Su-57 Stealth Fighter: News #5

dino00 wrote:Su-57 will be able to land on ultrashort lanes and aircraft carriers

One of the conditions outlined in the technical specifications for the Su-57 fighter was the possibility of its take-off and landing on the shortened lane.

The new Su-57’s mileage will be two times shorter than that of the Su-35, which allows it to be used from short lanes without special devices. This was announced by Mikhail Strelets, Chief Designer-Director of the Sukhoi Design Bureau, in a new release of the Military Acceptance program to the film crew of the Zvezda TV channel.

“The plane must land on a shortened lane without special means <...> I can’t give exact figures, because this is a secret thing, but they are two times smaller than those of the Su-35,” said Sagittarius.

It is worth noting that on the model of the Russian aircraft carrier of the future, which was presented at a number of military exhibitions, Su-57 was designated as aircraft

The ability to take off and land on shortened lanes is also necessary so that the aircraft can be used from aerodromes damaged during the fighting.

https://tvzvezda.ru/news/opk/content/201811081115-769z.htm

Almost 4 months to get some quality news. Big deal if true. You still need a big carrier tho... no ways to slice it.

dino00 wrote:Su-57 will be able to land on ultrashort lanes and aircraft carriers


“The plane must land on a shortened lane without special means <...> I can’t give exact figures, because this is a secret thing, but they are two times smaller than those of the Su-35,” said Sagittarius.

It is worth noting that on the model of the Russian aircraft carrier of the future, which was presented at a number of military exhibitions, Su-57 was designated as aircraft

https://tvzvezda.ru/news/opk/content/201811081115-769z.htm

With the expression " without special means" are they implying that it could possibly perform a shipborne rolling landing i.e. without the need of arrestor cables?

Isos wrote:

marcellogo wrote:With the expression " without special means" are they implying that it could possibly perform a shipborne rolling landing i.e. without the need of arrestor cables?

Not really if they need 300-350m to stop then they need a carrier of 450-500m long ...

This is a good news for landing on destroyed airports as you can found 400m out of the couple of km of runway clean for landing even if 1 or 2 missiles touched it.

The carrier issue is not clear. The landing strip in a carrier is like 200 m but we don't know what would be the effects of carrier + overboard wind speed on the landing distance, besides they refused to give exact numbers.

Maybe the plane would normally use arrestors but the whole deck could be cleared for an emergency landing over its complete length. This would provide additional alternatives (and hence tactical advantages like reduction of min reserve fuel) in case of damages / unavailability of the arresting gear or the main landing strip.

In any case, if they managed to reduce min. speed of the plane to the point it can almost land without arrestors, navalization efforts, weight increase and performance loss of the carrier version would be very small. Maybe even no wing fold as in Rafale, for a carrier bigger than K but with the same air wing. This would keep the overload factor of the naval plane in line with the air force model

As to the thrust reverser, it is a possibility, have you seen any evidence of how it could be implemented? Nozzles seen until now are not of that type. Maybe bypass air could be used, but these are low bypass ratio engines...

The ability to take off and land on shortened lanes is also necessary so that the aircraft can be used from aerodromes damaged during the fighting.

Interesting that the MiG-35 design has also be optimised for use on aircraft carriers, so there is clear recognition that they don't want separate development for different aircraft types for different branches of the military... so Ka-52 for Army and Navy, Ka-35 for Army and Navy, MiG-35 for Aerospace defence forces and Navy, Su-57 for Aerospace defence forces and Navy etc etc

It makes a lot of sense to make navalised models of existing land based types including SAMs and land attack missiles and aircraft operated missiles too.

Amazing news, and hats-off to eehnie for correctly picking this up, this is a real breakthrough. Half the distance of the Su-35 would mean 300-350 m landing distance. Any ideas how they achieve this? Maybe they managed a really low minimum speed to start with, which would be the best also to minimize the stress to the airframe during landing. And hence reduce the extra weight needed for a naval version. Will be very interesting to understand how this is done and all the possibilities it opens up.

