F-35A versus Saab Gripen NG

[ricnunes]

Dare I ask why the YF-16 is in this thread - they were a bit smaller with a smaller / different nose as well and never had an FCR - only a ranging radar for testing the gun and were never representative of anything operational.

Yeap, what you say makes sense and explains why the YF-16 had lower RCS than production F-16s (namely non-Have Glass aircraft).
Thanks for the heads up.

[swiss]

The YF-16 has an RCS of 1.2m2 with MSA Radar. So i would guess 1m2 or even a bit lower cold be possible for the Gripen-E thanks to the AESA and RAM.

But as Hornetfinn pointed out. We talk about small differences here.

I didn't know that the YF-16 (the F-16 prototype) had a lower RCS than the production F-16A. Are you sure?
It would be interesting to know what made the RCS go up from the YF-16 (1.2m2) to the F-16A (3m2 to 5m2, depending on the source).

Dare I ask why the YF-16 is in this thread - they were a bit smaller with a smaller / different nose as well and never had an FCR - only a ranging radar for testing the gun and were never representative of anything operational.

I don't know where these figures are coming from however the production F-16A had Have Glass from the early 80s to reduce its RCS.

Because the RCS of the YF-16 is mention in this book.https://books.google.fi/books?id=fjx4Dw ... CS&f=false


And i assume the f-16 with have glass should be in the same ballpark. 5 m2 seems to high for me. That would be on the same level like the Mig-29.

[loke]

Where did Saab claim an RCS value of 0.1 square meters? I have seen that some people on the internet make such claims, but I cannot recall having seen Saab make such a claim. Can you please provide the link to this claim from Saab.

As you're probably aware (but I'll indulge you nevertheless) that 0.1 square meter claim comes from an official Swedish government document which stated that the RCS goal for the Gripen E was to be those 0.1 square meters.
Unfortunately the site/page where I saw that documents hosted (keypublishing.com forum) is apparently down for maintenance but here's the full link nonetheless:
https://forum.keypublishing.com/forum/m ... 5-03/page2

In a previous posting you clearly stated that Saab had made the claim of 0.1 square meters. Now you change your story and say that it comes from an "official Swedish Government document" (which is a dubious claim, by the way, I need to look further into that). What seems to be completely lost on you is the possibility that this "official Swedish Government document" may not make such a claim; and that perhaps this is just a claim raised by Gripen fanboys based on a misinterpretation of the "Swedish Government document". Also; where do you read that "the RCS goal for the Gripen E was to be those 0.1 square meters"? I have not been able to find any claims like that in any "official Swedish Government document". Please provide a source.

So, we have now moved from "Saab claims..." to "Gripen fanboys claim...".

I hope you can learn from this incident, and that we can have a higher precision in the discussions moving forward, hopefully with more facts and less dubious assumptions
Assumptions are of course fine on a discussion forum, however then they should be clearly marked as such, and not presented as "facts".

[loke]

They ended up purchasing it based on cost anyway.

Cost and technical requirements... They made clear 2 things: 1. Gripen was not the most capable of the three (actually it was the least capable) and 2. in the end it was deemed to meet minimal requirements. Also strange that it was invited to this second round, especially since SH and F-35 are also in the race this time around. If for some (political) reason F-35 is not chosen then the SH seems the obvious choice, right? Highly capable and much cheaper than Rafale/Typhoon. Thus that leaves no room for a fighter that does not meet requirements -- unless of course it does...

That is incorrect. In the Swiss competition, the Gripen didn't even meet the basic requirements and it was specifically noted that the Gripen was behind in multiple scenarios to the F-18 that it was slated to replace.

Sources please?

