PAK-FA / Sukhoi Su-57 - Updates and Discussions

[Speedster1]

Stealth aircraft are RCS tested after maintenance. Plus panels are designed in such a way that they fit in seamlessly from the start. A pilot also visually inspects the aircraft before flying it, paying more attention to whatever was worked on by the ground crew

The durability of Su-57 stealth coatings has been tested so far in controlled conditions. You'd need at least a couple of squadrons worth of airframe to even establish a baseline.

Russia doesn't have solid credentials in terms of maintenance let alone stealth maintenance. The IAFs operational tempo/sortie rate is likelt far hig
her in peacetime than RuAF's in wartime.

One reason why the IAF prefers buying Western ac (Rafale) at higher upfront cost than higher-lifecycle-cost Russian equivalents (Su-35S). Since MMRCA, the IAF has considered LCC in its cost calculations. Russian ac have been a disadvantage in IAF tenders since then.

 

[randomradio]

That was to compensate for their lack of a working LDP. Their Sapsan-E targeting pod was so poor that even the RuAF rejected it. So they built a low cost nav/attack system running CCIP algorithms to improve bombing accuracy. It was a jugaad solution at best

There's no relation between the two. The SVP-24 was just designed to make dumb bombs as accurate as smart bombs without having to spend on a guidance kit.

One of their dedicated guided bombs ironically was less accurate than when using the SVP-24.

 

[randomradio]

The durability of Su-57 stealth coatings has been tested so far in controlled conditions. You'd need at least a couple of squadrons worth of airframe to even establish a baseline.

Russia doesn't have solid credentials in terms of maintenance let alone stealth maintenance. The IAFs operational tempo/sortie rate is likelt far hig
her in peacetime than RuAF's in wartime.

All those are assumptions.

And the Russian low serviceability myth was busted in 2018 under Op Gaganshakti. It was junk Western propaganda based on the lack of parts after the Cold War to service Warsaw Pact jets. India suffered for a time too.

"Gagan Shakti" May Give China & Pakistan a Cause for Concern

11000 sorties by 1100 aircraft, disaster-relief evacuation drills and more, the air warriors are ‘shaking the heavens and splitting the Earth’

www.sps-aviation.com

IAF was able to achieve 80 per cent serviceability of aircraft while radars and surface to air guided weapons maintained a serviceability of 97 per cent, which included some of the legacy systems that were over 40 years old. Focused effort enabled a dispatch rate of more than 95 per cent for the Combat Assets, 100 per cent availability of Combat Support Systems and almost 100 per cent dispatch rates of Combat Enablers.

By bringing in Indian standards to Russian jets a decade ago, a Russian jet's serviceability is no different from a Western jet.

One reason why the IAF prefers buying Western ac (Rafale) at higher upfront cost than higher-lifecycle-cost Russian equivalents (Su-35S). Since MMRCA, the IAF has considered LCC in its cost calculations. Russian ac have been a disadvantage in IAF tenders since then.

That has a lot to do with the change in generations. MKI and Mig-29 may be 4th gen, but their maintenance standards are closer to 3rd gen, whereas Rafale is closer to 5th gen standards.

The Su-57 bridges that gap. For example, MKI (AL-31FP) and Su-35 (117S) use engines with overhaul rates at 1000 and 1500 hours resply, whereas Rafale's engine (M88-4E) is at 3000 hours. Su-57's interim engine (117) is at 4000 hours. AL-51F is even higher. So the Russians have caught up with the West.

As for stealth, the F-22 is built using titanium and its stealth is 95% dependent on shaping. Su-57 is made of majority composites + some titanium + RAS and only 70% of it is dependent on shaping. So, while people complain about Su-57's shaping being less special, which is actually false, and unlike the F-22, the airframe itself absorbs radar signals. AMCA too is 60% dependent on shaping, the rest comes from RAS + RAM.

Russia's disadvantage in MMRCA/MRFA tenders is deliberate. The IAF wants them to lose. They openly said that. Anyway, their products are as junk as the American ones. I'd rate an AESA-equipped Su-35 higher than any of their Teens.

 

[Lolwa]

Stealth aircraft are RCS tested after maintenance. Plus panels are designed in such a way that they fit in seamlessly from the start. A pilot also visually inspects the aircraft before flying it, paying more attention to whatever was worked on by the ground crew.

People make whatever excuses they want just to not support what they don't want to support.

Think about it this way, the IAF is happy with the Bars radar and think it will remain useful for many more years. The F-22 and F-35 are still flying with analog AESA radars. But everybody has a problem with the Russians already operating better tech than what's on the F-22/F-35, ie, a generation ahead of the Bars, which even the IAF is fine with, and on an aircraft that's as stealthy as the F-22/F-35. And the Russians claim the Su-57 is much cheaper to operate than the Flanker, which gives it an advantage over the F-22.

