic. The only time we can see a flight control surface's visible displacement is at TO-L speed, but when the aircraft is at cruising speed, which is normally several hundreds km/h to just below Mach, large displacements would make aircraft 'depart from controlled flight'.

You can see examples of what I said here...

U.S F-16 Flight (cockpit view)

At various timestamps such as 1:48 where we can see the F-15's external view, its flight control surfaces' movements are barely noticeable. Then at the end when the jets are landing do we see large deflections of flight control surfaces.

So there is no 'goal to minimize canard movement'. There can be no such goal to accommodate other desires.

 

[marshall]

This reveals you do not know what you are talking about but can only patch together words to put on a pretense of knowledge. Just like the Chinese boys here.

Anyway, computer assisted/augmented or completely FBW-FLCS flight control surfaces deflections are governed by calculations from these sources:
...
...
The pilot have no control over their calculations. If the J-20 canards are active flight control elements, and signs are likely that they are, then they are constantly in motion. Their deflection angles and rate of deflections are necessary to maintain stable flight in all regimes, from TO-L to supersonic. The only time we can see a flight control surface's visible displacement is at TO-L speed, but when the aircraft is at cruising speed, which is normally several hundreds km/h to just below Mach, large displacements would make aircraft 'depart from controlled flight'.
...
...
At various timestamps such as 1:48 where we can see the F-15's external view, its flight control surfaces' movements are barely noticeable. Then at the end when the jets are landing do we see large deflections of flight control surfaces.

So there is no 'goal to minimize canard movement'. There can be no such goal to accommodate other desires.

Why am I not surprised you would bring up yet another irrelevant out-of-context red-herring? The point is to maintain maximum stealth in a threat environment. The speculation was about the development of a FBW flight mode to do just that. Notice the use of the term FBW (Fly By Wire)...which is basically computer control of flight surfaces...something already mentioned even though you find it necessary to say is wrong while saying it is right at the same time. LOL

The goal is to ensure maximum stealth in a threat environment. In a threat environment, you can have many illuminating radars. For a stealth aircraft trying to penetrate this sort of tactical environment, every kilometer matters and the stealth issues with a moving canard are magnified. Your ridiculous example of an F-16 flying in calm weather under blue skies is NOT a threat environment. Sigh! As I said in the past, strategic thinking is not your forte....and neither is tactical thinking it appears. In any case, you are free to post irrelevant factoids ad nauseum to your heart's content.

 

[marshall]

I swear, your eyes are terrible. The T-50/Pak-Fa IRST probe is about the size of a pilot's head. What do you think will happen to a plane's radar signature when you stick a pilot's helmet on the plane's nose (like an IRST probe)? That's right. It's a giant radar reflector. You really are totally clueless.

In radar detection, paradoxical as it sounds, because of the 10-lambda rule, the larger the spheroid structure, it may be appear smaller to the seeking radar. Now go and look up my explanation of the 10-lambda rule.

Considering the context in which you are referencing the lambda rule, you could propose to the US Air Force that IRST probes should be made much larger...like 5 feet wide...this will make them more stealthy, according to you, since you posted this little factoid in the context of the above message from "Martian2" about a non-faceted spheroidal IRST. I'm sure you can convince China's communist government to finance your proposal to the US Air Force.

 

[siegecrossbow]

Link to video from the 27th.

The Good:

Couple of ultra tight figure 8s from 4:40 onwards.

The bad:

You can't see a darn thing cause the video is so grainy.

Enjoy:

歼20-27日机动视频 - 视频 - 优酷视频 - 在线观看

 

[amalakas]

Link to video from the 27th.

The Good:

Couple of ultra tight figure 8s from 4:40 onwards.

The bad:

You can't see a darn thing cause the video is so grainy.

Enjoy:

æ*¼20-27日机动视频 - 视频 - 优酷视频 - 在线观看

Good videos man. thanks

The question I guess still remains. Is there any info (more) in chinese news if the plane is after all a fighter like the F-15 say or a strike plane like the F-15E ?

 

[ARSENAL6]

Why am I not surprised you would bring up yet another irrelevant out-of-context red-herring? .

You Shouldn't be its redneck retard Gambit here , STill believing in fairytales, Moon is made out of cheese, ISrael is a force for good, the world's still flat and OBL is not part of the CIA.
Gambit has his head up the ar$£ , musta smelt reall good down their gambit ?

 

[siegecrossbow]

Good videos man. thanks

The question I guess still remains. Is there any info (more) in chinese news if the plane is after all a fighter like the F-15 say or a strike plane like the F-15E ?

There is nothing official. Judging from past papers (including the one written by Dr. Song, designer of J-10) and interview with General He Wei-Rong in 2009 the plane will assume air superiority and interception roles. We were able to verify some of Dr. Song's designs, such as the creation of lift enhancing vortices generated by LEX, LERX, and canards, in some of the high-def photos that J-20 watchers managed to snap.

We were also able to verify that the J-20 is around 20.5 meters long using high-def photos of the J-20 next to the J-10A and J-10B. I think Sweetman addressed this in a recent article as well. However the J-20's physical "body length" is still larger than that of the F-22 due to the fact that much of the F-22's length are added by the horizontal stabilizors. The nose to nozzle length of the F-22 is only around 16 meters. However the J-20 has a smaller cross sectional area than the raptor. In the end I think that the J-20 is probably heavier than the raptor, but not by too much. Since the engine currently being used are still AL-31 variants the full potential of the plane has yet to be unleashed. We will have to wait until WS-15s are installed before we see it doing anything special.