99 replies to this topic

[Martian]

My annual review of T-50/Pak-Fa progress or lack thereof

Two years have passed since the January 2010 unveiling of the T-50/Pak-Fa. Let's look at the stealth design issues that remain.



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By the way, none of the Russian T-50/Pak-Fa problems exists on the Chinese J-20 Mighty Dragon stealth fighter.

Terrific J-20 Mighty Dragon close-up photographs

J-20 taxiing

Another day of tests

[Note: Thank you to Hu Songshan and J-20 Mighty Dragon Continue Flight Testing in February 2012 ~ Chinese Military Review]

[Martian]

Russian Embassy in India official website states 0.5m2 RCS for T-50/Pak-Fa

India, Russia close to pact on next generation fighter

[Siddharth]

wow.. amazing analysis.

Do you know that when we say reduced RCS, usually it means frontal RCS? A plane can never be invisible from all angles if you are relying only on the curves of an aircraft (which your above analysis suggests).

Its all about combination of special skin of aircraft, material and curves (ofcource).

I used to have a copy of JDW which had an elaborate photo op of skin which was developed and shown for F22.

Quote

"Gaps between airducts and fuselage reflects wave"

Really?? Now DSI is the only solution for engine air intake? http://kimdy.gri.re....ghter/f22-9.jpg

[Martian]

Illustration of the need for a flat underside to achieve stealth

For example, let me illustrate why the T-50's uneven underside is not stealthy.


The uneven underside on the T-50/Pak-Fa third prototype creates a natural 90-degree angle. This allows enemy radar to reflect off the fuselage, bounce off the inside-face of the air-inlet, and return to the transmitter/detector for detection.

The enemy radar can see the T-50/Pak-Fa, because of the uneven underside. This result should not surprise you. The Su-30 (which is not stealthy) also has an uneven underside like the T-50/Pak-Fa.


When the same enemy radar (either airborne or ground-based) tries to detect a Chinese J-20 Mighty Dragon, it fails.

Both the J-20 Mighty Dragon and F-22 Raptor have smooth and flat undersides to deflect radar away from the transmitter/detector. On this criterion, it is obvious the J-20 and F-22 are stealthy. It is also equally obvious the uneven underside of the T-50/Pak-Fa third prototype is not stealthy.

If Sukhoi ever fixes this problem then I would credit Sukhoi with another stealth characteristic. However, right now, the T-50/Pak-Fa third prototype is deficient in comparison to the J-20 and F-22 across at least 10 stealth design requirements (which I discussed in detail in post #98).

[Note: In both pictures, I performed a ray trace of the incoming radar and its reflection off of the underside of the Russian T-50/Pak-Fa third prototype and China's J-20 Mighty Dragon. You are familiar with a ray trace, because you see visible light bouncing off mirrors all the time.

Radar is an electromagnetic wave like visible light. The only critical differences are that radar has a much longer wavelength and it's invisible to the naked eye. Otherwise, a ray trace of radar resembles visible light.]

[Siddharth]

Mr Martin, please read my previous post. Its not always the curves which determine how stealthy you are.

Its special material and skin which goes into its production, information on which is still scarce and confidential.

P.S. Although even i am not very enthusiastic about current state of PAK FA, but wait and see. Russians are not idiots.

[Martian]

Su-30 is not stealthy. Therefore T-50/Pak-Fa is not stealthy.

Everyone agrees the Su-30 is not stealthy. In the following picture, I have identified 10 important non-stealth features of the Su-30. Interestingly, the T-50/Pak-Fa has the exact same 10 non-stealth features.

It seems to me there are only two logical choices. Either you agree with me that the T-50/Pak-Fa is not stealthy. Or you can make the incredible claim that both the T-50 and Su-30 are stealthy. I leave the choice to you.


Su-30 is not stealthy. Here are 10 non-stealth features.


In an interesting coincidence, the T-50/Pak-Fa shares all ten Su-30 non-stealth features.

[Siddharth]

ok ok.. you win sir.

Su 30 and PAK FA are same. If you have some more of your research time please do have a look at smooth shiny "production F-35" baby bottom.

[Martian]

World stealth fighter rankings



#1 F-22 Raptor - RCS is 0.0001 m2 (from GlobalSecurity citation)

#2 J-20 Mighty Dragon - RCS is intermediate between F-22 and F-35 (Frontal and side-aspect RCS are 0.0001 m2 like F-22. Rear-aspect RCS with round LOAN engine nozzles is 0.005 m2 like F-35. See Australia Air Power citation below.)

#3 F-35 Joint Strike Fighter - RCS is 0.005 m2 (from GlobalSecurity citation)

#4 T-50/Pak-Fa - RCS is 0.5 m2 (from Russian Embassy in India official website citation)

References:

GlobalSecurity: Radar Cross Section (RCS)

Russian Embassy in India official website: India, Russia close to pact on next generation fighter

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Australia Air Power: J-20 is a "genuine Very Low Observable design"

J-20 Mighty Dragon is a "genuine Very Low Observable design" except for round engine nozzles, which can be fixed.

The Chengdu J-20: Peace in Our Time?

"This study has therefore established through Physical Optics simulation across nine radio-frequency bands, that no fundamental obstacles exist in the shaping design of the J-20 prototype precluding its development into a genuine Very Low Observable design.



Above: L-band RCS, below X-band RCS head on, both in PCSR format (M.J. Pelosi).



Engineers and Scientists who work in ‘stealth’ (AKA ‘Low Observable’) designs have a way for explaining it to lay people: ‘Stealth’ is achieved by Shaping, Shaping, Shaping and Materials (Denys Overholser).

The F-22A is clearly well shaped for low observability above about 500 MHz, and from all important aspects. The J-20 has observed the ‘Shaping, Shaping, Shaping’ imperative, except for the axisymmetric nozzles, and some curvature of the sides that smears a strong, but very narrow specular return into something of a more observable fan. The X-35 mostly observed the ‘Shaping, Shaping, Shaping’ rule, but since then, to quote a colleague, ‘hideous lumps, bumps, humps and warts’ have appeared on the JSF to disrupt the shaping imperative, forcing excessive reliance on materials, which are at the rear-end of the path to ‘Low Observability’.

While discussing ‘rear-ends’, both the F-35 and the J-20 have large signature contributions from their jet nozzles. However, the difference is much like the proverbial ‘Ham Omelette’: the F-35 ###### is committed, but the J-20 Chicken is a participant. If the Chinese decide that rear sector Low Observability is tactically and strategically important, they are at the design stage where they can copy the F-22A nozzle design for the production configuration of the J-20."

[Note: Thank you to HouShanghai and 蓝胖 for the picture.]