The Su-57 is a real 5th gen aircraft, and new variants with modifications are coming in. There will be a Su-57M, even an M2, and a Su-60 and a Su-63 and a Su-64 and all successive models will be more stealthy than the one previous to it, all within a decade from now, and all more capable than the F-22/F-35.

People have consumed so much Western propaganda that even Western analysts have started taking back their criticisms of the Su-57.

People are yet to see the final version before true RCS tests can be conducted by outsiders.
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Su-57 in its present state is still not a pure 5th gen aircraft. It has an RCS closer to rafale and super hornet than the f-35 or even j-20 for that matter.

 

[Lolwa]

I'd rate an AESA-equipped Su-35 higher than any of their Teens

The su-35 doesn't have an aesa. It still uses a PESA that got jammed by rafale in Egypt. Russian aesa tech is questionable at best in its present state compared to west.

 

[RASALGHUL]

It still uses a PESA that got jammed by rafale in Egypt

oh Really? LOL!!
Any Sources...... I mean Legitimate Sources?

 

[Speedster1]

There's no relation between the two. The SVP-24 was just designed to make dumb bombs as accurate as smart bombs without having to spend on a guidance kit.

The SVP-24 is likely not very accurate either. Why else would RuAF Su-34 pilots be using commercial Garmin GPS devices to improve bombing accuracy over Ukraine?

The Russians have been sorely lacking a decent LDP, for years. After Sapsan failed, the RuAF even considered buying a French-origin pod but later decided to wait until the new one for the Su-57 was ready.

 

[randomradio]

Su-57 in its present state is still not a pure 5th gen aircraft. It has an RCS closer to rafale and super hornet than the f-35 or even j-20 for that matter.

I've spent multiple posts explaining that it's VLO.

Flat nozzles are useless if the jet isn't stealthy.

 

[Speedster1]

All those are assumptions.

And the Russian low serviceability myth was busted in 2018 under Op Gaganshakti. It was junk Western propaganda based on the lack of parts after the Cold War to service Warsaw Pact jets. India suffered for a time too.

From engines to radars, MTBO/F figures for Western jets have been way better than their Soviet/Russian counterparts. The IAF chose to terminate Su-30 production at 272 precisely because they were/are maintenance hogs. This despite being historically low on squadron strength. It's purely because of IAFs ingenuity + the use of predictive maintenance and spares management (HUMS, IMMOLS) that the IAF has been able to slowly close the gap in serviceability rates between Western vs Russian ac in the inventory. No thanks to the Russians.

 

[randomradio]

The su-35 doesn't have an aesa. It still uses a PESA that got jammed by rafale in Egypt. Russian aesa tech is questionable at best in its present state compared to west.

Jamming is a matter of luck and pilot proficiency. It also depends on what signal they used, a familiar one or an unfamiliar one. Even today, the F-35 does not have the ability to jam an unfamiliar signal. Rafale requires pilot input and that takes time.

If IAF has no complaints when operating Bars, why would they complain about the Su-57's more advanced radar? The Bars has been tested in Red Flag and performed very well in that environment.

Anyway, the Russian radar is superior to what's on the F-22 and F-35 today.

 

[randomradio]

From engines to radars, MTBO/F figures for Western jets have been way better than their Soviet/Russian counterparts. The IAF chose to terminate Su-30 production at 272 precisely because they were/are maintenance hogs. This despite being historically low on squadron strength. It's purely because of IAFs ingenuity + the use of predictive maintenance and spares management (HUMS, IMMOLS) that the IAF has been able to slowly close the gap in serviceability rates between Western vs Russian ac in the inventory. No thanks to the Russians.

IAF's original MKI fleet wasn't supposed to exceed 190. That's why the option for 140 jets was only 40 more. It climbed up by 80 more than planned due to LCA delays. Those 80 extra jets were used to replace Mig-21s in forward bases.

Russia's 117's MTBO exceeds all Western engines except F414 today. It's 4000 hours. All other engines are 3000 hours or below. Only F414 is at 6000 hours. It's possible that AL-51F matches the F414.

The Su-57's maintenance manhours is also said to be much lower than the Flanker's. Even if it's half that, it would mean the Su-57 is easier to maintain than the F-16.

 

[randomradio]

oh Really? LOL!!
Any Sources...... I mean Legitimate Sources?

Any radar can be jammed. There's nothing special about it.

Creating new waveforms is the responsibility of the operator (Egypt), not the seller (Russia). New waveforms are harder to jam, whereas if the Su-35 used waveforms that are already known to the Rafale, then it's easy to jam it. That's why war reserve waveforms are never revealed during peacetime.

