Sukhoi PAK FA

[bhramos]

 

[bhramos]

 

[Blademaster]

How stealthy is this plane if you can see the rivets sticking out like a sore thumb?

 

[Super Flanker]

How stealthy is this plane if you can see the rivets sticking out like a sore thumb?

Can you please point out where you can see rivets on Su-57? And talking about how stealthy the Su-57 is, then it is having a higher RCS than other 5th generation stealth fighters like F-22 or F-35. In my opinion, even J-20 is more Stealthy than Su-57.

 

[Blademaster]

Can you please point out where you can see rivets on Su-57? And talking about how stealthy the Su-57 is, then it is having a higher RCS than other 5th generation stealth fighters like F-22 or F-35. In my opinion, even J-20 is more Stealthy than Su-57.

Starting at 7 seconds you can see the rivets in the background and then at 11 seconds and then even more prominently at 14 seconds. The biggest one was around 17 seconds as the pilot was climbing up to the cockpit.

 

[Super Flanker]

Starting at 7 seconds you can see the rivets in the background and then at 11 seconds and then even more prominently at 14 seconds. The biggest one was around 17 seconds as the pilot was climbing up to the cockpit.

All planes have rivets in them, even other Stealth planes like F-22, F-35 or J-20 have some form of rivets in them, so the Su-57 is no exception here, it too has rivets in it. Not just military planes, like I said before, pretty much every plane built today has rivets in them, even civillian airliners made by companies like Boeing or Airbus have rivets in their airframe.

1. Here is Photo of F-22 with rivets.

2. Here is Photo of J-20 with rivets.

 

[Blademaster]

All planes have rivets in them, even other Stealth planes like F-22, F-35 or J-20 have some form of rivets in them, so the Su-57 is no exception here, it too has rivets in it. Not just military planes, like I said before, pretty much every plane built today has rivets in them, even civillian airliners made by companies like Boeing or Airbus have rivets in their airframe.

1. Here is Photo of F-22 with rivets.

View attachment 179397

2. Here is Photo of J-20 with rivets.

View attachment 179399

yes but they don't stick out like a sore thumb as the Su-57 does.

 

[Super Flanker]

yes but they don't stick out like a sore thumb as the Su-57 does.

In my opinion, the Su-57's rivets stick out just like the rivets on any other stealth plane like J-20, F-22, F-35 etc.

 

[Blademaster]

And talking about how stealthy the Su-57 is, then it is having a higher RCS than other 5th generation stealth fighters like F-22 or F-35. In my opinion, even J-20 is more Stealthy than Su-57.

If it wasn't for the rivets sticking out like a sore thumb I would rate Su-57 more stealthy than the J-20.

 

[Super Flanker]

If it wasn't for the rivets sticking out like a sore thumb I would rate Su-57 more stealthy than the J-20.

Why do you keep saying that the rivets on Su-57 stick out like a sore thumb? The Su-57, like any other stealth plane like J-20, F-22 or F-35 has rivets which are well built into their airframe and are optimised for stealth. Also, the newly upgraded Su-57 which Sergey Bogdan flew recently seems to be a prototype to me, if we compare the rivets on that of Su-57's prototypes and that of its production models then there is a noticeable difference, the rivets on production models of Su-57 are built into the airframe better and more "flushed" in comparison to rivets on Su-57 prototypes. The above Su-57 in the video seems to be most likely a prototype to test new technologies as evident that it is a new variant of Su-57 which further proves to me that this is indeed a prototype. Coming to comparison between J-20 and Su-57, even if J-20 and Su-57 had the same level of build-quality in their rivets then too the J-20 would be more Stealthy than Su-57.

