J-20 goes operational again

[weasel1962]

CASI estimate of J-20 numbers. 8 combat brigades (160-200 units excl training), 48-60 annual production rate. 1,5,8,9,41,56,97,111 bde.

https://www.airuniversity.af.edu/CASI/D ... -the-j-20/

3.5 years production to parity in 5G fighter numbers.

[alfa_particle]

J20 for UAE?
https://nationalinterest.org/blog/buzz/ ... ast-210712

speculative story by NI. consider that uae has joined brics and bought L15s. not far fetched.

As far as I'm aware, the J-20 export restricted like the Raptor. In my opinion, China probably wouldn't even entertain the idea until their 6th Gen is in mature operational service.

The most UAE is gonna get is probably the FC-31 (NOT to be confused with the J-31/35).

CASI estimate of J-20 numbers. 8 combat brigades (160-200 units excl training), 48-60 annual production rate. 1,5,8,9,41,56,97,111 bde.

https://www.airuniversity.af.edu/CASI/D ... -the-j-20/

3.5 years production to parity in 5G fighter numbers.

Regarding this, I would like to point out that once the J-20A is sufficiently mature, a notable increase in the amount of airframes produced may be seen as it truly enters FRP with WS-15. Add that the J-35 is close to production status, the 3.5 years figure is probably pretty far off from reality. Even more so if the PLAAF decides to adopt the J-31 into service.

[Corsair1963]

As far as I'm aware, the J-20 export restricted like the Raptor. In my opinion, China probably wouldn't even entertain the idea until their 6th Gen is in mature operational service.

The most UAE is gonna get is probably the FC-31 (NOT to be confused with the J-31/35).

I don't think the issue with the J-20 not being exported is because China doesn't want it sold abroad. Just the simple fact they can't spare any aircraft for export. As the PLAAF need everyone they can get for the foreseeable future.

As for the UAE I have my doubts they would acquire the J-20 and/or J-31. They can just wait a few months in case Trump is back in office and the F-35 will be back on the table.

[alfa_particle]

I don't think the issue with the J-20 not being exported is because China doesn't want it sold abroad. Just the simple fact they can't spare any aircraft for export. As the PLAAF need everyone they can get for the foreseeable future.

As for the UAE I have my doubts they would acquire the J-20 and/or J-31. They can just wait a few months in case Trump is back in office and the F-35 will be back on the table.

Obviously, but I consider these reasons mutually inclusive, not exclusive. There's literally no reason to export the J-20 right now. They need all the J-20s they can get, but that's not the only reason. Why would they sell the most advanced fighter aircraft in their inventory right now? Cause if they really wanted to, CAIG can totally ramp up the J-20's production rate with their new assembly halls and still be able to phase out their older fleet of fighters in an ideal/acceptable rate. But there's a few reasons why this is a completely ridiculous thought:

- As the J-20A variant and WS-15s are nearing to be mature enough to be adopted into service, the PLAAF probably will want the less/least amount of regular J-20s to be adopted into service, aside from maintaining their modernisation rate.

- Right now, the J-20 is still their most advanced fighter in service. Exporting it means you are confident that the risks of it being compromised are incredibly low or that you already have next generation equipment ready and you don't care. In this case, neither is true.

- The J-20 was never advertised as an export product by AVIC. OPSEC reasons aside, no country really need what makes the J-20 a threat (aside from stealth): range. The J-20 is tailor-made for China's needs with their landmass and the SCS/Pacific operations. On the other hand, the FC-31 is advertised as an export product. A mid-sized stealth fighter, IMHO, suits most countries that will want to purchase stealth fighters better than a full-on heavyweight.

Until there's official interest from China to export the J-20, IMHO all rumours that the J-20 will be exported can be disregarded.

P.S. For now, it appears that the FC-31/J-31E will be different from J-31/35. I'm inclined to believe that the export model will be closer to FC-31V2 models than the J-35, such as the lack of the hump behind the canopy.

[disconnectedradical]

Just see the WS-10 low pressure fan section and compare it with the AL-31F and then with the F110. The WS-10 looks more like an F110 with the lookalike nozzle from the D-30F6, than an AL-31F. Even the LP-HP stage configuration (3+9) is same as the F110. The AL-31F has a compressor with 4+9 stages.

Depends, the WS-10B installation on the J-16 has an iris nozzle similar in appearance to EJ200, while the WS-10C on the J-20 has an ejector nozzle that looks like a D-30F6.

