SDF Aerospace and Aerodynamics Corner

Re: J-20... The New Generation Fighter III

HKSDU said:

OK. Then where are these extra regiments of J-10 situated then? Not all bought engines are used to build new aircraft, they are also used as spares and replacements. If they bought 500 AL-31FN then judging by your thinking they should have 500 J-10's

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i will ask you do you have an official source saying at this moment China has 200 J-10s?
Second China has bought 500 Al-31s, but not all the Al-31 have been delivered yet in fact it is probable they have not gotten 200-150 engines yet,
they have not recieved 122 Al-31 for sure since they just signed the contract for them in October 2011.
While there is a small chance a few J-10 might be re-engined, it is not logic if you have WS-10 do not re-engine them with WS-10s, most J-10s have less than 7 years.

Second if WS-10 wiill replace Al-31s soon re-engine J-10s in 2014-2017 might be logic.

Now most likely it was designed with the ability to be fitted into J-10s using Al-31, that is the most logic design criteria.

I will ask you why then China has bought 500 Al-31s if the entire fleet of J-10s is 200 jets? it means production is slow, i doubt J-10s can not be produced in numbers of 30 jets a year or even 40, if production is so low and the fleet so young even having WS-10s, it leaves you three possible reasons:

A) production of J-10 will speed up and numbers increase that is the reason they bought 500 Al-31s and WS-10 is still not ready


B)production J-10 is very high that WS-10 production is not enough, but you say production is slow

C)Early J-10s can not be fitted with WS-10, production is slow and they will switch to WS-10 soon, see here the contradiction, Chengdu did not design J-10s with the ability to accept easily WS-10s so they have to buy 2 engines per plane, two Al-31s equal 6 million dollars, it means fitting Ws-10 to an early J-10 is more expensive than 3 million dollars.


So Chengdu obviously favours not WS-10, their own engine, who wins Saturn


So my conclusion is WS-10 is not ready, why? simple Chengdu favours WS-10, so by logic they designed it with the ability to be retrofitted to J-10s currently using Al-31 at a low price per modification, lower than buying newer Al-31s.

Third in order to protect the national jet engine industry they will try to make last Al-31s the longest so each Al-31 goes to a new J-10 airframe and its replacement will be a WS-10 even in J-10s currently using Al-31s

"I will ask you why then China has bought 500 Al-31s if the entire fleet of J-10s is 200 jets? "

Maybe for exports for the JF-17 fighters. China doesn't want anybody know how the WS-10 works, at least not yet.

The AL-31 is in a different weight class and would never be able to fit in the fuselage of the JF-17.

Re: J-20... The New Generation Fighter III

MiG-29 said:

i will ask you do you have an official source saying at this moment China has 200 J-10s?
Second China has bought 500 Al-31s, but not all the Al-31 have been delivered yet in fact it is probable they have not gotten 200-150 engines yet,
they have not recieved 122 Al-31 for sure since they just signed the contract for them in October 2011.
While there is a small chance a few J-10 might be re-engined, it is not logic if you have WS-10 do not re-engine them with WS-10s, most J-10s have less than 7 years.

Second if WS-10 wiill replace Al-31s soon re-engine J-10s in 2014-2017 might be logic.

Now most likely it was designed with the ability to be fitted into J-10s using Al-31, that is the most logic design criteria.

I will ask you why then China has bought 500 Al-31s if the entire fleet of J-10s is 200 jets? it means production is slow, i doubt J-10s can not be produced in numbers of 30 jets a year or even 40, if production is so low and the fleet so young even having WS-10s, it leaves you three possible reasons:

A) production of J-10 will speed up and numbers increase that is the reason they bought 500 Al-31s and WS-10 is still not ready


B)production J-10 is very high that WS-10 production is not enough, but you say production is slow

C)Early J-10s can not be fitted with WS-10, production is slow and they will switch to WS-10 soon, see here the contradiction, Chengdu did not design J-10s with the ability to accept easily WS-10s so they have to buy 2 engines per plane, two Al-31s equal 6 million dollars, it means fitting Ws-10 to an early J-10 is more expensive than 3 million dollars.


So Chengdu obviously favours not WS-10, their own engine, who wins Saturn


So my conclusion is WS-10 is not ready, why? simple Chengdu favours WS-10, so by logic they designed it with the ability to be retrofitted to J-10s currently using Al-31 at a low price per modification, lower than buying newer Al-31s.

