J-20 goes operational

Military aircraft - Post cold war aircraft, including for example B-2, Gripen, F-18E/F Super Hornet, Rafale, and Typhoon.
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weasel1962

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Unread post12 Nov 2018, 15:05

14200kgf is a bit dated (pre 2010). 14500kgf (31900 lbf) was achieved in 2012 which was also what was stated in the Czech link.

http://aviationweek.com/awin/some-tests ... ne-upgrade

32600 lbs is the mathematical translation of 145kn which is what is normally cited for the FM2 at least in news sites that no longer exists. But its a meaningless difference. Even at 31900 lbs, that's a TWR of 0.91 when Imho, 0.88 is not a significant difference even against 0.93. Bearing in mind, that's with western estimates of weights and fuel load. Really waste of time to argue over estimates.

p.s. On A2G, LD-10 comes to mind which is fielded but I wouldn't be surprised if there is a ARM version of the PL-15. imho, current J-20s are still primarily interceptors. Absolutely no A2G role yet. The current brigades are assigned aggressor roles replicating "orange" or "blue force". Not sure what orange means but we all know what blue stands for.
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marsavian

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Unread post12 Nov 2018, 15:30

For those curious here is the aerodynamic thinking, c2001, that maybe behind the J-20 by one of its designers Dr. Song Wencong which shows that they were purposely thinking about developing a stealthy canard fighter then.

https://defence.pk/pdf/threads/translat ... ng.165231/
https://ethw.org/Song_Wencong
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Unread post12 Nov 2018, 17:10

mixelflick wrote:If the reports out of India are true, their SU-30MKI's detected the J-20 some months back.


I don't trust those Indian claims at all. The Indian Air Force have made some pretty boastful claims in the past.

Apparently J-20 is currently flying with AL-31FM2 and WS-15 is still being tested.
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Unread post12 Nov 2018, 18:21

mixelflick wrote:
If the reports out of India are true, their SU-30MKI's detected the J-20 some months back.


Without knowing the context, it's hard to say what they detected. J-20 has been flying about everywhere with Luneberg lenses. Doesn't make too much sense for them to give IAF an accurate reading of J-20's frontal RCS. And even if it's not flying with that next to the Indian borders, it's not exactly stealthy from all angles. From PLAAF's version of red flag exercises, the stories coming out are that other fighter jets and land based radars are having real trouble picking J-20 up. If I was IAF, I would not be basing my hope on Su-30s finding J-20.

Those are some pretty deep bays. It could easily carry 6x AMRAAM equivalents in the main bays if each bay door holds a missile.

I wonder what air to surface munitions it can fit; it looks like most Chinese anti-ship and land-attack cruise missiles are too long for those bays.

it's pretty standard A2A load for PLAAF. That's what you normally see flankers with. I'm sure if they really wanted to, they could go for a more heavy load. But there is no need to carry more than needed with underpowered engines. They will probably creating some new AShM to be internally carried, but that will be a little bit further down the road.
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ricnunes

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Unread post12 Nov 2018, 21:22

marsavian wrote:Going from 10 to 1 sq m is a 90% reduction, not 10%, and the modelling was around 50% for all wavebands.


Yes, you're right. It was my bad there.

A 10% decrease on 10 sq. meters is 1 sq. meter which bring it to 9 sq. meters which by its turn is still a much bigger gain compared to if applied to lower RCS values like for example 0.5 sq meter. So in the first case you have a gain (decrease) of 1 sq. meter while in the former (0.5 sq meter) you have a gain of only 0.05 sq meters (or basically a gain of 20 times less compared with the 10 sq. meter example) which bring it to the 0.45 sq. meter values that I mentioned earlier.


marsavian wrote:It's a question of degree not absolutes.


No, in fact it is not. However the lower we get in terms of RCS, the harder will be to reduce it further - at least to reduce it to really noticeable values.


marsavian wrote:But both methods work to varying degrees but RAM works less effectively and comes with a significant weight penalty which is why shaping is normally the first order of business when it comes to designing a stealth aircraft as extra weight is not good news when it comes to overall kinematic performance.


Yes, weight is probably the most important or among the most important factors on aviation of when designing aircraft. So even if you are right here you cannot simply put loads of RAM material coating on aircraft (this unless someone invents Anti-Gravity engines :mrgreen: ). But even then there's so much you can do with RAM materials in order to reduce the RCS of a not so optimized shaped (for lower RCS).
A 4th/4.5th gen fighter aircraft stands about as much chance against a F-35 as a guns-only Sabre has against a Viper.
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Corsair1963

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Unread post13 Nov 2018, 02:59

Corsair1963 wrote:The real "sleeper" is the J-31....."IMHO"



J31XXX.jpg



This is what I've been saying for sometime now......