From what I've gathered, the WS-10 Taihang family had a long gestation period since the 1980s before becoming an engine with acceptable operational characteristics. Originally, the WS-10 was to be a 12-14 metric ton thrust engine, with 13.2 metric tons (130 kN) being the goal, and had a core based on the CFM56 (F101 core) but they had difficulty with the engine control system and at one point, reportedly directly applied an AL-31F control unit. It was dogged with reliability and durability problems and also issues with spool up time. The WS-10A was developed in the 2000s to address these problems, but it still took quite a number of years since performance was still unsatisfactory. Poor quality was also cited, directly by AVIC, no less. In fact it had to be de-rated to 110-125 kN in the early 2000s just to achieve any kind of durability with lifespan well under 1,000 hours. Only the later batches of engines in the early-to-mid 2010s achieved acceptable characteristics, with 130 kN thrust and durability of 1,200 hours TBO and 2,000 hours overall life.

Once they got the WS-10A to an acceptable standard they likely developed more powerful versions of it so that they can ween off Russian engines as soon as possible, so in 2014 Zhuhai Air Show, AVIC revealed a "14 [metric] ton Taihang" which became the WS-10B with 137 kN thrust that was eventually installed on the J-16 and broadly comparable to the AL-41F1S (izd.117S) in terms of performance, although based on an interview with a J-16 pilot, the WS-10B still lagged behind the AL-41F1S even though they have the same rated static thrust, so possibly the WS-10's dynamic thrust lags somewhat. But the turbomachinery itself was run harder so the durability decreased to 900 hours TBO and 1,500 hours overall life.

In 2016 Zhuhai Air Show, AVIC revealed a "14.5 [metric] ton Taihang" which likely became the WS-10C with 142 kN thrust that is now installed on the J-20. This engine is roughly comparable to the AL-41F1 (izd.117) and likely the durability numbers are similar to the WS-10B. It has an ejector nozzle rather than an iris nozzle and this may be due to IR signature concerns, since ejector nozzles cool the exhaust better. The WS-15 is an entirely different animal, and has much longer exhaust petals for better exhaust expansion and specific thrust. Just because it's flying on prototypes doesn't mean it's in service, but I think that may happen some time late this decade.

While the Chinese are still about 1 to 2 decades behind the Western state of the art, they've largely achieved parity with Russia at this point, which considering how late they started developing jet engines, is still quite an achievement.

[disconnectedradical]

Picture of J-20A prototype bort number 2053 with the bigger hump behind the canopy likely for reduced drag, and WS-15s. It does look like the exhaust petals are longer than on the WS-10C, so should have better nozzle pressure ratio for supercruise.

Also, here's a good comparison of the different engines and their nozzles on the J-20.

[f119doctor]

Just to be clear - the longer divergent section of the nozzle is needed to effectively utilize a higher engine ratio (or more specifically a higher nozzle pressure ratio), not to create a higher pressure ratio. The turbomachinery has to be able to produce the high pressure ratio and sustain it at supercruise inlet conditions, and the nozzle design has to efficiently turn that pressure ratio into exhaust velocity for it all to work.

[sharon_11]

Hello, Long time lurker, 1st time post. I have a question.

The GE F-110 service life is said to be 8000 or more hours. the Chinese seem happy with less than 2k hours of life. How do the cope with engines having such a short service life. Do they just buy more engines? Do you scale back flying hours? and how does this factor in a protracted conflict like the one in Rusian ATM?

[disconnectedradical]

Well service life for Western engines is measured a bit differently, it's mainly in cycles rather than hours since it was discovered that throttle changes affect service life more than just steady state operation. But general rule of thumb is that 2 cycles equal to about 1 hour, and the current production F110-GE-129 has TBO of 6,000 cycles for hot section and 12,000 cycles for cold section, so roughly 3,000 hours and 6,000 hours when it comes to lifespan of most of the parts in those sections. I think the current F100-PW-229EEP has the same durability.

So the current F110-129 and F100-229 use the same technology as the F110-132 and F100-232 developed in the early 2000s, but since those engines are tuned to produce 32,500 lbs (144.6 kN) of thrust, they have durability reduced to 4,300 cycles and 8,600 cycles for hot and cold sections.

[allesmorobranna]

Well service life for Western engines is measured a bit differently, it's mainly in cycles rather than hours since it was discovered that throttle changes affect service life more than just steady state operation. But general rule of thumb is that 2 cycles equal to about 1 hour, and the current production F110-GE-129 has TBO of 6,000 cycles for hot section and 12,000 cycles for cold section, so roughly 3,000 hours and 6,000 hours when it comes to lifespan of most of the parts in those sections. I think the current F100-PW-229EEP has the same durability.