Third in order to protect the national jet engine industry they will try to make last Al-31s the longest so each Al-31 goes to a new J-10 airframe and its replacement will be a WS-10 even in J-10s currently using Al-31s

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...unless there is a supply shortage.

latenlazy said:

The AL-31 is in a different weight class and would never be able to fit in the fuselage of the JF-17.

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Hmm...how about export for the J-10As?

Re: J-20... The New Generation Fighter III

latenlazy said:

...unless there is a supply shortage.

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smart answer so Chengdu made J-10s unable to be fitted with WS-10s so they have to buy 2 engines Al-31 for 7 million dollars ah, so they did not design WS-10 with the ability to be retrofitted into early J-10s ummmh............ so China pays 500 million dollars for 123 new replacements uhmmmmmmmm interesting very smart of Chengdu, and they say they have now 240 J-10s, in one decade they built 240 J-10s that equals 24 J-10s a year, so from 2012 they will build 100 J-10s 80 with WS-10 and 20 with Al-31 because you know Saturn and Saliut can deliver around 30 a year, interesting answer latenlazy

Re: J-20... The New Generation Fighter III

MiG-29 said:

smart answer so Chengdu made J-10s unable to be fitted with WS-10s so they have to buy 2 engines Al-31 for 7 million dollars ah, so they did not design WS-10 with the ability to be retrofitted into early J-10s ummmh............ so China pays 500 million dollars for 123 new replacements uhmmmmmmmm interesting very smart of Chengdu, and they say they have now 240 J-10s, in one decade they built 240 J-10s that equals 24 J-10s a year, so from 2012 they will build 100 J-10s 80 with WS-10 and 20 with Al-31 because you know Saturn and Saliut can deliver around 30 a year, interesting answer latenlazy

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I never said the J-10A was unable to be fitted with WS-10s. That's Engineer's position, which personally I think is unnecessary.

Your cost analysis is irrelevant. You can't buy more engines than what your factories can produce, and if your factories can't produce enough supply even putting money into it requires that you wait until your factories are operational before you can fix the supply problem. It's not like I realize I can't produce enough engines to meet demand, I build a new factory, and *BAM* 1 hour later new factory full functional is ready to churn out the goods. When I put down money for a new factory I need to wait until it's finished being built and tested before it can start producing more orders. Given that it's only been a year since they've sorted out production problems it's unlikely they've expanded beyond one production line. The WS-10 has to fulfill more than the J-10's number requirements, but also the J-11's. A supply shortage is not an unreasonable outcome.

It seems like you're implying that they would only spend 500 million because they would prefer the AL-31. However, that only holds water if the WS-10 is a viable alternative. If it isn't a viable alternative, it doesn't have to mean the product itself sucks. It might also not be viable because there aren't enough of them. If I needed chocolate ice cream for a party and I ended up buying vanilla, it doesn't mean I suddenly thought vanilla was the better ice cream. It could also imply that the store ran out of chocolate ice cream. In other words, because you need some kind of ice cream, you buy a substitute good when there is no supply.

Similarly, you spend 500 million to buy 123 new AL-31FNs if you figure that you're going to have a supply shortage, because you're not going to stop producing the rest of the J-10 just because the alternative engine isn't ready. That would be stupid, and it would be costly due to inventory storage and interest cost accumulation. In short, all the WS-10s that can be produced are going to the J-11, so the J-10 will need to look for another engine until there are enough WS-10s being produced for both of them

I did not say that they would build 100 J-10s in 2012 with whatever made up number of engines. You're talking nonsense, and it's making me doubt you get what I mean by supply shortage.

In any case, we know that Saturn and Salyut can make more than 30 Al-31s a year, because they also need to supply the global Flanker fleet. That said, they also have had more than three decades to expand their production capacity, so it's not unexpected that they could make more than 30 turbofans a year.

Re: J-20... The New Generation Fighter III

MiG-29 said:

i will ask you do you have an official source saying at this moment China has 200 J-10s?
Second China has bought 500 Al-31s, but not all the Al-31 have been delivered yet in fact it is probable they have not gotten 200-150 engines yet,
they have not recieved 122 Al-31 for sure since they just signed the contract for them in October 2011.
While there is a small chance a few J-10 might be re-engined, it is not logic if you have WS-10 do not re-engine them with WS-10s, most J-10s have less than 7 years.

Second if WS-10 wiill replace Al-31s soon re-engine J-10s in 2014-2017 might be logic.

