broadsword
Brigadier
Your kind of mentality has been written by you for all to see. We're not children who can't understand visceral human emotions of cause and effect.
J-20 5th Gen Fighter Thread IV (Closed to posting)
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Your kind of mentality has been written by you for all to see. We're not children who can't understand visceral human emotions of cause and effect.
AssassinsMace
Lieutenant General
Yeah anyone remember that Red Flag debriefing posted on the internet? What killed MKIs were when the Indians used their TVCs, it killed their speed. All those tricks you see like in that F-22 vs Su-35 video are fun for an air show but in combat you're dead.
I'm still not entirely convinced that there isn't a place for post stall maneuvers though.
Not getting into a long argument over this, but note that the F-22 and PAK-FA are conventional wing-tail aircraft.
Note also that the Boeing F/A-XX is a finless canard-delta, presumably with TVC; and also note the finless canard-deltas tested by the US in their X-planes, showing superior maneuverability to current finned-tail designs.
I think the likelihood of the Chinese at least testing a finless J-20C once the TVC becomes reliable is extremely high. The RCS reduction and maneuverability improvements of a J-20C using TVC + canards is significant enough that as an ultimate end-goal the J-20C would be highly desirable.
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With regards to canard stealth; I'm fully aware of the Northrop ATF, but I do have to say that canards complicate emissions control at the very least and at the most limit the effects of RCS reduction.
If you look at Kopp's RCS estimate of the J-20, you'll note that there are angles on the J-20's frontal 180 degrees where the aircraft has huge RCS spikes. Where do these spikes come from?
Even if you go to note the Chinese papers on RCS-reduction for canards, the figure cited is an addition of 0.001m^2 dB with transparent materials. That's -30 dBsm; the F-22 is purported to have a -40 dBsm RCS, and the F-35 has a -40 frontal dBsm.
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I am not getting into a long pissing contest here. I've said my peace.
Note also that the Boeing F/A-XX is a finless canard-delta, presumably with TVC; and also note the finless canard-deltas tested by the US in their X-planes, showing superior maneuverability to current finned-tail designs.
I think the likelihood of the Chinese at least testing a finless J-20C once the TVC becomes reliable is extremely high. The RCS reduction and maneuverability improvements of a J-20C using TVC + canards is significant enough that as an ultimate end-goal the J-20C would be highly desirable.
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With regards to canard stealth; I'm fully aware of the Northrop ATF, but I do have to say that canards complicate emissions control at the very least and at the most limit the effects of RCS reduction.
If you look at Kopp's RCS estimate of the J-20, you'll note that there are angles on the J-20's frontal 180 degrees where the aircraft has huge RCS spikes. Where do these spikes come from?
Even if you go to note the Chinese papers on RCS-reduction for canards, the figure cited is an addition of 0.001m^2 dB with transparent materials. That's -30 dBsm; the F-22 is purported to have a -40 dBsm RCS, and the F-35 has a -40 frontal dBsm.
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I am not getting into a long pissing contest here. I've said my peace.
I think the overall commentary is more concerned with why single out canards, when any surface complicates emission returns.
AssassinsMace
Lieutenant General
I'm sure there maybe but maintaining a certain speed in combat is important hence why the MKIs were taken out. They were probably not in a position to try.
Whenever the India MKI example is brought up, I usually take it more as a sign that the IAF doesn't know how to integrate post stall maneuvers into combat intelligently than as an indication that TVC or post-stall is useless.
MiG-29
Banned Idiot
LERX and canards have the same effects, basicly creating vortices and moving the pressure center ahead reducing the pressure center shift at supersonic speeds.
That has been the reason Americans and Russians prefer LERXed aircraft while the Chinese and Europeans have opted for canards.
None is superior, everything is mission dependent, J-20 chose that configuration due to other elements in their design.
About the Canard being less stealthy, the reality is not, it is not less stealthy, but imposes more restrictions in terms of aerodynamics, therefore it is preferable to ditch it, either with LEVCONS or LERX.
If Chengdu chose it it is simply their requierements.
The less stealthy aircraft is always the one with less surfaces, so a tailess is always more stealthy.
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MiG-29
Banned Idiot
Post stall is not useless, that is just a mere myth, what really happens is now they have HHOBS and DAS, you do not need now to be ultra agile, your missiles will do it for you, your helmet mounted sight will do it for you, so TVC simple becomes an aid at supercruise and and aid for stealth.
In fact the victories of Eurofighter over Su-30MKI are due to HHOBS
Engineer
Major
You are repeating the same theory that has a big gapping hole. What's more, there is no correlation between lack of vertical stabilizer and maneuverabiliy. Maneuverability depends on aerodynamics potential of the airframe. Removing the fins and add thrust vectoring is not going to boost maneuverability.
Once again, there is no concrete proof showing canard is detrimental to stealth. That is the problem. You are holding on to someone's claim that has no support whatsoever. A lot of features can complicate emission control, and there is no basis on which you can assert canard will definately produce huge RCS spike. The fact that many stealth fighter concepts exist with canard further illustrates how the claim about canard being detrimental to stealth is nothing more than a myth.
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