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

[Deino]

https://twitter.com/x/status/1309187335196758016

View: https://twitter.com/vladwlad777/status/1309187335196758016

 

[haavarla]

https://twitter.com/x/status/1309187335196758016

View: https://twitter.com/vladwlad777/status/1309187335196758016

What a riddicules good angle!
Thx Deino.

 

[AGS-1787]

I still don't understand how the russians can make such beautiful airplanes but can't build a decent car. They do build some awesome trucks though.

 

[Josh_TN]

Russian aircraft always seemed oldly beautiful to me. Even older, more boxy/angular designs seemed to have such a functional utility look to them. The Russians seem in their element when they are designing an airframe or missile system to kill a similar airframe.

There's a quote in the book Cryptonomicon in a WWII flashback that I can't quite remember but it was roughly "Russians can be a little messy sometimes but put them to work killing Germans and suddenly they are fucking Einstein."

 

[AGS-1787]

On the video posted by TR1, they show the radar signature testing range and they have some parts of the su-57 covered, like the intakes and exhausts, but interestingly they also covered the edges of the elevator actuator or articulation, I remember that part being called out as un- stealthy by another enthusiast, it looks like that is one part of the aircraft that will be reworked for testing later. Any idea what prototype is the one used for radar signature testing? Another thing I wonder is how the gun cover works? does it push down leaving the cannon exposed? Instead of using a door like the f-35?

 

[apparition13]

I still don't understand how the russians can make such beautiful airplanes but can't build a decent car. They do build some awesome trucks though.

This is the only one I think is really attractive. I kinda like the Su-24, MiG-31, Tu-160 and sorta the Su-34 (not the rest of the Su-27 family though, the nose on the other planes seems both too long and too droopy to me), but the Su-57 is the only Russian or Soviet plane I look at and think "that's gorgeous".

 

[stealthflanker]

On the video posted by TR1, they show the radar signature testing range and they have some parts of the su-57 covered, like the intakes and exhausts, but interestingly they also covered the edges of the elevator actuator or articulation, I remember that part being called out as un- stealthy by another enthusiast, it looks like that is one part of the aircraft that will be reworked for testing later. Any idea what prototype is the one used for radar signature testing? Another thing I wonder is how the gun cover works? does it push down leaving the cannon exposed? Instead of using a door like the f-35?

you can browse few pages back and found that the prototype being tested is T-50KNI.

and the gun cover appears to work by Rotation. Made a simple animation on it.

 

[haavarla]

I still don't understand how the russians can make such beautiful airplanes but can't build a decent car. They do build some awesome trucks though.

This is the only one I think is really attractive. I kinda like the Su-24, MiG-31, Tu-160 and sorta the Su-34 (not the rest of the Su-27 family though, the nose on the other planes seems both too long and too droopy to me), but the Su-57 is the only Russian or Soviet plane I look at and think "that's gorgeous".

Well "attractions" aside. The long nose on the Flanker family has several vital design advantages.
The long downward pointing nose is vital for how the air hits and diverege onto LERX and wing/body of the airframe. This was all done at TzAGI wind tunneling senter back in the T-10M era.
So we are spesifficly talking about where and how(efficient) the Flanker design handle Air vortices.

Hense why you have a 25tons class fighter behaving like a ballerina, and have very decent Inst/sustained turnrate.
And can fly very slow(heck they even put in on a Carrier!) and fly above Mach 2.0 as well. Its a Jack of all trade design, and very good at it too.

Beside, large nose gives you extra space for Radar AND all the systems stacked behind it, which mean you can store more fuel right behind the pilot seat section.
Talk about functionality meets attractions..

 

[TomcatViP]

The forward protruding nose with the heavy radar set is also what makes the Flanker dynamically balanced (inertia - see that as a pendule weight).
No "big" nose, no Cobra.

 

[haavarla]

The forward protruding nose with the heavy radar set is also what makes the Flanker dynamically balanced (inertia - see that as a pendule weight).
No "big" nose, no Cobra.

Well dunno if this is a thing VIP.