Now most likely it was designed with the ability to be fitted into J-10s using Al-31, that is the most logic design criteria.

I will ask you why then China has bought 500 Al-31s if the entire fleet of J-10s is 200 jets? it means production is slow, i doubt J-10s can not be produced in numbers of 30 jets a year or even 40, if production is so low and the fleet so young even having WS-10s, it leaves you three possible reasons:

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A forth reason is that Al-31FN has low service life that each J-10 requires nearly two engines, with one engine use for spares and acting as replacement. Ignoring the recent purchase, we see approximately 2:1 ratio of engines to planes, supporting this forth reason.

MiG-29 said:

A) production of J-10 will speed up and numbers increase that is the reason they bought 500 Al-31s and WS-10 is still not ready

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Wrong. We have seen J-11B and one of the J-10Bs using WS-10A, thus WS-10A is ready. That's a fact. It's the J-10B which is not ready, which is why you still haven't seen WS-10A in service on the J-10s.

MiG-29 said:

B)production J-10 is very high that WS-10 production is not enough, but you say production is slow

C)Early J-10s can not be fitted with WS-10, production is slow and they will switch to WS-10 soon, see here the contradiction, Chengdu did not design J-10s with the ability to accept easily WS-10s so they have to buy 2 engines per plane, two Al-31s equal 6 million dollars, it means fitting Ws-10 to an early J-10 is more expensive than 3 million dollars.

So Chengdu obviously favours not WS-10, their own engine, who wins Saturn

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There is no contradiction. J-10A was designed to use Al-31 more than ten years ago because at that time, WS-10A was not available. Ten years later, they redesign the J-10 to take on WS-10A, and the J-10B is born. WS-10A wasn't ready ten years ago does not mean WS-10A isn't ready now. In fact, WS-10A is already being used on aircraft that are in service with PLAAF, debunking your theory that WS-10A is not ready.

MiG-29 said:

So my conclusion is WS-10 is not ready, why? simple Chengdu favours WS-10, so by logic they designed it with the ability to be retrofitted to J-10s currently using Al-31 at a low price per modification, lower than buying newer Al-31s.

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That is a delusion, not a conclusion. Your theory would work if and only if none of the plane in service with PLAAF uses WS-10A engines. We know your theory is nothing but a delusion because there are plenty of J-11Bs using WS-10A. In fact, WS-10A is so ready that both CAC and SAC use the engine on J-10B and J-15 prototypes. We have plenty of photographic evidences support this.

MiG-29 said:

Third in order to protect the national jet engine industry they will try to make last Al-31s the longest so each Al-31 goes to a new J-10 airframe and its replacement will be a WS-10 even in J-10s currently using Al-31s

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WS-10A will not go into the J-10A, and we have no indication that this is possible because we never see photographic evidence of J-10A retrofitted with WS-10A. We only see WS-10A fitted into the J-10B. So, many of those newly purchased Al-31FN will definitely go into old aircraft as replacement. Some of those engines will be used to build new J-10A so J-10s can be produced to replace old fighters. However, J-10A uses Al-31FN does not support the idea that Al-31FN is more reliable than WS-10A, nor does it support your delusion that WS-10A is not ready.

Re: J-20... The New Generation Fighter III

latenlazy said:

Similarly, you spend 500 million to buy 123 new AL-31FNs if you figure that you're going to have a supply shortage, because you're not going to stop producing the rest of the J-10 just because the alternative engine isn't ready. That would be stupid, and it would be costly due to inventory storage and interest cost accumulation. In short, all the WS-10s that can be produced are going to the J-11, so the J-10 will need to look for another engine until there are enough WS-10s being produced for both of them

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More like, just because the redesigned version of J-10 isn't ready, that doesn't mean they have to cease all production to show support for WS-10A. Likewise, the continue production of J-10A isn't a sign of lack of faith in the WS-10A.

Re: J-20... The New Generation Fighter III

Engineer said:

More like, just because the redesigned version of J-10 isn't ready, that doesn't mean they have to cease all production to show support for WS-10A. Likewise, the continue production of J-10A isn't a sign of lack of faith in the WS-10A.

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We'll have to disagree on that one. I see no reason why they couldn't stick the WS-10 into the J-10's fuselage, since it's meant to be interchangeable with the J-11. One potential reason could be based on planning and logistics, but other than that a supply shortage renders that an unnecessary conclusion.