 

[Blademaster]

Why do you keep saying that the rivets on Su-57 stick out like a sore thumb? The Su-57, like any other stealth plane like J-20, F-22 or F-35 has rivets which are well built into their airframe and are optimised for stealth. Also, the newly upgraded Su-57 which Sergey Bogdan flew recently seems to be a prototype to me, if we compare the rivets on that of Su-57's prototypes and that of its production models then there is a noticeable difference, the rivets on production models of Su-57 are built into the airframe better and more "flushed" in comparison to rivets on Su-57 prototypes. The above Su-57 in the video seems to be most likely a prototype to test new technologies as evident that it is a new variant of Su-57 which further proves to me that this is indeed a prototype.

Please take another look at the video and compare to the F-22 and J-20. At least those rivets are flushed while Su-57's rivets aren't. If you can't see what I am see, then it is just a matter of opinion and we are not going to agree on this.

 

[Super Flanker]

Please take another look at the video and compare to the F-22 and J-20. At least those rivets are flushed while Su-57's rivets aren't. If you can't see what I am see, then it is just a matter of opinion and we are not going to agree on this.

If you are Comparing the Su-57 in the video then you are most probably comparing a prototype because like I said before, the Su-57 in the video was an upgraded one and was used to test new technologies so this further proves my point that this is indeed a prototype. You are comparing the rivets on a prototype to that of production models of fighters like F-22 and J-20, ofcource the production models will have a better build quality and obviously their rivets will be more flushed in comparison to a prototype. Also the in the video, the timestamp at which Sergey Bogdan is climbing the ladder to sit in the Su-57, we can see rivets in the nosecone section of the fuselage, these rivets look really similar in build quality to the ones found on F-22 (of which I had posted a photo before) so I don't see how they are not flushed like on F-22 and J-20. Ofcourse we both have different views on it, so we can always feel free to disagree.

 

[blackjack]

can we atleast compare rivets of the aircrafts to each other, I think a discussion about this shit has gone 100 pages back. Atleast lets get creative and judge the Su-70 or Su-75 drone and aircrafts stealthiness on a seperate thread because we have been over this shit so many times.

 

[bhramos]

 

[StealthFlanker]

To be honest, That doesn’t look anything like a hypersonic missile. It doesn’t have any inlet to be a scramjet missile. The nozzle look more like jet engine rather than rocket engine. There is also no wing/fin for stability.
I also can’t find any other source for that photo
except your twitter. Where do you originally get the photo from?

 

[bhramos]

To be honest, That doesn’t look anything like a hypersonic missile. It doesn’t have any inlet to be a scramjet missile. The nozzle look more like jet engine rather than rocket engine. There is also no wing/fin for stability.
I also can’t find any other source for that photo
except your twitter. Where do you originally get the photo from?

FB my source. pic from Ace combat is just for reference not original.

 

[blackjack]

Just want to keep the photonic radar hype for Su-57 alive. http://www.promweekly.ru/book/Phasatron-100_years.pdf

pdf page 14

The inexhaustibility of scientific thought
Among the promising developments are conformal AFARs that can fit
into the aircraft fuselage, and
the so-called "smart" airframe skin.
In next generation fighters,
including PAK FA, it will become, as it were, a single transceiver locator, providing the pilot with complete information
about what is happening around the aircraft.
Fazotron-NIIR continues development
national radar. The Corporation has developed and mass-produced
multifunctional airborne radar stations of the “4+” and “4++” generation
for the Russian Air Force and foreign customers.
Photonic technologies used today
will expand the capabilities of the radar,
reduce its mass by more than half, and increase its resolution tenfold.
Such radars with radio-optical phased antenna arrays are capable of making a kind of “X-ray image”
aircraft located more than
500 kilometers, and give them a detailed, three-dimensional image. This technology
allows you to look inside the object, find out
what equipment does it carry, how many people are in it
located, and even see their faces.
Fazotron-NIIR Corporation in the 21st century —
one of the most significant strategic
defense enterprises of Russia thanks to its unique technologies, know-how,
production base and highly professional personnel. Today color and pride
his scientific school is A. Kanashchenkov,
Yu. Guskov, V. Frantsev, I. Ryzhak, I. Tsivlin, O. Samarin, V. Babichev, A. Matyushin,
V. Ratner, V. Kustov, V. Kurilkin, N. Gorkin,
P. Kolodin, S. Loginov, S. Zaikin and others.
No matter what ups and downs it goes through
enterprise, one for a hundred years
existence was unchanged - work
for the defense of the country, for aviation, the creation of first-class equipment that has no analogues
in the country, and sometimes in the world. And ahead
Fazotron-NIIR Corporation has a wide
front of work, which, undoubtedly, has not yet been
once glorify both the enterprise itself and the country

