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Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 07:57
by wrightwing
sprstdlyscottsmn wrote:.6 would be at full internal and external load. Max gross.

Exactly. Nobody compares T/W ratios at MTOW.

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 09:45
by weasel1962
F-35B should still have the best TWR of the 3 variants at max fuel + 4AAMs.

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 11:13
by linkomart
sprstdlyscottsmn wrote:Looking at the "weapon bay" shot on the previous page, I can see better the area around the ventrals. My initial concern was that they were a corner reflector, but that doesn't seem to be much of the case with looking at them and the surrounding area.


Agree, looking at the details of the design, there is no hesitation from my side that it is a real, engineered design and not a copy-ripoff. They have designed the surfaces with low RCS in mind, all details are aligned in a good way, they have done Aero-research of the configuration, the weapon bays are designed for supersonic weapon release, fins are designed to counter drawbacks of delta-twin fin configuration etc.

Of course the question is how well did the succeed with their intentions, how good is the engines, what are their sensors performance, have they managed all the small details to get low RCS etc. That I don't know, but from what I can tell, I can not see any obvious mistakes.

my 5 cent.

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 14:37
by mixelflick
weasel1962 wrote:F-35B should still have the best TWR of the 3 variants at max fuel + 4AAMs.


Why is that? 4000lbs less internal fuel?

I would have thought the B was heavier (than the A) due to the lift fan, but apparently not?

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 14:42
by weasel1962
On weight, just look at any LM fast fact pdf, add empty weight to max fuel. The B is heavier than the A by 3.5k lbs but it carries 4.5k lbs less fuel. That difference would be offset if the B carries a gun pod.

P.s. What it'd be a mistake to do is assume that the J-20A is the final product. As happened with the J-10 e.g. the air inlets design, its going to improve. What its also a mistake imho is highlighting some of the design issues in too much detail in a public forum.

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 15:18
by mixelflick
weasel1962 wrote:On weight, just look at any LM fast fact pdf, add empty weight to max fuel. The B is heavier than the A by 3.5k lbs but it carries 4.5k lbs less fuel. That difference would be offset if the B carries a gun pod.

P.s. What it'd be a mistake to do is assume that the J-20A is the final product. As happened with the J-10 e.g. the air inlets design, its going to improve. What its also a mistake imho is highlighting some of the design issues in too much detail in a public forum.


I've had that thought before, yes. The Chinese certainly aren't bashful about stealing information now, are they?

But you have to hand it to them with this design, or at least bringing it to fruition. They're well ahead of the Russians, and if I'm not mistaken they began flying prototypes around the same time. I'd guess they have more money, more resources and more of a true military need. Whereas the Russians seemed to be developing the SU-57 as an article of national pride. Where is the military need there?

They're not going to stand toe to toe with the US, NATO etc.. What they have (Flankers galore) are adequate to deploy to theaters close by (like Syria). The Chinese are clearly looking out over the South China Sea, perhaps toward Japan and of course Taiwan. They correctly deduced the J-20 probably wasn't going to be a Raptor killer. But if push comes to shove the J-20 will have to deal with the Raptor, and perhaps F-35 as well.

I shudder to think about how much of a leg up it has on our Super Hornets, assuming trouble kicks off its far more likely our carriers see action first. The 7th fleet is no slouch, but we're literally looking at a stealth vs. no stealth situation there... unless Marine F-35B's are part of a CVN deployment. Might not be a bad idea, because being on the wrong end of stealth vs. no stealth isn't going to end well IMO...

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 15:23
by sprstdlyscottsmn
An F-35A with full fuel and no weapons has a nominal T/W around 0.9. As I understand it, the airshow is done with ~60% fuel. That would give a 1.06 nominal T/W.

Why 60% when a Viper or a Raptor uses 100%? AB duration.

6,000lb of usable, non reserve, fuel on the F-16 with a nominal 29,000lb of thrust and AB TSFC of 2 gives 6.2 minutes of useable AB time. Obviously a whole demo is not done in AB but the demo also lasts longer than 6 minutes.

16,000lb of non reserve fuel in a Raptor with a nominal 70,000lb of thrust and the same TSFC gives 6.9 minutes of AB duration.

16,500lb of non reserve fuel in an F-35 with a nominal 43,000lb of thrust and the same TSFC gives 11.5 minutes of AB time.
9,060lb (60% full with same reserve fuel as above) in an F-35 gives 6.3 minutes of AB time.

