AL-31F / FN in China and background

Deino said:

But by Your own source (even from 2007), it has only entered the bench tests ... that's far from ready.

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let me explain you, back in 2007, both Salyut and Saturn were competing to see who was going to power PAKFA, Al-31F-M2/3 were in competition with 117, as the first stage engine type 30 is the second stage, due to be flight tested next year, now is in bench tests.

If you go to the - UEC page you will see 117 is in production, but no Su-27 variant flies with M2 or M3, since Russia has decided 117 is the winner, they are not going to produce different versions so is highly unlikely J-20 flies with any M2/M3 variant, and Al-31FN series 3 is not a engine as powerful and advanced as 117

b787 said:

let me explain you, back in 2007, both Salyut and Saturn were competing to see who was going to power PAKFA, Al-31F-M2/3 were in competition with 117, as the first stage engine type 30 is the second stage, due to be flight tested next year, now is in bench tests.

If you go to the - UEC page you will see 117 is in production, but no Su-27 variant flies with M2 or M3, since Russia has decided 117 is the winner, they are not going to produce different versions so is highly unlikely J-20 flies with any M2/M3 variant, and Al-31FN series 3 is not a engine as powerful and advanced as 117

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Au contraire mon ami ... IMO it makes now even more perfect sense:

As You explained, both the 117 and later 117S from Saturn and the AL-31FM1/-2/-3 from Salut were competing for the Su-35and T50's engine and indeed for their domestic demand Saturn won.
However since Salut was always CAC's preferred major supplier of engines for the J-10A (AL-31FN) and later J-10B/C (AL-31FN Series 3) it was more than a logical chose that this loosing engine became the export-related product and CAC was already an established customer, a new special tailored version - as just reported - based on the M2 became the J-20's powerplant.

Honestly I have to thank You for this eye-opening discussion ... it now makes al perfect sense !

Deino

Deino said:

Au contraire mon ami ... IMO it makes now even more perfect sense:

As You explained, both the 117 and later 117S from Saturn and the AL-31FM1/-2/-3 from Salut were competing for the Su-35and T50's engine and indeed for their domestic demand Saturn won.
However since Salut was always CAC's preferred major supplier of engines for the J-10A (AL-31FN) and later J-10B/C (AL-31FN Series 3) it was more than a logical chose that this loosing engine became the export-related product and CAC was already an established customer, a new special tailored version - as just reported - based on the M2 became the J-20's powerplant.

Honestly I have to thank You for this eye-opening discussion ... it now makes al perfect sense !

Deino

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however there is a small problem, if you go to the salyut page you will find they only have as products in the Russian version Al-31F-M1 and Al-31FN. there is no entry in Salyuts page where they say M2/M3 are in production, further more UEC does not have M2/M3 as in production, so what you are reporting is not a fact, but a rumor which is highly unlikely since Su-35 uses 117 and Russia needs the duma to allow the sale, you can believe Chinese forums, but there is no evidence M2 or M3 are in production and specially since M2 has TVC nozzles, if J-20 would have it, i can assure you will see it doing post stall, but it is not doing it, the Russians are not going to sell 10 or 20 engines, they will sell 300 or more, at least 75, plus China would not even being interested in Su-35, which basically sell each aircraft in a almost 80 million dollar a piece, just for Su-35 and its spares

b787 said:

however there is a small problem, if you go to the salyut page you will find they only have as products in the Russian version Al-31F-M1 and Al-31FN. there is no entry in Salyuts page where they say M2/M3 are in production, further more UEC does not have M2/M3 as in production, so what you are reporting is not a fact, but a rumor which is highly unlikely since Su-35 uses 117 and Russia needs the duma to allow the sale, you can believe Chinese forums, but there is no evidence M2 or M3 are in production and specially since M2 has TVC nozzles, if J-20 would have i can assure you will see it doing post stall, but it is not doing it, the Russians are not going to sell 10 or 20 engines, they will sell 300 or more, at least 75, plus China would not even being interested in Su-35, which basically sell each aircraft in a almost 80 million dollar a piece Su-35

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Agreed ... but how long did it take that the AL-31FN for the J-10 appeared on their page ? The J-10 was long in operational service and everyone with a slightest bit of common sense and understanding was clear that this engine is an AL-31-derivate. However both sides decided to keep the true nature of that engine secret as long as possible.
Have there been reports about a production of the AL-31FN before it was officially acknowledged?