Everyone remembers how the photonic radar antennas looked like, if you havent here is a refresher.

only these radar antennas make a smart skin possible than just usually putting them in the fuselage because they were reported as being thinner than paper.

I will be busy looking at some random promweekly.ru articles, the only reason i was browsing the website was for KRET magazines but I cant find them there since they did before provide us radar information from the K-27M and the Ka-52 Katran.

 

[blackjack]

@StealthFlanker I see your username being thanked by this author Su-57 Radar scattering simulation – Aircraft 101 (wordpress.com) Can you ask the author to unban Bart by any chance since I heard he thanked you materialize the project assuming that you guys happen to be well acquainted by any chance? I want to create an account just to get Bart's email and see if he can join this forum along with some other forums. This post is just from another user from Russia defense net and everything below this paragraph is not from me.

Just going to drop this here in case anyone has seen the new simulation of Su-57's RCS, where the Su-57 doesn't seem to do so well:

In the comments below that article you can see a little thread between the author and a certain "Bart", who challenges the simulation results somewhat. The conversation ends with the author doubling down on his position, namely that the "tunnel" between the two engines on the bottom of the aircraft serves as a corner reflector for radars illuminating the aircraft from the nose aspect and that is why the aircraft has a really poor bottom nose aspect RCS.

Now, because I am, shall we say, prosaically united to Bart, and I have it on good authority that Bart cannot post any more comments on that thread due to what appears to be a ban (and Bart waited a week for any potential technical issues to be resolved, while in the meantime other people posted on other threads on that page without issue it seems), I want to answer the author's final comment here, so there is an online reference to what Bart would have said had he not been banned:


I've already stated that yes, the "engine tunnel" can be regarded as a dihedral corner reflector (actually two, one for waves coming from the bottom left beam aspect and one for waves coming from the bottom right beam aspect). That does not, however, apply to waves coming from the nose aspect:
look carefully at the image you posted and you will see that the points of incidence of the rays on the two surfaces are all in a straight line (with one 90° turn at the edge where the two planes join), which traces the longitudinal middle axis of the two planes; this is because those rays are all located in the same two-dimensional plane, which intersects the dihedral reflector at that axis. So to transfer the analogy to the "engine tunnel" of the Su-57 you would have to shoot the waves in a 2D-plane perpendicular to the longitudinal axis of the aircraft, i.e. from one of the beam aspects of the aircraft, not the nose aspect.

Shooting waves from the nose aspect will mean the rays are not perpendicular and so will simply bounce off the planes and continue in the other direction; in order for them to return to the sender, you either need a dihedral reflector that is properly oriented (arguably this could be the intake and SRAAM bays, more on that in a bit) or you need a trihedral reflector, such as in the following image:

See how in the above image a ray comes in, bounces off one plane, then another and then it would actually keep traveling away from the ray's source if it were not for the third plane, which makes it go back. There is no such third plane in the "engine tunnel".

