Sukhoi Su-57 / T-50 / PAK FA - flight testing and development Part II [2012-current]

[Squirrel]

New engines are not made so quickly, this is work for another 15 years. The letter that you read as the letter M is not it, it is 2 letters L in Russian transcription Л. That stands for Flying Lab (летающая лаборатория). English is not my native language, sorry for the mistakes.

Hm,there is T-50-2LL (Bort number 052 blue ) as that Flying Laboratory and Su-57M ( Bort number 511 blue) as Modernised. I know Russian language/letters.

 

[Dreamfighter]

Here you can see how efficient Su-57 is when rolling at high AoA, and at what speed it can point its nose in any direction.

Assuming the (test-)pilot executes such (demo-)manoeuvres regularly, I wonder at what speed he can now point his own nose in any direction. And if his wife is still complaining about his roll rates during 'high AoA' nights.

 

[RadicalDisconnect]

I can see there is some differences between serated petals, tnx . That engine is ?

That Salyut nozzle, they proposed AL-31FM3 and a follow on for PAK-FA but Sukhoi chose Saturn. Salyut nozzle clearly vectors differently from AL-41F1 and AL-31FP style nozzle.

 

[TSARb]

I can see there is some differences between serated petals, tnx . That engine is ?

...is photographed at the Salut's fab.

 

[stealthflanker]

Well, clearly there are still many who confused between Salyut and Saturn engine.

Current Su-57 engine are made by NPP Saturn, While NPP Salyut instead continue development of AL-31F lines making FM series and FN for China.

 

[Avimimus]

New engines are not made so quickly, this is work for another 15 years. The letter that you read as the letter M is not it, it is 2 letters L in Russian transcription Л. That stands for Flying Lab (летающая лаборатория). English is not my native language, sorry for the mistakes.

Your English is better than many of us native speakers!

 

[Willythekid]

HD wallpaper



This image has already made my whole year!

 

[PeregrineFalcon]

Your own chart shows that those lines terminate with hashed symbols, and above that, those lines are dashed. This strongly indicate that they're structural placard limits. This is specifically stated on the chart, “перегрузки,превышающие ограничения” or overload exceeds limits. The reference for 9g in the Su-27SK manual is used in conjunction with the 171,000kg overload under Mach 0.85, this overload chart may indicate a peacetime limit of 8g at 20,000kg, and I’ve not seen statements to say that ~171,200kg overload can be exceeded. So, I see nothing on how those limits can be exceeded, or by how much, other than assumptions. Probably it can aerodynamically pull that many g and structurally within the safety margin that’s designed for, but is structurally is off limits in normal use and severely reduces service life. Similar to the “paddle switch” on the F/A-18E/F Super Hornet that lets you override the g-limit but the aircraft immediately needs to be inspected for damage, so not a structural load it can regularly handle. Same with Su-27, pulling beyond the limit absolutely risks damaging airframe and is not to be done regularly.
Note this isn’t the same as F-15C with OWS, that system does raise the overall limit to 9g at appropriate weights. Without OWS, 7.33g.

You have basicaly repeated everything I have said, but we obviosly have different interpretations.
“перегрузки,превышающие ограничения” doesn't mean that going over the 8G limit will "overload/overstress" the airframe. Dashed lines represent the load factor in G's that the plane can sustain when the 8G limit is exceeded. Nowhere is it stated that if the 8G limit is overridden, the aircraft immediately needs to be inspected for damage, especially because at 20,000 kg and 8 G's, the plane is generating 160,000 kg of lift, which is below the 171,000 kg threshold anyway. That means tht the plane can pull 8,5G's and still be below the171,000 kg threshold.

Here is the data from the TsAGI:

It states that the maximum operational load factor below Mach 0.85 is 9G, the same as the F-15, but the maximum load factor above Mach 0.85 is 7.5G (if I remember correctly, the real G load for the F-15 in the transonic region is 7.33, as indicated on the chart). So, we can see that the transonic G limit differs from the limit in the chart you have posted, which is 7G and 139000kg.



On this chart, we can see that the "structural placard limits" are set at 8.5 G for the subsonic region and 7.5 G for the transonic and supersonic region. Does the subsonic 8.5 G "structural placard limit" mean that it is structurally off-limits to exceed it in normal use and that this will severely reduce the service life of the plane, as you have suggested?
I don't think so, because pulling the 9G at 19,000 kg is in line with the 171,000 kg threshold. The point I'm making is that without knowing the precise reasoning behind the suggested limits, we can't draw the most objective conclusions.

I might be wrong, so can you without more data at our disposal?!

Oh? What measurements do you have about the F-22's L/D? At what airspeeds? Validated by flight testing? Because this is entering into the territory of speculations down to a level of precision that's meaningless. And you're basing all your derivations and conclusions based on that?
And you say the Su-57 being unstable in pitch, which isn't even a unique feature of the aircraft as ALL modern fighters are unstable in pitch, beginning with the F-16. And to my knowledge the static margin of these fighters are unknown, nor the MAC aft limit so I don't see how this is a way to draw conclusions of anything.