The CG of the Flanker is mostly decided by the main large fuel tanks behind the cockpit. Lots of weight there, which does balance the aft engine section and the sweptback airfoils.
All the other fuel tanks, the 4 of them feeds fuel back to the senter fuel tank, and that is positioned quite a bit foreward of CG.
Seems to me the T-10M design is a marvel of engineering!

As to Cobras. On Vanila Su-27, they had to cut power on engines to do the Cobra. On later variant with TVC, well the thrust direction could make the jet do anything, kind of cheating on the Aerodynamics this is.. or bypassing it.

As to the Long nose. There is ofc one drawback and this is cited by RuAF pilots; upon final approach and landing(rotation).
The long nose does obscure view quite a bit. But it is something to be acustomed to. In contrast to the Mig-29.

 

[TomcatViP]

@haavarla : At the time of induction, the Flanker did not have TVC and relied only on aerodynamic forces. The Cobra is simply a deep stall that you recover from and for that the pendulum effect of that long moment arm created by the mass at the tip of that long nose helps in the recovery (as the fact that the airplane is neutrally stable) and obviously in rotating the aircraft on the initial stage. Once in deep stall, you are in post stall maneuvering, what means that aerodynamic forces are not the primarily forces governing the balance of flight but drag (dynamic pressure) and inertia are.
Cg variations are nearly insignificant post stall since the range of variation is usually fairly small considering the distribution of masses along the entire aircraft. What imports most in that domain is the distribution of masses away from the rotation axis.

As an illustration, we know how coupled inertia in roll can affect safe flying if an aircraft is rolling too fast along its main axis.

 

[AGS-1787]

I thought the cobra was possible due to having an unstable design with the center of gravity very far back and the drag created by the sudden pith up stabilizing the jet nose back down. For example, you don't do tail slides at more than 70 degrees in a su-27 because you can end up on a deep stall really hard to recover due to the far back center of gravity... at least that was what I thought. Also, I just read several Ukrainian pilot's accounts about flying the su-27 for the first time and they said that the visibility was great, they felt like they were going to fall off the airplane. Going back to the su-57 it has even better forward visibility, but the backward visibility looks a bit iffy, I wonder if that is the perspective since in some angles it looks like the back of the cockpit tapers so it might not be that bad after all.

 

[overscan (PaulMM)]

YF-17 and MiG-29 can both do Cobra manouvre, though not to the same angle. MiG-29 makes it to about 90 deg compared to 110-120 deg for Su-27, i believe YF-17 made 60-80 deg. Both are stable designs. F-16 cant due to nasty departure characteristics above 35 degrees AOA.

John Boyd was doing a dynamic deceleration via a rapid pitchup on the F-100 - it was his 'signature' move. Risky as hell though.

 

[haavarla]

@haavarla : At the time of induction, the Flanker did not have TVC and relied only on aerodynamic forces. The Cobra is simply a deep stall that you recover from and for that the pendulum effect of that long moment arm created by the mass at the tip of that long nose helps in the recovery (as the fact that the airplane is neutrally stable) and obviously in rotating the aircraft on the initial stage. Once in deep stall, you are in post stall maneuvering, what means that aerodynamic forces are not the primarily forces governing the balance of flight but drag (dynamic pressure) and inertia are.
Cg variations are nearly insignificant post stall since the range of variation is usually fairly small considering the distribution of masses along the entire aircraft. What imports most in that domain is the distribution of masses away from the rotation axis.

As an illustration, we know how coupled inertia in roll can affect safe flying if an aircraft is rolling too fast along its main axis.

Yes, but all i am saying. The Vanila Su-27 cannot do a Cobra unless it cuts power on engines, and then Inertia takes over as it rotate. Nose goes up but still travel along its original axes.
If it let the power on, it would simply go into a steep inst climb routine.
My point is, the CG of the jet does not matter much eighter way, when we are talking about Cobra manuvere.

