Russian Su-57 Aircraft Thread (PAK-FA and IAF FGFA)

b787

Captain
225 million per copy is a KRAP load of money for an airplane that has yet to prove any significant L/O capability, it will be agile, one would hope?? but for a Russian airplane, that is a bunch of money, for an airplane that has yet to see a single proto-type?, especiallyn light of the Russians cutting their own buy to 12 aircraft?
To understand PAKFA you have to see what they say, Russia hs issued the PAKFA patent long time ago here are some extracts

Двигатели самолета расположены в хвостовой части, вплотную друг к другу, что при расположении воздухозаборников по бокам фюзеляжа позволяет реализовать изогнутую форму каналов воздухозаборников. Данное решение применяется для снижения радиолокационной заметности двигателя, и, как следствие, самолета в целом в передней полусфере, благодаря экранированию компрессоров двигателей конструкцией каналов воздухозаборников. Отклоняемые в вертикальных плоскостях створки «плоских» сопел реактивных двигателей позволяют обеспечить управление вектором тяги, что, в свою очередь, позволяет реализовать возможность управления самолетом в канале тангажа на режимах малых скоростей полета, а также обеспечивает запас пикирующего момента на закритических углах атаки совместно с цельноповоротным горизонтальным оперением. Подобное решение обеспечивает функцию сверхманевренности (Lockheed Martin F/A-22 Raptor: Stealth Fighter. Jay Miller. 2005). В качестве недостатков известного самолета можно указать следующее: - невозможность управления в каналах крена и рысканья при полете на малых скоростях, поскольку двигатели расположены вплотную друг к другу, что не позволяет создать достаточный для управления момент; - расположение двигателей вплотную друг к другу делает невозможным расположение в фюзеляже грузовых отсеков; - изогнутая форма каналов воздухозаборников требует увеличения их длины, и, следовательно, массы самолета; - невозможность обеспечения «схода» самолета с закритических углов атаки при отказе системы управления реактивными соплами двигателей; - применение неподвижных килей с рулями направления требует увеличения потребной площади вертикального оперения для обеспечения путевой устойчивости на сверхзвуковых режимах полета, что приводит к росту массы оперения, и, следовательно, самолета в целом, а также к увеличению лобового сопротивления. Технический результат, на достижение которого направлено изобретение, заключается в создании самолета, обладающего малой радиолокационной

Aircraft engines located in the rear, close to each other that
at the location of the air intakes on the sides of the fuselage allows for
curved air intake duct. This solution is used for
reducing the radar signature of the engine, and as a result, the aircraft as a whole
in the forward hemisphere, through screening engine compressors
design air intake duct. Rejects in vertical planes
leaf "flat" jet nozzles allow for management
thrust vector, which in turn allows for control over
aircraft in the pitch channel modes on low flight speeds, as well as
It provides a margin of diving moment at supercritical angles of attack, together with
tselnopovorotnym horizontal tail. This solution provides
supermaneuverability function (Lockheed Martin F / A-22 Raptor: Stealth Fighter Jay Miller..
2005).
The following can be noted as disadvantages of the aircraft:
- The inability to control the channels in the roll and yaw when flying at low
speeds since the motors are located close to each other that do not
creates sufficient management time;
- The location of the engine close to each other making it impossible
location in the fuselage cargo compartments;
- Curved shape of the air intake channel requires an increase in their length, and,
consequently, the aircraft mass;

- Inability to provide "gathering" aircraft with supercritical angles of attack at
refusal jet engine nozzle control system;
- The use of fixed keels with rudders requires increasing
required area of the vertical stabilizer to provide directional stability
supersonic flight regimes, which leads to an increase in mass of feathers, and
consequently, the aircraft as a whole, as well as an increase in drag
.
The technical result, which is aimed at achieving the invention,
It is to provide an aircraft having a low radar

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The patent says why they used the Su-27 basic layout and the shortcomings they saw on F-22, this is another translation of the patent

0mT29hq.jpg

The fuselage is described as having ‘dogtooth extensions’ which are similar in shape and role with the leading root extensions (LERX) of many modern jet fighters and popular with Sukhoi. The fuselage houses the engine and their inlets at its edges and in between it is flattened, providing lift and also space for internal payload

The horizontal tail is all-moving and provides pitch control in all flight regimes by moving in-phase. At supersonic speed it also provides roll control by differential movement.


