J-20 goes operational

Corsair1963 · by **Corsair1963** » 12 Nov 2018, 01:52

The real "sleeper" is the J-31....."IMHO"

sferrin · by **sferrin** » 12 Nov 2018, 03:53

If China wanted it could easily replace the Flanker as the Go-To fighter for those who can't buy the F-35.

nefory · by **nefory** » 12 Nov 2018, 05:01

Another J20 clip of high resolution.
Take a look at how those vortexes are generated and coupled among the canard, strake and the wing.
It's quite something to watch.
https://www.youtube.com/watch?v=tNss2y__xGE

wrightwing · by **wrightwing** » 12 Nov 2018, 05:19

mixelflick wrote:.

What's the J-20 T/W ratio?[/quote]

According to this article https://www.nextbigfuture.com/2017/10/c ... -2019.html, the new engine produces 19 tons of thrust. So that's 38,000lbs per engine, x2 would be 76,000lbs of combined thrust.

According to wiki, it's empty weight is 42,750. Also per wiki, it carries 25,000lbs of fuel, so that brings it up to 68,750. Add in 5,000lbs of internal weapons and we're at 73,750lbs.

So a 1.03 thrust to weight ratio, or thereabouts.

That's considerably better than the F-35 at full internal fuel and weapons (.75), but considerably worse than the Raptor at 1.14. Thrust to weight ratio isn't everything, but I'd expect the J-20 to be a fearsome threat to all but the F-35 and F-22. The F-35 won't dogfight with the J-20, instead it'll rely on its superior stealth and sensors to kill it BVR, or near BVR if it has to get in close. The Raptor outclasses it considerably, but they're building 500 J-20's to our 180 or so F-22's. We best hope we don't lose any to accidents or combat, because every one is a national treasure.

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.

edpop · by **edpop** » 12 Nov 2018, 05:57

J-20 Missile load............

weasel1962 · by **weasel1962** » 12 Nov 2018, 07:09

Based on current
J-20 - 2x AL31FM2 = 65,200 lb. MTOW (37k kg) = 81,400 lbs = 0.8
F-35A - 1 x F135 = 43,000 lb. MTOW (31.8k kg) = 70,000 lbs = 0.6

nefory · by **nefory** » 12 Nov 2018, 08:14

weasel1962 wrote:Based on current
J-20 - 2x AL31FM2 = 65,200 lb. MTOW (37k kg) = 81,400 lbs = 0.8
F-35A - 1 x F135 = 43,000 lb. MTOW (31.8k kg) = 70,000 lbs = 0.6

How about the t/w in a hypothetical combat situation, say both with half fuel and with standard air-to-air arrangement?

weasel1962 · by **weasel1962** » 12 Nov 2018, 08:25

We had a thread filled with disagreements over what the J-20 actual empty weight really is. No public info but only estimates. Below are western estimates (china numbers generally @ lower weights)

F-35A empty 29k + max fuel (18k) + 2k weapons (6 AAM) = 49,000 = 0.88. TWR 1.08 at 50% fuel.
J-20 empty 43k? + max fuel (25k?) + 2k weapons (6 AAM) = 70,000 = 0.93. TWR 1.13 at 50% fuel.

nefory · by **nefory** » 12 Nov 2018, 08:35

weasel1962 wrote:We had a thread filled with disagreements over what the J-20 actual empty weight really is. No public info but only estimates. Below are western estimates (china numbers generally @ lower weights)

F-35A empty 29k + max fuel (18k) + 2k weapons (6 AAM) = 49,000 = 0.88. TWR 1.08 at 50% fuel.
J-20 empty 43k? + max fuel (25k?) + 2k weapons (6 AAM) = 70,000 = 0.93. TWR 1.13 at 50% fuel.

Is this 29k of F35 and 43k of J20 dry empty weight or operational empty weight?
From what I've read from Chinese sources, the dry empty weight of J-20 is somewhat close to 43k, and operational empty weight of J20 is around close to but not yet 49k.

weasel1962 · by **weasel1962** » 12 Nov 2018, 09:12

nefory wrote:
weasel1962 wrote:We had a thread filled with disagreements over what the J-20 actual empty weight really is. No public info but only estimates. Below are western estimates (china numbers generally @ lower weights)

F-35A empty 29k + max fuel (18k) + 2k weapons (6 AAM) = 49,000 = 0.88. TWR 1.08 at 50% fuel.
J-20 empty 43k? + max fuel (25k?) + 2k weapons (6 AAM) = 70,000 = 0.93. TWR 1.13 at 50% fuel.

Is this 29k of F35 and 43k of J20 dry empty weight or operational empty weight?
From what I've read from Chinese sources, the dry empty weight of J-20 is somewhat close to 43k, and operational empty weight of J20 is around close to but not yet 49k.

We had a thread filled with disagreements over what the J-20 actual empty weight really is. No public info but only estimates.

marsavian · by **marsavian** » 12 Nov 2018, 11:04

The J-20 like the Su-57 has entered service with an existing engine and the new engines are years away. Shouldn't T/W ratios be calculated with this engine rather than the future upgrade because you could play the same game with F-35 and start calculating with Advent/PW potential upgrades which would have as much relevance. Let's deal in current reality first.

weasel1962 · by **weasel1962** » 12 Nov 2018, 13:44

J-20s are currently equipped with twin AL-31FM2s. All numbers are based on AL-31FM2.

Scorpion1alpha · by **Scorpion1alpha** » 12 Nov 2018, 13:48

edpop wrote:J-20 Missile load............
J-20 Missile load.jpg

Not bad. I must admit, she's like a mystery girl I keep glancing at...

Who's a little bit athletic...

marsavian · by **marsavian** » 12 Nov 2018, 14:14

weasel1962 wrote:J-20s are currently equipped with twin AL-31FM2s. All numbers are based on AL-31FM2.

The thrust of the AL-31FM2* is 14,200 kgf / 31,300 lbf which gives a TW ratio of 0.89 at your fully loaded air superiority 70,000lbs weight which is the same rounded to 2dp as the F-35A. It has no thrust/weight advantage and the aerial display does not suggest otherwise either.

* http://www.leteckemotory.cz/motory/al-31/index.php?en

knowan · by **knowan** » 12 Nov 2018, 14:40

edpop wrote:J-20 Missile load............
J-20 Missile load.jpg

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.