[Simpleton]

China's stealth jet will not enter service this year: report

2012/03/09 15:28:38 Taipei, March 9

(CNA) China's stealth fighter, the J-20, will not be operational this year as previously speculated, a Beijing-based evening paper reported Thursday, citing ranking Chinese Air Force officials.

Several Chinese media outlets reported recently that the J-20, a Chinese stealth jet fighter, or its fifth-generation twin-engine fighter, will enter service earlier than scheduled following the plane's successful tests last year in the western Chinese city of Chengdu.

However, Gao Shouwei, a lieutenant general of the People's Liberation Army Air Force, told the Legal Evening News that test flights are still under way and the jet is not expected to be operational this year.

Commenting on the fighter's capacities, Gao said on the sideline of a National People's Congress meeting that the J-20 fighter has both advantages and disadvantages if comparing with the stealth jets of other countries, including F-22 of the United States.

The J-20, developed by China's Chengdu Aircraft Industry Group, has attracted much attention since it made its maiden flight in Chengdu Jan. 11, 2011.

Reports of the stealth's successful tests have surprised the world with the speed with which China has developed its stealth jet, and have fomented anxieties in Western countries including Russia that are developing their own stealth jets.

(By Kang Shih-ren

[Martian]

Why hasn't Russia fixed the T-50's problems in the last two years?


Sukhoi hasn't fixed a single stealth design problem in two years.

The list of T-50/Pak-Fa design problems is well known. The more interesting question is why hasn't Sukhoi fixed a single problem in two years. I believe Russia has reached its technological limits.

1. Protruding IRST - To recess the IRST, it would displace space in the nose section of the plane. This would affect the size of the radar that can be installed. Apparently, there isn't enough space for both a recessed IRST and the planned radar.

2. Metal-framed canopy - Only two countries, the United States and China, have built a frameless bubble canopy. This is a high-tech item that must withstand sustained supersonic speeds or a bird strike. Russia apparently lacks the technology to build a frameless bubble canopy.

In addition to stealth, a frameless bubble canopy provides an unobstructed view of the airspace.

3. Tall fuselage behind pilot - If you make a detailed comparison between the T-50 and the Su-30, you will find many similarities. The T-50 appears to be an evolutionary design of the Su-30 and not a completely new design.

The tall fuselage area behind the pilot appears to house satellite communication equipment and cannot be reduced readily.

4. Engine fan blades in straight airduct - To build a stealthy S-duct, the T-50 would have to be completely redesigned. Sukhoi chose the practical option of installing a linear engine pod, because a S-duct would crimp the payload area.

Also, it is very difficult for maintenance to access a S-duct integrated into the fusleage of the fighter. To design a F-22 or J-20, it would require countless hours of CAD design to ensure that every part was accessible to maintenance personnel.

Sukhoi was willing to sacrifice stealth for ease of maintenance.

5. Vents reflect radar - In the design of the T-50 and Su-30, the vents are important to shape the airflow and probably to achieve the proper pressure in the engines. Sukhoi cannot simply remove the vents to improve the stealthiness of the T-50.

6. Metal engine pods reflect radar - Engines are hot and they need to be properly cooled. Sukhoi cannot simply encase the metal engine pods in RAM. Once the engine pods are encased in insulating RAM, Sukhoi must resolve the cooling requirement by building a plumbing network to redistribute the heat.

This would add weight, complexity, and cost to the T-50. Sukhoi may have decided the costs outweighed the benefits of stealth.

The primary purpose of the T-50 is not to win battles against the F-22 or J-20. Russia relies on its thermonuclear arsenal to ensure its safety. In other words, the effectiveness of the T-50 against the F-22 or J-20 is not an issue for Russia.

For foreign purchasers of the T-50, the exposed metal engine pods are a death knell for their airforce. The RCS for exposed metal engine pods is huge. The T-50's exposed metal engine pods are no different from a fourth-generation non-stealthy Su-30 and they can be detected at tremendous distances.

7. Gaps between airducts and fuselage - The gaps between the airducts and fuselage cannot be eliminated, because there are vents along the side of the airducts that provide a vital aerodynamic function.

Also, you can't just move the airducts and engine pods against the fuselage. There are aerodynamic airflow considerations, heat issue, and maintenance access problems. The airducts and engine pods on both the Su-30 and T-50 were intentionally placed at their exact locations.

If you move the airduct and engine pod, the center of mass of the wing changes and it affects the stability of the plane.

8. Uneven heights of underside - To achieve a smoother and stealthier underside, there are only two choices. Either reduce the size of the airducts and engine pods or expand the fuselage and extend it downwards.

The airduct size can't be changed, because the engines require a flow of a minimum cubic feet of air per second. The engine pods can't be reduced, because the combustion chamber needs a minimum size to achieve a desired thrust.

The other choice is to extend the fuselage downwards. This is not a simple proposition. This affects the rigidity of the entire fuselage. The fuselage ribs will be much larger (i.e. heavier) and it may compromise airworthiness. Preserving the same width, longer fuselage ribs are weaker and cracks may develop earlier.

Also, an extended fuselage will block the internal side vents. This is a constant theme. If Sukhoi tries to improve the stealth characteristic of the current T-50, it tends to conflict with an existing aerodynamic need.

9. Lack of stealthy saw-toothed edges on bay doors - If you look closely at pictures of a J-20 with its saw-toothed bay doors closed, it is impossible to see the outline of the saw-toothed edges. This is a credit to China's machine tool industry. The precision of the machining can achieve very fine tolerances.

On the other hand, pictures of the closed straight-edged bay doors on the T-50 show the clear outlines of the doors. Without machining to fine tolerances, Sukhoi has probably concluded the closed bay doors aren't stealthy anyway. There is no point in introducing non-stealthy saw-toothed bay doors.

Russia lacks an advanced machine tool industry and stealthy saw-toothed doors are beyond her current technological capability.

10. Round engine-pod shape reflects radar - I've already covered this issue in item #6. Sukhoi cannot just encase the hot engine pods in RAM material.

11. Lack of gold-colored transparent RAM for cockpit canopy - There are pictures of F-22 and J-20 with gold-colored transparent RAM on their frameless cockpit canopies. To date, I have never seen a T-50 picture with similar transparent RAM.

Russian material science technology appears to have reached its limit. Russia may be capable of manufacturing opaque RAM for the plane in general. However, in two years, Sukhoi has not been able to produce transparent gold-colored RAM.

On the other hand, Sukhoi may have decided gold-colored transparent RAM is pointless. Since the metal-framed cockpit canopy is already reflecting radar, there is no point in applying transparent RAM to the T-50 cockpit canopy.