Engine placement is a crucial part of T-50’s architecture. The two engines are placed wide apart leaving space for payload between them. The air intakes are located similarly on each side of the fuselage and they are beveled in two planes in order to keep the flow attached even at high angles of attack
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this is an Article by Paul Bulat which explains why they used regular nozzles and not flattened ones

Кислое с пресным - две большие разницы А американцы на F-22 поставили плоские сопла. На первый взгляд - странное решение. Ведь эксперименты НПО «Сатурн» выявили существенные недостатки двухмерных сопел. Они заметно тяжелее осесимметричных из-за необходимости противостоять не только растягивающим, но и изгибающим напряжениям. Велики потери тяги по сравнению с идеальным соплом Лаваля. Больше и внешнее сопротивление плоских сопел почти во всем диапазоне чисел Маха (рис.19). Все это верно ... Если рассматривать сопла обособленно от конструкции фюзеляжа. Преимущество плоских сопел в том, что они прекрасно компонуются в хвостовой части самолета, что позволяет значительно уменьшить суммарное сопротивление (рис.20).


Sour with unleavened - two big differences
The Americans on the F-22, put the flat nozzle. At first glance - a strange
decision. After all, "Saturn" experiments revealed significant shortcomings
dimensional nozzles. They are much heavier than axially symmetric because of the need
resist not only stretching but bending stresses. Veliki
loss of traction compared with the ideal Laval nozzle. More and external
resistance of flat nozzles in almost the entire range of Mach numbers (Figure 19). All
this is true ... If we look at the nozzle apart from the fuselage structure.
An advantage of flat nozzles that are well arranged in the tail
of the aircraft, which can significantly reduce the total resistance
(Figure 20).

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b787

Captain
225 million per copy is a KRAP load of money for an airplane that has yet to prove any significant L/O capability, it will be agile, one would hope?? but for a Russian airplane, that is a bunch of money, for an airplane that has yet to see a single proto-type?, especiallyn light of the Russians cutting their own buy to 12 aircraft?
here you can see the Russians studied the flat nozzles
XnkXDZD.jpg


Now let us see their view on Stealth

Still, not a single side is giving up on stealth technology. A number of stealth technologies were incorporated into the design of the last Soviet fighter jets, the MiG-29 and MiG-27. New Russian aircraft, including the Su-34 fighter-bomber, the MiG-35 light frontline fighter, and the Su-35S heavy fighter utilize technology that reduces their visibility. The future fifth-generation Russian aircraft, such as the PAK FA heavy multipurpose fighter jet and the PAK DA long-range strategic bomber, are being designed as stealth aircraft.

Incidentally, the PAK FA, which is currently undergoing state testing, will be equipped with active phased array radar developed by KRET. The angled plane of the antenna significantly reduces the aircrafts’ electron paramagnetic resonance, making it less visible to radar.

In spite of practically identical design requirements for both fifth-generation Russian and American fighters, there is a basic difference, as the Americans favor stealth over agility.

According to Russian specialists, maneuverability is becoming increasingly important in military aviation, not only because of the development of radar, including new high-frequency radar, but the gradual decrease of the American monopoly on fifth-generation fighter technology. But only when the two stealth fighters meet will combat tactics return to the past.
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They claim PAKFA is stealthier upon some angles and less stealthy at others than F-22, but in general it is stealthier
The fifth-generation T-50 (PAK FA) fighter jet is equipped a number of technologies produced by Rostec companies that make the plane even less visible to the enemy radar. This design solution moves the T-50 ahead of all aircraft in its class, including the American F-22.

The aircraft company Sukhoi managed to greatly reduce the effective surface scattering of the PAK FA, which is the basic element for visibility on aircraft radars. The average value of this indicator for the T-50 fighter is between 0.1 and 1 square meter.

Thanks to these new design solutions, the T-50 is now ahead of not only all other fighters of the Russian Army, but also foreign models. For example, the visibility of the American fifth-generation F-22 fighter is 0.3-0.4 square meters, according to PAK FA chief designer Alexander Davidenko.