It is not really a magic trick... the Su-57 is smaller and lighter than the Su-33, but with more powerful engines and no external weapons drag... plus it appears to have an enormous wing surface area.... and of course thrust vector engines should allow short take off runs and good control at much lower flight speeds...

Almost 4 months to get some quality news. Big deal if true. You still need a big carrier tho... no ways to slice it.

If you are going to build a carrier then it makes no sense to waste money on a small one of limited endurance and capacity... even with VSTOL fighters a bigger carrier is just worth the extra money.

Not really if they need 300-350m to stop then they need a carrier of 450-500m long ...

Or a carrier sailing into a 20 knot wind at 15 knots could allow for a 300m landing roll or less...

This is a good news for landing on destroyed airports as you can found 400m out of the couple of km of runway clean for landing even if 1 or 2 missiles touched it.

Any section of motorway could be used... even if the motor way is only 100km long there is no way NATO has enough bombs to make holes every 400m along it... just not possible.

I would expect naval operations would be conducted with a tailhook and that would be easily enough to ensure a safe landing.

Isos wrote:The jet always land at the 3/4 of the strip they can't touch at the very beggining and stop at 2cm from the end of the strip. That's why they need either 500m of space or arresting cables.

I know, and that was my original discussion with eehnie. But with a landing distance close to 300 m we are in the ball park of a carrier deck, so we moved from "completely impossible" to "thinkable". An automated landing program + slower approach due to improved aero could help making a better use of the strip's length.

The guy said it's secret so we won't see it anyday soon. In my opinion it should be something in the engine because the structure doesn't seem to have anything special and loiks much more aerodynamic than su-35 , that doesn't help. Or maybe bigger parachutes ?

What is special in the air vehicle is that it was designed for high performance both in supersonic flight and also at low speeds, this is in the patent document. It has a very big wing area (ca. 79-82 m²) + huge lifting body, whose effectiveness is greatly improved at high AoA with the LEVCONS + TVC. But maybe there are thrust reversers yes, I have seen something from paralay about this...

GarryB wrote:It is not really a magic trick... the Su-57 is smaller and lighter than the Su-33, but with more powerful engines and no external weapons drag... plus it appears to have an enormous wing surface area.... and of course thrust vector engines should allow short take off runs and good control at much lower flight speeds...

Well, no magic but a good trick indeed, they have halved the landing distance of Su-35. That is very significant and I doubt it comes alone from wing area and weight, but rather from aero config and maybe engines. 30% more wing area than Su-35. Weights should be similar, though we don't have confirmed values for the Su-57.

Take-off would not be an issue with springboard, but can you explain how do you consider TVC would help there? They are positioned way after CG, you would need to compensate that torque at the front or you would end with the nose diving into the sea. In any case, the thorny issue is the landing as far as I can see.

The landing gear of the Su-57 was were strong from the beginning (first prototype). That helps by short starts and "rough" landings. But I doubt that a shipborne aircraft would skip the arrestor hook. A very low landing speed would nevertheless reduce the pain of an arrested landing.

Part 1 of 4 PAK-FA specials from "Military Acceptance" is out:

https://www.youtube.com/watch?time_continue=1&v=DN2zCJ5WBn4

Just take the claim of the shortened landing distance with grain of salt. We have no idea yet what kind of configuration allows that or what kind of device being developed.
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Other than that i pray for the Izd-30. Can't wait to see pair of those in Su-57.

marcellogo wrote:

dino00 wrote:Su-57 will be able to land on ultrashort lanes and aircraft carriers


“The plane must land on a shortened lane without special means <...> I can’t give exact figures, because this is a secret thing, but they are two times smaller than those of the Su-35,” said Sagittarius.