The Swiss competition produced thousands of pages of documents. Just a very limited number was leaked, presenting a part of the story at one particular point in time. Also keep in mind that the leaks most likely were done to influence the process... Several pages were missing from the leaked documents, which seems strange. The main point however seems to be that at the time of the initial eval Gripen E was very far from being finished. This led, as stated in my previous posting, to the implementation of the "uncertainty factor". It is my understanding that in subsequent evaluation (later parts of the eval that for some reason were not leaked) the Swiss received updated information on Gripen E development which may have led to a change in the "uncertainty factor" and by implication, a higher score in some subcategories. In any case, the Swiss government did state that:

1. Gripen E was not the highest performing
2. Gripen E did meet minimal technical requirements.

A leaked 2009 report shook that confidence, as it revealed that the Gripen finished below the Rafale and Eurofighter in almost all areas, and was rated as not meeting competition specifications in key areas like air superiority. Swiss authorities countered that the JAS-39E version offered in the 2010 RFP was fully compliant, and subsequent ratings did give it a “good enough” score.

https://www.defenseindustrydaily.com/sw ... -5s-04624/

[marsavian]

From the original source study which I linked to twice now and indicates where they expected NG to come out at;

JAS 39 vilket har skrov där signaturdämpande åtgärder har vidtagits. Radarmålarea 0,1 m2

aka

JAS 39, which has hulls where signature-reducing measures have been taken. Radar target area 0.1 m2

[loke]

From the original source study which I linked to twice now and indicates where they expected NG to come out at;

JAS 39 vilket har skrov där signaturdämpande åtgärder har vidtagits. Radarmålarea 0,1 m2

aka

JAS 39, which has hulls where signature-reducing measures have been taken. Radar target area 0.1 m2

Thanks for linking to this document, it is indeed very interesting.

However, I interpret the contents very differently from you. The way I read this document, is that it is a theoretical work, describing some very interesting aspects of modern warfare. To do this, it helps a lot to make it more concrete, using specific numbers as examples -- however, it is very naive to believe that the Swedes would publish highly classified numbers like RCS of existing Swedish systems in such a research document. Thus, the obvious conclusion is that the numbers presented in this document is probably disconnected from the real values, they should be considered as theoretical examples only.

Think: do you really believe that researchers in Sweden would be allowed to publish such highly classified data??

Ricnunes: I do not know if this was the document you were referring to? If yes, please carefully study my arguments above, and please spend some time to reflect on this; however, in addition, please also note the following: In addition to being a purely theoretical work with some example numbers, this theoretical work does NOT refer to Gripen E (at least, I was not able to find any reference to Gripen E). How and where did you "find" that piece of "information"? You often demand from others to back up their claims by a source -- now the time has come for you to present sources of your claims.

Again: hopefully the level of precision will from now on increase in this discussion...

[marsavian]

No it doesn't. The engine face has always been hidden on Gripen (kudos) but the Canards are the dogs bullocks sticking out. And there is no lipstick one can put on them. Even if they are planformed to the delta wing, its been explained in here several times that theres no fixing them.

How do the Chinese manage to fix theirs on the J-20 and claim an RCS of 0.05 sq m which optics calculations, e.g APA, have confirmed is a LO if not VLO airframe ?

You're not really using APA, (Koop, Goon and co clown club) as a source, are you? You've just lost the argument before you started.
It's reported that the Indians said, the SU-57 is 0.5

Yes, when they are quoting actual scientific studies. I am not biased against sources unlike some others here who seem very tribal in their arguments.

http://www.ausairpower.net/APA-2011-03.html

Conclusions

This study has explored the specular Radar Cross Section of the Chengdu J-20 prototype aircraft shaping design. Simulations using a Physical Optics simulation algorithm were performed for frequencies of 150 MHz, 600 MHz, 1.2 GHz, 3.0 GHz, 6.0 GHz, 8.0 GHz, 12.0 GHz, 16.0 GHz and 28 GHz without an absorbent coating, and for frequencies of 1.2 GHz, 3.0 GHz, 6.0 GHz, 8.0 GHz, 12.0 GHz, 16.0 GHz with an absorbent coating, covering all angular aspects of the airframe.

In addition, the performance of a range of Chinese developed radar absorbers was modelled, based on a reasonable survey of unclassified Chinese research publications in the area. None of the surveyed materials were found to be suitable for use as impedance matched specular radar absorbers.

If the production J-20 retains the axisymmetric nozzles and smoothly area ruled sides, the aircraft could at best deliver robust Very Low Observable performance in the nose aspect angular sector.

