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

I surely hope so. Checkmate and su-57 are so awesome.

I love Russian aircraft. Might be wrong here but it seems Russia is the only military power with totally different doctrine and as a result their designs are usually quite different from the norm. Finally fifth gen fighters that have soul imo. China has different military doctrines as well and I love their fighters but they seem much more aligned with western style of fighting when it comes to air power.
 
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It sounds like flight testing won’t happen this year if they are doing durability testing and ground testing. I wonder if the war results have revived the interest for a lower signature nozzle.
 
PRA27 said:
what? airliner style thrust reversal? on a 5th gen fighter?
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So long as it can be done without damaging the coatings - it might make sense... for the same reasons the Viggen had it.

Given the experience in the current war, the Soviet emphasis on being able to operate off rush/short strips seems to be well validated.
 

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They're still shy showcasing the Izd-180 and 810 eh ? Also the Kh-69 seems absent too from there.
 
stealthflanker said:
They're still shy showcasing the Izd-180 and 810 eh ? Also the Kh-69 seems absent too from there.
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Kh-69 was show at separate KTRV box.
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photo (c) BMPD.
No 180 and 810, however.
 
I had always wondered what the maximum speed was for the Su-57 at altitude was, as I had previously read that it was just above Mach 2 with no further information given.
 
flateric said:
180 was shown without big fanfares together with LTS mockup two years ago.
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Was it? There was a RVV-SD, with standard fins, buut it was never stated that this is a 180.
For all we know there might be 170-1 with lattice fins, standard fins, and 180 with standard fins.
 
icyplanetnhc (Steve) said:
2,500 km/h is Mach 2.35 at altitude, which is the same maximum speed as the original specification for PAK FA that became the Su-57.
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It was stated (was it Bondarev?) that maximum speed of the plane was reduced to 2M and ever since it has been widely assumed that to be the case, but for some stubborn people like myself. Do you remember this argument of yours when we discussed about the point of having variable intakes on the Su-57?

icyplanetnhc (Steve) said:
Sukhoi’s own patents and documentations even stated a reduction in maximum Mach to around Mach 2 in order to increase the amount of composite materials used.
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It was General Vladimir Mikhaylov, chief of the Russian Air Force, who stated the top speed requirement of Mach 2 in 2006.

Модернизированный стратегический бомбардировщик Ту-160 в конце декабря был принят на вооружение ВВС РФ // АвиаПорт.Новости

Стратегический бомбардировщик Ту-160, прошедший глубокую модернизацию, принят на вооружение ВВС указом президента России, заявил главнокомандующий ВВС РФ В. Михайлов
www.aviaport.ru www.aviaport.ru

As far as variable geometry inlets on the Su-57, it may indeed be meant to support a top speed of Mach 2.35 at altitude, although frankly the utility of dashing faster than Mach 2 has always been questionable, especially if it involves additional mechanical complexity and weight involved. The F-22 has immense excess thrust, using only 36% afterburner at Mach 2.0 at 40,000 ft and with structural total temperature limit that can support greater speeds, yet it is operationally limited to that because the RAM itself has lower temperature limit than the aircraft's aerodynamic and structural limit.
 
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Just because we might think it is unnecessary doesnt mean it is unnecessary as we do not know the intent and purpose for why it was made the way it was. maybe it is largely useless excess but we dont know that for certain.
 
To replace the interceptor with a maximum speed of 3000 km / h, it is necessary to rest against the lower edge of the thermal barrier. For duralumin it is 2650 - 2700 km/h.The air intake and Su-57 engines allow you to reach 2500 km/h guaranteed
 
icyplanetnhc (Steve) said:
As far as variable geometry inlets on the Su-57, it may indeed be meant to support a top speed of Mach 2.35 at altitude, although frankly the utility of dashing faster than Mach 2 has always been questionable, especially if it involves additional mechanical complexity and weight involved.
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The original idea with these "supercruising" (misleading word IMHO) planes was that they would not need to dash in the traditional sense, since they would remain in mil power even under combat conditions, hence why I was arguing about the relevance of speeds as high as possible in mil power. But when the threats include other supercruising planes like the F-22, then it is beneficial to have speed advantages to try to dictate the terms of the engagement. Both planes as far as I know are able to go beyond 2M even with the limitation of the RAM and composites, as explained in the Sukhoi document, therefore the tactical relavance needs to exist, and as you say excess power with such engines is plentiful.
 
I think they want to be able to get fast and high to give their missiles more energy to reach whatever they want to reach. Also, they might end up replacing mig-31s with the su-57. I have a hunch the f-22 can go faster than match 2.0.
 
LMFS said:
The original idea with these "supercruising" (misleading word IMHO) planes was that they would not need to dash in the traditional sense, since they would remain in mil power even under combat conditions, hence why I was arguing about the relevance of speeds as high as possible in mil power. But when the threats include other supercruising planes like the F-22, then it is beneficial to have speed advantages to try to dictate the terms of the engagement. Both planes as far as I know are able to go beyond 2M even with the limitation of the RAM and composites, as explained in the Sukhoi document, therefore the tactical relavance needs to exist, and as you say excess power with such engines is plentiful.
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However, you don’t need the variable inlets for supercruise less than M2.0. It becomes an weight, cost and complexity disadvantage unless you are pushing past M2, in AB.
 
