Sukhoi Su-57 flight testing and development

NovaGA said:
No censure because these are photos done by spotters, and why there must be something else from Al-41F-1? Are you expecting Izd-177?
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In fact Izdeliye-30 or AL-51F.

One more detail.... Bort number 01 blue ( as second serial aircraft) has reg. number RF-81774 and this Bort number 26 red has 81797 so it is maybe 24th delivered Su-57 ?
 
Squirrel said:
In fact Izdeliye-30 or AL-51F.

One more detail.... Bort number 01 blue ( as second serial aircraft) has reg. number RF-81774 and this Bort number 26 red has 81797 so it is maybe 24th delivered Su-57 ?
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There are a lot of 57 with no reg. number. 02 red from GLIC is an example, 21 red also lacked one.
 
What are the chances that those two images were taken at Tolmachevo Air Base during the flight of that two Su-57s from the KnAAZ to western Russia?
 
Bmpd's take on the recent Su-57 delivery:
bmpd.livejournal.com

Новые Су-57 в Новосибирске

Опубликованы сделанные в начале апреля 2025 года (выложены в сети 10 апреля) в новосибирском аэропорту Толмачево споттерские фотографии двух истребителей Су-57 ВКС России с бортовыми номерами 25 красный (регистрационный номер RF-81796) и 26…
bmpd.livejournal.com bmpd.livejournal.com
 
Serial (operational) Su-57's with so far known 'Bort numbers'....

01 blue ( GLITs emblem)

Su-57 01 blue.jpeg

02 red with GLITs emblem

Su-57 02 red.jpg

02 red w/o GLITs emblem

Su-57 02 red 1.jpg

11 red with GLITs emblem

Su-57 11 red.jpg

21 red

Su-57 21 red.jpg

25 red

Su-57 25 red.jpg

26 red

Su-57 26 red.jpg

52 blue

Su-57 52 blue.jpg

52 red

Su-57 52 red.jpg

53 red

Su-57 53 red.jpg

54 red

Su-57 54 red.jpg

Are there any more?

Note: ''A information in bmpd LiveJournal say that is also airplane 51, what involve long internet discussions on some forums. Not only photos can confirm if that plane even exists. Possibly a fourth (or fifth if rumours about 51 are true) aircraft from 52nd series is 02 RF-81780, first time displayed in August 2023 in Army-23 exhibition. Tactical number 02 is not mistake, it's really second red 02.''

 
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Squirrel said:
Serial (operational) Su-57's with so far known 'Bort numbers'....

01 blue ( GLITs emblem)
Click to expand...


I think Su-57 No.11 is same aircraft from second Serial Su-57 No.01, it.s can find number of pitot

Life of Tyo said:
I don't know The Su-57 similar like 01Su-57 on Desember 2020 if see the Pitot , but After than Pitot was remove on next production
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Serial Su-57 01 blue from the 'mouse perspective' ...

Su-57 01 blue 929 GLITs.jpg


Photo is from this article :

bmpd.livejournal.com

Министерство обороны России получило первый серийный истребитель Су-57

Как сообщил телеканал Звезда , Единый день военной приемки 29 января 2021 года ознаменовался грандиозным и долгожданным событием для наших Вооруженных сил. Первый в серии многоцелевой истребитель Су-57 передан ВКС. Борт номер один вошел в состав Государственного…
bmpd.livejournal.com bmpd.livejournal.com
 
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Max (possible) Mach number depending on the cockpit canopy and windscreen strenght ( temp. limitation).

Let us see what is the limitation for the old Su-27S according to the Su-27SK Flight Manual :

''На Су-27 максимальное время нахождения на скорости М=2.15-2.35 по РЛЭ ограничено пятью минутами (лимитируется прочностью остекления фонаря).''

''On the Su-27, the maximum time spent at a speed of M=2.15-2.35 according to the flight manual is limited to five minutes (limited by the strength of the canopy glazing).''

Now back to the Su-57. From the article...

Су-57: стекло кабины — крепче стали

glass-297x300.jpg

aviation21.ru

Су-57: стекло кабины - крепче стали » Авиация России

В России разработаны новые технологии изготовления остекления кабин военных и гражданских самолётов из силикатного стекла. Такие изделия легче и прочнее, чем
aviation21.ru aviation21.ru

Опубликованы кадры жестких испытаний фонаря новейшего истребителя Су-57

VK.com | VK

vk.com vk.com

I've found some data ( don't know if they are accurate).

''Фонарь кабины на первой машине Т-50-1 переплетный, на серийных Т-50 предполагается использование фонаря кабины с использованием беспереплетных секций силикатного фонаря нового типа, создаваемого с 2009 г. по программе НИР "Ашуг" (стоимость НИР 60 млн. руб, 2009 г.).
Габариты секции - 1525 х 805 мм
Толщина остекления - менее 14 мм
Коэффициент светопропускания - 0.8
Насыщенность цветового фона - не более 3.5 сатрон
Температура среды - +55 град.С (рабочая), +130 град.С (кратковременная), +150 град.С (предельная)''

Can someone make some calculations based on this data, of course in the relationship with the max possible Mach number in the stratosphere?
 
paralay said:
Neural networks without agreement give M = 2.36, which corresponds to 2.36 * 1062 km/h = 2500 km/h
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So basically it is in the level of Su-27S ( not some values like 2.6M or more).Besides the limitation from the windscreen and cockpit canopy ,maybe there is limitation from the RAM layers on the skin?
 
