Chengdu J-20 5th Generation Aircraft News & Discussions

[ptldM3]

I dont think he meant the canopy color.. rather the coating on it.

That makes no sense, the coating gives the canopy the color, and yes it's very obvious he was talking about the coating which happens to be yellow/orange.

 

[Martian2]

J 20

This is a fantastic video. The J-20 Mighty Dragon shows off its super-maneuverability and the advantage of a canard-based (instead of F-22 horizontal tailplane-based) stealth fighter design.

Canards and horizontal tailplanes are both horizontal stabilizers that provide stability and control for an airplane. However, a canard enables superior maneuverability.

Supermaneuverability - Wikipedia, the free encyclopedia

"The theory behind canards as the sole elevator surface is that no elevator configuration aft of the wings is truly satisfactory for maneuvering purposes; the airflow over the wings creates turbulence, however small, and thus affects elevators placed directly behind the wings."

[Note: Thank you to HouShanghai for the video.]

 

[ptldM3]

This is a fantastic video. The J-20 Mighty Dragon shows off its super-maneuverability and the advantage of a canard-based (instead of F-22 horizontal tailplane-based) stealth fighter design.

Sorry, but I did not see anything remotely close to super-maneuverability, just an aircraft making wide turns.

The theory behind canards as the sole elevator surface is that no elevator configuration aft of the wings is truly satisfactory for maneuvering purposes; the airflow over the wings creates turbulence, however small, and thus affects elevators placed directly behind the wings."

This is silly, maneuverability or ability to pull high angles of attack goes beyond just canards versus horizontal tail plain. Every fuselage, every wing, almost anything on an aircraft (including canards) gives off vortexes which interfere with airflow on any lifting surface.

And I have yet to see any canard configuration pull extreme AoA maneuvers such as the cobra yet the ancient Mig-29A with no digital fly-by-wire and no thrust vectoring can, even F-18's can pull off cobras. In fact I have yet to see any canard configuration (bar Sukhoi) do anything special in terms of high AoA. Aircraft such as the F-22 and SU-35bm/s and even the Mig-29 put most canard platforms to shame.

 

[Martian2]

J-20 Mighty Dragon and F-22 Raptor have the best planform alignment

Definitions and Terminologies:

Stealth technology - Wikipedia, the free encyclopedia

"Planform alignment is also often used in stealth designs. Planform alignment involves using a small number of surface orientations in the shape of the structure. For example, on the F-22A Raptor, the leading edges of the wing and the tail surfaces are set at the same angle. Careful inspection shows that many small structures, such as the air intake bypass doors and the air refueling aperture, also use the same angles. The effect of planform alignment is to return a radar signal in a very specific direction away from the radar emitter rather than returning a diffuse signal detectable at many angles."

F-22 Stealth
"Jul 7, 2011 – The leading and trailing edges of the wing and tail have identical sweep angles (a design technique called planform alignment)."

----------

Let's examine the planform alignment for the Chinese J-20 Mighty Dragon, U.S. F-22 Raptor, and Russian Pak Fa/T-50. The comparison will focus on the main wings and the winglets (e.g. canards for J-20 and tailplanes for the F-22 and T-50).

The J-20 Mighty Dragon edge alignment for its main wings and canards has only five different sweep angles (e.g. red, green, orange, yellow, and blue).

The F-22 matches the J-20 in edge-alignment design for its main wings and rear horizontal tailplanes. The F-22 also has a total of only five different sweep angles (e.g. red, green, orange, yellow, and blue).


The Pak Fa/T-50 has the worst edge-alignment design for its main wings and rear horizontal tailplanes. The Pak Fa/T-50 has a massive total of 11 different sweep angles (e.g. addition of pink, light blue, purple, dark red, black, and white).

In conclusion, the Pak Fa/T-50 cannot match the stealthiness of the planform alignment design of the main wings and winglets for the J-20 and F-22. With an extra six different sweep angles, the Pak Fa/T-50 is clearly more detectable by radar in many more directions.

[Note 1: There is a small correction to this post. This picture of the Pak Fa led me to conclude that the Pak Fa has a total of 11 different sweep angles. If you look at other more vertical pictures of the Pak Fa, it is clear the Pak Fa has nine different sweep angles. The conclusion of this post doesn't change. The Pak Fa's nine different sweep angles are still almost twice as many as the J-20's and F-22's five sweep angles.]

