T-50 Fighter To Feature Higher Stealth Capabilities

[Gessler]

Well the F-22 has similar aerodynamic characteristic to that of the F-15. The F-119 engine and 2D thrust vectoring help immensely.

Izdeliye 30 engine with Variable Cycle characteristics and 3-D TVC is way better.

We shall have to wait and see just how effective the Russians are with the plasma burst or active active cancellation of radio waves. No-one else has even come near to perfecting this kind of technology yet

Just something I wanted to add - Russians ain't looking to cover the plane in a cloak of ionized gas for
the entire length of the combat sortie. The plasma ducts will simply fire up for a few seconds, severely
reducing or altering the aircraft's RCS levels or recognizability - any pursuing radar-guided missile
will lose it's lock on the PAK-FA and fall away.

This is more of a factor when PAK-FA uses plasma & also deploy radar countermeasures, chaff or ESM
at the same time - it literally kills a radar-guided missile's chance of hitting sure.

 

[trident2010]

PAK-FA is evolving by the time we see the finished product it will have all the required capabilities of 5th gen fighter. VLO has high but not the top priority.

 

[Gessler]

@UKBengali

Just something on active cancellation technology, an early form of which is already present
on Rafale's SPECTRA suite; the following narrative is from a French technical specialist who
had previously worked on complex military systems in the past -

Carbone is a demonstrator of an escort-jamming system where dedicated platforms and crews is replaced by a combination of integrated systems featuring a solid-state phased-array jammer, with very high transmitted power and real-time steering of multi-beam . This is fitted in an automatic pod carried by a multirole fighter for the stand-in/escort jamming mission.

Carbone is significantly more powerful than existing or upgraded offensive-jamming pods. Carbone use DRFM receiver and real-time geolocation algorithms, such as those implemented in Spectra.

Operational trials have demonstrated Carbone's effectiveness, and particularly its capability to jam through scattered lobes (NATO MACE X field trials in August 2000).

I understand that the philosophy of Carbone was to analyse incoming signal with interferometry , locate the emitter, duplicate the signal with DRFM, and send it several time to the emitter. So it's not just noise as in general for offensive jammer.

But remember that Carbone was just a demonstrator, perhaps the objective was just to demonstrate a real time capability to duplicate signal. Because if you are able to do that in real time, no doubt that you will be able to slighty modify the replica to make smarter jam.Finally technologies are the same as SPECTRA : DRFM, localisation, but the power is bigger and the jamming approach is less smart. The corresponding operational system is perhaps SPECTRA.

How does SPECTRA work?

First you need to know perfectly the "signature" of your own aircraft. Due to the complexity of the SPECTRA traitment, Rafale start to simplify its signature: the aircraft is designed so that its untreated radar signature is concentrated in a few strong "spikes," which are then "attenuated" by the selective use of RAM. The collection of these few strong spikes are the "model" of Rafale.

Second it would be nice to cancel the reflected radar signal. The original incoming signal from the radar will be reflected from the spikes. Each spikes will produce an individual reflection with its own, often unique, amplitude and phase. The return signal, picked up by the radar, would look somewhat chaotic, consisting of background noise and "spikes". By removing these "spikes" from the radar screen the aircraft may blend in with the background noise, which is normally ignored by the radar operators.

If you look at where are SPECTRA active antenna, surprisingly they are close to areas that can generate spikes.

To remove these spikes the aircraft, when painted by a radar, transmits a signal which mimics the echo that the radar will receive from the spikes, but one half-wavelength out of phase, so that the radar sees no return from them. The advantage of this technique is that it uses very low power, compared with conventional EW, and provides no clues to the aircraft's presence; the challenge is that it requires very fast processing. This fast processing was demonstrated by Carbone.

Please read it all to get an understand of the oncept of reducing RCS by eliminating "spikes" in signal return,
therefore pushing your aircraft into the clutter-rejection threshold of enemy radars.