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In conclusion, Sukhoi hasn't tried to fix all of the well-known problems with the T-50/Pak-Fa because the alteration of part of the plane affects the performance of other parts of the plane. In other words, Sukhoi is trapped.

Sukhoi can't make the T-50/Pak-Fa more stealthy, because the Su-30 airframe was never meant to be used as a stealth platform. To build a F-22 or J-20 class stealth fighter, Sukhoi needs to start with a clean sheet. However, the development of a world-class stealth fighter can take a decade or more.

Russia doesn't have the luxury of starting with a new design and it needs a "stealth" fighter for export now. Hence, the result is a severely-compromised T-50/Pak-Fa. The T-50 is an evolutionary improvement on the basic Su-30 airframe by having a stealthy shaped nose, internal weapon bays, planform alignment, canted forward airduct, and canted vertical stabilizers.

If you are counting, you will notice the T-50/Pak-Fa lacks 12 stealth design elements (when you include non-serrated round engine nozzles) and only has five stealth design features.

The T-50/Pak-Fa is clearly not competitive with the F-22 or J-20. Sukhoi has a long way to go. It will be interesting to see if Sukhoi is able to improve on the currently deficient third T-50/Pak-Fa prototype.

[Simpleton]

China's J-20 Stealth Fighter Is Already Doing A Whole Lot More Than Anyone Expected

Eloise Lee and Robert Johnson |  Mar. 9, 2012, 12:03 PM

New pictures of the China's J-20 Mighty Dragon stealth fighter have surfaced and are making their way across military blogs.
This newest round of photos show the J-20 in the skies somewhere over mainland China.

The prototype is said to be using the Saturn AL-31 turbofan engine developed by the Russian's for their Su-27 air superiority fighter.

Reuben Johnson at The Washington Times reports the Chinese may be as much as 10 years away from producing an original stealth engine to slip into the J-20.

In the meantime, they'll have to take comfort in the fact that while the F-22 Raptor may be more agile and made entirely in the U.S., the Dragon carries more fuel and weapons than Lockheed's fighter.

The J-20's development is also moving along much faster than anyone had expected. Back in 2009, Gen. He Weirong, deputy commander of the People’s Liberation Army Air Force said in a TV interview that the J-20 wouldn't be operational until 2017-2019. That estimate will likely be revised if work continues at the current pace.

Bill Sweetman at AviationWeek points out that for all its headway, no one is yet sure what the J-20 is for. He speculates that given the aircraft's size and weapons bays, it may be used to "threaten intelligence, surveillance and reconnaissance assets and tankers, by using stealth and speed to defeat their escorts."

[Simpleton]

http://chinesemilita...ighter-jet.html

[platinum786]

J-20, a thing of beauty.

I have a question, I'm not engineering minded, but in the picture of the Pak-FA and the SU-30MKI a gap is shown between the airducts and the feusalage. Particularly in the picture of the MKI in post 6.

Stealth aside, why is that there? Is is a design feature? What purpose does it serve? I'd assume it'd increase drag.

[Caesar]

F-22 is 1980s technology ..... China and Russia and the rest of the world are still trying to match US for this tech. With all the black projects in US just imagine what US has.

[ISI2003]

Caesar, on 10 March 2012 - 07:55 AM, said:

F-22 is 1980s technology ..... China and Russia and the rest of the world are still trying to match US for this tech. With all the black projects in US just imagine what US has.

a generation has gone by, what the research budget has been shrunk and shift towards low intensity war and asymetric challenges, not so much conventional anti-china/anti-soviet-russia capabilities since the f-22 was developed

UCAVs are probably the most significant tech development and iran's drone capture has shown the current limits of that tech at the moment

[Martian]

platinum786, on 10 March 2012 - 05:15 AM, said:

J-20, a thing of beauty.

I have a question, I'm not engineering minded, but in the picture of the Pak-FA and the SU-30MKI a gap is shown between the airducts and the feusalage. Particularly in the picture of the MKI in post 6.

Stealth aside, why is that there? Is is a design feature? What purpose does it serve? I'd assume it'd increase drag.

1. Form follows function - The purpose of the airduct is to optimize the flow of air to the engines. Bolting the airduct to the bottom of the airframe would change the shape and disrupt the airflow.

2. Cooling - The airduct is connected to an engine. Having more exposed surface area will help cool the engine.

3. Vibration dampening - A partially free-hanging frontal airduct can serve as a vibration dampener. If the frontal airduct was bolted to the bottom of the airframe, all of the engine vibrations will be transmitted to the airframe beneath the cockpit.

4. Ease of maintenance - If the front of the airduct was bolted to the bottom of the airframe, the maintenance crew will have to expend more time in disassembling the engine pod and airduct for service or repair.

5. Minimizing weight - Attaching an aerodynamic interface to eliminate the gap between the airduct and the bottom of the airframe will increase the weight of the airplane. Also, the drag will probably increase because there will be more surface area for air friction. The thin edge of the current frontal airduct will create vortices, but they're minor.

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Su-30 is not stealthy. Therefore T-50/Pak-Fa is not stealthy.

Everyone agrees the Su-30 is not stealthy. In the following picture, I have identified 10 important non-stealth features of the Su-30. Interestingly, the T-50/Pak-Fa has the exact same 10 non-stealth features.

It seems to me there are only two logical choices. Either you agree with me that the T-50/Pak-Fa is not stealthy. Or you can make the incredible claim that both the T-50 and Su-30 are stealthy. I leave the choice to you.


Su-30 is not stealthy. Here are 10 non-stealth features.


In an interesting coincidence, the T-50/Pak-Fa shares all ten Su-30 non-stealth features.

[Martian]

In this post, I discuss stealth design. It will help you to develop a better understanding. You don't really need to see the original questions, because the answers are mostly self-explanatory.

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Technical reply to issues raised by Angeldemon_007.

1. Su-30 and T-50/Pak-Fa IRST creates a radar signature, because AESA radar is X-band. X-band wavelength is 2.5 (one inch) to 4cm. Also, IRST is a round sphere and not a shaped nose (e.g. duck bill shape/continuous curvature or faceted/diamond shape).

Therefore, X-band radar will detect the Su-30/Pak-Fa IRST. Hence, the Su-30/Pak-Fa is not stealthy.

Citation: HowStuffWorks "How does stealth technology work?"

"How does stealth technology work?
...
Most conventional aircraft have a rounded shape. This shape makes them aerodynamic, but it also creates a very efficient radar reflector. The round shape means that no matter where the radar signal hits the plane, some of the signal gets reflected back:
..."


Three posts ago, Gambit was arguing the T-50/Pak-Fa IRST probe is like a two-dimensional saw-toothed edge and is therefore stealthy. Do you agree with him? Or does the T-50/Pak-Fa IRST probe look like an excellent round radar reflector to you?