So whatever exercise took place between Rafale and Su-35 was using known waveforms because Egypt does not operate the Su-35, and Russia's not going to come to Egypt with unknown waveforms.

It was always a dumb assertion.

 

[Picdelamirand-oil]

The Su-57 bridges that gap. For example, MKI (AL-31FP) and Su-35 (117S) use engines with overhaul rates at 1000 and 1500 hours resply, whereas Rafale's engine (M88-4E) is at 3000 hours. Su-57's interim engine (117) is at 4000 hours. AL-51F is even higher. So the Russians have caught up with the West.

I think that for the M88-4E the TBO is not defined in hours but in cycles, but it's been a long time since I looked into this.

 

[Speedster1]

Russia's 117's MTBO exceeds all Western engines except F414 today. It's 4000 hours. All other engines are 3000 hours or below. Only F414 is at 6000 hours. It's possible that AL-51F matches the F414

To me, these look like brochure figures. 117S is an evolution of the AL-31F after all. Generally, Russian ac need twice as many engine replacements vs Western jets over a 30 year service life. The AL-51F is still untested in real-world conditions like the jet it powers.

 

[randomradio]

I think that for the M88-4E the TBO is not defined in hours but in cycles, but it's been a long time since I looked into this.

All engines are defined by cycles, but it is converted to hours based on how the cycles are calculated.

A takeoff, climb to altitude, fly on-station, and back is more or less 1.5-2 cycles to an hour. If you bring in combat, the number of cycles increase and number of hours decrease.

How are jet engine RPM cycles used to monitor LCF life?

Can someone please define what are N1 and N2 throttle cycles? These are used to keep track of the accumulated low cycle fatigue (LCF) life of rotating components. But I cannot find an exact definit...

aviation.stackexchange.com

Typically, 1 cycle is from idle to max speed, and back to idle. 60% to max and back to 60% may be 0.5 cycles, and 75% to max and back to 75% 0.25 cycles, as an example. So, if you take-off, from idle, do a climb at max RPM, throttle back in cruise to 60%, return to max before landing, and then shutdown the engine, you have accumulated 1+0.5+0.25=1.75 cycles in the flight. (Recognising that when you go from 60 to max back to 60, you have meet the criteria for both the 0.5 and 0.25 cycles.)
Every time you accelerate or decelerate, you add to the cycle count, and the amount of time flown while consuming cycles gives you hours flown.

With combat, as much as 4 or 5 cycles could be equal to an hour.

Anyway, from what I remember, M88-2's inspection cycle was 250 hours and that was improved to 800 hours on M88-4E. And I think 3 inspections seem more logical than 2. So 800x4 gives us 3200 hours for overhaul. With the engine providing a total life of 6000-7000 hours, 3000-3200 hours before TBO makes sense.

AL-31FP is the same, 250 hours inspection, 1000 hours overhaul, 2000 hours lifespan. 117 is likely 1000 hours, 4000 hours, and 8000 hours resply, matching the Su-57's lifespan.

How many engines do airlines go through in a typical lifespan?

The number of engines airliners go through in their life depends on several factors, Dr. Omar Memon informs for Simple Flying.

www.militaryaerospace.com

"The average number of cycles before the first overhaul for modern narrowbody engines is 12,000 flight cycles," Dr. Memon writes. "For the two subsequent maintenance visits, the number of cycles may be reduced to 8,000 and 4,000, respectively. With an overhaul costing several million dollars, further shop visits could not be economically viable for operators. The average number of hours before the first overhaul for modern widebody engines is 20,000 flight hours. Subsequent maintenance visits reduce this number to as low as 5,000 flight hours."

 

[randomradio]

To me, these look like brochure figures. 117S is an evolution of the AL-31F after all. Generally, Russian ac need twice as many engine replacements vs Western jets over a 30 year service life. The AL-51F is still untested in real-world conditions like the jet it powers.

Maybe so, the engine is yet to undergo its first overhaul in an operational setting while the AL-51 is yet to be fielded. But it could be close, it could even exceed it. And engine life depends on how you fly the jet anyway. My previous post explains that.

Also, no. Su-57 is expected to carry the same engine throughout its life, the same as Western jets. Flanker life is already 6000 hours, and 117S has a 3000 hour life. AL-31FP has been boosted to 2500 hours, with the final goal being 3000 hours too. So Flankers need multiple engines. Su-57 at 8000 hours will need a 117 with 8000 hours. And AL-51 could give 10000 hours too, with the subsequent Su-57 variant matching that number.

So the Russians have caught up with the West with Su-57+117 and will exceed the West with Su-57M/M2+AL-51F.

It's unclear what engine Mig-41 will use. A turbofan or turbojet combined with a pulse detonation engine.