Can you link me to this study? I like to know the source of your modeling and Cl and Cd numbers. Sure, the LEVCONs have aerodynamic benefits for the Su-57 shape but should not be considered an isolated benefit that can be individually compared to other aircraft without it. The LEVCONs are a way to control the particularly large strakes that the Su-57 has, an aircraft without similarly large strakes may not need it. And large strakes also add to surface area to increase parasitic drag.
All this can be modeled to an extent but unless they're from actual manufacturer modeling and data taking into account various fluid mechanics effects, and verified by flight testing, they can't be used to draw definite conclusions of anything.

I don't have a habit of making things up, and since my laptop broke, I have lost all my saved data. I have spent a considerable amount of time trying to find that study, but without success. Even without it, we can conclude that in cruise flight, the Su-27 has a superior L/D ratio even if we exclude the fuel fraction from the equation. Put 8,200 kg of fuel (which is 100% of the Raptor's internal fuel capacity) in the Su-27, and you can cover around 3,132 km, which is significantly more than what the F-22 can cover with the same amount of fuel. We can say that the F-22 has slightly less efficient engines, but that is not even close to making up for the difference.
And actually, it is you who has been speculating all this time. Unlike you, I'm just trying to present as much data available to make a point. This is the second time you are making this kind of baseless suggestions.
We can put to the test your claims of the influence of large strakes, and wide lifting body on overall drag of a plane.

Let us take, for example, the Su-27, which is the most classical example of a fighter with large strakes and a wide lifting body (blended wing body), and the F-15C, which is a classical example of a fighter with a conventional configuration without strakes. The F-15C actually has a superior thrust-to-weight ratio and superior wing loading, and despite that, the Su-27 has considerably superior instantaneous turn rate (ITR) and superior sustained turn rate (STR) at sea level.
For example, at 600 km/h, the Su-27 can pull around 9G while having around 30 deg/s ITR, or it can sustain slightly more than 20 deg/s at that speed. On the other hand, the F-15C can pull around 6.4G and have "just" 21 deg/s ITR, and around 18 deg/s at the same speed.
This only shows the aerodynamic efficiency of the LERX - wide lifting body layout, even if the plane in question has an inferior thrust-to-weight ratio and worse wing loading. The Su-57 patent claims that they have managed to increase the lift coefficient and reduce drag in both, subsonic and supersonic range of speed, which is absolutely unquestionable when looking at what the plane has been capable of doing thus far.

Here is what the Sergey bogdan has to say about it:

Сергей Богдан: свой пилотаж я оцениваю весьма сдержанно » Авиация России

Украшением и кульминацией любого Московского авиасалона, стали полёты российского истребителя 5-го поколения — Су-57 (ПАК ФА, Т-50). Об этом самолёте

aviation21.ru

And what does "LEVCONs are a way to control the particularly large strakes that the Su-57 has" even mean? LEVCONs are not controlling strakes; they act as canards during takeoff, serve a role similar to the LE flaps at conventional AoA regions to increase the L/D ratio, and function as pitch and roll/yaw control surfaces in the post-stall region.

Here is the link for the LEVCON study:

Leading-Edge Vortex Controller (LEVCON) Influence on the Aerodynamic Characteristics of a Modern Fighter Jet

The purpose of this paper is to assess the influence of a novel type of vortex creation device called the leading-edge vortex controller (LEVCON) on the aerodynamic characteristics of a fighter jet. LEVCON has become a trending term in modern military aircraft in recent years and is a...

www.mdpi.com

Even with suboptimal LEVCON deflection the results were extremly possitive.

Now, here is the information from the article by Dr. Song Wencong and proposals regarding the J-20:

"Post stall maneuvers require the aircraft to have good controllability and stability. After the plane enters the post stall region, however, the decrease in stability and control efficiency of conventional rudder surfaces become irrecoverable. One must carefully design an aircraft to enable sustained controllability at high AOA. Although it is possible to solve the problem of post-stall controllability through the use of thrust vectoring nozzles, the aerodynamic configuration itself must provide enough pitch down control capability to guarantee the aircraft to safely recover from post-stall AOA should the thrust vectoring mechanism malfunction. As a result, it is vitally important to study unconventional aerodynamic control mechanisms for high AOA flights.

Trans-sonic lift to drag characteristics determine an aircraft's maximum range and sustained turn capability. The future fighter's demands for these characteristics will exceed those of modern 4th gen. fighters. Modern fighters employ the strategies of relaxing longitudinal stability, adapting wings with medium sweep and aspect ratio, twisting the wing, and adding wing-bending mechanisms to greatly improve the lift-to-drag characteristics. Due to the future fighter's requirement for supercruise, supersonic drag characteristic is a critical design point and designers must avoid using aerodynamic measures that may potentially increase supersonic drag. As a result, the wing shape and wing twist coefficient can't be selected based on trans-sonic lift to drag characteristics alone. It is necessary to employ wing-bending mechanisms but its aerodynamic efficiency has already been exhausted.

