J-XY/J-35 carrier-borne fighter thread

Schwerter_

Schwerter_

Junior Member
Registered Member
latenlazy said:
I think a few other factors came into play. I think that numbers do in fact matter in full intensity military engagements, and a mid sized fighter was probably seen as more desirable to head off against the USN than a large sized fighter if you could field more of them on your carriers, especially if the only main advantage of the large sized fighter would be side bays for short range missiles. I also suspect that SAC’s work on making an FC-31 based design lower cost and more efficient to produce might have played a role too. I’ve suspected for a few years now that actually testing the capabilities of J-20 against their 4th gen fighter fleet has fundamentally altered the PLA’s thinking about how to deal with other stealth fighters, and that might have shaped interests towards inducting a cheaper “low” stealth fighter that they can produce much more quickly, and the FC-31, if not fully intended to slot into such a purpose, might be being trialed for it.
Click to expand...
Also I want to point out that seemingly SAC has been testing new manufacturing techneques (not least additive manufacturing) since the 1.0 variant, which (referring to manufactoring techneques, not necessarily the FC-31 1.0) has quite a bit of advantage in both production capability as well as performance when compared with more traditional designs. This may very well have played a part in J-XY being adopted
 
D

Dishi

New Member
Registered Member
iantsai said:
The reasons FC-31 fans deny J-20 for the carrier-borne fighter aircraft competition are:
  • J-20 is difficult to take off and land in an aircraft carrier with canards.
  • J-20 is too large for the Chinese aircraft carriers.
  • CAC can't produce sufficient J-20s needed for the Navy because the orders from the Air Force has taken up its production capacity for the next 20 years.
Is that for real and reasonable?

As far as we can see, French Navy has been operating Rafales for 15 years, they never complained on the canard layout of Rafales even when they were operating in a carrier with smaller deck.

J-15 is longer, wider-spanned and higher than J-20, but PLAN-AF never complained on their size and weight. And the upcoming 018 and future vessles will be even larger than Liaoning and Shandong.

CAC is not a private company, and its contract with the Air Force is not tied by commercial terms that are irrevocable, but determined by the Central Military Commission. There is no reason for the CMC to deny the navy orders for J-20.

So why the cannards, size, weight and production capacity could be the obstacles that J-20 cannot pass to be a carrier-borne fighter? Even the Air Force variant of J-20 just entered service in 2018. Maybe the PLAN is waiting for the new WS15 and the new CATOBAR carriers to enter service.

On the other hand, the performance of FC-31 has been modified by fans magically. The WS-19 engineer, being a upgrade product of WS-13 the localization solution of RD-93, was bragged to have 12 tons thrust (means thrust-to-weight ratio 12!). The MTOW of FC-31 was bragged to 29 tons. With such MTOW, it will still keep a significantly smaller dimensions of 20-ton fighter. That's not science, it's creating miracles.

Unlike the Air Force facing different level opponents, the PLAN-AF will defnitely confront the F-35s of US Navy, JASDF and RoKAF. So would they accept a mediocre medium weight, medium range fighter? I don't think so.
Click to expand...
I also want to chime in on the argument of the issue of canards. Now I’m no aerodynamics expert, but my understanding about the downsides of why canards is a bad choice for a carrier fighter is the issue of relatively high angle of attack during approach. Compare Rafael’s 14 to f-18’s 8 degrees AOA on approach, this makes a world of difference in terms of visibility and operational safety. The French being less financially endowed have to make do with a compromised design for a do-it-all ‘Omni-role’ fighter for both the airforce and navy, but the US and China doesn’t have to live with that compromise, so why go down that path?

Also, canard designs’ wings are difficult to scale, if you need a carrier fighter with lower wing loading for lower landing speeds, you’ll have to increase wing area. You can easily do that without huge modifications to your overall airframe and planform for a conventional design, like the f-35c. But for a J-20, you’re looking at an almost complete redesign to reposition almost every control surface, and that’s going to take way too long and much too costly. Simply not worth the effort.

And with regards to size, bear in mind that whenever you’re working onboard a ship, space comes at a premium, the smaller the better. Be it shuttling around, engine out maintenance etc. At the end of the day, carrier ops is all about sortie rate and deck efficiency. Just because you can have a bigger and better plane, doesn’t make it the ideal plane for a carrier. Carrier air wings are about the sum of its parts, and not the performance of a single unit. I’m pretty sure the PLAN planners (no puns intended) has done exhaustive cost benefit analysis on this subject and determined that the compromises of a smaller plane are acceptable in the face of better operation effectiveness. And just because the J-15 works, doesn’t mean that it’s an ideal solution, it has always meant to be a stopgap measure that’s more of a teaching tool than the final goal. The PLAN 10-15 years ago was a very different organization and there wasn’t much choices back then, if any.

Lastly, and this is purely my personal guess, is that the choice of a fighter that uses a medium thrust engine is a conscious logistical choice as the future PLAN air wing is expected to work with UCAVs like GJ-11 derivatives equipped with the same engine. The same engine means streamlined training, spare parts and tools. This may or may not be a key decider, but certainly an added bonus nonetheless.
 
K

kriss

Junior Member
Registered Member
Dishi said:
Lastly, and this is purely my personal guess, is that the choice of a fighter that uses a medium thrust engine is a conscious logistical choice as the future PLAN air wing is expected to work with UCAVs like GJ-11 derivatives equipped with the same engine. The same engine means streamlined training, spare parts and tools. This may or may not be a key decider, but certainly an added bonus nonetheless.
Click to expand...
Or they could use a large thrust engine which could be the same engine of J-15 fleet which won't go anywhere soon.
 
Phead128

Phead128

Captain
Staff member
Moderator - World Affairs
I thought twin engines is preferable for carriers since if one engine fails or shot out, the plane can still return to ship? Is twin medium thrust engine produce not as much power as a single engine like F-35? Thanks in advance.
 
G

gelgoog

Brigadier
Registered Member
Phead128 said:
I thought twin engines is preferable for carriers since if one engine fails or shot out, the plane can still return to ship? Is twin medium thrust engine produce not as much power as a single engine like F-35? Thanks in advance.
Click to expand...

You are correct that a twin engine is more reliable. As for engine power the F-35 engine has 125 kN dry thrust and 191 kN wet thrust. Each RD-93 engine used in the JF-17 has 49.4 kN dry thrust and 84.4 kN wet thrust. So that would be roughly 100 kN dry thrust and 170 kN wet thrust. The thing is the aircraft they design should likely have lower weight and be smaller. The main thing is keeping the thrust to weight and payload reasonable. The J-XY will likely need the 4th generation engines to have similar performance to the F-35.
 
You must log in or register to reply here.
Top