2. Look at the picture above with the rivets. Does it look like a metal-framed canopy to you? Even China's advanced materials science doesn't have the high-strength plastics that you are theorizing. Everyone has to climb the same tech ladder.

The F-22 uses a frameless bubble cockpit canopy. China also developed a frameless bubble cockpit canopy for the J-20. It is highly unlikely that Russia could just leapfrog past the next technological step of a frameless bubble cockpit canopy.

3. Look at your picture again (see below). I have drawn the surface area of the fuselage behind the pilot. The T-50/Pak-Fa is much taller and occupies a lot of area. This will strongly reflect radar at many angles.

If you look at other pictures of the F-22 and J-20, you will notice they use continuous curvature to shape the area behind their cockpit canopy. However, when you look at pictures of the T-50/Pak-Fa, you will see two large triangular slabs from the side.


Compare the small surface area behind the F-22 pilot to the large surface area behind the T-50/Pak-Fa pilot.

4. RULE #1 - never look at cartoons in performing an analysis. Let me show you real photographs of the T-50/Pak-Fa. All of them show there is no S-duct on the T-50/Pak-Fa.


From the midpoint of the airduct to the midpoint of the engine, it is a straight line. There is no curved duct. The T-50/Pak-Fa engine layout is identical to the Su-30.


From a lateral view, we will once again draw a line from the midpoint of the airduct to the midpoint of the engine. It is clearly a straight line. There is no curved duct.

5. It has been two years and Sukhoi's T-50/Pak-Fa third prototype looks exactly like the first prototype externally. Unless Sukhoi performs a radical redesign (which increasingly appears unlikely), a straight airduct will mean the T-50/Pak-Fa will be almost as non-stealthy as a Su-30.

When the enemy radar waves bounce off the single-crystal metallic engine fan blades on the T-50/Pak-Fa, the F-22 or J-20 radar screen will light up like a Christmas tree.

6. It has been two years and Sukhoi hasn't been able to wrap the T-50/Pak-Fa engines in RAM cladding. As more years pass, it becomes increasingly unlikely that Sukhoi can fix this problem. I believe it is a cooling issue.

If we keep seeing this exposed metal-engine problem on the next few prototypes then it means Sukhoi can't change the design due to a likely cooling need for the engines.

7. When the T-50/Pak-Fa or Su-30 bay doors are closed during flight, they lie flush against the fuselage. However, due to the non-saw-toothed edges, enemy radar will reflect off the large discontinuities. The F-22, F-35, and J-20 all have saw-toothed bay doors to minimize this RCS problem.

8. Vents are not stealthy, because of radar scattering from edge diffraction.

9. An uneven underside is not stealthy. It creates many new angles for a radar reflection. Australia Air Power wrote a detailed report and criticized the modified F-35 for the "lumps and bumps" along its underside. The original F-35 prototype had a clean and flat underside like the F-22 and J-20.

Due to the need for air-to-air missiles with the development of the J-20, the F-35 underside is a mess and it is less stealthy.

Reference: Assessing Joint Strike Fighter Defence Penetration Capabilities

10. When an enemy radar hits the "back wall" (or intersection between fuselage and airduct), it will produce a nice radar return. This is poor stealth design. This problem exists on both the Su-30 and T-50/Pak-Fa.

[Martian]

T-50/Pak-Fa IRST is not stealthy.

Do you see the giant radar return (see top diagram below) from a one-foot metal sphere? The T-50/Pak-Fa IRST is approximately a foot in diameter and should have a similar radar return.

How far away do you think an AWACS can detect the T-50/Pak-Fa IRST? The IRST is clearly not stealthy and it is terrible stealth design to have a round sphere on the T-50/Pak-Fa nose.

An AWACS has 4 massive engines that produce an incredible amount of power, which can be fed into the AWACS AESA radar. In the anechoic chamber test, they used a low-powered X-band radar. An AWACS should be able to identify a bat/IRST at great distances.


Measuring radar cross sections in an anechoic chamber is a fundamental part of validating radar measurements. The above images show radar cross section measurements made in the anechoic chamber of the University of Oklahoma Radar Innovations Laboratory. Data of a live tethered bat were collected using a low-power X-band pulsed Doppler radar. A 12-inch metal sphere was used for calibration. Results are shown in the plots. Similar data are being collected for other species.

Reference: Animal Migration Research, Jeff Kelly Lab

[Martian]

US AWACS can detect T-50/Pak-Fa IRST probe at 108km


Sukhoi IRST on both Su-35 Flanker (left) and T-50 (right)

The Sukhoi IRST probe on the Russian T-50/Pak-Fa is about a foot in diameter with half-a-sphere located on the plane's nose. Let's calculate the surface area of the non-stealthy IRST.

The surface area of a sphere is 4*pi*r^2.

The IRST radius is 6 inches * (2.54cm / inch) = 15.24cm = 0.1524m

The IRST surface area is 4*3.14*[(0.1524m)^2] = 0.2917 m2

An enemy AESA radar will only illuminate 1/4 of the IRST surface area (e.g. we can ignore the backface and the IRST is only half-a-sphere).

Exposed IRST surface area to AESA radar is 0.2917m2 / 4 = 0.073m2 RCS for Russian T-50/Pak-Fa IRST probe

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Reference from page 221: http://www.au.af.mil...torm/kiziah.pdf

"A typical cruise missile with UAV-like characteristics has an RCS in the range of 1 m2; the U.S.'s Tomahawk air-launched cruise missile (ALCM), designed in the 1970s utilizing the fairly simple low-observable technologies then available, has an RCS of less than 0.05 m2. The U.S. AWACS radar system was designed to detect aircraft with an RCS of 7 m2 at a range of at least 370 km. Using the physics of radar detection, which dictates that detection range varies with the object's RCS raised to the one-fourth power, the AWACS radar could detect the typical, non-stealthy cruise missile at a range of at least 227 km, and the stealthy cruise missile would approach air defenses to within a range of 108 km before being detected. Traveling at a speed of 805 kph (500 mph), air defenses would have only 8 minutes to engage and destroy the stealthy missile and 17 minutes for the non-stealthy missile."

We know an US AWACS can detect a RCS of "less than 0.05m2" at a "range of 108km." Earlier, we calculated the radar-illuminated RCS of the Russian T-50/Pak-Fa to be 0.073m2 (which is larger than 0.05m2).

Since we know an object with a RCS of 0.05m2 can be detected by an US AWACS at 108km, we can conclude the non-stealthy Russian T-50/Pak-Fa IRST probe alone can also be detected at 108km.