[Note 2: I want to credit "Phaid" (post on 10/3/2010 8:03:28 AM) with noticing the inferior planform alignment of the Pak Fa/T-50. Though he did not perform the detailed analysis that I just did, I want to credit him with the earlier insight.]

 

[Martian2]

A few more observations about Russian T-50 non-stealthy underside

Russian T-50 aircraft aerobatic flight at Moscow air show (MAKS-2011) on August 19, 2011

I have a few more complaints (in addition to the lack of "S" ducts) about the T-50 underside that I want Sukhoi to fix.

1. I've already mentioned the non-stealthy gaps, vents, and stuff jutting out. Notice the engine pods and fuselage are at different heights.

2. It has been over a year since the T-50 debut. There is no excuse to not cover the exposed T-50/Pak Fa engine nacelle with RAM material. Do you see the non-stealthy gleaming metal? If Sukhoi has a cooling problem, hire more engineers to fix the problem.

3. The air ducts are canted only for the forward-portion. The photograph clearly shows that Sukhoi did not bother to encase the engine pod in a fully canted air duct. The rear-part of the air ducts are the round engine pods, which are not stealthy.

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The underside of a stealth superfighter should look like China's J-20 Mighty Dragon:

J-20 Mighty Dragon enters into a dive.

1. No vents, gaps, or stuff jutting out.

2. Engine pods are completely enclosed in RAM material.

3. Entire air duct is canted.

[Note: Thank you to Marchpole for the J-20 picture.]

 

[帅的一匹]

RUssian is smart human race.what they lack of is cash otherwise they wil never sell s27 to CHina.Not to offend,Pak Fa is more like suhoi company going through the motions with developing capital shortage.

 

[ptldM3]

J-20 Mighty Dragon and F-22 Raptor have the best planform alignment

Definitions and Terminologies:

Stealth technology - Wikipedia, the free encyclopedia

"Planform alignment is also often used in stealth designs. Planform alignment involves using a small number of surface orientations in the shape of the structure. For example, on the F-22A Raptor, the leading edges of the wing and the tail surfaces are set at the same angle. Careful inspection shows that many small structures, such as the air intake bypass doors and the air refueling aperture, also use the same angles. The effect of planform alignment is to return a radar signal in a very specific direction away from the radar emitter rather than returning a diffuse signal detectable at many angles."

F-22 Stealth
"Jul 7, 2011 – The leading and trailing edges of the wing and tail have identical sweep angles (a design technique called planform alignment)."

----------

Let's examine the planform alignment for the Chinese J-20 Mighty Dragon, U.S. F-22 Raptor, and Russian Pak Fa/T-50. The comparison will focus on the main wings and the winglets (e.g. canards for J-20 and tailplanes for the F-22 and T-50).

The J-20 Mighty Dragon edge alignment for its main wings and canards has only five different sweep angles (e.g. red, green, orange, yellow, and blue).

The F-22 matches the J-20 in edge-alignment design for its main wings and rear horizontal tailplanes. The F-22 also has a total of only five different sweep angles (e.g. red, green, orange, yellow, and blue).


The Pak Fa/T-50 has the worst edge-alignment design for its main wings and rear horizontal tailplanes. The Pak Fa/T-50 has a massive total of 11 different sweep angles (e.g. addition of pink, light blue, purple, dark red, black, and white).

In conclusion, the Pak Fa/T-50 cannot match the stealthiness of the planform alignment design of the main wings and winglets for the J-20 and F-22. With an extra six different sweep angles, the Pak Fa/T-50 is clearly more detectable by radar in many more directions.

[Note 1: There is a small correction to this post. This picture of the Pak Fa led me to conclude that the Pak Fa has a total of 11 different sweep angles. If you look at other more vertical pictures of the Pak Fa, it is clear the Pak Fa has nine different sweep angles. The conclusion of this post doesn't change. The Pak Fa's nine different sweep angles are still almost twice as many as the J-20's and F-22's five sweep angles.]

[Note 2: I want to credit "Phaid" (post on 10/3/2010 8:03:28 AM) with noticing the inferior planform alignment of the Pak Fa/T-50. Though he did not perform the detailed analysis that I just did, I want to credit him with the earlier insight.]

One again you proved your ignorance and unrelenting drive to downplay the pak-fa no matter how foolish and wrong your arguments are.

Firstly, those angles are there to redirect EM energy from coming back to the original source. You never want the wings to be parallel because the returns will be great especially when wing flaps are in the equation, thus those angles are necessary to redirect EM energy. It does not matter how many angles you have so as long as those angles redirect EM energy.