Avic’s J-31 Fighter Is a Winner After All

Nov 9, 2018 Bradley Perrett and Steve Trimble | Aviation Week & Space Technology


Not long after the J-31 fighter prototype from Avic’s Shenyang Aircraft Corp. appeared in 2012, analysts realized that it was not, after all, a new combat aircraft for the Chinese military. It was just a technology demonstrator from a well-resourced but frustrated state company that had lost two air force fighter competitions in a row. Now the J-31 has indeed become a government-funded project, apparently rescued by the shortcomings of the J-15, a naval Flanker derivative also built ...http://aviationweek.com/defense/avic-s- ... -after-all
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linkomart

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Unread post13 Nov 2018, 07:21

sprstdlyscottsmn wrote:Back in 2009, I was impressed by the T-50. Once more information came out I was only impressed by it's aero layout. Right now, I am tentatively impressed by the J-20. It seems like a good first attempt. Those ventral fins need to go though, those are going to be hell on RCS.


On the contrary, IMHO. The ventral fins is the one thing that saves the RCS in the side sector. Otherwise the exhausts with all their gaps and angles would light up a radar receiver like a christmas tree if it is looking from the side (+-10 degrees elevation.) Now the ventral fin shields the exhausts, and they don't need a F-22 style exhaust.

My 5 cent.

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Unread post13 Nov 2018, 13:47

That may be true.
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tphuang

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Unread post13 Nov 2018, 15:48

linkomart wrote:
On the contrary, IMHO. The ventral fins is the one thing that saves the RCS in the side sector. Otherwise the exhausts with all their gaps and angles would light up a radar receiver like a christmas tree if it is looking from the side (+-10 degrees elevation.) Now the ventral fin shields the exhausts, and they don't need a F-22 style exhaust.

My 5 cent.

Best regards.

I think you are right here. one reason to have ventral fin is to block off exhausts.
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sprstdlyscottsmn

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Unread post13 Nov 2018, 16:01

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.
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Unread post13 Nov 2018, 16:56

.[/quote]
I seriously doubt the J-20 will have a T/W ratio of >1:1 with 25k lbs of fuel and 5k lbs of ordnance, or 500 aircraft. Secondly, the F-35 doesn't have a .75 T/W ratio.[/quote]

Geez you're right. It's actually worse at .6. And that's for the F-35A, the lightest of the 3 variants. Yes, I realize that's fully loaded and it gets above 1:1 when 50% fuel is used but still. Does anyone know what the Paris demo internal fuel load was? I've read where the Raptor performs at full internal fuel when flying displays, but the F-35's sprightly performance at Paris leads me to believe it sure didn't have a .6 TTW ratio.

50% internal maybe?
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Unread post13 Nov 2018, 17:38

weasel1962 wrote:14200kgf is a bit dated (pre 2010). 14500kgf (31900 lbf) was achieved in 2012 which was also what was stated in the Czech link.

http://aviationweek.com/awin/some-tests ... ne-upgrade

32600 lbs is the mathematical translation of 145kn which is what is normally cited for the FM2 at least in news sites that no longer exists. But its a meaningless difference. Even at 31900 lbs, that's a TWR of 0.91 when Imho, 0.88 is not a significant difference even against 0.93. Bearing in mind, that's with western estimates of weights and fuel load. Really waste of time to argue over estimates.

p.s. On A2G, LD-10 comes to mind which is fielded but I wouldn't be surprised if there is a ARM version of the PL-15. imho, current J-20s are still primarily interceptors. Absolutely no A2G role yet. The current brigades are assigned aggressor roles replicating "orange" or "blue force". Not sure what orange means but we all know what blue stands for.


“Orange” stands for “intervention force”.
The scenario would probably be that of an ongoing exercise among 4th gens playing red vs blue, where at one point a third party intervenes with 5th gens as reinforcement to one side.
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sprstdlyscottsmn

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Unread post13 Nov 2018, 19:58

.6 would be at full internal and external load. Max gross.
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Unread post14 Nov 2018, 01:34

mixelflick wrote:.

I seriously doubt the J-20 will have a T/W ratio of >1:1 with 25k lbs of fuel and 5k lbs of ordnance, or 500 aircraft. Secondly, the F-35 doesn't have a .75 T/W ratio.[/quote]

Geez you're right. It's actually worse at .6. And that's for the F-35A, the lightest of the 3 variants. Yes, I realize that's fully loaded and it gets above 1:1 when 50% fuel is used but still. Does anyone know what the Paris demo internal fuel load was? I've read where the Raptor performs at full internal fuel when flying displays, but the F-35's sprightly performance at Paris leads me to believe it sure didn't have a .6 TTW ratio.

50% internal maybe?[/quote]

Apples and Oranges.....we really debating the T/W again???

https://youtu.be/96Kx6b7oKA8
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weasel1962

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Unread post14 Nov 2018, 02:26

The B is the lightest in the air at mtow.
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