Regarding the modeling of material: APA will still have to have defined an inlet shape, because they need to constrain where the "black hole" ends. They could have defined this "black hole" as being inside the engine nacelles and thus not affecting waves interacting with the outside of the nacelle; in fact, that is the most reasonable assumption about their analysis and how it's usually done if one doesn't want to model the engines.
It is correct that we just can't know the exact makeup of RAS/RAM and material distribution, so I'm not faulting you for using an all-metal model, but my point still stands: any strong return signal, such as your model and, to some degree, APA's model show in the lower frontal sector needs to be treated with suspicion, because the engineers involved in the aircraft's design will know how to conduct these kinds of analyses, too, and try to eliminate such problems (since the aircraft is supposed to have a significantly reduced signature, i.e. that's one of the design goals).
This means that returns from places that are clearly not load bearing (such as the inlets and SRAAM covers) should be suspected to have materials properties, which make them not reflect in that worst-possible way. This could be thin metal liners beneath RAS/RAM, which have a slightly different shape or it could mean that they are radar transparent. In the case of this potential dihedral corner reflector formed from the inlet side and the medial part of the SRAAM bay, a radar transparent inlet would actually completely remove the problem. In the case of the SRAAM bay as its own source of specular reflection, I suspect that RAS/RAM and some metal liner with unknown exact angle is indeed used beneath the composite material.
And finally, the DIRCM turret itself (not the cover) is actually quite small and made of unknown material; there is no reason why it couldn't be 3D-printed from some kind of plastic, for example, either completely without metal parts or with metal parts that are smaller than the pilot tubes (which the F-35 also has, btw.). So stating that modeling of the DIRCM cover as 100% metal is going to produce a lower RCS than alternatives is not true. And since it is supposed to be transparent to strong laser light, the choice of metal layers would also be limited in order to not interfere with the DIRCM function. A more reasonable assumption here is that it does not contain such a metal layer (unlike the canopy, which almost certainly does).

So now that I've defended Bart's honor in the face of this NAFO imbecile who can't understand that space has three dimensions (and what's worse, another NAFO imbecile has already started liking his posts...Lord have mercy!), I want to end on the positive note of how this whole encounter actually made me like the Su-57 even more:
If one looks at the APA results for, e.g., 6 GHz, it becomes clear that the bad returns in the above mentioned blog's simulation correspond to the "four streaks" in the middle of the following image taken from APA (somewhat vertical lines in the middle horizontally and in the third quarter from the top vertically) as well as the stronger signal directly below that:

The "four streaks" come from the corner reflector created by the apico-lateral inlet surface and the medial SRAAM surface, which is easily verifiable, e.g. by looking at an appropriate image of the Su-57 (e.g. see below, ignore the pod) and using two hand-held mirrors and a shut eye while emulating the angles (or just use your brain):

As my syn-prosopon would have pointed out, this corner reflector only works if it is assumed that the apical inlet and SRAAM bay surfaces are entirely made out of metal; even if just the first, lets say, 15 cm of the inlet are radar-transparent composite or have some RAS mitigation, the effect is lost. The stronger signal referred to above, that is in the APA image below the "four streaks", can in turn be explained by the lower apical intake lip, which would be a direct specular reflector for such angles; as it is very likely to have the same mitigation, that means this part of the RCS signature should also be disregarded.

Therefore, I suspect that the Su-57 may have even better frontal aspect stealth than the F-35!
And all the NAFO trolls can do is ban/de-platform/propagandize

If anyone should agree with me and feel the need to correct the injustice of the banning of Bart, feel free to leave comments on the above linked blog...I recommend not using straight up insults, as the author has set up strict content moderation with pre-approval for new commenters and there's no need for that; instead, how about limb-style comments like:
"Has the F-35B and F-35C fixed the problem of being essentially an expensive sub-sonic aircraft yet?"
"Isn't a round nozzle on the F-35 really bad for stealth?"
"I read that the US military has said that the F-35 has failed. Why is that?"

Or, a bit less emo-marxist:
"Why does your article about stealth imply that the F-35 has smaller RCS than an insect when the pilot tubes alone are bigger than most insects?"

Or, related to Bart's above reply:
"If a bullet ricochets twice when you shoot it down a perfectly straight tunnel, does it reverse its flight path and fly back to you?"