The list of non-stealth features on the Russian T-50/Pak-Fa is very extensive. Just the protruding IRST alone can be detected at 108km by an US AWACS. After doing nothing for two years, I suggest Sukhoi start work on fixing all of the non-stealth features on the T-50/Pak-Fa.

[paki power]

Mr martian i have say that your assumption and arguments r baseless, how can u compare PAK FA's IR ST has bigger radar cross section than huge canard surface than J-20, please elaborate,  but i agree that PAK FA has more flaws than J-20, and BTW as for your information soviet/Russian aircraft industry is more mature than Chinese aerospace industry.
Think sincerely

[paki power]

And as for APA physical optics experiment is wrong because they're not know what material used in the construction of J20, what kind of RAM coating is applied to the J-20,canard has a bad effects on front RCS for sure,no matter how sophisticated canard r.

[Martian]

##Pakistani## power, on 12 March 2012 - 04:12 AM, said:

Mr martian i have say that your assumption and arguments r baseless, how can u compare PAK FA's IR ST has bigger radar cross section than huge canard surface than J-20, please elaborate,  but i agree that PAK FA has more flaws than J-20, and BTW as for your information soviet/Russian aircraft industry is more mature than Chinese aerospace industry.
Think sincerely

The Russians themselves do not claim the T-50/Pak-Fa is comparable to the F-22 or J-20 in stealth. (See item #4 below)

Five reasons why 0.5m2 RCS for the T-50/Pak-Fa is correct.

There are five reasons to believe the 0.5m2 RCS for the T-50/Pak-Fa is correct.

1. The stated 0.5m2 RCS is on the official Russian Government Embassy in India website. This is official Russian government information.

2. If they believed it was incorrect, Sukhoi has had two years to correct the 0.5m2 RCS for the T-50/Pak-Fa. We can only conclude Sukhoi has silently agreed to the 0.5m2 RCS on the Russian Embassy government website.

3. The Indian minister who leaked the secret RCS information was part of an Indian government delegation to negotiate joint development of the T-50/FGFA program. He did not pull the information out of thin air. Most likely, Sukhoi informed the Indian minister of the 0.5m2 RCS for the T-50/Pak-Fa. This is leaked official Indian government information.

4. The Russian Air Force Colonel pointedly avoided claiming the T-50/Pak-Fa is as stealthy as a F-22 Raptor or J-20 Mighty Dragon. A 0.5m2 RCS for the T-50/Pak-Fa is consistent with the Russian Colonel's comparison of the T-50/Pak-Fa, F-22, and J-20. (See Russia to Increase Number of 5G Fighters in Test Flights)

5. After waiting two years, a technical analysis of the deficiencies in the stealth design of the third T-50/Pak-Fa prototype justifies the T-50's RCS of 0.5m2; which we expect to be considerably higher than the F-22 or the J-20 (see technical analysis below). None of these stealth design problems exists on the F-22 or the J-20.


Sukhoi hasn't fixed a single stealth design problem in two years.

##Pakistani## power, on 12 March 2012 - 05:15 AM, said:

And as for APA physical optics experiment is wrong because they're not know what material used in the construction of J20, what kind of RAM coating is applied to the J-20,canard has a bad effects on front RCS for sure,no matter how sophisticated canard r.

When an analysis is performed on the shape of an aircraft and its ability to reflect radar away from an emitter, the exact RAM material is not that critical. Furthermore, it is widely known that RAM material absorbs about 99.684% of the radar energy (see citation below).

Citation for RAM coating reduction of 99.684% reduction in radar energy.

From my February 12, 2011 post:

Revised final estimate for J-20 canards' radar return energy is 1.035 x 10^-17

I find Gambit's arguments for a -25 dB reduction, instead of -50 dB, from RAM coating to be convincing. I have revised my calculations for the effect from China J-20's canards. Quickie is correct that -25 dB is equivalent to 99.684% reduction (e.g. 10^2.5; take inverse; and convert to percentage). Thank you to Delft for highlighting the issue.
...
After hitting the canards, we know that 99.684% of the reflected energy is reduced by the military-grade RAM. (See Radar-absorbing materials: Definition from Answers.com) This means that only 0.00316 (e.g. 1 - 0.99684 = 0.00316) of the impacting radar energy survives contact with the canard's RAM surface.

gambit said:

Even if you do not have relevant experience in the field, IF you actually read your source carefully, scant as it is, you would not have made the ridiculous claim that an airborne absorber would affect up to five-9s of the impinging signal.

Your quite general source reads...


The quarter wavelength rule is quite applicable to airborne absorber. As material DECREASING thickness approaches quarter wavelength of the targeted freq, absorber performances decreases. In most cases, the targeted freq is the X-band, which is the centimetric (cm) band. We found out a long time ago that increasing thickness to greater than quarter wavelength would incur an unacceptable weight penalty, especially if the absorber is of the magnetic type, which are ferrite particles in a dielectric containment, aka sheet or liquid applique.

Here is a source to prove that...

HYFRAL™ CATALOGUE - Types of absorbers (THEOREMS AND PRINCIPES) - ELECTROMAGNETIC ABSORBERS


The only type of absorber that can affect up to five-9s of the impinging signal would be the pyramidal type...



Absorber performance is highly dependent upon the targeted freqs, even if it is 'wideband'.

Here is an F-22 in an EM anechoic chamber...



All those pyramidal absorbers would give us the most accurate RCS measurement of any object since they will absorb any chamber walls reflections that could constructively interfere with the reflections off the aircraft.

If absorber in general would affect five-9s of the impinging radar signal as you (falsely) claimed, there would be no need for shaping at all since whatever left of the signal -- the echo -- would lose even more energy on the way back to the seeking radar. What is that about energy loss to the square of the distance rule? Why not coat the whole aircraft with the stuff instead of just the canards? If this is true, we would have never built the F-117 in the first place looking funky as it is?

[Martian]

Multi-angle sights of China's J-20 fighter - Xinhua | English.news.cn

Multi-angle sights of China's J-20 fighter
English.news.cn | 2012-02-13 10:57:51 | Editor: Chen Zhi


(Photo: news.cn/mil)

----------

China's J-20 fighter unfolds landing gear bay - People's Daily Online

China's J-20 fighter unfolds landing gear bay
(People's Daily Online)
14:54, February 28, 2012

Edited and Translated by Ye Xin, People's Daily Online


Photo taken on Feb. 20, 2012 shows the sharpest-ever image of the landing gear of Fighter J-20 shortly after its takeoff. (huanqiu.com)


China’s J-20 stealth jet fighter is prepared for a test flight on Feb. 26, 2012. (huanqiu.com)


China’s J-20 stealth jet fighter conducts a test flight on Feb. 26, 2012. (huanqiu.com)

[Simpleton]

Chinese ‘Mighty Dragon’ doomed to breathe Russian fire

Published: 11 March, 2012, 16:18

While Beijing is proudly leaking more images of J-20 fifth-generation stealth fighter jet, China continues to buy Russian military jet engines and spare parts, which might indicate China is in a technological deadlock.