 

[LowObservable]

A vital part of the Cobra story was revealed at the University of Michigan symposium in 1989, the first such US meeting to have a MiG delegation. Many teen-series aircraft could do the Cobra dynamic deceleration, but to do it at an air show risked more than embarrassment because vortices might break asymmetrically leading to a dramatic whoa BETTY! lateral/directional disturbance. Belyakov disclosed that the answer was a pair of small vanes where the pitot joined the radome, which tripped the vortices symmetrically and predictably. A close look at the Su-27 revealed a butterfly set of vanes that did the same thing. Gripen also has vanes on the front of the radome.

 

[overscan (PaulMM)]

YF-17 has those mini strakes on the extreme nose, possibly do the same?

Teen series steered away from pitot tubes in front of their radars.

 

[Trident]

A close look at the Su-27 revealed a butterfly set of vanes that did the same thing.

Only on the very earliest airframes though - I'm not certain the feature even made it properly into production. The only examples that I am positively sure have those vortex generators are the #388/389 pair which made the debut at Le Bourget '89.

I suppose the chined radome tips on the F-5/20 and Su-47 serve a similar purpose.

 

[TomcatViP]

Regarding Su-27 feather vanes, I think it's a legend. This was discussed extensively in aeronautical magazines in the 90's and stuck in the imagination of westeners. I was myself too among those contaminated.

Don't take me wrong, it certainly can help but the main effect is independant of their presence or not...

 

[LowObservable]

I photographed the feather vanes myself.

 

[Arjen]

Reality is frequently inaccurate.

 

[Ronny]

I photographed the feather vanes myself.

Do you still have thephoto

 

[TomcatViP]

I photographed the feather vanes myself.

Don't take me wrong, I remember seeing them on pictures.

 

[Ejajjs]

 

[Ejajjs]

100 years of GLITs : Photo report from Akhtubinsk

 

[TR1]

 

[Cool ice]

Interesting , wondering if the Iz-180 , being carried in packs of 4 internally , is a limit of the airplane, or is it because of the internal AKU launcher configuration being similar to when they fired the 40 cm wide cruise missiles in syria , Twice as much box width as the article 180.
Seems a bit odd if 2 180's , 20 cm of box width each , are a limit , especially considering that the bay is over 100 cm wide , considering how the same bay held bigger payloads before , and considering how 16 suspension points (thus 6 external + 10 intenal) was mentionned in numerous official interviews. Along with the capacity of carrying 8 folded wing MRAAMS.

 

[stealthflanker]

Interesting , wondering if the Iz-180 , being carried in packs of 4 internally , is a limit of the airplane, or is it because of the internal AKU launcher configuration being similar to when they fired the 40 cm wide cruise missiles in syria , Twice as much box width as the article 180.
Seems a bit odd if 2 180's , 20 cm of box width each , are a limit , especially considering that the bay is over 100 cm wide , considering how the same bay held bigger payloads before , and considering how 16 suspension points (thus 6 external + 10 intenal) was mentionned in numerous official interviews. Along with the capacity of carrying 8 folded wing MRAAMS.

Maybe for safety and aerodynamics clearance purpose.

 

[LMFS]

Interesting , wondering if the Iz-180 , being carried in packs of 4 internally , is a limit of the airplane, or is it because of the internal AKU launcher configuration being similar to when they fired the 40 cm wide cruise missiles in syria , Twice as much box width as the article 180.
Seems a bit odd if 2 180's , 20 cm of box width each , are a limit , especially considering that the bay is over 100 cm wide , considering how the same bay held bigger payloads before , and considering how 16 suspension points (thus 6 external + 10 intenal) was mentionned in numerous official interviews. Along with the capacity of carrying 8 folded wing MRAAMS.

The configuration in the picture is the one that has been known since the begining of the program, some of us think there can be developments increasing that capacity in the future, some don't. Sukhoi is to this day extremely secretive with the internal layout of the bays (still no image of their internals has been released, at least that I know) and there is a second stage being developed, so there might be more going on in regards of internal armament than what we know. There was talk about a future long range missile with multiple detachable warheads, that may be another option on increase the internal capacity without increasing the number of suspension points, but it would not be so flexible.

Do you maybe have a link where those 16 suspension points are mentioned by an official source?

 

[totoro]

So is R74 smaller than R73? Why can't R73 be carried internally as well? It could be dimensions or guidance limits due to internal carriage.