It is worth noting that on the model of the Russian aircraft carrier of the future, which was presented at a number of military exhibitions, Su-57 was designated as aircraft

https://tvzvezda.ru/news/opk/content/201811081115-769z.htm

With the expression " without special means" are they implying that it could possibly perform a shipborne rolling landing i.e. without the need of arrestor cables?

No

Interesting bit about the PAK-FA's/Su-57's wing loading near the end. Before this video I came to the conclusion that the wing loading should never exceed within 20% of it's max. Turns out the wing loading max is almost 105%, however from what the maneuverability tests or demonstrations we have seen of PAK-FA it's been revealed that it has never exceeded beyond 80% (as I expected), and most times never exceeded 50% (better than I expected):

This first episode revealed many things, both visually and technically, that I didn't know before and I'm following the development of this plane quite closely.

I'm really hoping to see more of the 2nd stage engine in the upcoming episode. The engine looks extremely high tech. judging from the pictures and considering the techincal specifications sheet it's going to be quite a performer.

Isos wrote:When  will be the english version available ?

As soon as you learn Russian

Take-off would not be an issue with springboard, but can you explain how do you consider TVC would help there?

Have you ever been in a small motor boat?

When you are just sitting in the water and turn on the outboard motor the boat goes from sitting deep in the water to rising up and riding on less water... this reduces the drag the water imposes on the boat so the boat can go much faster once it is up and out of the water.

By changing the angle of the thrust from the outboard motor you can help the boat sit up out of the water allowing it to go much faster than it would if the thrust was fixed and designed to hold the boat down in the water.

By changing the trim of the engine propeller wash you can rapidly lift the boat out of the water so it is almost plaining... this is not a hydrofoil but uses a similar principle.

Now think of an aeroplane taking off... the first thing you do when taking off is angle the nose of the aircraft up 15-25 degrees or so to increase the wing angle and generate more lift, but with fixed engines that means the engine nozzles are now pointing down when in actual fact you want them pointed horizontally backwards to generate the most forward speed you can manage to accelerate faster.

On a Harrier jump jet in a rolling takeoff the engines are not horizontal and they are not vertical either, they have them at 45 degrees backwards to generate lift, but to also generate forward speed so the wings generate lift as well to support the aircrafts weight and to allow it to get airborne with more weight.

With a modern fighter whose engines don't go down 45 degrees... and even if they did you wouldn't use that setting because the engines are at the back and the rear would flip up and the nose would go down because it is not balanced lift you would never do that... you would either vector the thrust down to assist with lift generated by the wings or angle the engines up to angle the nose of the aircraft up to maximise acceleration while using maximum wing and fuselage lift.

TVC is also very useful in very high speed flight because the engine nozzles can be used to trim the aircraft instead of control surfaces... using tail or wing surfaces to trim the aircraft in supersonic flight increases drag and also RCS with deflected tail and wing surfaces... using the engine nozzles improves high speed cruise performance.

In any case, the thorny issue is the landing as far as I can see.

Arrester hook landing is the best option for all aircraft... TVC and large wing area means lower landing speeds which is always good, but catching cables is the best way to land.

Stop saying stupid things likr that. You need something that works always not in specific conditions. What if you send 10 su-57 in the air for training and the ship's stop working ? You loose 10 su-57, almost 1 billion dollars.

You have inflight refuelling aircraft that can allow them to divert to friendly airfields... besides when landing they will have very low fuel and they never carry a heavy weapon load... their primary function is air to air so most of the time when they land with full air to air weapons they are much lighter than when they took off.

Why would the ship stop working?

One of the offshoots of the EMALS work... they could incorporate the landing system with the cat launch system so that as well as accelerating the aircraft for take off it could also slow down aircraft for landing using an EM system.

And by the way if the landing system did fail pointing the ship into the wind and accelerating to max speed is the first thing you do before trying to recover aircraft... it is just common sense.