­China is making an attempt to catch up with world leaders and develop hi-tech vehicles in the absence of crucial military know-how and technology, like engines for ultrasonic cruise flights and active phased array antennas.

“As of now, it is too early to say that China is capable of creating a fifth-generation jet from start to finish,” told RT Vasily Kashin from the Center for Analysis of Strategies and Technologies.
­Chinese 5th-gen fighter jet

­The Chinese J-20 (Mighty Dragon) fith-generation fighter jet program is advancing in truly huge strides. The jet has already made over 60 test flights, performing elements of aerial acrobatics.

In 2009, General He Weirong, Deputy Commander of the People’s Liberation Army Air Force estimated that the J-20 would be operational no earlier than in 2017-2019. Now it appears Chinese engineers have done a great job and the jet is much closer to being ready than expected.

Created by Chengdu Aircraft Corporation, this heavy fighter jet is the first military plane China has constructed on its own, without visible attempts at copying foreign technology. It resembles neither the American Raptor F-22, nor the Russian T-50 PAK-FA.

Though peculiar forms of the jet and technical decisions allegedly realized in the vehicle might be questionable, one thing about this plane is an established fact.

As of now, the J-20 flies with two Russian AL-31F jet engines it borrowed from the Russian Su-27 fighter jet that entered Chinese service in the mid-1980s.

China also tried to put engines of their own on a second test J-20 vehicle, but the copycat of the Soviet engine AL-31F made by China is not in the same league as the Russian analogue for reliability and durability.

The real problem is both AL-31F and Chinese version are engines of the previous generation.

No question the Chinese jet is a prototype model and technology demonstration vehicle called to test new equipment and technology. Defined as a technology showroom, it may fly whatever engines its creator considers possible. But China has no working engine for a 5G jet.

Despite the fact that China tries to sell clones of the Russian jets at discount prices on the international arms market ($10 million for a J-11, while the Russian original Su-27 is well over $30 million), China continues to buy Russian engines and certain parts of these engines in quantities that far exceed the necessity to do routine maintenance of the Russian planes they use.

Chinese dependence on Russian engines can only be explained by technological inferiority of Chinese engine-building.

Beijing has found itself in a position when getting a decent 5G fighter jets with complying engines means buying engines in Russia, because no other country will sell them anything similar.
Why China needs Russian 4++ fighter jets

­This week, news came that Moscow and Beijing are close to striking a deal on China buying 48 Su-35 multifunctional fighter jets for $4 billion. The main reason for this remarkable purchase could be Russia’s jet engines.

The Su-35 flies with two next generation AL-41F1C engines that enable it to achieve hypersonic speed without afterburner, a feature attributed to 5G jets. And AL-41F1C actually is a de-rated version of the AL-41F1 (117C) engine used on the undergoing tests T-50 PAK-FA, Russian 5G fighter jet.

The new Russian engine AL-41F1C is what China needs to make J-20 fly as a 5G jet.

In 2010, when Russia’s Defense Minister Anatoly Serdyukov was on visit to China, Beijing proposed to buy 117C engines, but the offer was turned down.

Russians agreed to sell only assembled planes and in addition insist on signing a special anti-copycat agreement, designed to prevent the Chinese from copying the vehicle and its parts, as has happened before.

This demand has become a stumbling block in the negotiations. After the news about the deal emerged, the Chinese Ministry of Defense rushed to deny that negotiations on Su-35 with Moscow are in the terminal stage.

“Actually, any negotiations with China always come to the following: they try to buy a small lot [of arms] for examination and possible further replication. Naturally, Russia is aware of such risks and refuse to sell arms in small quantities,” said Vasily Kashin, explaining China’s canny moves to obtain missing technology.

Russia has great doubts concerning the practicability of selling AL-41F1C engines to Beijing without the special replication clause. This does not suit China because in the end they need technology to organize a production line for such engines of their own.
Chinese dragon with Russian engines

Kashin predicts that after long negotiations Moscow and Beijing will finally strike a separate jet engine deal and Russia will supply engines for the J-20 program, the way it already supplies engines to all four major types of Chinese fighter jets which are actually copycats of Soviet-made planes.

“Buying the Su-35 to dismantle its engines to put on J-20 would be madly expensive for the Chinese,” said Kashin.

“The J-20 is a very technically-risky project because there is no guarantee that Chinese will be capable to put into shape by 2017 several systems they are developing for the project, including special munitions and an active phased array antenna of they own in-house design,” Kashin told RT.

The J-20s will most likely fly with Russian engines for years before they make a reliable engine of their own, Kashin said.

The expert also pointed out that while the Chinese stated earlier they attempted to make a jet with the characteristics of an American F-22, they more likely are now working not on a fighter, but a stealth assault jet.

The J-20 will presumably be capable of piercing an enemy’s air defense to strike an important target – something like an aircraft carrier, as could be seen in J-20 “Attack on all fronts” advertising clip.

[paki power]

Simpleton, on 13 March 2012 - 01:47 AM, said:

Chinese ‘Mighty Dragon’ doomed to breathe Russian fire

Published: 11 March, 2012, 16:18

While Beijing is proudly leaking more images of J-20 fifth-generation stealth fighter jet, China continues to buy Russian military jet engines and spare parts, which might indicate China is in a technological deadlock.

­China is making an attempt to catch up with world leaders and develop hi-tech vehicles in the absence of crucial military know-how and technology, like engines for ultrasonic cruise flights and active phased array antennas.

“As of now, it is too early to say that China is capable of creating a fifth-generation jet from start to finish,” told RT Vasily Kashin from the Center for Analysis of Strategies and Technologies.
­Chinese 5th-gen fighter jet

­The Chinese J-20 (Mighty Dragon) fith-generation fighter jet program is advancing in truly huge strides. The jet has already made over 60 test flights, performing elements of aerial acrobatics.

In 2009, General He Weirong, Deputy Commander of the People’s Liberation Army Air Force estimated that the J-20 would be operational no earlier than in 2017-2019. Now it appears Chinese engineers have done a great job and the jet is much closer to being ready than expected.

Created by Chengdu Aircraft Corporation, this heavy fighter jet is the first military plane China has constructed on its own, without visible attempts at copying foreign technology. It resembles neither the American Raptor F-22, nor the Russian T-50 PAK-FA.

Though peculiar forms of the jet and technical decisions allegedly realized in the vehicle might be questionable, one thing about this plane is an established fact.