Also, mid wing hardpoints seem to point out to dual pylon? Station 10a and 10b, and station 9a and 9b. Is that correct? Yet, if so, the A2A missiles on that hardpoint are not shown to be doubled. Why not?

 

[Deino]

What happened her?

https://twitter.com/x/status/1312344286621429761

View: https://twitter.com/HaoGao12/status/1312344286621429761

 

[CiTrus90]

Pretty sure that's part of the testing program, similarly to this:

https://twitter.com/x/status/1009520743628136449

View: https://twitter.com/baesystemsplc/status/1009520743628136449

 

[Ejajjs]

 

[flanker]

I just want to see what kind of mental gymnastics TomcatViP will resort to this time to claim that the sidebays are not, in fact, sidebays. Cause he has so far spent years on claiming that, despite even the footage of a launch from the bay. And despite it being known to be sidebays on day one of T-50-1's first flight, now over 10 years ago.

The missile has quite large fins (looks to be a standard R73) that seems to me larger than the side bays can allegedly contain.

Regarding the displayed missile launch, do I am the only one to think that what we see (missile with fins) doesn't seems to be able to fit inside the alleged side missiles bay?

Well, you should know that opinion is the panacea of the free men and cease to be only when proved irrefutably to be wrong. Then denial or negationism they can be.

Untill this day, you will have to let me say what I honestly think is a valid assersion my dear. Thank you.

 

[sferrin]

What happened her?

https://twitter.com/x/status/1312344286621429761

View: https://twitter.com/HaoGao12/status/1312344286621429761

Testing the convertible model? The Tomcat was available in convertible as well.

 

[TomcatViP]

I just want to see what kind of mental gymnastics TomcatViP will resort to this time to claim that the sidebays are not, in fact, sidebays. Cause he has so far spent years on claiming that, despite even the footage of a launch from the bay. And despite it being known to be sidebays on day one of T-50-1's first flight, now over 10 years ago.

The missile has quite large fins (looks to be a standard R73) that seems to me larger than the side bays can allegedly contain.

Regarding the displayed missile launch, do I am the only one to think that what we see (missile with fins) doesn't seems to be able to fit inside the alleged side missiles bay?

Well, you should know that opinion is the panacea of the free men and cease to be only when proved irrefutably to be wrong. Then denial or negationism they can be.

Untill this day, you will have to let me say what I honestly think is a valid assersion my dear. Thank you.

Gimme a picture instead of picturing me.

 

[TR1]

Heh, Tomcat is a nice guy at the end of the day

The real comedy was that loon @ Keypub who argued for years Su-57 would enter service with external weapons only.

 

[flanker]

Gimme a picture instead of picturing me.

"I was wrong." That simple, yet of course you will never do it because self imposed delusion is that hard to break apparently.

Heh, Tomcat is a nice guy at the end of the day

The real comedy was that loon @ Keypub who argued for years Su-57 would enter service with external weapons only.

Well atleast he was in a good company then - considering basically whole keypub was a bunch of loon's.

 

[Ejajjs]

Izd.180？

via:robognus inf1kek

 

[helmutkohl]

Well atleast he was in a good company then - considering basically whole keypub was a bunch of loon's.

there were a lot of interesting characters there..
a guy who believed DSI on everything was superior
a guy who was pro Russia on every single thing
a guy obsessed with 3rd gen aircraft
a few guys who believed the J-11 had better finish than the Su-30
and a guy who was named after food

 

[flanker]

Well atleast he was in a good company then - considering basically whole keypub was a bunch of loon's.

there were a lot of interesting characters there..
a guy who believed DSI on everything was superior
a guy who was pro Russia on every single thing
a guy obsessed with 3rd gen aircraft
a few guys who believed the J-11 had better finish than the Su-30
and a guy who was named after food

A guy that overanalyzed every single nut and bolt including to a hilarious fashion that T-50-3 vertical stab intakes were faceted to a millionth degree.

Izd.180？

via:robognus inf1kek

Yup, sure looks like it. Just wondering where mah Izd.810 is at.