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RT - T-50 Pak Fa Stealth Fighter Has RCS Of Tennis Ball With Passive Stealth Technology
 
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tphuang

Lieutenant General
Staff member
Super Moderator
VIP Professional
Registered Member
225 million per copy is a KRAP load of money for an airplane that has yet to prove any significant L/O capability, it will be agile, one would hope?? but for a Russian airplane, that is a bunch of money, for an airplane that has yet to see a single proto-type?, especiallyn light of the Russians cutting their own buy to 12 aircraft?
I'm assuming that since India will be getting this at the start of production run, the cost will naturally be high at that point. Of course, we also need to see what else gets included in the contract =)
 

Air Force Brat

Brigadier
Super Moderator
To understand PAKFA you have to see what they say, Russia hs issued the PAKFA patent long time ago here are some extracts



The patent says why they used the Su-27 basic layout and the shortcomings they saw on F-22, this is another translation of the patent

0mT29hq.jpg



this is an Article by Paul Bulat which explains why they used regular nozzles and not flattened ones

So here we are again, I would note that we have referred to PAK-FA as the F-22Ski, and the resemblance is striking, yes the Russians have attempted to copy the F-22?? just as they did the B-17 and B-29. They have an airplane that flies well, and I will make an assumption that it possibly could be as maneuverable or even more maneuverable than the F-22, maybe faster, whatever?

But, you are a modeler, I am a pilot, nothing wrong with either, but I understand pitch, yaw, and roll in a way that only a "practitioner" may? You are able to interpret the Russian? that's helpful, but I am able to interpret the "fluid dynamics" and shaping as an end user. I have read and studied the flying characteristics of literally hundreds of aircraft, from ultralights to the A-380. You may not realize it, but the 747 had some very serious issues with flutter beyond a certain Mach #, it required a massive amount of intuition and engineering to turn the 747 into the very safe, fine flying aircraft that became the world standard for decades, the A-380 also has had to overcome some very serious issues with structural cracking in the wing ribs, particularly with the "rib feet", and other areas, it does appear to be doing well now, and flying well.

My point is that aircraft are much more technically complex than most of us realize, and the claims made for PAK-FA are NOT proven as of yet??, while the F-22 is a very mature design, and has enjoyed a wealth of engineering expertise and maturity.
 

Air Force Brat

Brigadier
Super Moderator
I'm assuming that since India will be getting this at the start of production run, the cost will naturally be high at that point. Of course, we also need to see what else gets included in the contract =)

I'm assuming that since India will be getting this at the start of production run, the cost will naturally be high at that point. Of course, we also need to see what else gets included in the contract =)

and I'm also assuming that you can see me bowing deeply to you brother, even as I humbly disagree that 225 is a bargain of sorts? I absolutely agree with Master Brumby that given the Indian procurement??? voodoo???? or whatever, and the Russian gamesmanship??? it will be a total miracle if this deal ever comes to "fruition"?
 

kwaigonegin

Colonel
When you combine Indian negotiation and Russian promises, what do you get? An epic saga that even "the bold and beautiful" series would have difficulty competing in duration and surprises. For what it is worth, just enjoy the fun and entertainment.

Lol .. Exactly!!
Indian defense contracts + future Russian fighter promises = Tolstoy + the great mythologies of Lord Rama.

Truly a perfect match made in soap opera heaven.
 

b787

Captain
So here we are again, I would note that we have referred to PAK-FA as the F-22Ski, and the resemblance is striking, yes the Russians have attempted to copy the F-22?? just as they did the B-17 and B-29. They have an airplane that flies well, and I will make an assumption that it possibly could be as maneuverable or even more maneuverable than the F-22, maybe faster, whatever?


My point is that aircraft are much more technically complex than most of us realize, and the claims made for PAK-FA are NOT proven as of yet??, while the F-22 is a very mature design, and has enjoyed a wealth of engineering expertise and maturity.
If you noticed, i never said my opinion, only what they say, one was the original patent for T-50 PAKFA and the others were Rostec`s description and explanation of T-50`s stealth features, they quoted Alexander Davidenko who is the Sukhoi General designer in charge of the PAKFA program

qKGurN5.jpg


Paul Bulat in his article about the engine for 5th generation fighters, quotes several aerodynamic articles from Russian and American studies made by NASA and TsAGI.

The status of T-50 well to be honest that something i can not affirm or claim any thing beyond what they say.

My personal opinion is they are designing a fighter with less emphasis on Stealth because they think radars will detect Stealth fighters and they will need to be fast and agile.