So the current F110-129 and F100-229 use the same technology as the F110-132 and F100-232 developed in the early 2000s, but since those engines are tuned to produce 32,500 lbs (144.6 kN) of thrust, they have durability reduced to 4,300 cycles and 8,600 cycles for hot and cold sections.

Except two things.
The current F110GE129C does not have the GE132 blisk low pressure fan and the radial AB flameholders, while the current PW229 does not have the modified low pressure compressor section of the PW229A (PW232), which designe based on the F119PW100 LPC section.
That's why the F100PW229A had a longer LPC and a reduced length AB chamber, to keep the overall length/diameter and the mounting points same.

An F-15E in 1998, which was equipped with two PW229As, was able to fly Mach 2 without an inlet ramp movement.
That particular testbed had same T/W ratio as the legendary Streak Eagle had.

[disconnectedradical]

Except two things.
The current F110GE129C does not have the GE132 blisk low pressure fan and the radial AB flameholders, while the current PW229 does not have the modified low pressure compressor section of the PW229A (PW232), which designe based on the F119PW100 LPC section.
That's why the F100PW229A had a longer LPC and a reduced length AB chamber, to keep the overall length/diameter and the mounting points same.

An F-15E in 1998, which was equipped with two PW229As, was able to fly Mach 2 without an inlet ramp movement.
That particular testbed had same T/W ratio as the legendary Streak Eagle had.

Actually the current F110-129 is up to the -129D for F-16 and -129E for F-15, and these are the ones that incorporate the -132 and CFM56 upgrade technology to increase total life to 6,000 cycles (cold section life should be double this). The current F100-229EEP should incorporate much of the same durability improvements as the -232 (-229A) without the increased thrust and is reportedly also 6,000 cycles for hot section and 12,000 cycles for cold section. The point is that the current WS-10C on the J-20 is approximately the performance equivalent of an F100-232 or F110-132 with about 1/2 to 2/3 the lifespan, so there's still a gap between Western and Chinese engines but it has greatly narrowed especially considering how far behind China was even 2 decades ago.

https://www.geaerospace.com/news/press- ... nd-f404414

And yes the F-15E with the F100-229A (or -232) is a beast, empty weight (34,600 lbs) plus full internal fuel (13,000 lbs), and completely slick, you have a T/W ratio of 1.37 which close to the original Streak Eagle. You'd run out of gas very fast though.

[viperzerof-2]

Except two things.
The current F110GE129C does not have the GE132 blisk low pressure fan and the radial AB flameholders, while the current PW229 does not have the modified low pressure compressor section of the PW229A (PW232), which designe based on the F119PW100 LPC section.
That's why the F100PW229A had a longer LPC and a reduced length AB chamber, to keep the overall length/diameter and the mounting points same.

An F-15E in 1998, which was equipped with two PW229As, was able to fly Mach 2 without an inlet ramp movement.
That particular testbed had same T/W ratio as the legendary Streak Eagle had.

Actually the current F110-129 is up to the -129D for F-16 and -129E for F-15, and these are the ones that incorporate the -132 and CFM56 upgrade technology to increase total life to 6,000 cycles (cold section life should be double this). The current F100-229EEP should incorporate much of the same durability improvements as the -232 (-229A) without the increased thrust and is reportedly also 6,000 cycles for hot section and 12,000 cycles for cold section. The point is that the current WS-10C on the J-20 is approximately the performance equivalent of an F100-232 or F110-132 with about 1/2 to 2/3 the lifespan, so there's still a gap between Western and Chinese engines but it has greatly narrowed especially considering how far behind China was even 2 decades ago.

And yes the F-15E with the F100-229A (or -232) is a beast, empty weight (34,600 lbs) plus full internal fuel (13,000 lbs), and completely slick, you have a T/W ratio of 1.37 which close to the original Streak Eagle. You'd run out of gas very fast though.

Not sure the WS-10B or C is F110-132 level.

Pakistan is pretty consistent the F-16 Block 15 MLU and Block 52 beat the J-10C in thrust to weight and acceleration. J-10C weighs about as much as a Block 60 but doesn’t seem to have similar performance in this regard

https://m.163.com/dy/article/I6649OFF05 ... ss=adap_pc


https://thaimilitaryandasianregion.blog ... 0.html?m=1

download/file.php?id=43190&mode=view

[disconnectedradical]

Not sure the WS-10B or C is F110-132 level.