In the Su-57, different elements correspond to a maximum speed of M = 2.35. The angles of the radio-transparent cone and the air intake, the main material of the structure, and so on.
The probable enemy's fighters fly slower than M = 2.1, so M = 2.35 is quite enough.
 
paralay said:
Neural networks without agreement give M = 2.36, which corresponds to 2.36 * 1062 km/h = 2500 km/h
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Only at particular combinations of air temperature and relative humidity. Air temperature varies greatly with height.
Earlier discussion here:
More here:
en.wikipedia.org

Speed of sound - Wikipedia

en.wikipedia.org en.wikipedia.org
By far, the most important factor influencing the speed of sound in air is temperature. The speed is proportional to the square root of the absolute temperature, giving an increase of about 0.6 m/s per degree Celsius. For this reason, the pitch of a musical wind instrument increases as its temperature increases.

The speed of sound is raised by humidity. The difference between 0% and 100% humidity is about 1.5 m/s at standard pressure and temperature, but the size of the humidity effect increases dramatically with temperature.
Click to expand...
 
Yup, it often piss me off to no end that Mach 1 varies all the way from 1062 to 1235 km per hour. As much a giant PITA as imperial to metric conversion, bleh.
 
density-pressure-speed-of-sound-temperature-jpg.583188

1225 km/h at sea level. Drops roughly linearly to 1062 km/h when you reach an altitude of 11 km, then holds steady to an altitude of 20 km. Then speed of sound rises again to 1188 km/h when an altitude of 50 km is reached.
M = 2.36, which corresponds to 2.36 * 1062 km/h = 2500 km/h
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This looks like numerical precision, but is in fact only valid at a temperature of 216 Kelvin / -57 degrees Celsius, which usually corresponds to an altitude between 11 and 20 km.
If an aircraft is speed limited by Mach number, that translates to different speeds between sea level and 11 km, as well at altitudes above 20 km.
 
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Thank you for the very precise numbers. Must stuff that in my brain.
 
Things can be lot easier with excel. Like to find temperature of an object moving at certain mach, one can use this simple approximation from Raymer's book :

1745126209844.png

All that need is then someone to implement that standard atmosphere to get the ambient temperature then plot it against Mach number. like say, 10000 m altitude have ambient temperature of -49.85 degrees Celcius or 223 Degrees Kelvin, then some plane move at Mach 2.5 there. The stagnation temperature is about 229.08 Degrees Celcius, if the canopy starts having problem or thermally limited at less or equal to that temperature, maybe one should avoid moving that fast at that altitude.
 
Just a question concerning the AL-51F ... how many T-50 prototypes or Su-57 are currently testing this engine?

Per my understnading it is confirmed only one prototype with one engine ... or am I wrong?
 
Deino said:
Just a question concerning the AL-51F ... how many T-50 prototypes or Su-57 are currently testing this engine?

Per my understnading it is confirmed only one prototype with one engine ... or am I wrong?
Click to expand...

There is some sources which mention that prototype/flying laboratory T-50-2LL ( 052 blue) has AL-51F ( of F1 nevermind), with that new stealth flat nozzle in the left engine nacelle. Btw, AL-51F is in serial production now and as Russian sources mentioned, from this year serial Su-57's will be equipped with them.
 
Squirrel said:
There is some sources which mention that prototype/flying laboratory T-50-2LL ( 052 blue) has AL-51F ( of F1 nevermind), with that new stealth flat nozzle in the left engine nacelle. Btw, AL-51F is in serial production now and as Russian sources mentioned, from this year serial Su-57's will be equipped with them.
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I‘ll wait for proof instead of claims by the Russian media or whatever … this was posted already last year and the first batch delivered lasted week, were clearly NOT powered by the AL-51F.
 
Squirrel said:
There is some sources which mention that prototype/flying laboratory T-50-2LL ( 052 blue) has AL-51F ( of F1 nevermind), with that new stealth flat nozzle in the left engine nacelle. Btw, AL-51F is in serial production now and as Russian sources mentioned, from this year serial Su-57's will be equipped with them.
Click to expand...

The public only seen the engine with flat nozzles in December of 2024, of course it’s possible they tested it out months before going public but we don’t know for sure. The nozzles have been in development for some years and were tested in a laboratory vigorously before Sukhoi installed them for a test flight. With that being said there is zero possibility that they tested the engine nozzles for the first time in December and certified them in January. Even if the actual engine is ready, which I’m not even sure it is, it would take extensive testing of the new nozzles.
Even if the engine and production facilities for the AL-51F are complete I would guess that we will not see the new engines with flat nozzles earlier than the 3rd quarter of 2025 and that is optimistic, realistically we might see it early to mid 2026 or even later. I would imagine they would want at the minimum almost a year of real world testing with just the nozzles alone.
 