Further decreasing the aircraft's longitudinal relaxed stability is an excellent solution to this problem. Diagram 1 shows how the variation tendency of trim-drag coefficients against longitudinal instability of a conventional fighter aircraft in a tight, sustained turn. Modern fighters fix their longitudinal instability at 3% the average aerodynamic chord length. The future fighter could enjoy a significant improvement in lift-to-drag if the longitudinal instability could be increased to a magnitude of around 10%.

Further relaxing the longitudinal instability could not only enhance trans-sonic lift to drag characteristics but also improve super sonic lift to drag capabilities, increase take-off and landing characteristics, and maximize low-speed lift characteristics. This is akin to killing three birds with a single stone. Yet a increase in longitudinal instability will also increase the burden on high AOA pitch down control and subsequently increase flight control complexities. As a result the design team should not "over-relax" the longitudinal stability.

So, it is clear from the text that the further relaxing of the longitudinal instability in comparison to curent fighters, like the F-16 you mentioned, is very beneficial, but there are certain problems associated with it, and the next chapter addresses just that:

"The requirement for high AOA pitch down control capability is closely related to the longitudinal static instability requirement. The greater the longitudinal static instability, the higher the demands for pitch down control capabilities. As described in chapter 3, the future fighter will hopefully increase its longitudinal static instability to around 10% its average aerodynamic chord length to enhance the trim's lift to drag and lift characteristics. As a result there should be a corresponding improvement in the pitch down control capability. We can categorize two types of control surfaces based on the relative position of the pitch control surfaces with respect to the aircraft's center of mass: positive load pitch down control surface and negative pitch down control surface. Control surfaces placed behind the center of mass, including the vertical stabilizers and trailing edge flaps, generate pitch down control torque by increasing lift. They are considered positive load control surfaces. Control surfaces placed in front of the center of mass, like the canards, are negative load control surfaces. Since the main wing's ability to generate lift tends to saturate under high AOA conditions, the positive load control surfaces' pitch down control capabilities tend to saturate under high AOA as well. Therefore it will be wise to employ negative load control surfaces for pitch down control under high AOA conditions. Figure 7 compares the pitch down control capabilities of the canards and horizontal stabilizers. From the high AOA pitch down control stand point, it will be wise to use canards on the future fighter. Canards on close coupled canard configuration aircraft have relative short lever arms. Employing the LERX canard configuration can increase the canards’ lever arms while retaining the benefits of positive canard coupling. Considering the overall lift enhancement effect and pitch down control capabilities, we can set the canards’ maximum relative area to around 15% and the maximum canard deflection to 90 degrees.

Yaw control ability under high AOA is another noteworthy problem. Control surface efficiency deteriorate rapidly with an increase in AOA for tailless and even conventional configuration fighters. Therefore it is necessary to consider control mechanisms other than conventional control surfaces. Studies on differential LERX, drag rudder, differential wingtips, and all moving vertical stabilizers indicate that differential LERX and drag maintained relatively high yaw control efficiency under high AOA conditions."

Now, the Russians have solved that problem by using a more innovative solution in the form of LEVCON.
LEVCONs retain all the benefits canards provide, but unlike canards, they can be used for directional control at high AoA with differential deflection. Moreover, unlike canards, they do not produce downwash that interferes with the main wing, and they also do not require anhedral or dihedral placement; thus, they can be blended with the fuselage.
According to the Su-57 patent, they provide controllability and the ability to control the pitch axis at AoA close to 90 degrees!

Самолет интегральной аэродинамической компоновки

Изобретение относится к многорежимным самолетам

poleznayamodel.ru

"Поворотная часть 8 наплыва 2 фюзеляжа 1 при отклонении вниз уменьшает площадь плановой проекции фюзеляжа 1 перед центром масс самолета, что способствует созданию избыточного момента на пикирование при полете на углах атаки, близких к 90 градусам. Таким образом, в случае отказа системы управления реактивных сопел 14 обеспечивается возможность перехода с режима полета на закритических углах атаки к полету на малых углах атаки без использования управления самолетом посредством отклонения вектора тяги двигателей. Одновременно поворотная часть 8 наплыва 2 является механизацией передней кромки наплыва 2 фюзеляжа 1. При отклонении поворотной части 8 наплыва 2 вниз на режиме крейсерского полета она выполняет функцию, аналогичную функции поворотного носка 9 крыла."

They also state that this is not possible with the F-22 in the case of TVC malfunction.

So, the use of the LEVCONs is extremly beneficial from the point of decreasing the aircraft's longitudinal relaxed stability, and they can bassicaly "unload" the horizontal and vertical tails, (while reducing trim drag) so that you can make them smaller, increasing L/D ratio in the procces.

Here are few more quotes from the Dr. Song Wencong paper:

"Advanced modern fighters utilized research on detached vortices from the 1960s and 70s to gain excellent lift characteristics with their max lift coefficient peaking at around 1.6. They either employ conventional LERX configuration or canard configuration to accomplish this. The future fighter has higher requirements for max lift coefficient and the situation is further complicated by the fact that the use of twin vertical stabilizers is detrimental to lift (see figure 4.2). As a result the design team must raise the max lift coefficient to a whole new level. It will be difficult to realize this goal simply employing conventional LERX configuration or canard configuration.