As of now, the J-20 flies with two Russian AL-31F jet engines it borrowed from the Russian Su-27 fighter jet that entered Chinese service in the mid-1980s.

China also tried to put engines of their own on a second test J-20 vehicle, but the copycat of the Soviet engine AL-31F made by China is not in the same league as the Russian analogue for reliability and durability.

The real problem is both AL-31F and Chinese version are engines of the previous generation.

No question the Chinese jet is a prototype model and technology demonstration vehicle called to test new equipment and technology. Defined as a technology showroom, it may fly whatever engines its creator considers possible. But China has no working engine for a 5G jet.

Despite the fact that China tries to sell clones of the Russian jets at discount prices on the international arms market ($10 million for a J-11, while the Russian original Su-27 is well over $30 million), China continues to buy Russian engines and certain parts of these engines in quantities that far exceed the necessity to do routine maintenance of the Russian planes they use.

Chinese dependence on Russian engines can only be explained by technological inferiority of Chinese engine-building.

Beijing has found itself in a position when getting a decent 5G fighter jets with complying engines means buying engines in Russia, because no other country will sell them anything similar.
Why China needs Russian 4++ fighter jets

­This week, news came that Moscow and Beijing are close to striking a deal on China buying 48 Su-35 multifunctional fighter jets for $4 billion. The main reason for this remarkable purchase could be Russia’s jet engines.

The Su-35 flies with two next generation AL-41F1C engines that enable it to achieve hypersonic speed without afterburner, a feature attributed to 5G jets. And AL-41F1C actually is a de-rated version of the AL-41F1 (117C) engine used on the undergoing tests T-50 PAK-FA, Russian 5G fighter jet.

The new Russian engine AL-41F1C is what China needs to make J-20 fly as a 5G jet.

In 2010, when Russia’s Defense Minister Anatoly Serdyukov was on visit to China, Beijing proposed to buy 117C engines, but the offer was turned down.

Russians agreed to sell only assembled planes and in addition insist on signing a special anti-copycat agreement, designed to prevent the Chinese from copying the vehicle and its parts, as has happened before.

This demand has become a stumbling block in the negotiations. After the news about the deal emerged, the Chinese Ministry of Defense rushed to deny that negotiations on Su-35 with Moscow are in the terminal stage.

“Actually, any negotiations with China always come to the following: they try to buy a small lot [of arms] for examination and possible further replication. Naturally, Russia is aware of such risks and refuse to sell arms in small quantities,” said Vasily Kashin, explaining China’s canny moves to obtain missing technology.

Russia has great doubts concerning the practicability of selling AL-41F1C engines to Beijing without the special replication clause. This does not suit China because in the end they need technology to organize a production line for such engines of their own.
Chinese dragon with Russian engines

Kashin predicts that after long negotiations Moscow and Beijing will finally strike a separate jet engine deal and Russia will supply engines for the J-20 program, the way it already supplies engines to all four major types of Chinese fighter jets which are actually copycats of Soviet-made planes.

“Buying the Su-35 to dismantle its engines to put on J-20 would be madly expensive for the Chinese,” said Kashin.

“The J-20 is a very technically-risky project because there is no guarantee that Chinese will be capable to put into shape by 2017 several systems they are developing for the project, including special munitions and an active phased array antenna of they own in-house design,” Kashin told RT.

The J-20s will most likely fly with Russian engines for years before they make a reliable engine of their own, Kashin said.

The expert also pointed out that while the Chinese stated earlier they attempted to make a jet with the characteristics of an American F-22, they more likely are now working not on a fighter, but a stealth assault jet.

The J-20 will presumably be capable of piercing an enemy’s air defense to strike an important target – something like an aircraft carrier, as could be seen in J-20 “Attack on all fronts” advertising clip.

what SU-35 is hypersonic plane

[Dizasta]

The Russian news source is ill-informed and biased.

I can appreciate the Russian sentiment that China has used the Su-27 Flanker design for it's J-11B fighter-jet. But Russia should also know and realize that China has not sold a single J-11B to any other country. In fact, the J-11Bs are exclusively for PLAAF and this is because the aircraft uses Chinese technology in engines, avionics, radars, electronic warfare, missiles and precision munition. And since China has not sold any J-11Bs to any foreign customer, Russia simply cannot argue that the J-11B is eating in to Su-27SM's or Su-30MK's sales.

Also, to say that China is in a dead lock when it comes to engine technology, is unfair and misinformation. One would be blind not to see the J-10Bs and J-11Bs being powered by Chinese WS-10 Taihan engines. Both fighter aircraft are powered by Chinese engines, which makes these fighters, totally indigenous and independent of any foreign technology. This in turn means that China is not dependent on any foreign military hardware supplier, as use to, in the past from Russia. Any country, has the right to self-reliance and independence in military manufacturing technology.

Russia has a good aircraft in Su-35 Super Flankers and what Russia really needs to improve on, is establishing a smooth, unhindered after-sales support services to it's customers. As there are plenty of very interested and keen customers for the Su-35 Super Flankers and providing efficient after-sales support services, would go a long way in re-establishing Russia's name in foreign military sales sector. Countries like Venezuela, Algeria, Brazil, Iran, Sudan, Malaysia and Nigeria, are emerging economies with an appetite to consolidate it's economic success by strengthening it's military machine.

Both Russia and China need to realize that it is tremendous benefit to themselves, that these two great nations, get along. The Western Nations are most certainly threatened by the rapid growth in both Russia and China. But what they fear the most, is that in the process of Russia and China's growing economic success, the countries would inevitably expand their trade with more and more countries. This would, in turn, eventually lead to confrontation with Western Nations who're involved meddling with sovereign country's internal affairs.

Sudan, Libya, Syria and Nigeria are prime examples of the Western treachery and meddling.

For this reason alone, Russia and China should work toward developing mutually beneficial alliance with each other and with countries like Kazakhstan, Turkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, Iran, Pakistan, Venezuela, Argentina, Brazil and Syria. Ensuring that no pro-western puppet regime has any foothold in any of these countries and establish economic growth spawning cooperation with these countries and each other.

[paki power]

Martian, on 12 March 2012 - 05:54 PM, said:

The Russians themselves do not claim the T-50/Pak-Fa is comparable to the F-22 or J-20 in stealth. (See item #4 below)

Five reasons why 0.5m2 RCS for the T-50/Pak-Fa is correct.

There are five reasons to believe the 0.5m2 RCS for the T-50/Pak-Fa is correct.

1. The stated 0.5m2 RCS is on the official Russian Government Embassy in India website. This is official Russian government information.