Even well-designed fixed inlets can push beyond Mach 2.0, as both the YF-23 and the F-22 can push well past Mach 2.2 at altitude in terms of materials and structures, with the RAM being the principal limitation. Perhaps Sukhoi developed the inlet as a separate component that can be used for a future Mach 2.8-class PAK DP competitor to replace the MiG-31 and aimed to reduce costs by spreading some of the development onto the PAK FA, even if the T-50/Su-57 itself doesn’t operate at such speeds.
 
icyplanetnhc (Steve) said:
Even well-designed fixed inlets can push beyond Mach 2.0, as both the YF-23 and the F-22 can push well past Mach 2.2 at altitude in terms of materials and structures, with the RAM being the principal limitation. Perhaps Sukhoi developed the inlet as a separate component that can be used for a future Mach 2.8-class PAK DP competitor to replace the MiG-31 and aimed to reduce costs by spreading some of the development onto the PAK FA, even if the T-50/Su-57 itself doesn’t operate at such speeds.
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Agreed. It may also be possible that the Levcon aero design is integral with the performance of the Su-57, and once you have the movable inlet leading edges, the rest of the variable inlet is easy and logical to include?
 
In my, admittedly, layman opinion that variable inlet was a choice to minimize or remove losses for 117 engine which have 1t lower thrust than F119, and being a derivative of Al-31 isn't optimised for supercruise and hi-alt flight as much as F119 with it's big core and lower bypass ratio.
So while F-22 can allow additional losses on fixed inlet at high speed and flat nozzles, Su-57 can't.
Now, as Marchukov said, with more powerful izd.30 engine Sukhoi wants a flat nozzle.
 
F119Doctor said:
However, you don’t need the variable inlets for supercruise less than M2.0. It becomes an weight, cost and complexity disadvantage unless you are pushing past M2, in AB.
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Though I seem to recall that variable inlets start providing discernible advantage from 1.6M onward, Sukhoi patent states flight regime between Mach 2 and 3 as design goal for the intake. Probably related to the interceptor role included in the PAK-FA, as Paralay mentioned.
 
The Su-57 is an ultimatum fighter going to replace the Su-27 and MiG-31, it should be as capable as possible in all flight modes.
The F-22 replaced the only interceptor F-106, the main design mode of its flight is M = 1.5. For other modes, "crutches" in the form of a bypass are used
 
paralay said:
The F-22 replaced the only interceptor F-106
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Erm... the last Delta Dart was decomissioned in 1988. The first Raptor flight was a decade later. And ATF program was never intended to replace the continental defense interceptors (their functions were already shifting to Air National Guard); they were supposed to replace F-16 and F-15.
 
The Su-57 is not achieving MiG-31-like speeds of Mach 2.8; materials alone would preclude this, and it's unlikely to have the excess thrust, especially as it requires the use of afterburner to achieve supercruise of Mach 1.3 with the current AL-41F1, per Evgeniy Marchukov of OAK Saturn. There is a reason that there is a separate PAK DP project to replace the MiG-31; that said, I think it's possible that Sukhoi may also be vying to compete for PAK DP and decided to trial some components on the PAK FA like the inlet to reduce risk and cost and see how the inlet behaves up to Su-57's top speed of Mach 2.35.
 
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icyplanetnhc (Steve) said:
The Su-57 is not achieving MiG-31-like speeds of Mach 2.8; materials alone would preclude this, and it's unlikely to have the excess thrust, especially as it requires the use of afterburner to achieve supercruise of Mach 1.3 with the current AL-41F1, per Evgeniy Marchukov of OAK Saturn. There is a reason that there is a separate PAK DP project to replace the MiG-31; that said, I think it's possible that Sukhoi may also be vying to compete for PAK DP and decided to trial some components on the PAK FA like the inlet to reduce risk and cost and see how the inlet behaves up to Su-57's top speed of Mach 2.35.
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Who is saying it reaches 2.8M? But it is a fact that Sukhoi stated it shares the characteristics of a strike plane, fighter and interceptor. Of course such a flexibility precludes ultimate performance of more specialized planes. Your argument about the speed, based on the use of the interim engine is not very convincing, rather an argument about the convenience of developing izd. 30. Lastly, the idea of putting an unnecessary intake on the Su-57, jeopardizing its design and negligently using the program to develop a solution for another plane with (according to you) completely different requirements is a nice conspiracy theory but makes no sense.
 
LMFS said:
Who is saying it reaches 2.8M? But it is a fact that Sukhoi stated it shares the characteristics of a strike plane, fighter and interceptor. Of course such a flexibility precludes ultimate performance of more specialized planes. Your argument about the speed, based on the use of the interim engine is not very convincing, rather an argument about the convenience of developing izd. 30. Lastly, the idea of putting an unnecessary intake on the Su-57, jeopardizing its design and negligently using the program to develop a solution for another plane with (according to you) completely different requirements is a nice conspiracy theory but makes no sense.
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I’m frankly being charitable here. Marchukov stated that the Su-57 with the AL-41F1 does not achieve supersonic cruise without afterburners. Given that the Su-35 with the AL-41F1S attained Mach 1.1 without afterburners, I presumed that the Su-57 is capable of achieving the same, and that supersonic cruise refers to speeds beyond transonic region (Mach 0.8-1.2), hence Mach 1.3 or so.

An aircraft having components that are designed to operate beyond the overall system’s boundaries is not new, nor is it unique to Sukhoi. The North American Rockwell B-1B retains the same engine as the B-1A, despite being designed for Mach 1.25 rather than the latter’s Mach 2.2 top speed. The F-22’s APGS likewise has a design altitude limit well in excess of the aircraft’s operational limit. I’m not saying this is definitely the case with the Su-57, but it’s a possibility.
 

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