Because Russia is a smaller country in terms of population close to 150 million people, Russia has less than half of the USA population and with a PPP per capita GDP of only $24,000 USD around 45% of the USA`s per capita GDP, Russia has to make a cheaper fighter.

In my opinion they are right, they are making the right choice, the T-50 will be in many ways superior to any of the current 5th generation fighters at least in agility, speed and frontal RCS and it only might turn to be inferior if the opposition has better avionics.
 

Hyperwarp

Captain
Since the subject of flat nozzles arose, here are some of the Sukhoi testing:

Su-27 UB LL-UV(PS) - From 2:07:26 - 2:08:30

It was none other than Mikhail Pogosyan who was in charge of this project. And, it was a part of the their earlier 5th gen tech demonstrations/testing. The flat nozzole might make its way back to the T-50 when the much higher thrust Izdeliye 30 (165 - 170 kn) engine is available. Square nozzle have thrust penatly/loss compared to the round ones. Can someone do the calculations. I heard it could be high as 20%. (Square water hose vs around hose o_O)

Su-27_LL-UV-PS_01 copy.jpg

PhominSu-27_091_1_zps7e6cfc5d.jpg

PhominSu-27_091_3_zpsb7c9ffff.jpg

PhominSu-27_091_2_zpsfeb0d52c.jpg
 

Air Force Brat

Brigadier
Super Moderator
Since the subject of flat nozzles arose, here are some of the Sukhoi testing:

Su-27 UB LL-UV(PS) - From 2:07:26 - 2:08:30

It was none other than Mikhail Pogosyan who was in charge of this project. And, it was a part of the their earlier 5th gen tech demonstrations/testing. The flat nozzole might make its way back to the T-50 when the much higher thrust Izdeliye 30 (165 - 170 kn) engine is available. Square nozzle have thrust penatly/loss compared to the round ones. Can someone do the calculations. I heard it could be high as 20%. (Square water hose vs around hose o_O)

View attachment 24795

PhominSu-27_091_1_zps7e6cfc5d.jpg

PhominSu-27_091_3_zpsb7c9ffff.jpg

PhominSu-27_091_2_zpsfeb0d52c.jpg

This crude monstrosity is the perfect illustration of why the F-22 is so far superior to the PAK-FA, its huge, the nozzle is obviously very large and in-efficient, where the nozzle on the F-22 is small and highly refined. That is also why we went with the 2D nozzle as opposed to 3D, because the very last place you want to hang that much weight is at the VERY AFT station on your weight and balance???

If some of us are as bright as we think we are, you will recognize that side profile which shows this huge ducting as opposed to the starboard ducting is where all this in-efficiency of the square nozzle comes from. The F-22 aside from being very efficient is also very "Kool" and shield the very hot exhaust gases with aircraft structure.

More to the point, everything on the F-22 is of a very high level of build and refinement, as this ducting/nozzle illustrate, this is rather crude, and many of the Russian systems are still in their infancy and lack refinement.
 

b787

Captain
Russia has developed a fifth generation fighter jet, the T-50, which is due to enter service by the year-end and will be equipped with a brand-new aircraft cruise missile, media reports said.


The fifth generation T-50 fighter jet, also known as
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, is set to enter service with the Russian Armed Forces later this year. The plane is expected to be equipped with highly advanced X-74M2 cruise missiles, according to
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.


The X-74M2 is a supersonic missile which has a speed of more than Mach 4, which means that the missile is capable of reaching targets in just few seconds, preempting the possibility of its detection by enemy aircraft radar systems, according to Zvezda
This anti-radar missile will have a flight speed exceeding Mach 3.5, Zvezda said, touting the X-58USHK's characteristics, including its relatively small size.

Additionally,
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will be equipped with the tactical X-35UE air-to-ship missile, which weighs about 145 kilograms and is capable of hitting targets at a distance of 260 kilometers while remaining invisible to radars.




For air-to-air combat, the T-50 is expected to carry four beyond-visual-range missiles in its two main weapons bays and two short-range missiles in its wing root weapons bays.


The T-50 is a single-seat, twin-engine jet fighter, and the first operational aircraft in Russian service to use stealth technology. It was designed by
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. The aircraft will be used to achieve air superiority and assist in ground attacks.

Besides its ability to fly at speeds well above Mach 2, the T-50 boasts other, even more important, features such as invisibility to radar and powerful weapons. It is equipped with advanced avionics and a cutting-edge phased array radar system.




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