It is beneficial to choose canard configuration from a high AOA pitch down control stand point(see figure 4.3). Blending lift body LERX characteristics with the conventional canard configuration to form a "lift body LERX canard configuration" will greatly enhance the max lift characteristics. Exploration of the lift body LERX canard configuration will solve three important technical issues. The first problem is the aerodynamic coupling between canards and medium sweep, medium aspect ratio wings. The second problem is the coupling between the canards, the LERX, and detached vortices generated by the wings. The third problem concerns the gains and losses of employing body lift on a canard configuration aircraft.

Traditionally close coupled canard configuration aircraft utilize constructive coupling between the canards and detached wing vortices to enhance the max lift coefficient. Only wings with large back-sweep angle and small aspect ratio could generate detached vortices that are powerful enough for the task. As a result most modern canard configuration fighter aircraft have a leading edge backsweep angle of around 55 degrees and an aspect ratio of around 2.5. For these aircraft, the canards could generate around a 3 to 4 times increase in max lift coefficient with respect to their wing areas. Ideally we hope to employ wings with medium leading edge backsweep angle and medium aspect ratio in order to improve lift characteristics over the entire AOA range. This wing shape, however, could not effectively generate leading edge detached vortices. Could the canards still attain their original lift enhancing effects? The answer is yes according to wind-tunnel tests. As the slope of the aircraft's lift curve increases, the lift enhancing capabilities of the canards are the same as those on traditional close coupled canard configuration aircraft (see figure 2). The key influence on aerodynamic coupling between the canards and medium back-sweep, medium aspect ratio wings should not be interference among detached vortices. Preliminary studies indicate that down-wash on the wings generated by the canards play a far greater role.

It is a well known fact that LERX could improve the max lift characteristics on medium back sweep, medium aspect ratio wings. In order to obtain even better lift characteristics, we should consider using both canards and LERX to create a canard-LERX configuration. Study shows that employing both canards and LERX not only retain the lift enhancing effects of the two mechanisms when they are used separately but also help achieve higher lift-coefficient (see figure 3). This means that there is beneficial coupling among the canards, LERX, and the wings.

Blended wing lift body configurations could utilize lift generated by the aircraft's body to increase internal load and enhance stealth characteristics at relatively low costs to drag. Lift-body configurations have been adapted by many conventional configuration aircraft and achieved excellent results. Yet until now now canard configuration fighter utilized lift-body configuration. This isn't because aerodynamic experts failed to realize the tremendous advantage of the lift body configuration but the result of a canard configuration aircraft's need to place the canards above the aircraft's wings. It is difficult for lift-body configuration aircraft to satisfy this demand. Our experimental results indicate that although the canards on a canard-LERX configuration aircraft employing lift-body suffered a decrease in lift-enhancing effects, the overal lift characteristic of the aircraft was still superior to that of a canard-LERX aircraft not employing lift-body (see figure 4). Figure 5 shows the vortex generation on the wings and body of a lift-body canard configuration aircraft observed using laser scanning. It demonstrates that planes employing this configuration derive excellent lift characteristics not only from coupling among the canards, LERX, and detached vortices but beneficial interaction between the left and right detached vortices. The latter contribute to significant lift on the body of the plane and greatly contributed to the enhancement of lift characteristics. Figure 5 also indicates that the detached vortices primarily contribute to lift on the body and inner portions of the wings. Consequently, most of the lift produced under high AOA conditions are generated in the corresponding areas.

Supersonic drag characteristics

The key to lowering supersonic drag is to minimize the max cross sectional area of the aircraft. Accomplishing this requires excellent high level design skills. Placement of the engines, engine intakes, landing gears, cartridge receiver, weapons bay, and main structural support all influence the max cross sectional area of the aircraft. Attention to details and careful considerations are necessary to design decision making.

Wingshape has profound effects on supersonic drag characteristics. Small aspect ratio wings with large backsweep have low supersonic drag but are detrimental to low speed lift and trans-sonic lift to drag characteristics. If we select the liftbody LERX canard configuration we can expect to retain relatively good lift to drag characteristics while using medium backsweep wings. Under high AOA conditions, liftbody LERX canard configuration aircraft concentrate lift on the body and inner portions of the wings so moderately lowering the aspect ratio will not only not lower the max lift coefficient but raise it (see figure 10). Because of this, employing small aspect ratio wings on a lift-body LERX canard configuration aircraft will settle the conflicts among supersonic drag characteristics, low speed lift characteristics, and trans-sonic drag characteristics."

So, the Russians basically had the same requirements, but they have managed to employ the true blended lifting body layout which is the most efficient from the perspective of volume utilization, since the J-20 is using basically the same fuselage/air ducts/weapons bay arrangement, and it was also stated in the Su-57 patent that the F-22's huge S-shaped intakes and weapons bay placement increase the weight and cross-sectional area of the plane.
Su-57 layout also benefits from the flight performance perspective!

Since when is Su-57 supercruising at Mach 2?

I don't know, you tell me?