If the production J-20 introduces a rectangular faceted nozzle design, and refinements to fuselage side shaping, the design would present very good potential for robust Very Low Observable performance in the S-band and above, for the nose and tail aspect angular sectors, with good performance in the beam aspect angular sector.

In conclusion, this study has established through Physical Optics simulation across nine frequency bands, that no fundamental obstacles exist in the shaping design of the J-20 prototype, which would preclude its development into a genuine Very Low Observable design.

http://www.ausairpower.net/APA-J-XX-Prototype.html

Technical Observations on the Prototype Design

The J-XX/J-20 is a large fighter, similar in size to an F-111. This first-of-type aircraft presents with a large dihedral canard-delta wing configuration; with a pair of outward/rearward canted all moving combined vertical/horizontal tails; and, similarly large, outward canted ventral fins/strakes which, if all moving like the tails and retained on any production version, will make for some quite advanced capability options in the areas of controllability and manoeuvrability. There is little doubt this configuration is intended to provide good sustained supersonic cruise performance with a suitable engine type, and good manoeuvre performance in transonic and supersonic regimes.

The stealth shaping is without doubt considerably better than that seen in the Russian T-50 PAK-FA prototypes and, even more so, than that seen in the intended production configuration of the F-35 Joint Strike Fighter.

The J-XX/J-20 design appears to be largely built around the stealth shaping design rules employed in the F-22A Raptor:

The chined J-XX/J-20 nose section and canopy are close in appearance to the F-22, yielding similar signature performance in a mature design.

The J-XX/J-20 trapezoidal edge aligned engine inlets are closest to the F-22, though appear to be larger and employ an F-35 style DSI (Diverterless Supersonic Inlet) design, obviously intended to improve on F-22 inlet edge signature.

The J-XX/J-20 wing fuselage join, critical for beam and all aspect stealth, is in shaping and angle very similar to the F-22, and clearly superior to both the Russian T-50 PAK-FA prototypes and the F-35 Joint Strike Fighter.

The J-XX/J-20 flat lower fuselage is optimal for all aspect wideband stealth, and emulates the F-22 design closely.

Planform alignment of the J-XX/J-20 shows exact angular alignment between canard and delta leading edges, and exact crossed (starboard to port, port to starboard) angular edge alignment between canard and delta trailing edges. Leading edge sweep is ~43°, clearly intended for efficient supersonic flight.

The J-XX/J-20 nose and main undercarriage doors employ X-band optimised edge serration technology, based on F-117A and F-22 design rules.

The aft fuselage, tailbooms, fins/strakes and axi-symmetric nozzles are not compatible with high stealth performance, but may only be stop-gap measures to expedite flight testing of a prototype.

[SpudmanWP]

Since Koop was involved in the "study" itself, that pretty much negates it's results.

[optimist]

You're not really using APA, (Koop, Goon and co clown club) as a source, are you? You've just lost the argument before you started.
It's reported that the Indians said, the SU-57 is 0.5

Yes, when they are quoting actual scientific studies. I am not biased against sources unlike some others here who seem very tribal in their arguments.

http://www.ausairpower.net/APA-2011-03.html

Conclusions

This study has explored the specular Radar Cross Section of the Chengdu J-20 prototype aircraft shaping design. Simulations using a Physical Optics simulation algorithm were performed for frequencies of 150 MHz, 600 MHz, 1.2 GHz, 3.0 GHz, 6.0 GHz, 8.0 GHz, 12.0 GHz, 16.0 GHz and 28 GHz without an absorbent coating, and for frequencies of 1.2 GHz, 3.0 GHz, 6.0 GHz, 8.0 GHz, 12.0 GHz, 16.0 GHz with an absorbent coating, covering all angular aspects of the airframe.

In addition, the performance of a range of Chinese developed radar absorbers was modelled, based on a reasonable survey of unclassified Chinese research publications in the area. None of the surveyed materials were found to be suitable for use as impedance matched specular radar absorbers.

If the production J-20 retains the axisymmetric nozzles and smoothly area ruled sides, the aircraft could at best deliver robust Very Low Observable performance in the nose aspect angular sector.