Deino said:
I‘ll wait for proof instead of claims by the Russian media or whatever … this was posted already last year and the first batch delivered lasted week, were clearly NOT powered by the AL-51F.
Click to expand...

Yes,all news. Yury Slyusar already said in Dec 2023 something like this : ''The Izdyelie 30 engine has passed all tests. All aircraft that will be delivered in 2024 will be equipped with new engines, which will reportedly be designated AL-51F. Those delivered between 2020 and 2023 will not receive new engines.''

We shall see if next finished Su-57's will be equipped with AL-51F.

flateric said:
O RLY?
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I'm convinced that they are.As I wrote ,we shall see during this year what will happen with them if they are really in serial production like many sources wrote about.

Galaxy said:
The public only seen the engine with flat nozzles in December of 2024, of course it’s possible they tested it out months before going public but we don’t know for sure. The nozzles have been in development for some years and were tested in a laboratory vigorously before Sukhoi installed them for a test flight. With that being said there is zero possibility that they tested the engine nozzles for the first time in December and certified them in January. Even if the actual engine is ready, which I’m not even sure it is, it would take extensive testing of the new nozzles.
Even if the engine and production facilities for the AL-51F are complete I would guess that we will not see the new engines with flat nozzles earlier than the 3rd quarter of 2025 and that is optimistic, realistically we might see it early to mid 2026 or even later. I would imagine they would want at the minimum almost a year of real world testing with just the nozzles alone.
Click to expand...

That is the catch. We did not see the engine itself but only the flat nozzle. I already wrote that many sources mentioned that engine inside of the left nacelle of the T-50-2LL is AL-51F. My personal opinion and assume is that inside of the left nacelle is completely new engine ,the three-stream ACE. Е. Marchukov told some details about that engine on June 2023. I came to such an assumption after a detailed view of what we can see through the nozzle, which is the AB-chamber without a stabilizer. Maybe I am wrong but we shall see.
 
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Squirrel said:
Yes,all news. Yury Slyusar already said in Dec 2023 something like this : ''The Izdyelie 30 engine has passed all tests. All aircraft that will be delivered in 2024 will be equipped with new engines, which will reportedly be designated AL-51F. Those delivered between 2020 and 2023 will not receive new engines.''

We shall see if next finished Su-57's will be equipped with AL-51F.
Click to expand...


But the point is - and here again against your strong believing - not only all delivered in 2024 but also those from the recent delivery aka April 2025 were NOT using the AL-51F!

So if the engine was already in serial production in Dec. 2023, why are none yet fitted with them?

As such, like I noticed thru all the years - almost decades - now since starting to follow this, there is a huge gap in terms of facts & fiction between what Russian official sources claim and what in the end comes out!
 
Deino said:
But the point is - and here again against your strong believing - not only all delivered in 2024 but also those from the recent delivery aka April 2025 were NOT using the AL-51F!

So if the engine was already in serial production in Dec. 2023, why are none yet fitted with them?

As such, like I noticed thru all the years - almost decades - now since starting to follow this, there is a huge gap in terms of facts & fiction between what Russian official sources claim and what in the end comes out!
Click to expand...
Considering how long is production cycle, if it's true, we'll likely see AL-51 either in late 2025 or 2026 batches.
 
paralay said:
In the Su-57, different elements correspond to a maximum speed of M = 2.35. The angles of the radio-transparent cone and the air intake, the main material of the structure, and so on.
The probable enemy's fighters fly slower than M = 2.1, so M = 2.35 is quite enough.
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As far as I remember, during the discussion on your forum, the expert assessment of the forum members on the angle of the radio-transparent cone was in the range of 2.9 - 3.0 M.
The patent for the air intake states that it is designed for speeds up to 3M.
If we consider the materials of the structure, then first of all it is necessary to consider the materials located in the most heat-loaded places, which are: the nose cone, the leading edges and the front part of the lamp.
The front part of the cockpit fairing is made of silicate glass, not plexiglass. Given that silicate glass is heavier but more heat-resistant, it is logical to assume that its use is caused by the need to withstand high temperatures.
If we consider the radio-transparent cone and the leading edges, then we see that the leading edges of the Su-57 cover the radars, therefore, they are also radio-transparent. Given that, for example, the materials used on the MIG-25 or MIG-31 were quite capable of flying at high speeds, it is logical to assume that the SU-57 should not have any problems with the selection of materials.
Of course, I have assumptions about why you mention a speed of 2.35M, but I leave them out of the brackets and focus only on the arguments.
 
Archibald said:
That's a little dated, I mean, as in "delays" or "sanctions" or "that war with Ukraine".

Christ !
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It's from a more civilized age, when F-35 blk.4 was still on time.
No one updates us this way on Su-57M and J-20B.
I personally don't think first contract was meant to include megapolis birds, but that's my speculation.
I.e. I'll be surprised to see them in series until 2028. Testing? Perhaps, for that we probably should get to see a full (not partial) prototype soon enough.
 

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