Because the F-35 carries more fuel than an F-22 but has just a bit over half the thrust it can use a lot less fuel for the same length of a demo.

Re: J-20 goes operational

Unread postPosted: 14 Nov 2018, 15:40
by weasel1962
Agreed, that's the same argument why the F-35A could have an advantage over the F-35B is precisely the additional energy the extra fuel can accord in an extended A2A engagement. However, there is a planned sortie duration, and it boils down to fuel management. Even with a B, it can be enough fuel to fulfil the mission. Same with raptor.

Re: J-20 goes operational

Unread postPosted: 15 Nov 2018, 01:17
by Corsair1963
The extra fuel carried by the F-35 is an advantage. As you can trade it for energy on scale most fighters could only dream of. Funny, that the critics of the F-35's T/W leave that out....

Re: J-20 goes operational

Unread postPosted: 15 Nov 2018, 08:23
by linkomart
weasel1962 wrote:
P.s. What it'd be a mistake to do is assume that the J-20A is the final product. As happened with the J-10 e.g. the air inlets design, its going to improve. What its also a mistake imho is highlighting some of the design issues in too much detail in a public forum.


There is no such thing as the "final" product in the fighter business until the last plane rolls off the assembly line IMHO....
J10A was not either, but it is operational in ...large... numbers in China, J10B will replace some A but there might be a C and a D and....
J20A will probably be evolved but before that they will crank out a few divisions to get operational experience from the beast, even if it wont have the "right" engine or radar or....

MHO

Re: J-20 goes operational

Unread postPosted: 15 Nov 2018, 11:06
by nefory
linkomart wrote:
weasel1962 wrote:
P.s. What it'd be a mistake to do is assume that the J-20A is the final product. As happened with the J-10 e.g. the air inlets design, its going to improve. What its also a mistake imho is highlighting some of the design issues in too much detail in a public forum.


There is no such thing as the "final" product in the fighter business until the last plane rolls off the assembly line IMHO....
J10A was not either, but it is operational in ...large... numbers in China, J10B will replace some A but there might be a C and a D and....
J20A will probably be evolved but before that they will crank out a few divisions to get operational experience from the beast, even if it wont have the "right" engine or radar or....

MHO


The production of J10B has already stopped. Only 24 of them were delivered to PLAAF. They are currently producing J10C.

Re: J-20 goes operational

Unread postPosted: 15 Nov 2018, 12:10
by linkomart
Ok, didn't know that, but Still C can be replaced with a D and so on...

Re: J-20 goes operational

Unread postPosted: 17 Nov 2018, 14:31
by weasel1962
The other piece of news which CCTV released recently is that they finally managed to integrate a retractable aerial refuel probe into the j-20, rightside of cockpit.

Re: J-20 goes operational

Unread postPosted: 17 Nov 2018, 16:54
by mixelflick
Corsair1963 wrote:The real "sleeper" is the J-31....."IMHO"


J31XXX.jpg



Agreed. But they are going to have to hustle. More and more F-35's roll off the assembly lines every day and are beginning to proliferate. There will always be nations that can't get it however, and its here the J-31 will excel. Of course, that all assumes the Chinese can 1.) Get it to work and, 2.) Offer it at a reasonable price.

Considering the difficulties we had developing the F-35, it could be another decade (or 2) getting the J-31 into the same ballpark. And then they'll have to determine how to not compromise its stealth secrets. Interesting quandry, given the Chinese are usually the ones doing the stealing!

Re: J-20 goes operational

Unread postPosted: 18 Nov 2018, 17:28
by sferrin
mixelflick wrote:
Corsair1963 wrote:The real "sleeper" is the J-31....."IMHO"


J31XXX.jpg



Agreed. But they are going to have to hustle. More and more F-35's roll off the assembly lines every day and are beginning to proliferate. There will always be nations that can't get it however, and its here the J-31 will excel. Of course, that all assumes the Chinese can 1.) Get it to work and, 2.) Offer it at a reasonable price.

Considering the difficulties we had developing the F-35, it could be another decade (or 2) getting the J-31 into the same ballpark. And then they'll have to determine how to not compromise its stealth secrets. Interesting quandry, given the Chinese are usually the ones doing the stealing!



J-31 doesn't have to worry about a STOVL version.