Shenyang FC-31 / J-31 Fighter Demonstrator

Kejora

Junior Member
Registered Member
@Bltizo quick question, do you think the current FC-31v2 already mature enough to be used as combat aircraft? let's say some country is interested with procuring FC-31 based stealth fighter without the carrier requirement of PLAN, how fast do you think they could convert the current prototype to production model?
 

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
@Bltizo quick question, do you think the current FC-31v2 already mature enough to be used as combat aircraft? let's say some country is interested with procuring FC-31 based stealth fighter without the carrier requirement of PLAN, how fast do you think they could convert the current prototype to production model?

How much money does some country have?
And how much is the PLA willing to allow the nation's aerospace resources to be diverted to make the FC-31V2 a viable fighter for some country rather than prioritizing those aerospace resources for J-XY?
How much is PLA willing to allow its own relevant subsystems have variants for FC-31V2 for some nation, or will some nation require a clean sheet design of all the key subsystems of an aircraft (sensors, datalinks, mission computer, rest of avionics, weapons systems, etc).


The point I'm raising is that the airframe itself isn't the only important thing, but all of the subsystems, testing of airframe+subsystems, and developing and setting up dedicated logistics/support infrastructure are all part of developing a new aircraft.


.... which in turn I suppose is a long way of saying that no foreign nation will procure an FC-31 variant unless the PLA buys it first, due to above costs and complexities.
That's why I believe the most likely way in which FC-31 may eventually see export orders, is in the form of the PLA buying a land based J-XY variant and foreign nations buying an export cleared land based J-XY variant.
 

gelgoog

Brigadier
Registered Member
Well I think it wouldn't have been impossible for them to export the FC-31 in principle. After all it was with the intent to do that which they showed it up at international military trade shows. There is also a precedent with the export of the FC-1. The avionics and other electronics and weapons subsystems wouldn't need to be more advanced than what is to be used on the FC-1 Block III. Same deal with the engine which would likely be similar except there would be two of them.

The FC-31 also seems to use more modern computer control based manufacturing methods so it is likely that they would need minimal aircraft specific fabrication tools and facilities.

I agree with you that it is unlikely a 3rd party would buy the FC-31 without it being in service with the PLA however.
 

keiko

Just Hatched
Registered Member
J-35 being a PLAN only project makes sense because they have enough desire to forgo that cost consideration. They need a full high spec 5th gen fighter but it needs to be no larger than F-18/F-35/Rafale class mid weight. Hence twin engined J-35 - Not for PLAAF.
Would PLAN choose single engine design over twin - cost and weight saving with WS-15? Have J-35 and J-15 mix on carrier like US F-35 and F/A-18?
 

ougoah

Brigadier
Registered Member
My point is that for a J-10 style role to be performed by a stealth fighter with the requisite internal bays, you would effectively need a middle weight class fighter.

New doctrines aren’t developed in one generation. It’s very bad force planning to put all your chips into a force doctrine that hasn’t even been properly developed yet. The problem is not a matter of technological capability but of developing tactical and strategic utility. That part of any new combat theories requires time to vet and refine. It’s not a good idea to make your force structure wait till those ideas are mature enough to invest in at scale, and and even worse idea to make broad based investments without really knowing what you’re getting. The US may be building loyal wingman drones but it’s not replacing its mainstay with those drones. That’s for a reason. They’re not dumb enough to replace their mainstay with unproven combat doctrines.

Yeah a midsize fighter with one engine though. Not a twin engine midsize. Midsize doesn't necessarily mean twin engine. Of course China will need the WS-15 to mature and be in twin engine service for a while before this can be realistic. WS-10 may or may not offer enough thrust.

Two medium thrust engines are just a lot more costly than one high thrust.
 

ougoah

Brigadier
Registered Member
Would PLAN choose single engine design over twin - cost and weight saving with WS-15? Have J-35 and J-15 mix on carrier like US F-35 and F/A-18?

No because WS-15 isn't ready for single engine use. It's not even entirely ready for service on the J-20 even if everything's been finalised and they're only working on production program.

J-35 will use WS-13 or WS-19 when it is ready. This sort of goes towards showing that the J-35 isn't developed as some low end 5th gen to supplement the J-20 in the same way the F-16 is to the F-15 and the J-10 is to the J-11/16.
 

Kejora

Junior Member
Registered Member
Would PLAN choose single engine design over twin - cost and weight saving with WS-15? Have J-35 and J-15 mix on carrier like US F-35 and F/A-18?
Russia is working on 5th gen single engined fighter Mikoyan LMFS with MTOW of 25,000 kg.
But it will require the next generation engine that will power up Su-57 (39,700 lbs thrust). It seems they confident that they could produce enough engines for both Su 57 and LMFS.
 

latenlazy

Brigadier
Yeah a midsize fighter with one engine though. Not a twin engine midsize. Midsize doesn't necessarily mean twin engine. Of course China will need the WS-15 to mature and be in twin engine service for a while before this can be realistic. WS-10 may or may not offer enough thrust.

Two medium thrust engines are just a lot more costly than one high thrust.
One heavy thrust engine would cost more than one medium thrust engine. The combined difference in price is not that stark. The F135 engine costs about $16 million a piece. Not totally comparable in terms of technology level, but an EJ-200 costs about $7 million. I don’t know where you’re getting the idea that two medium thrust engines would cost significantly more than a heavy thrust engine. Even if the costs don’t scale perfectly linearly for the amount of thrust you’re purchasing, the overall difference in total cost is pretty modest relative to the overall cost of the whole plane.
 

ougoah

Brigadier
Registered Member
One heavy thrust engine would cost more than one medium thrust engine. The combined difference in price is not that stark. The F135 engine costs about $16 million a piece. Not totally comparable in terms of technology level, but an EJ-200 costs about $7 million. I don’t know where you’re getting the idea that two medium thrust engines would cost significantly more than a heavy thrust engine. Even if the costs don’t scale perfectly linearly for the amount of thrust you’re purchasing, the overall difference in total cost is pretty modest relative to the overall cost of the whole plane.

Not the fairest comparison - F135 with EJ200. Wonder what the difference is between a Al-31 and RD-33. It's probably nowhere near 2 times greater. Then there's twice the maintenance man hours and material consumed. Also more chances of aircraft being grounded or at least a lower serviceability rate since twin engined fighters have twice the chance of engine drama that reduces their readiness. These are all cost factors, not only the purchase price of the engine. If this weren't such a big deal, the Americans wouldn't have bothered with the F-16 or F-35.
 
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