China Flanker Thread II

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Lion

Senior Member
Do you have any source that says China can produce their own AL-31?

China can reproduced most of the AL-31 parts and those parts are superior than the Russian stock. Meaning extended lifespan of the original AL-31 engines.

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The Chinese People's Liberation Army Air Force (PLAAF) has developed its own service life extension modifications for the Russian-made Salyut AL-31F engine, a Moscow-based defence and foreign policy think-tank has reported.

The modifications to the AL-31F/FN P.2 series engine increase its operational limits by more than 65 per cent - from 900 to 1,500 flight hours, according to the privately owned Centre for the Analysis of Strategies and Technologies (CAST).

The AL-31F engine is the powerplant for several types of aircraft in the PLAAF inventory: the Sukhoi Su-27 (which is also licence-produced at the Shenyang Aircraft Works as the J-11), the Su-30MKK and the Chengdu Aerospace Corporation J-10. The AL-31FN is a special derivative of the original AL-31F design that was developed by the Salyut plant in Moscow for a single-engine application to be fitted to the J-10.

The service life modifications were reportedly developed at the PLAAF Overhaul Plant Number 5719. The key to the service life extension is a specific set of improved, Chinese-made components that are part of what is described as a "re-manufacturing kit" that is introduced during the process of a full-scale remanufacturing and overhaul process.

The plant is located near the city of Chengdu in Sichuan province, employs 2,000 personnel and is reported to be a model of innovation within the PLAAF's network of repair plants. During the past several years the facility has initiated 63 different research and development programmes and has been awarded more than 20 state prizes for achievements in technological innovation. In the same time period, the plant's assets have more than doubled from CNY1.1 billion (USD147.2 million) in 2004 to CNY2.9 billion today.

The plant's officials credit the success of their overhaul process to a decision taken in 2004, when some of the first AL-31F engines were presented to the plant by the PLAAF for overhaul. A decision was taken, according to the Chinese news sources originally cited, to completely reorganise the overhaul process. This streamlining of the overhaul disassembly and servicing line resulted in a 27.3 per cent decrease in the time required to complete an overhaul and increased the plant's production capacity by 60 per cent.

This level of improvement in the engine's design demonstrates that the Chinese have achieved near autonomy in the support of these Russian-made engines. Russian specialists who spoke to Jane's state that this is "another example of how the technology sold to the Chinese during the 1990s has now been fully assimilated by them. It is only a matter of time before the engines that China produces will be as good as or better than anything designed here in Russia".
 

jackliu

Banned Idiot
That article says China can service all AL-31 engines on their own, which is excellent, because I recall in one of the article I read that when India need to service their AL-31 on their SU-30MKI, they need to wrap it up and send it to Russia, and it would take at least 6 month to send back.

But the article didn't say if China is able to manufacturer their own AL-31 from nothing though.

Also this would explain why China did not retro fit J-10A with WS-10, because even if Russia immediately stops exporting engine to China, they still can keep them running.
 

plawolf

Lieutenant General
Do you have any source that says China can produce their own AL-31?

You will never find any open Chinese sources stating such because that would be as good as the Chinese admitting a breach of contract with Saturn since the Russians never authorized the Chinese to clone the AL31. And we are actually talking about an actual clone in this case.

However, as I said, there are compelling indicators that the Chinese can and have made brand new improved AL31s from scratch themselves.

As Lion's article already shows, China was able to drastically increase the MTBO, and overall life of their Russian built AL31 engines, which was achieved by using Chinese turbine blades iirc. The turbine is the critical part in engines, and if you can make those, the rest of the engine is easy in comparison. So in terms of technical feasibility, there isn't an issue.

But the more interesting thing about the PLAAF is how their J11As and other AL31 powered Flankers are all flying fine even though the Russians have pretty much cut SAC off from new engines and replacement parts.

According to most reports, the whole dispute started when the Chinese refused to accept any more Su27SK kits after the 95th was delivered.

Now, I haven't been keeping a tab on J11s, but I am pretty sure there are more than 95 AL31F powered J11s flying about in the PLAAF. In addition, it is customary to have additional spare engines in stock, so that any damaged engines, or engines that are due for overhaul could be switched out without impacting on the availability of the fighters.

I am not sure what the PLAAF's spare engine ratio is, but 1 spare for 5 fielded engines, or a 1 for 5 ratio would serve as an example of a ballpark figure. So to keep 100 AL31 equipped J11s operating at normal availability, you would need 2 x 100 x 1.2 = 240 engines.

As I said, I don't keep tack of the number of engines the Chinese have bought any more, (more specifically, AL31Fs, since the AL31FNs for the J10s have their gearboxes on the underside and thus cannot be used in J11s). However, when I did do some quick back on the envelope calculations years back, the numbers simply did not add up.

Something else to consider is that the AL31F only has a total service life of 4,000 hours. We know that some of the first Su27Sks used up all their airframe life (5,000 hours) as early as 2009. That means it is clear that the PLAAF share birds between at least two pilots, so those 4,000 hours could be gone in 10 years if 2 pilots were flying 200 hours each per year.

If you took all that into account and get up-to-date figures from those members who keep track of engine deliveries and J11A numbers and batches (to work out exactly how many use AL31s), I am pretty sure that the number of engines ordered and delivered would not be anywhere near enough to sustain the number of AL31 powered Flankers and J11s the PLAAF have been operating.
 

Quickie

Colonel
But the article didn't say if China is able to manufacturer their own AL-31 from nothing though.

That would be considered making unlicenced copy. OTOH, maintaining the engines that were originally bought by rebuilding some or most of the parts wouldn't be considered illegal. I wouldn't be surprised quite a few of the engines have been rebuilt to as good as new.
 

jackliu

Banned Idiot
You will never find any open Chinese sources stating such because that would be as good as the Chinese admitting a breach of contract with Saturn since the Russians never authorized the Chinese to clone the AL31. And we are actually talking about an actual clone in this case.