And now we are in the nearly same situation: Everyone with a slightest bit of common sense and understanding is clear that the J-20 uses an AL-31-derivate, but all contracts known and officially acknowledged are only related to the J-10B (even the numbers fit)... as such is it so much unlikely that history repeats itself and CAC again managed to arrange a still secret contract for a still secret customised version based on exactly the loosing contender ??? Even more since the J-20 is at least by now not officially unveiled.

I agree with You that much is still in the dark but I'm sure that the Sino-Russian military cooperation stands on much more solid ground than most expect, more than most are willing to accept or even able to officially announce.

Deino


PS: By the way please do me favour The Su-35 uses the engine 117S whereas the T50 uses the 117; both are different.

Deino said:

Deino


PS: By the way please do me favour The Su-35 uses the engine 117S whereas the T50 uses the 117; both are different.

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i will do you that favor when United aircraft corparation declassifies the specifications of PAKFA and United engine corporation has in the 117 engine not only the Su-35 as user of 117, officially 117S is the engine powering Su-35 in the official page, but PAKFA is classified, most forums will say then 117 is the engine used on PAKFA, but there is no official confirmation of that, that is the reason they have in the United Aircraft corporation website page all the technical characteristics classified and that includes the engine

To reconcile the difference between you two, which engine do you think the J-20 uses? Deino's stance is pretty clear, so what about you, b787?

dingyibvs said:

To reconcile the difference between you two, which engine do you think the J-20 uses? Deino's stance is pretty clear, so what about you, b787?

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Truth is outsiders like us don't know what engine the J-20 is using. The AL-31FN Series 1/2/3 are strictly for the J-10. Its designed that way. You can't fit an AL-31FN Series 3 in the J-10B/C on to the J-20. Salut has to create a modified version for the J-20. But are the changes limited where gearbox is or did CAC want things like added thrust (maybe increase of 500 kgf - 1000 kgf?) without ruining the lifespan? There were rumors of extended high-powered CAC/PLAAF visits to Salut and money is being poured in. Worst case scenario would be the thrust is no better than the AL-31FN Series 3. That is around 135kN max.

One guy who know the answer is "flateric". He is the one who initially dropped the hints on the CAC visits to Salut. But flateric has gone pretty quiet lately. Maybe somebody put a gag-order.

Hyperwarp said:

Truth is outsiders like us don't know what engine the J-20 is using. The AL-31FN Series 1/2/3 are strictly for the J-10. Its designed that way. You can't fit an AL-31FN Series 3 in the J-10B/C on to the J-20. Salut has to create a modified version for the J-20. But are the changes limited where gearbox is or did CAC want things like added thrust (maybe increase of 500 kgf - 1000 kgf?) without ruining the lifespan? There were rumors of extended high-powered CAC/PLAAF visits to Salut and money is being poured in. Worst case scenario would be the thrust is no better than the AL-31FN Series 3. That is around 135kN max.

One guy who know the answer is "flateric". He is the one who initially dropped the hints on the CAC visits to Salut. But flateric has gone pretty quiet lately. Maybe somebody put a gag-order.

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Indeed ... @flateric is our man ! IMO one of the few who can bring at least a bit light into this story ... if he wants to do so.

But: why is it impossible to fit a standard AL-31FN Series 3 into the J-20 and why does have Salut to create a special version ? Is the twin-engine configuration a reason to prevent its use ?

Deino

Due to the on-going IMO very interesting but by now far off-topic (since no longer Su-35-related) discussion on the AL-31FN and its version in Chinese use, its application and mystery surrounding the version used by the J-20 I start a new thread separated from the Su-35-discussion.

So please continue here.

Deino

Deino said:

Indeed ... @flateric is our man ! IMO one of the few who can bring at least a bit light into this story ... if he wants to do so.

But: why is it impossible to fit a standard AL-31FN Series 3 into the J-20 and why does have Salut to create a special version ? Is the twin-engine configuration a reason to prevent its use ?

Deino

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All the AL-31FN series have a different location for gearbox accessories. All AL-31FN are essentially customized AL-31F so it can be fitted on the J-10. No other plane used the FN series. There are several other minor changes including dimesntions and weight.AL-31FN Vs. AL-31F.

You definitely cannot fit the FN series to a Flanker. I'd assume that the J-20 requires original gearbox layout instead of the modified FN arrangement.