 

[StealthFlanker]

@StealthFlanker I see your username being thanked by this author Su-57 Radar scattering simulation – Aircraft 101 (wordpress.com) Can you ask the author to unban Bart by any chance since I heard he thanked you materialize the project assuming that you guys happen to be well acquainted by any chance? I want to create an account just to get Bart's email and see if he can join this forum along with some other forums. This post is just from another user from Russia defense net and everything below this paragraph is not from me.

Just going to drop this here in case anyone has seen the new simulation of Su-57's RCS, where the Su-57 doesn't seem to do so well:

In the comments below that article you can see a little thread between the author and a certain "Bart", who challenges the simulation results somewhat. The conversation ends with the author doubling down on his position, namely that the "tunnel" between the two engines on the bottom of the aircraft serves as a corner reflector for radars illuminating the aircraft from the nose aspect and that is why the aircraft has a really poor bottom nose aspect RCS.

Now, because I am, shall we say, prosaically united to Bart, and I have it on good authority that Bart cannot post any more comments on that thread due to what appears to be a ban (and Bart waited a week for any potential technical issues to be resolved, while in the meantime other people posted on other threads on that page without issue it seems), I want to answer the author's final comment here, so there is an online reference to what Bart would have said had he not been banned:


I've already stated that yes, the "engine tunnel" can be regarded as a dihedral corner reflector (actually two, one for waves coming from the bottom left beam aspect and one for waves coming from the bottom right beam aspect). That does not, however, apply to waves coming from the nose aspect:
look carefully at the image you posted and you will see that the points of incidence of the rays on the two surfaces are all in a straight line (with one 90° turn at the edge where the two planes join), which traces the longitudinal middle axis of the two planes; this is because those rays are all located in the same two-dimensional plane, which intersects the dihedral reflector at that axis. So to transfer the analogy to the "engine tunnel" of the Su-57 you would have to shoot the waves in a 2D-plane perpendicular to the longitudinal axis of the aircraft, i.e. from one of the beam aspects of the aircraft, not the nose aspect.

Shooting waves from the nose aspect will mean the rays are not perpendicular and so will simply bounce off the planes and continue in the other direction; in order for them to return to the sender, you either need a dihedral reflector that is properly oriented (arguably this could be the intake and SRAAM bays, more on that in a bit) or you need a trihedral reflector, such as in the following image:

View attachment 185249
See how in the above image a ray comes in, bounces off one plane, then another and then it would actually keep traveling away from the ray's source if it were not for the third plane, which makes it go back. There is no such third plane in the "engine tunnel".

Regarding the modeling of material: APA will still have to have defined an inlet shape, because they need to constrain where the "black hole" ends. They could have defined this "black hole" as being inside the engine nacelles and thus not affecting waves interacting with the outside of the nacelle; in fact, that is the most reasonable assumption about their analysis and how it's usually done if one doesn't want to model the engines.
It is correct that we just can't know the exact makeup of RAS/RAM and material distribution, so I'm not faulting you for using an all-metal model, but my point still stands: any strong return signal, such as your model and, to some degree, APA's model show in the lower frontal sector needs to be treated with suspicion, because the engineers involved in the aircraft's design will know how to conduct these kinds of analyses, too, and try to eliminate such problems (since the aircraft is supposed to have a significantly reduced signature, i.e. that's one of the design goals).
This means that returns from places that are clearly not load bearing (such as the inlets and SRAAM covers) should be suspected to have materials properties, which make them not reflect in that worst-possible way. This could be thin metal liners beneath RAS/RAM, which have a slightly different shape or it could mean that they are radar transparent. In the case of this potential dihedral corner reflector formed from the inlet side and the medial part of the SRAAM bay, a radar transparent inlet would actually completely remove the problem. In the case of the SRAAM bay as its own source of specular reflection, I suspect that RAS/RAM and some metal liner with unknown exact angle is indeed used beneath the composite material.
And finally, the DIRCM turret itself (not the cover) is actually quite small and made of unknown material; there is no reason why it couldn't be 3D-printed from some kind of plastic, for example, either completely without metal parts or with metal parts that are smaller than the pilot tubes (which the F-35 also has, btw.). So stating that modeling of the DIRCM cover as 100% metal is going to produce a lower RCS than alternatives is not true. And since it is supposed to be transparent to strong laser light, the choice of metal layers would also be limited in order to not interfere with the DIRCM function. A more reasonable assumption here is that it does not contain such a metal layer (unlike the canopy, which almost certainly does).