Pakistan is pretty consistent the F-16 Block 15 MLU and Block 52 beat the J-10C in thrust to weight and acceleration. J-10C weighs about as much as a Block 60 but doesn’t seem to have similar performance in this regard

https://m.163.com/dy/article/I6649OFF05 ... ss=adap_pc


https://thaimilitaryandasianregion.blog ... 0.html?m=1

download/file.php?id=43190&mode=view

Reading those two articles (translation for the first), it seems like the issue is that while the J-10C instantaneous turn is very good, but it bleeds a lot of energy in sustained turning, so it's more about the aircraft's aerodynamics than engine power. Also the F-16 Block 50/52 is about 2,000 lbs lighter than a Block 60, and combine that with the J-10's canard-delta bleeding more energy in sustained turn than an F-16, I wouldn't say it's because of the engine. The article itself even considers the WS-10B to be about the same league as the F110-132.

[viperzerof-2]

Not sure the WS-10B or C is F110-132 level.

Pakistan is pretty consistent the F-16 Block 15 MLU and Block 52 beat the J-10C in thrust to weight and acceleration. J-10C weighs about as much as a Block 60 but doesn’t seem to have similar performance in this regard

https://m.163.com/dy/article/I6649OFF05 ... ss=adap_pc

https://thaimilitaryandasianregion.blog ... 0.html?m=1

download/file.php?id=43190&mode=view

Reading those two articles (translation for the first), it seems like the issue is that while the J-10C instantaneous turn is very good, but it bleeds a lot of energy in sustained turning, so it's more about the aircraft's aerodynamics than engine power. Also the F-16 Block 50/52 is about 2,000 lbs lighter than a Block 60, and combine that with the J-10's canard-delta bleeding more energy in sustained turn than an F-16, I wouldn't say it's because of the engine. The article itself even considers the WS-10B to be about the same league as the F110-132.

They do mention the vertical climb of the J-10C is better than the JF-17 and Mirage but inferior to the F-16.

In addition to its excellent detection capabilities, the J-10C's vertical climb and acceleration capabilities are also super strong. The J-10C has a greater thrust due to the improved engine. The climbing performance is significantly better than the Mirage-2000 and JF-17.

Especially at the beginning of the circle, the instantaneous turning ability of the J-10C even the F16 of the same type of the US military could not keep up, but after the early advantage time, the overall climb ability is still better than that of the F16. Therefore, the climb capability of the J-10C is only inferior to that of the F-16 among all single-engine fighters.

Also at least according to the PAF the WS-10B is a 29000 class engine

http://zzwave.com/plaboard/posts/3974094.shtml

The crews were taken aback after engaging afterburner (AB). The kick was bigger than the F-16. “There was an unbelievable amount of thrust when I opened up the afterburner for the first time. The J-10C can produce 29,000 lb thrust, which is 10,000 lbs excess thrust than the JF-17 produces, and as much power as two and a half Mirages put together. A single Mirage produces 14,000 lb thrust,” Sqn Ldr Jibran Rashid said. The speed increment was so fast that post-take-off procedures had to be executed in rapid succession to remain with the aircraft. Once in the air, handling the jet was not the most difficult aspect, Wg Cdr Bilal Raza said adding, “It is actually a really easy plane to fly, the aircraft comes with Voice Recognition Capability which makes your life much easy.”

It does seem strange if the J-10C has all this power it struggles so much against old F-16 and bleeds energy so severely, when the Rafale another close coupled delta canard aircraft with modest engines is said to be able to fight an F-16 and Eurofighter and is inferior but still respectable in sustained turning and acceleration.

[disconnectedradical]

I guess it depends on how badly it bleeds airspeed, don’t know if anything is lost in the translation, but perhaps the J-10C sustained turn is somewhere between a Gripen and a Rafale, the former is also noted to be not great at sustained turn compared to an F-16. The Typhoon is a bit unfair though, the thrust to weight ratio is a step above competitors and when clean it can challenge an F-22 even at higher altitudes.

I’ve seen several thrust figures of the J-10C engine from Pakistan sources and it varies a bit from 29,000 lbs to 32,000 lbs. In general seems like the WS-10B is somewhere between an F110-129 and F110-132 in thrust which aligns with Chinese insider sources that the WS-10B is 14 metric ton class or “almost 14 tons”. The J-10C being about 2,000 lbs heavier than a Block 52 doesn’t help when it comes to sustained turns. The WS-10C which is what powers the current J-20 appears to be uprated a bit to 14.5 metric tons and would be more comparable to F110-132.