I wasn't claiming that it can, but that the goal with the new engines is likely very close to Mach 2, and that there are objective reasons for the use of the variable intakes.
In 2013 Стрелец Михаил Юрьевич claimed that the performance numbers for the supercruise with the first stage engines were much higher than expected, as well as maneuverabilty.

Source that combat range is 3,500km? Is this with or without the weapon bay fuel bladders? The cruise range given in Su-57E product card (differing from Su-57 in IFF, cockpit instrument readings, some fire control modes, same airframe and engines) indicates different range numbers, given as:
Max range flight at altitude of cruise flight without refueling / with one refueling / with two refueling - 2,800km / 5,200km / 7,800km

But regardless these single numbers mean nothing without context or additional details.

https://qph.cf2.quoracdn.net/main-qimg-2862d0fab952d301e999b150304ae2e4

Data is coming from Mikhail Pogosyan; I have watched that interview, and I'm pretty sure that it doesn't involve weapon bay fuel bladders because the Su-57 should have at least a comparable range to the Su-27 since it can store more fuel in standard configuration, and has more fuel-efficient engines.
The Su-57E product card is basically a useless piece of information, as I can remember they even had spelling errors. Sukhoi already had similar cards for the Su-57 with totally different (far more realistic data/performance numbers), so I would not take Su-57E product card serious at all.

Airshow turn rate comparison means nothing without knowing the weight. An F-16C at 22,000 lbs turns at 21.7 degrees per second. Increase weight to 26,000 lbs at near full fuel and it decreases by 4.4 degrees per second to 17.3, and the F-16C and F-22 demos are done at full fuel, and the minimum radius turn happens at the beginning of the demo. Sukhoi demos are not done at full fuel.

That wasn't a scientific comparison, but it is pretty telling regarding Su-57 performance. I have used the fastest F-22 turn rate for the 360 deg circle that can be found on the net, and it wasn't done on the standard air show day. Usually, the F-22 is significantly slower at an air show.
Yes, most of the time the F-22 is using a full fuel load for the air show, except when it is loaded with air-to-air missiles; then the fuel load is less than 100%. Depending on the demo, the F-16 is not always using a full fuel load, and Sukhoi demos are not done at full fuel load because they have significantly higher fuel fraction.
At 25 tons, the Su-35S can match the F-22's max range, but the demo is far more impressive.

And I don't have time for further debate about the weight unless you can explain where all that excess weight is coming from. The F-22 is the size of the F-15C, and it is more than 7 tons heavier, while the F-35, which is a small single-engine fighter (with the same S duct - weapons bay layout as the F-22), is actually heavier than the F-15C!
Also, there is no data of any kind suggesting that the Su-57 is heavier, or as heavy as the F-22. On the contrary, it seems that the plane is lighter while being slightly bigger.
To me, it is obvious that the excess weight comes from the significant strengthening of the airframe, but I'm happy to hear your explanation.
Just to be clear, I don't think that the operational Su-57 is as light as Su-27, far from it! Felon also needs structural strenghtening for various reasons.

 

[Squirrel]

That Salyut nozzle, they proposed AL-31FM3 and a follow on for PAK-FA but Sukhoi chose Saturn. Salyut nozzle clearly vectors differently from AL-41F1 and AL-31FP style nozzle.

First tnx for the info about AL-31MF3/nozzle.In the meantime I corrected those numbers in the previous comment ( from 1164 to 1461).About metallic /non-metallic structural materials of Sukhois.Interestingly, Su-27S has very light and strong Al-Li Alloy 1420 also, besides V95/T and Dural and % of Al Alloys in the empty weight is about 50%. About 30% of the empty weight is from Ti Alloys ( main one is OT-4) . Unlike MiG-29, Su-27S has almost no polymer composites at all. They are only used in the radome.Su-27S is in fact an 'all metallic' fighter with metallic main and skin structure . The empty weight is about 16.5 tons and Su-27 is heavier then F-15A/C almost 4 tons.On the other side, new T-50/Su-57 is from the very beginning constructed from light and strong structural materials: Al Alloys ( Al-Li, maybe 1420,1441? then V95T etc) which has about 50% in the empty weight of the serial Su-57,like Su-27S . Polymer composites with 20-25% and Ti Alloys ( VT22,VT23 ? ) about 20%, Steel Alloys and other materials up to 10%.

It is certain that Su-57 has strengthened structure from the beginning and from the 2nd stage ,Sukhoi designers tried to lighten it even more with the V-1461 Al Alloy. As it was written in the book ,they failed to do that but obviously that Alloy found application in the airframe. So we have a situation where they increased weight with that big cross metallic ( obviously Al Alloy) skin part of the centroplane and at the same time decreased it with application of 1461 in some non-load bearing parts.About structural strengthening ,yes there must be that around those FWC,centroplane section etc.Those FWC's are in fact big empty spaces ( 4.5x1x0.7m ? ) so Su-57S has much more 'empty volume' than Su-27S. Another comparison e.g. Su-57's air intakes are from Al Alloys, on Su-27 they are from Ti/Steel. So besides all that structural strengthening Su-57 must have very light empty weight.