So now that I've defended Bart's honor in the face of this NAFO imbecile who can't understand that space has three dimensions (and what's worse, another NAFO imbecile has already started liking his posts...Lord have mercy!), I want to end on the positive note of how this whole encounter actually made me like the Su-57 even more:
If one looks at the APA results for, e.g., 6 GHz, it becomes clear that the bad returns in the above mentioned blog's simulation correspond to the "four streaks" in the middle of the following image taken from APA (somewhat vertical lines in the middle horizontally and in the third quarter from the top vertically) as well as the stronger signal directly below that:

View attachment 185250
The "four streaks" come from the corner reflector created by the apico-lateral inlet surface and the medial SRAAM surface, which is easily verifiable, e.g. by looking at an appropriate image of the Su-57 (e.g. see below, ignore the pod) and using two hand-held mirrors and a shut eye while emulating the angles (or just use your brain):

View attachment 185251
As my syn-prosopon would have pointed out, this corner reflector only works if it is assumed that the apical inlet and SRAAM bay surfaces are entirely made out of metal; even if just the first, lets say, 15 cm of the inlet are radar-transparent composite or have some RAS mitigation, the effect is lost. The stronger signal referred to above, that is in the APA image below the "four streaks", can in turn be explained by the lower apical intake lip, which would be a direct specular reflector for such angles; as it is very likely to have the same mitigation, that means this part of the RCS signature should also be disregarded.

Therefore, I suspect that the Su-57 may have even better frontal aspect stealth than the F-35!
And all the NAFO trolls can do is ban/de-platform/propagandize

If anyone should agree with me and feel the need to correct the injustice of the banning of Bart, feel free to leave comments on the above linked blog...I recommend not using straight up insults, as the author has set up strict content moderation with pre-approval for new commenters and there's no need for that; instead, how about limb-style comments like:
"Has the F-35B and F-35C fixed the problem of being essentially an expensive sub-sonic aircraft yet?"
"Isn't a round nozzle on the F-35 really bad for stealth?"
"I read that the US military has said that the F-35 has failed. Why is that?"

Or, a bit less emo-marxist:
"Why does your article about stealth imply that the F-35 has smaller RCS than an insect when the pilot tubes alone are bigger than most insects?"

Or, related to Bart's above reply:
"If a bullet ricochets twice when you shoot it down a perfectly straight tunnel, does it reverse its flight path and fly back to you?"

Yes, I do know the author from F-16.net, she did ask me for some help
I don't think it is possible to ban someone on Wordpress, it is likely that if your comments have shortcut link or repetitive, it will just go to spam.
For the rest, the simulation ran by computer rather than some person physically trace the ray. Tracing the ray with a line like in your image won't be correct either because the beamwidth is affected by reflecting area, there are also sidelobes reflection and surfacewave with every reflection. To be close to the truth, you can make your own Su-57 model then ran it through Ansys or Matlab to see how it goes.
As for the DIRCM, the internal parts look like metal to me, there are also wiring and what not. But of course, you can always try modeling the internal without the hub and ran through Ansys /Matlab whatever then post your result for discussion

 

[Super Flanker]

Some photos of Su-57 which I got from online.

Here is a pic of Su-57 flying alongside a MiG-29. I remember watching a video on YouTube in which an Su-57 & MiG-29 were flying together, if I recall correctly it was at an Airshow. If I come across that video then I will quote this post & post the link of that video.

Spoiler: This pic is sort of very long & stretched so I am putting it in spoiler.