Any wow, that is all I can say about your childish illustrations. How can the pak-fa have 11 different sweep angles when all angles combined (whether they are the same or different) come out to be 8. it never ceases to amaze me how low you will stoop to degrade the pak-fa

Now if you were honest you would point out all the J-20's platform alignment.

So here are a few things you purposely missed:



Going off of your logic the J-20 is the worst perpetrator.

 

[ptldM3]

And Martian didn't you say you were done with Pakistan defense? Sometimes I wonder how you managed not to get banned even after bad mouthing the moderators and Pakistan defense. If that was not bad enough you derail threads with off topic subjects (f-22 and pak-fa) and use double standards (what applies to the pak-fa does not apply to the J-20).

 

[Martian2]

And Martian didn't you say you were done with Pakistan defense? Sometimes I wonder how you managed not to get banned even after bad mouthing the moderators and Pakistan defense. If that was not bad enough you derail threads with off topic subjects (f-22 and pak-fa) and use double standards (what applies to the pak-fa does not apply to the J-20).

Who's the one that was warned about outrageous improper behavior? That's right. It's you.

As I recall, you are the one who was in trouble with the WebMaster. He specifically told you to never start a thread about me again. You really should stop stalking me.

By the way, my J-20 video has 85,076 views. You should thank me for not making a video comparing the J-20 Mighty Dragon and the vastly inferior Pak Fa/T-50. Imagine having tens of thousands of people see the Pak Fa's flaws.

Have you come up with a ridiculous explanation for the Pak Fa's exposed non-stealthy metallic engine enclosures yet? Are you going to say something goofy like plasma stealth or Russian radar blocker? Ha ha ha. I can't wait to hear your lame excuse this time.

 

[rcrmj]

One again you proved your ignorance and unrelenting drive to downplay the pak-fa no matter how foolish and wrong your arguments are.

Firstly, those angles are there to redirect EM energy from coming back to the original source. You never want the wings to be parallel because the returns will be great especially when wing flaps are in the equation, thus those angles are necessary to redirect EM energy. It does not matter how many angles you have so as long as those angles redirect EM energy.

Any wow, that is all I can say about your childish illustrations. How can the pak-fa have 11 different sweep angles when all angles combined (whether they are the same or different) come out to be 8. it never ceases to amaze me how low you will stoop to degrade the pak-fa

Now if you were honest you would point out all the J-20's platform alignment.

So here are a few things you purposely missed:



Going off of your logic the J-20 is the worst perpetrator.

dont take different opinions as the meanings to degrate T-50, just tell me how come these stealthy?? the mysterious Plasma?

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and also please educate 'ignorant' me how a smooth surface is not stealthy?

 

[gambit]

Sorry, but I did not see anything remotely close to super-maneuverability, just an aircraft making wide turns.

Neither did I. The video was jerky, absolutely useless if the intention is to show maneuvers, which for clarity should show the aircraft in smooth transitions between positions and attitude. If that was fantastic, he should be stunned to silence at the T-birds vids.

This is silly, maneuverability or ability to pull high angles of attack goes beyond just canards versus horizontal tail plain. Every fuselage, every wing, almost anything on an aircraft (including canards) gives off vortexes which interfere with airflow on any lifting surface.

And I have yet to see any canard configuration pull extreme AoA maneuvers such as the cobra yet the ancient Mig-29A with no digital fly-by-wire and no thrust vectoring can, even F-18's can pull off cobras. In fact I have yet to see any canard configuration (bar Sukhoi) do anything special in terms of high AoA. Aircraft such as the F-22 and SU-35bm/s and even the Mig-29 put most canard platforms to shame.

The man is confused. The best -- if not the only -- advantage canards has over conventional tailplane design is that canards offers the aircraft a QUICKER attitude change compared to their size. Here is where things get suspicious: Not all FBW-FLCS are the same, just like hard linked mechanical FLCS. Thrust vectoring offers the same responsiveness regarding attitude changes as canards. The better the FBW-FLCS, the greater the deflection, rate of deflection, and size of the tailplane we can implement. Coupled the two together and any advantages that canards offers are negated while keeping RCS contributorship from the front to near zero. This make the FBW-FLCS on the J-20 suspect in that it may not be comparable to the F-22, hence the need for canards.

 

[ptldM3]

Who's the one that was warned about outrageous improper behavior? That's right. It's you.