If the production J-20 introduces a rectangular faceted nozzle design, and refinements to fuselage side shaping, the design would present very good potential for robust Very Low Observable performance in the S-band and above, for the nose and tail aspect angular sectors, with good performance in the beam aspect angular sector.

In conclusion, this study has established through Physical Optics simulation across nine frequency bands, that no fundamental obstacles exist in the shaping design of the J-20 prototype, which would preclude its development into a genuine Very Low Observable design.

http://www.ausairpower.net/APA-J-XX-Prototype.html

Technical Observations on the Prototype Design

The J-XX/J-20 is a large fighter, similar in size to an F-111. This first-of-type aircraft presents with a large dihedral canard-delta wing configuration; with a pair of outward/rearward canted all moving combined vertical/horizontal tails; and, similarly large, outward canted ventral fins/strakes which, if all moving like the tails and retained on any production version, will make for some quite advanced capability options in the areas of controllability and manoeuvrability. There is little doubt this configuration is intended to provide good sustained supersonic cruise performance with a suitable engine type, and good manoeuvre performance in transonic and supersonic regimes.

The stealth shaping is without doubt considerably better than that seen in the Russian T-50 PAK-FA prototypes and, even more so, than that seen in the intended production configuration of the F-35 Joint Strike Fighter.

The J-XX/J-20 design appears to be largely built around the stealth shaping design rules employed in the F-22A Raptor:

The chined J-XX/J-20 nose section and canopy are close in appearance to the F-22, yielding similar signature performance in a mature design.

The J-XX/J-20 trapezoidal edge aligned engine inlets are closest to the F-22, though appear to be larger and employ an F-35 style DSI (Diverterless Supersonic Inlet) design, obviously intended to improve on F-22 inlet edge signature.

The J-XX/J-20 wing fuselage join, critical for beam and all aspect stealth, is in shaping and angle very similar to the F-22, and clearly superior to both the Russian T-50 PAK-FA prototypes and the F-35 Joint Strike Fighter.

The J-XX/J-20 flat lower fuselage is optimal for all aspect wideband stealth, and emulates the F-22 design closely.

Planform alignment of the J-XX/J-20 shows exact angular alignment between canard and delta leading edges, and exact crossed (starboard to port, port to starboard) angular edge alignment between canard and delta trailing edges. Leading edge sweep is ~43°, clearly intended for efficient supersonic flight.

The J-XX/J-20 nose and main undercarriage doors employ X-band optimised edge serration technology, based on F-117A and F-22 design rules.

The aft fuselage, tailbooms, fins/strakes and axi-symmetric nozzles are not compatible with high stealth performance, but may only be stop-gap measures to expedite flight testing of a prototype.

We all started somewhere. I'm just glad it's in text. So I can link it back to you in a few years. We can reminisce. Remember when you used APA as a source and then doubled down with 2 links? They were fun times.
I'm not that far from Goon, I last spoke to him probable 5 years ago. He's not doing much, just rambles on twitter now. All the dreams and $2 companies of the group of misfits, have faded.

[loke]

Since Koop was involved in the "study" itself, that pretty much negates it's results.

Not necessarily -- I have seen people with a much deeper understanding of this than either of us, having a more nuanced view, and stating that "part of the APA analysis is bona fide"; however at the same time a lot of it is clearly pure crap. you need to be an expert to determine which is which, so therefore I agree that if you lack that level of understanding it is better to dismiss their analysis (just like one should be very sceptical of claims on Wikipedia) and instead rely on other, more credible sources.

[optimist]

Since Koop was involved in the "study" itself, that pretty much negates it's results.

Not necessarily -- I have seen people with a much deeper understanding of this than either of us, having a more nuanced view, and stating that "part of the APA analysis is bona fide"; however at the same time a lot of it is clearly pure crap. you need to be an expert to determine which is which, so therefore I agree that if you lack that level of understanding it is better to dismiss their analysis (just like one should be very sceptical of claims on Wikipedia) and instead rely on other, more credible sources.