With the expression " without special means" are they implying that it could possibly perform a shipborne rolling landing i.e. without the need of arrestor cables?

There is a land based cable landing system that uses trucks with the reduction gear and cables spread across an highway that can be used to land aircraft in shorter spaces of tarmac than what they could normally operate from... but I suspect they just mean "without assistance".... ie no cables, no brake chute...

GarryB wrote:Now think of an aeroplane taking off... the first thing you do when taking off is angle the nose of the aircraft up 15-25 degrees or so to increase the wing angle and generate more lift, but with fixed engines that means the engine nozzles are now pointing down when in actual fact you want them pointed horizontally backwards to generate the most forward speed you can manage to accelerate faster.

Not sure, @15º AoA and fixed nozzles your engines are going to produce ca. 97% of the horizontal thrust while having vertical component of ca. 26% of thrust lifting the plane. So you increase substantially lift at a very low cost in horizontal thrust.

With a modern fighter whose engines don't go down 45 degrees... and even if they did you wouldn't use that setting because the engines are at the back and the rear would flip up and the nose would go down because it is not balanced lift you would never do that... you would either vector the thrust down to assist with lift generated by the wings or angle the engines up to angle the nose of the aircraft up to maximise acceleration while using maximum wing and fuselage lift.

I guess it all depends on how broad your CL is. If you can compensate the thrust at the back with lift at the front (canards for instance) then it makes a lot of sense to angle nozzle down for lower minimum speed.

It should also be considered that unstable planes have a tendency to amplify their movements, once initiated. That means, an unstable plane could need some torque to initiate the rotation but not to maintain the AoA (as F-16 during rotation for instance). Depending on the TO condition and aero design, it may even have a tendency to keep the nose up, even when the nozzles pointing down to a certain extent.

In any case on a springboard, the plane does not need to take care of rotation but just push with the engines in horizontal position as much as it can. Once off the deck, TVC could maybe help (if compensated at the front) to generate lift and keep the plane flying at slow speeds... but with the thrust of izd. 30 this is probably not going to be necessary

Arrester hook landing is the best option for all aircraft... TVC and large wing area means lower landing speeds which is always good, but catching cables is the best way to land.

Agree. Interesting about latest news is, if the plane has a very low min. speed the impacts are going to be much less severe and the deceleration provoked by the arrestor cable also much smaller. And then you may have the option to land in emergency mode over the whole length of the carrier, should the landing strip / gear be not available, which is very valuable IMO. At least this seems remotely thinkable after last information from Sukhoi.

Surpasses all analogues: the developer revealed the features of the engine Su-57

The new engine for the Su-57 fighter exceeds foreign analogues, will significantly expand its capabilities and belongs to the 5+ generation.

The engine of the second stage for the fifth generation fighter Su-57 in its specific gravity surpasses all analogues in the world. About this in the new release of the program “Military acceptance” to the film crew of the TV channel “Zvezda” said the General Designer-Director “OKB im. A.M. Cradles "Yevgeny Marchukov.

“I would say that this generation 5+ is slightly ahead of the fifth one. It is to this generation that the engine corresponds to specific thrust, specific consuption and specific weight.``


https://tvzvezda.ru/news/opk/content/201811131419-5mml.htm

5+ huh? Interesting. I guess their lab. testing is giving them more than what they aimed for. Great news.

What's the official ETA on the release date?

Great info dino00

That would mean that they have gone beyond the T/W ratio of the F135, which was the reference until now (from what I know) by a wide margin and hence managed a considerable technical achievement IMO.

I have not found any reliable info about the weight of the F135, wiki says 1701 kg. In that case, T/W would be 11.46 for 191.3 kN wet. Assuming same weight for izd. 30 than for izd. 117, that would mean at least 159.7 kN wet for the new engine. But then, the izd. 30 will have less stages and therefore should be substantially lighter than the izd. 117. If you have reliable data for the weight of the F135 we could have a better estimation of course.