1420 and 1441 are 2nd gen Al -Li Alloys, 1461 and 1469 are 3rd gen .There is e.g. also 1481. About Al matrix composites there are many of them like :Ti-VKA1, Al-Ni-La etc.

https://viam.ru/news/2661

Now why I have opinion that serial Su-57(S) has the same if not even less empty weight then Su-27S.From lighter engines via lighter control systems parts and components,avionics at all,fuel and hydro-systems to lighter structural materials and components.Must keep in mind 25% less details ,big empty space with that FWC/UWC's .When I see that vertical stabilizers, it seems they are twice lighter then those on Su-27S.Maybe I am wrong but I think those 'e.w.-numbers' for the public are very questionable.

 

[Squirrel]

@PeregrineFalcon
This is one very interesting Soviet video from the Le Bourget 1989 and that famous flight demonstration on Su-27S by Sukhoi test pilot Victor Pugachev. Take off weight was 22 tons ( so with about 5.5 tons of fuel,'normal fuel weight'). Besides famous 'Cobra' ,Victor made that 360° turn within 10-15 sec.

Су-27 в Ле-Бурже. 1989 / Debut of the Su-27 at the Le Bourget - Paris Air Show in 1989​

''The first public demonstration of the Su-27 at the Le Bourget Air Show in 1989. The film of the TV studio of the Sukhoi Design Bureau, with comments by a specialist of the Design Bureau.''

View: https://www.youtube.com/watch?v=c_lzjVkVm-U


Su-57 demo-flight at Zhuhai Air Show ,normal fuel weight .

Su-57 crazy flying demonstration at ZhuHai Airshow 2024​

View: https://www.youtube.com/watch?v=3iaYyYFicMw


and this one....

Fighter Pilot Reacts to Russian SU-57 Performance at Zhuhai Airshow​

View: https://www.youtube.com/watch?v=Gsg-4Uk8Bzg

 

[Galaxy]

New poster here. I’m very existed about the new engine, I honestly did not think that the SU-57 was ever going to get a squared nozzle engine given how conservative the Russian design philosophy is. I must say the build quality of these new engines blew me away, it’s much better than any other Russian engine and at least as good or better than western engines (or at least the built quality of the nozzles).

A few observations, the seems between the engine and fuselage is almost nonexistent. Even if you take an F-22 and compare the engine figment and seems, the AL-51F1 is far superior, I also notice some type of vents, I would assume it helps with cooling? In any case this engine was the right choice even if some thrust is lost, the new engine will lower RCS from all aspects plus reduce IR emissions thus improve survivability. Looks very alien/sci fi

I just wish they got rid of that disgusting digital cam pixel paint. It looks so tacky and juvenile, like something a teenager would do to their car. The big blocky pixels just look bad, especially around the cockpit. It really just breaks up and distracts from the shape and curves of the aircraft. It’s like a makeup artist hiding the true shape of a face.

I wish they would just do one solid color like a shade of grey or even white like on the 053, yes it has pixelation but it doesn’t go beyond the wings:







I’m surprised no one at Sukhoi seen the base coat and said, wow that looks slick and it’s cheaper and quicker to get off the production line.

Instead we are stuck with Fast and Furious paint schemes

 

[haavarla]

But why does "the larger aircraft" need engines whose thrust nozzles can rotate around the longitudinal axis ? See at 0:32 in the video (please view at 0.25x speed).

ooh i don't know... perhaps that huge Russian Drone could use a flat nozzle. What about the new Russian Bomber.
It does not need the TVC obviously. But the nozzle itself.

 

[Squirrel]

There is some very interesting details about the engine with that new stealth flat rotating nozzle.As mentioned before, E.Marchukov said in 2019 that they developed new three-stream adaptive cycle ( 6th gen) engine in the same time as they develop 'second stage' engine Izd 30 later known as AL-51F.

Transl of citation:

''Plus stream , plus generation

In parallel with the development of the second stage engine for the Su-57, designers are already creating the scientific and technical basis for the sixth generation engines.First of all, research is aimed at improving the specific characteristics of the power plant compared to fifth-generation engines.
According to Marchukov, such a project involves adding a third external air stream to the power plant design. Thanks to this, it is possible to achieve low specific fuel consumption at supersonic cruising mode.
When flying at subsonic speeds, the third stream will be open. Thanks to this, the air flow from the fan will pass through the second and third stream and the engine will operate almost like a turbofan power plant with a high bypass ratio. In this mode, the power plant will have slightly greater thrust and significantly lower fuel consumption.
During supersonic flight, the third stream will be completely closed, and the second partially, due to which the engine will operate as a power plant with a low bypass ratio.''

On the ICAM-2020 held on May 2021 ,Marchukov said some very interesting details about that new engine.

International Conference on aviation motors

icam.ciam.ru

''On May 18, 2021, AEX.RU - A. Lulka Design Bureau - a subsidiary of"ODK-UMPO"is working on the formation of a scientific and technical backbone to create a sixth-generation engine for combat aviation. "This is a three-contour scheme, which the whole world is doing," Evgeny Marchukov, general designer of the Design Bureau, said at the ICAM-2020 conference. This is reported by the press service of the MAKS Air Show.
According to him, two options for implementing this scheme are being developed. The first stand tests of the demonstrator are due to take place in 2021. Using a three-contour scheme will allow to modernize the AL-41F-1 engine, improving its characteristics while maintaining dimensions.''