Lets get a bit of reality into this. Koop is a mobile phone guy
Goon was an engineer, who may have had a hand in the f-111 fuel tank sealing issue. He was given a couple of minor tasks after he retired, that led nowhere.They both had pipedreams of getting rich from redoing the F-111, that ended in tears. it was sour grapes for a few years, but the group have gone their own way. There were a couple of other retired RAAF guys in there. One was piss*d because he didn't get his last year in the reserve, on full pay to boost the pension payout. Another was a simmer who turned a board game into a sim on the site. the one where the SU rules the sky.

[swiss]

The Swiss competition produced thousands of pages of documents. Just a very limited number was leaked, presenting a part of the story at one particular point in time. Also keep in mind that the leaks most likely were done to influence the process... Several pages were missing from the leaked documents, which seems strange. The main point however seems to be that at the time of the initial eval Gripen E was very far from being finished. This led, as stated in my previous posting, to the implementation of the "uncertainty factor". It is my understanding that in subsequent evaluation (later parts of the eval that for some reason were not leaked) the Swiss received updated information on Gripen E development which may have led to a change in the "uncertainty factor" and by implication, a higher score in some subcategories. In any case, the Swiss government did state that:

1. Gripen E was not the highest performing
2. Gripen E did meet minimal technical requirements.

A leaked 2009 report shook that confidence, as it revealed that the Gripen finished below the Rafale and Eurofighter in almost all areas, and was rated as not meeting competition specifications in key areas like air superiority. Swiss authorities countered that the JAS-39E version offered in the 2010 RFP was fully compliant, and subsequent ratings did give it a “good enough” score.

Sorry Loke you are wrong. The Swiss Government was laying. The leaked Results say clearly the Gripen-E didn't reach the expected Capabilities. ( score 6) Which also means the Gripem was inferior to the Hornet C/D.










Here you can read the complete leaked evaluation.

https://de.scribd.com/doc/81390363/Swis ... the-Rafale

[loke]

The Swiss competition produced thousands of pages of documents. Just a very limited number was leaked, presenting a part of the story at one particular point in time. Also keep in mind that the leaks most likely were done to influence the process... Several pages were missing from the leaked documents, which seems strange. The main point however seems to be that at the time of the initial eval Gripen E was very far from being finished. This led, as stated in my previous posting, to the implementation of the "uncertainty factor". It is my understanding that in subsequent evaluation (later parts of the eval that for some reason were not leaked) the Swiss received updated information on Gripen E development which may have led to a change in the "uncertainty factor" and by implication, a higher score in some subcategories. In any case, the Swiss government did state that:

1. Gripen E was not the highest performing
2. Gripen E did meet minimal technical requirements.

A leaked 2009 report shook that confidence, as it revealed that the Gripen finished below the Rafale and Eurofighter in almost all areas, and was rated as not meeting competition specifications in key areas like air superiority. Swiss authorities countered that the JAS-39E version offered in the 2010 RFP was fully compliant, and subsequent ratings did give it a “good enough” score.

Sorry Loke you are wrong. The Swiss Government was laying. The leaked Results say clearly the Gripen-E didn't reach the expected Capabilities. ( score 6) Which also means the Gripem was inferior to the Hornet C/D.










Here you can read the complete leaked evaluation.

https://de.scribd.com/doc/81390363/Swis ... the-Rafale

Sorry but the leaked report did not include what happened later, please read the link I provided above.

[nathan77]

Quoting APA is like quoting Sputnik or RT - it's biased at best and complete propaganda most of the time.

I remember watching the Australian Senate hearing into the F-35, and the APA report was trotted out by Senator Xenophon. The Air Force simply said that their assumptions were completely wrong - and so their conclusions were completely wrong. I.e. manure in -> manure out.

To those who actually like to use them as a source, I normally just ask: "Is there anything that APA has ever gotten right?"
I certainly can't think of an example.

[kimjongnumbaun]

Sources please?

The multiple times they say that the F-18 is superior to the Gripen.

https://www.scribd.com/doc/81390363/Swi ... the-Rafale

Sorry but the leaked report did not include what happened later, please read the link I provided above.

Are you referring to the MS32 upgrades that were taken into account? Or are you referring to the Gripen E that was a paper airplane at the time(and still is)?