You can see how the spike in signal return which was very prominent & "recognizable" at first, is
now lost among the background clutter. No threat detection or target identification is possible when
this is the case.

However, these are still very early forms of active stealth methods. Rafale F4 with next-gen SPECTRA
would probably have full active cancellation tech which can provide RCS levels as low as F-35 if
a distributed-aperture active emitters are used.

I don't know if Russians will pursue active cancellation as earnestly as the French, but they will certainly
go all-out with plasma stealth. The sweet part is that Indian Air Force will have access to both. Active
cancellation tech through Rafale, and plasma stealth tech through PAK-FA/FGFA.

What I have shown above can be easily categorized as ECM, but that's the
foundation of active cancellation and French are very advanced in that field.

 

[UKBengali]

What is so stealthy in canards? Where did you see stealth planes with canards? What is so stealthy about 4th generation engines of SU-27 without any stealth measurements applied?

J-31 does not have canards. J-20 does but that is a deliberate compromise that the Chinese have decided in order to increase manoeuvrability for WVR dogfighting. It will anyhow not turn a still VLO fighter into LO. Maybe not quite at the level of F-22 but certainly better than F-35 and much less RCS than the LO PAK-FA

J-20 is having to use AL-31 as that is the only reliable engine that China has. Towards the latter half of the decade the WS-15 should be ready for flight testing. Using a different engine for flight testing is nothing new, as an example the French used an American engine for initial testing on the Rafale.

 

[UKBengali]

However, these are still very early forms of active stealth methods. Rafale F4 with next-gen SPECTRA
would probably have full active cancellation tech which can provide RCS levels as low as F-35 if
a distributed-aperture active emitters are used.

OK. This looks interesting but whether the French can achieve this level of radar cancellation is open to question.

Russians are not as advanced as the French in avionics anyway and so I would not think that they can produce something as good as the Spectra.

I am not saying that the PAK-FA won't be a decent fighter but I am very SUPRISED that the Russians did not go for VLO and used powerful 5th generation engines and 3D TVC to allow great aerodynamic performance at the same time.

 

[Kyle Sun]

fanboy stuff...there is no proof that Plasma tech is applicable on aircraft.

I mean RU is developing plasma steal tech . If the succeed , they can make Su-27 etc a steal aircraft .

BTW, RU developed first generation plasma generator at 1999 and tested it on aircraft successfully.

How you propose to create a layer of ionized gas in front of an aircraft with limited power generated from the aircraft? And how you suppress the IR signature of the ionized plasma?

I am not scientist of RU , maybe you ask the wrong person.

 

[sancho]

J-31 does not have canards. J-20 does but that is a deliberate compromise that the Chinese have decided in order to increase manoeuvrability for WVR dogfighting. It will anyhow not turn a still VLO fighter into LO. Maybe not quite at the level of F-22 but certainly better than F-35 and much less RCS than the LO PAK-FA

J-20 is having to use AL-31 as that is the only reliable engine that China has. Towards the latter half of the decade the WS-15 should be ready for flight testing. Using a different engine for flight testing is nothing new, as an example the French used an American engine for initial testing on the Rafale.

You didn't answered his questions though and actually are showing many double standards here. You "think" the Chinese fighters are stealthier, because of the shapings, but he made crucial points with the fact that there is no Chinese fighter currently availabe that uses a credible ammount of RAM and coatings, let alone NG engies with SC, TVC and reduced IR signature capabilites. All these featurers however count to advanced 4.5th and 5th gen capabilities and China hasn't mastered these so far, which puts them behind the US, Europe and Russia.
Also the same use of available engines or techs apply to Russia as well, when you take it as compromise for J20 and J31, because the T50 today is only in prototype stage too. The engines currently in use is a mix of upgraded Su 35 engine with MKI TVC, but it already offers SC capabilities and only because they used the engine coverings of the current Flanker generation at the prototypes, you concluded that the Russians have designed only a lo fighter.
And when all that is not impressive enough, the movable LERX, all moving canards and the sensor phalanx the prototype already has should make you understand, that the Russians have developed the currently most advanced and innovative 5th gen fighter!
There is no other fighter with this kind of flight performance, or sensor capability, be it active or passive detection and that is the part that we know so far, with still so much to come in the next years and the more interesting point still remains what weapon load it can carry and what changes the FGFA will have?
Btw, the flat designs of the YF23 was considered to have a lower RCS of the YF22 and the YF23 had comparable design features as the T50 today, be it the weapon bays between the air intakes, the bottom not flat to improve lift capability and personally, I still think that one can locate the T50 engine in a similar higher position as the YF23 had as well, which even makes the famous S-duct possible that many people think is always needed in a 5th gen fighter, which is bogus as well.