However, as I said, there are compelling indicators that the Chinese can and have made brand new improved AL31s from scratch themselves.

As Lion's article already shows, China was able to drastically increase the MTBO, and overall life of their Russian built AL31 engines, which was achieved by using Chinese turbine blades iirc. The turbine is the critical part in engines, and if you can make those, the rest of the engine is easy in comparison. So in terms of technical feasibility, there isn't an issue.

But the more interesting thing about the PLAAF is how their J11As and other AL31 powered Flankers are all flying fine even though the Russians have pretty much cut SAC off from new engines and replacement parts.

According to most reports, the whole dispute started when the Chinese refused to accept any more Su27SK kits after the 95th was delivered.

Now, I haven't been keeping a tab on J11s, but I am pretty sure there are more than 95 AL31F powered J11s flying about in the PLAAF. In addition, it is customary to have additional spare engines in stock, so that any damaged engines, or engines that are due for overhaul could be switched out without impacting on the availability of the fighters.

I am not sure what the PLAAF's spare engine ratio is, but 1 spare for 5 fielded engines, or a 1 for 5 ratio would serve as an example of a ballpark figure. So to keep 100 AL31 equipped J11s operating at normal availability, you would need 2 x 100 x 1.2 = 240 engines.

As I said, I don't keep tack of the number of engines the Chinese have bought any more, (more specifically, AL31Fs, since the AL31FNs for the J10s have their gearboxes on the underside and thus cannot be used in J11s). However, when I did do some quick back on the envelope calculations years back, the numbers simply did not add up.

Something else to consider is that the AL31F only has a total service life of 4,000 hours. We know that some of the first Su27Sks used up all their airframe life (5,000 hours) as early as 2009. That means it is clear that the PLAAF share birds between at least two pilots, so those 4,000 hours could be gone in 10 years if 2 pilots were flying 200 hours each per year.

If you took all that into account and get up-to-date figures from those members who keep track of engine deliveries and J11A numbers and batches (to work out exactly how many use AL31s), I am pretty sure that the number of engines ordered and delivered would not be anywhere near enough to sustain the number of AL31 powered Flankers and J11s the PLAAF have been operating.

tphuang have this on his blog

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The next question is whether or not the number of engines adds up. Based on some help from fellow SDF member asif iqbal, it seems like the delivery of AL-31FN from Russia have been the following.

54 ordered in 2000 delivered between 2001-2005
100 ordered in 2005 delivered between 2005-2008
122 ordered in 2009 delivered between 2010-2011
123 ordered in 2011 delivery’s due between 2011-2013

That would represent 399 AL-31FNs delivered by sometimes next year.

But like you suggests that AL-31FN is only for J-10A, does that mean there has been no new AL-31F ordered since early 2000s?

That means all the J-11B are now using WS-10A and all the old AL-31F on the J-11 air frame are still using the old models.


That would be considered making unlicenced copy. OTOH, maintaining the engines that were originally bought by rebuilding some or most of the parts wouldn't be considered illegal. I wouldn't be surprised quite a few of the engines have been rebuilt to as good as new.

That's kind of technically just like iPhone is "Made in China", where majority of iPhone's most expensive parts such as microchip made in US or Taiwan, and they are just putting it together in Chinese factories, where it represents less than 5% of value added in the whole merchandise chain. I don't know if Russians can accept this, but Americans does.
 
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Quickie

Colonel
That's kind of technically just like iPhone is "Made in China", where majority of iPhone's most expensive parts such as microchip made in US or Taiwan, and they are just putting it together in Chinese factories, where it represents less than 5% of value added in the whole merchandise chain. I don't know if Russians can accept this, but Americans does.

AFAIK, the Russian never agree to manufacturing the flanker engines under license in China.
 

Air Force Brat

Brigadier
Super Moderator
A bit of a newbish question: does the color of the radar dome indicate what type of radar will be used on the plane? Both J-10B and J-15 have grey radar domes. Is it safe to assume that some of electronically scanned radar will be used on the J-16 as well?

Actually siege, I would say that they can pigment the resin to nearly any shade they would like, it is translucent due to the glass and carbon fiber composite structure, so I don't think the radar would care what shade it was, as to the radar, that will largely depend on the role the PLAAF intends for the J-16, whether it is purelly a striker, or like the F-15e truly multirole?
 

Vini_Vidi_Vici

Junior Member
Most new jets dont quire the radar cover to be painted, because they're made of synthetic materials, such as carbon fibre and resins. Those materials will not corrode, hence they don't have to be painted. That's why they look black.
 

tphuang

Lieutenant General
Staff member
Super Moderator
VIP Professional
Registered Member
tphuang have this on his blog

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But like you suggests that AL-31FN is only for J-10A, does that mean there has been no new AL-31F ordered since early 2000s?

That means all the J-11B are now using WS-10A and all the old AL-31F on the J-11 air frame are still using the old models.




That's kind of technically just like iPhone is "Made in China", where majority of iPhone's most expensive parts such as microchip made in US or Taiwan, and they are just putting it together in Chinese factories, where it represents less than 5% of value added in the whole merchandise chain. I don't know if Russians can accept this, but Americans does.

They ordered a bunch of AL-31F as replacements for the existing fleet of Su-27 and MKKs.

As for J-11B, the first regiment uses AL-31F and the rest use WS-10A.
 

plawolf

Lieutenant General
They ordered a bunch of AL-31F as replacements for the existing fleet of Su-27 and MKKs.

As for J-11B, the first regiment uses AL-31F and the rest use WS-10A.

When were the engines ordered/delivered, and how many engines was the order for?
 
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