In fact,new Russian 6th gen engine ( three-stream adaptive cycle engine) was developed and is based on AL-41F-1 not on AL-51F( or F-1 never mind).

Now,let us hear what Marchukov said about engines from 1:44:20. It was at international scientific-technical conference from ODK achievements on Samara's University held on June 23 2023.First he mentioned AL-41F-1S for Su-35S and exported Su-35 ( from 1:44:50) .After that he talked about AL-41F-1 as '5-' gen engine because that engine does not provide supercruise capability to Su-57 ( from 1:45:52) After that he mentioned new Izdeliye 177S as 5th gen engine only for export ( for the Su-30SME,Su-30MKA,MKI,MKM etc ,from 1:46:32 ). Then he talked about Izdeliye 117B as non-AB engine for UCAV S-70 Hunter-B ( from 1:47:30). After that he talked about Izd 30 even he didn't mention designation and some technical details about it ( from 1:48:48). From 1:50:10 he talked about ODK's engines development phases and trends especially about 6 gen engine and technological achievements.Then from 1:51:28 he mentioned about that third stream as technology for 6 gen engines.In this part he talked about Izd 117 as basis for that new engine as they started 'from the 0' to develop such engine. Then from 1:52:17 we can see blured pic with that 'green engine' on the screen.

He said that it is 'stendovy variant dvigately' or it is the engine for static tests.One of the achieved results was 5% less consumption on cruise mode and he hope that in the real flight conditions it will be up to 10%. It is 'Product with third stream' as he mentioned'. It is of course adaptive cycle engine. From 1:53:17 there was story about its components and parts ( even meta-materials).Story about this new flat nozzle started from 1:54:13. He told that losses of thrust are not so high.Nozzle is made 90% from so called additive technology.He told that he hope nozzle will start flight tests during 2023. From 1:55:44 we can hear some details about other parts and components of the 6 gen engine like ceramic chamber e.g ( that nozzle is also made from ceramic materials) and other metallic parts.According to what he said then ,ceramic chamber was on static tests at the end of 2023.

Source: https://m.vk.com/video-69812_456239...nNk3lHRyO-ipIc-TTA_aem_rAkjogYjr1rJVv-a8s65Xw

Although this is only an illustration,engine with new flat nozzle is completely different in comparison with AL-51F-1 / AL-41F-1.

1000021637

Изображение 1000021637 расположенное в Radikal.HOST (Радикал.ру)

radikal.host

 

[QuadroFX]

Flat nozzle has been installed on two prototypes: T-50KNS(#057) and T-50-2(#052). T-50-2 is already flying.

 

[Acatomic]

Source:

https://twitter.com/x/status/1868297048644112457

View: https://x.com/la_souris_da/status/1868297048644112457?s=61

 

[QuadroFX]

And yes, have you ever seen a fighter jet perform aerobatics using TVC with the afterburner on? I see just now!

 

[Galaxy]

I have been reading thrust numbers, I assume the ~37,000lbs thrust is the total output with the roughly 5-6% loss due to square nozzles? Actual thrust is ~39,000lbs. Not bad considering it’s slightly smaller than the F119 engine and massively smaller than the F135 engine.

 

[QuadroFX]

Some caps

 

[Ainen]

I just wish they got rid of that disgusting digital cam pixel paint. It looks so tacky and juvenile, like something a teenager would do to their car. The big blocky pixels just look bad, especially around the cockpit. It really just breaks up and distracts from the shape and curves of the aircraft. It’s like a makeup artist hiding the true shape of a face.

Anecdotal evidence says they thoroughly tested it between test airframes and choose the best working one.
It isn't about style.

 

[Galaxy]

Anecdotal evidence says they thoroughly tested it between test airframes and choose the best working one.
It isn't about style.

Painting digital camo has no functionality whatsoever. Zero, none…it’s a waste of resources and money to mask off and use multiple colors.

On another note, it looks like they finally added serrated edges to the rear engine nacelles. A welcome and needed addition if they really want to lower RCS. Hopefully they do something about the square access hatches and IRST-T, the IRST-T is just plain laziness and definitely adds to RCS and that is not an option but fact.

 

[QuadroFX]

TVC with AB on:

 

[Squirrel]

TVC with AB on:

This is pic of T-50-1 from the early period of flight testing .Very unusual and interesting positions of the nozzles in the AB mode. Nozzle of the left engine was in neutral position ,nozzle of the right engine was deflected downwards.Also interesting deflections of LEVCONs.

 

[QuadroFX]

Manufactury:

 

[QuadroFX]

Flat nozzle moving:

 

[Squirrel]

Painting digital camo has no functionality whatsoever. Zero, none…it’s a waste of resources and money to mask off and use multiple colors.