2. If they believed it was incorrect, Sukhoi has had two years to correct the 0.5m2 RCS for the T-50/Pak-Fa. We can only conclude Sukhoi has silently agreed to the 0.5m2 RCS on the Russian Embassy government website.

3. The Indian minister who leaked the secret RCS information was part of an Indian government delegation to negotiate joint development of the T-50/FGFA program. He did not pull the information out of thin air. Most likely, Sukhoi informed the Indian minister of the 0.5m2 RCS for the T-50/Pak-Fa. This is leaked official Indian government information.

4. The Russian Air Force Colonel pointedly avoided claiming the T-50/Pak-Fa is as stealthy as a F-22 Raptor or J-20 Mighty Dragon. A 0.5m2 RCS for the T-50/Pak-Fa is consistent with the Russian Colonel's comparison of the T-50/Pak-Fa, F-22, and J-20. (See Russia to Increase Number of 5G Fighters in Test Flights)

5. After waiting two years, a technical analysis of the deficiencies in the stealth design of the third T-50/Pak-Fa prototype justifies the T-50's RCS of 0.5m2; which we expect to be considerably higher than the F-22 or the J-20 (see technical analysis below). None of these stealth design problems exists on the F-22 or the J-20.


Sukhoi hasn't fixed a single stealth design problem in two years.



When an analysis is performed on the shape of an aircraft and its ability to reflect radar away from an emitter, the exact RAM material is not that critical. Furthermore, it is widely known that RAM material absorbs about 99.684% of the radar energy (see citation below).

Citation for RAM coating reduction of 99.684% reduction in radar energy.

From my February 12, 2011 post:

Revised final estimate for J-20 canards' radar return energy is 1.035 x 10^-17

I find Gambit's arguments for a -25 dB reduction, instead of -50 dB, from RAM coating to be convincing. I have revised my calculations for the effect from China J-20's canards. Quickie is correct that -25 dB is equivalent to 99.684% reduction (e.g. 10^2.5; take inverse; and convert to percentage). Thank you to Delft for highlighting the issue.
...
After hitting the canards, we know that 99.684% of the reflected energy is reduced by the military-grade RAM. (See Radar-absorbing materials: Definition from Answers.com) This means that only 0.00316 (e.g. 1 - 0.99684 = 0.00316) of the impacting radar energy survives contact with the canard's RAM surface.

but i still not convinced with canard+wing platform, front of the aircraft is the most important part of an aircraft, canard+wing will give slightly higher surface area to enemy radar, and as for side there r two ventral fins which may increases radar reflection to side, i think J-21 more mature and balanced design than J-20

[ISI2003]

##Pakistani## power, on 14 March 2012 - 03:51 AM, said:

but i still not convinced with canard+wing platform, front of the aircraft is the most important part of an aircraft, canard+wing will give slightly higher surface area to enemy radar, and as for side there r two ventral fins which may increases radar reflection to side, i think J-21 more mature and balanced design than J-20

what design do you mean by j-21?

[Dizasta]

^^ I think that he might be indicating the design evolution of the J-20s, once they've received IOC. It is believed that the J-20's canards would either be modified or removed to better enhance the 'Plane-Form Alignment' of the fighter. As well as, the aircraft's surface-skin re-shaping to conform with performance aerodynamics and incorporation of sensors across the air-frame. The J-21, if it would be the evolution of J-20, would have certain distinct modifications to it's air-frame shape, just as the J-10A's air-frame differs from the J-10B's. Another example is the YF-22, that looked different to the actual fielded fighter, the F-22A Raptor. All in all, the J-21, will have the same size, over all dimensions as the J-20, but would be significantly an evolved air-frame all together.

Edited by Dizasta, 14 March 2012 - 06:27 PM.

[paki power]

ISI2003, on 14 March 2012 - 05:21 PM, said:

what design do you mean by j-21?

[Martian]

T-50/Pak-Fa Front Airfoil Gap Back-end is not shaped to deflect radar


T-50/Pak-Fa front airfoil gap will reflect radar when it bounces off the back end.


Another look at T-50/Pak-Fa radar-reflecting back-end of front airfoil gap.


Notice the subtle angled curve of the J-20 Mighty Dragon canard back-end to deflect radar.

[gnak]

j-20 still uses the al-31 russian engine

video proof? (can anyone translate)

[Martian]

Kinematic shots of J-20 Mighty Dragon in pursuit


This is a picture from the rear-view mirror of a F-35 JSF as the pilot is horrified to see a J-20 Mighty Dragon swing into position.


The F-35 pilot's mind is screaming: Why didn't Lockheed Martin build supercruise into the F-35?! How am I supposed to outrun the J-20 Mighty Dragon?! Mayday! Mayday!

[Note: Thank you to QuantumFx for the pictures.]

[ISI2003]

the j-20 needs a stealthier 2d tvc nozzle (once the engine is fully developed) to maximize that turning capability

[ISI2003]

j-21 with two ws-13 engines would be best for Pakistan, at least 100 for air superiority would at least hold the line

[paki power]

gnak, on 16 March 2012 - 05:41 PM, said:

j-20 still uses the al-31 russian engine

video proof? (can anyone translate)

No,flying prototype is using ws10G or some new engine

[Martian]

French Rafale is a very non-stealthy 4th generation fighter

Mr. Somnath picked a terrible example in the French Rafale when he attempted to illustrate a perceived deficiency in the J-20 Mighty Dragon canard design. The French Rafale is not to be emulated in any way in the design of a 5th generation stealth fighter. The round shielding to hide the canard gap is far less stealthy than the J-20's elegant back-end to deflect radar.

[BaburMissile]

Mr. Somnath is a madman. The Rafale is a 4th gen aircraft whereas the J-20 is a 5th gen aircraft.The Rafale might be a good aircraft in its own league. There's no contest between a fully fledged 5th gen stealth aircraft and a 4th gen platform.

[marchpole]

（Quite）possibly the 1st pictures of the 2nd J-20 prototype：

[Martian]

French Rafale has at least 21 non-stealth features


In this photograph of the French Rafale, I have incompletely labeled only 17 non-stealth features. The actual list is at least 21 non-stealth features. For example, the round engine nozzles, non-canted vertical stabilizer, non-saw toothed wheel bay doors, and lack of continuous curvature for the fuselage behind the cockpit are additional French Rafale non-stealth features.

It saddens me to see Mr. Somnath fall victim to French marketing. The French have made the silly claim that the Rafale is partially stealthy. Unfortunately, Mr. Somnath has swallowed the French propaganda. Aside from the partially stealthy S-duct, there are 20 fully non-stealthy features on the French Rafale.

In conclusion, the French Rafale suffers from 20 non-stealth features and one partial stealth feature. This means the French Rafale is just like any other non-stealthy 4th generation fighter.