As I recall, you are the one who was in trouble with the WebMaster. He specifically told you to never start a thread about me again. You really should stop stalking me.

Who was the one that got his post deleted and through a hissy fit? That's right. It's you. So after all the bad mouthing about the moderators and threats to never come back here, i'm still wondering why you are here?


You are truely petty, everytime i correct you like i did about the J-20 canopy you throw hissy fits and take it as an insult towards the J-20 even though i never said anything bad about your beloved J-20. As an example i only stated the J-20's canopy just like all other canopies are meant to keep EM energy out of the cockpit rather than absorb it.

Yet you resort to your old tricks by bringing the pak-fa into the thread and than bad mouthing it with the most rediculous arguments. What's wrong, can't take the heat? Why are you always going off topic and bring in the pak-fa?

By the way, my J-20 video has 85,076 views. You should thank me for not making a video comparing the J-20 Mighty Dragon and the vastly inferior Pak Fa/T-50. Imagine having tens of thousands of people see the Pak Fa's flaws.

Tell it to someone who cares, this video has 3,214,553, so what's your point? People will watch the dumbest things and your video is no different.

Fat Guy with little Pistol - YouTube

Have you come up with a ridiculous explanation for the Pak Fa's exposed non-stealthy metallic engine enclosures yet? Are you going to say something goofy like plasma stealth or Russian radar blocker? Ha ha ha. I can't wait to hear your lame excuse this time.

I don't need a rediculous explanation, the people at Sukhoi have already stated that they are working on radar blockers--and if that is hard for you to swollow than look no further than the F-117, and silent eagle both utalize radar blockers.

Cool video's i bet Chinese teenagers are drooling over it.

 

[ptldM3]

dont take different opinions as the meanings to degrate T-50, just tell me how come these stealthy?? the mysterious Plasma?

Look here, i didn't degrade anything, i corrected Martian about canopies, never did i say anything about the J-20--he through a hissy fit and started attacking the pak-fa (as he always does when he is wrong). In any case i applied Martians criteria to the J-20 and it backfired on him.

and also please educate 'ignorant' me how a smooth surface is not stealthy?

Smooth? Yea like those giant spheres under the wings? Or the uneven air brake--and yes even an uneven air brake makes a big difference.

 

[ptldM3]

The man is confused. The best -- if not the only -- advantage canards has over conventional tailplane design is that canards offers the aircraft a QUICKER attitude change compared to their size. Here is where things get suspicious: Not all FBW-FLCS are the same, just like hard linked mechanical FLCS. Thrust vectoring offers the same responsiveness regarding attitude changes as canards. The better the FBW-FLCS, the greater the deflection, rate of deflection, and size of the tailplane we can implement. Coupled the two together and any advantages that canards offers are negated while keeping RCS contributorship from the front to near zero. This make the FBW-FLCS on the J-20 suspect in that it may not be comparable to the F-22, hence the need for canards.

He is more than confused, there are many, many factors that effect an aircraft’s performance, yet he is clinging on to the notion that a canard setup is superior to the traditional horizontal stabilizer setup. It’s like throwing a pair of canards on a Q-5, and expecting it to have super maneuverability when in reality it might go from 747 performance to 737 performance. With the advent of a quality FTW systems that are in sync with TV, canards are redundant if not worthless. In some aircraft canards are not there because of choice but because of necessity as in the case of nose heavy aircraft.

 

[rcrmj]

Smooth? Yea like those giant spheres under the wings? Or the uneven air brake--and yes even an uneven air brake makes a big difference.

you just proved Martians point that T-50 is not a very stealthy aircraft according to the bold part you suggested. T-50 not only has the giant fan blade that will appear on radar as 'bright' as red light districts in Amsterdam, but also to many other details that T-50 design team didnt pay much attention to.

there no such fighter that can acheive 100% stealthness, not F-22 nor J-20 or T-50, they are the products of compromise between stealthness and manueverability. due to americans superior turbofan engine technology that enables F-22 to go very far on its stealthness. J-20 is in a different case, whereas its prime objective is to deal with F-22, however there is probably 20 years gap of engine techs so CAC spent lots time and money on areodymanics to off-set the inferior engine techs (70s-80s J-9 is a perfect example) and meanwhile to achieve fronto maximum stealthness.

and in T-50's case due to short funds and a decade stagnation of R&D, Russia didnt have the luxry to develop a well rounded 5th gen stealth fighter. the whole plane looks like a 'modified' version of Flanker family