On another note, it looks like they finally added serrated edges to the rear engine nacelles. A welcome and needed addition if they really want to lower RCS. Hopefully they do something about the square access hatches and IRST-T, the IRST-T is just plain laziness and definitely adds to RCS and that is not an option but fact.

Pls, take a look at sequences from 15:28 ....

From T-50 to Su-57. The most modern and the most classified Russian 5th generation airplane. Part 2​

View: https://www.youtube.com/watch?v=aDXNDA5xuS4

 

[QuadroFX]

View attachment 752428

Source:

https://twitter.com/x/status/1868297048644112457

View: https://x.com/la_souris_da/status/1868297048644112457?s=61

Not a single word was said about the AL-51F in this video.

 

[Ainen]

Painting digital camo has no functionality whatsoever. Zero, none…it’s a waste of resources and money to mask off and use multiple colors.

Feel free to send feedback to Sukhoi, what can I say.

 

[Acatomic]

@QuadroFX
Ok. I just put the source for that screenshot, that’s all

 

[Galaxy]

Pls, take a look at sequences from 15:28 ....

It’s the silliest thing i ever heard. Again putting some crappy digital camo won’t make an aircraft harder to see. Come on now, use common sense. It’s like Sukhoi still using that ancient green paint inside the cockpit claimed it has some benefits when MIG, MI, Lockheed, Rafale, ect do just fine using grey.

Sukhoi is know for dumpster fire camo jobs like the Smurf green and black SU-34, the half white, half grey SU-24, strange SU-35 prototype cammo combos, I’m surprised the MOD doesn’t order them to stop the stupidity as their paint jobs are always different and something out of Fast and Furious. Someone at Sukhoi needs to lose their job for such idiotic waste of resources.

 

[QuadroFX]

MFD and HMDS

 

[Life of Tyo]

more Su-57 serial on video https://www.1tv.ru/doc/pro-armiyu/v...ntalnyy-film-k-85-letiyu-okb-suhogo-i-okb-mig ( tvc 2D engine review same video)

 

[Galaxy]

That helmet looks great, the Zsh-3 should have been phased out long ago. In never looked like it had good ergonomics especially the oxygen mask that was far too large, far too long and interfered with downward head mobility.

Hopefully they fit the new helmet with a proper oxygen mask. Other than that I would be curious as to the new capabilities. Looks like it has a built in HUD and all around sensors, I would guess they slaved it to multiple sensors such as IRST

 

[Deino]

more Su-57 serial on video https://www.1tv.ru/doc/pro-armiyu/v...ntalnyy-film-k-85-letiyu-okb-suhogo-i-okb-mig ( tvc 2D engine review same video)
View attachment 752471

The link is dead!??

 

[QuadroFX]

It is old ones, already delivered this or past year.

 

[Life of Tyo]

The link is dead!??

maybe you should use VPN, i can open the link without VPN

 

[Galaxy]

I noticed something about the nozzle material. The black section looks like a textured composite, it looks like Saturn spared no expenses. The fitment looks very tight too and the exhaust flaps when opened are properly sealed off unlike the F-22 flaps that have the internals exposed. I do like the F-22 but this really pissed off many F-22 fanboys

 

[Squirrel]

I noticed something about the nozzle material. The black section looks like a textured composite, it looks like Saturn spared no expenses. The fitment looks very tight too and the exhaust flaps when opened are properly sealed off unlike the F-22 flaps that have the internals exposed. I do like the F-22 but this really pissed off many F-22 fanboys

Nozzle is made from ceramics using so called additive technology.

 

[Squirrel]

That helmet looks great, the Zsh-3 should have been phased out long ago. In never looked like it had good ergonomics especially the oxygen mask that was far too large, far too long and interfered with downward head mobility.

Hopefully they fit the new helmet with a proper oxygen mask. Other than that I would be curious as to the new capabilities. Looks like it has a built in HUD and all around sensors, I would guess they slaved it to multiple sensors such as IRST

ZSh-3 is а oldtimer in fact and even ZSh-5 is rare. They have ZSh-7(AP) as actual and of course new one ZSh-10.That helmet is newer one.

Авиационный шлем ЗШ-10 для самолета Су-57 (Т-50).​

https://dzen.ru/a/X9EVBnXjKDHY0Jo7

Details about the new helmet from 19:10 min .

From T-50 to Su-57. The most modern and the most classified Russian 5th generation airplane. Part 3​

View: https://www.youtube.com/watch?v=CrZ8knrxtVM&t=1318s


Even 40 years ago ,MiG-29 and Su-27 pilots could 'slaved' their IRST sensors with HMS 'Schel-3UM' (NVU-2M).

Sequences from 1:25:48 ....

View: https://www.youtube.com/watch?v=bCup20qZCvQ

 

[totoro]

So those production line photos...like this one attached below.
Is there any way to try to estimate production volume using such photos? Like, relying on completeness level of each airframe visible, is it possible to say that certain aiframes are 6 months or less away from delivery? And thst certain other airframes are 12 months or less away?
Any other time period estimate or comment or info or opinion are welcome.

 

[Geo]

The link is dead!??

Try it in any way other than through a large operator. Some local connection, it also works in the EU.