 

[SR-91]

WS-15(J-20) and WS-13A(J-31) are in development and should be ready towards the latter part of the decade.

Both AL-31 and RD-93 are wholly unsuitable to power the Chinese 5th generation fighters.

India has just been had by investing 5 billion in a non-stealthy fighter's R&D and also committing 20-25 billion more in buying them.

This goes out to show, how little you know.

 

[Gessler]

OK. This looks interesting but whether the French can achieve this level of radar cancellation is open to question.

Russians are not as advanced as the French in avionics anyway and so I would not think that they can produce something as good as the Spectra.

So far, no. But PAK-FA's suite should be better than SPECTRA. In terms of GaN technology, Russians
may even steal a lead over the French. They are putting GaN modules on things as small & compact as
a missile seeker. You know how complicated it is to miniaturize a normal T/R module, forget a GaN one.

But the French are ahead in using GaN on all the other sensors of Rafale, not just radar. GaN will be applied
in RF jammers as well - increasing their power output and processing capabilities phenomenally.

I am not saying that the PAK-FA won't be a decent fighter but I am very SUPRISED that the Russians did not go for VLO and used powerful 5th generation engines and 3D TVC to allow great aerodynamic performance at the same time.

If you consider F-35 as a VLO fighter, then no reason why PAK-FA isn't one. The Russians simply chose
to use unconventional methods to achieve stealth, that's all.

 

[Gessler]

The YF-23 Black Widow -

The fuselage both upper and lower portions is very uneven. The surfaces do not always end in sharp
angles. The canopy is framed. The engine fan-blades are visible from the front.

If you were to show this picture to a Chinese fanboy, they will simply dimiss it with a "YF-23 is not stealthy" tagline,
and a labelled image that points the features I listed above. But in reality, YF-23 was in the overall stealthier
than YF-22 (which later became the F-22 of today). That's how much they know about stealth.

What LOOKS stealthy isn't always stealthy, and what looks non-stealthy at first may even be stealthier
than something that actually looks the part. PAK-FA is not just low RCS, it's signal return is difficult
to recognize on radar mostly.

 

[egodoc222]

I always knew that the PAK-FA was a LO and not VLO aircraft.

This should really help Pakistan as it can induct VLO J-31 and have a massive advantage over the PAK-FA.

The better J-31 will help Pakistan offset the Indian numerical strength in the PAK-FA.

what is j-31 ?

 

[kurup]

what is j-31 ?

Shenyang J-31 - Wikipedia, the free encyclopedia

 

[My-Analogous]

But they failed to copy properly. J 20 has problem in everything from Engine, to location of engine, Weapon bay, Wings, fuselage. There is not even a single part which is not ill designed.

Remember that not every plane is LCA

 

[egodoc222]

Shenyang J-31 - Wikipedia, the free encyclopedia

looks like a mock up!

 

[gambit]

Please read this about the efficacy of the L-band against 'stealth'...

Fundamentals of Stealth Design & Concepts of RCS Reduction | Page 3

As for 'plasma stealth', please do keywords search 'plasma antenna'. This is a far more practical and feasible solution than creating a plasma cloud enveloping the aircraft at several hundreds km/h.