Chengdu J-20 5th Generation Aircraft News & Discussions

[Deino]

you asked a question my answer was right, in fact i was not off topic since you were the one that asked, I never did anything wrong, i fact i wonder why you never said you are wrong or right, why my answer was wrong, are not people to exchange ideas in forums?

In fact I gave you an understanding at least that PAKFA, F-18 or even F-35 use V tails, but if you think that is wrong, then this thread should be re-name no discussion J-20 photo album and to be honest it will become so boring, that is why I like secret projects forum, there they have a much better tolerance and overscan was pretty smart in the thread he has about J-20 DSI intake quiet en-lighting in fact pretty smart guy and all the forum members there quiet respectful, here is a bunch of insults and intolerance and pretty much low level conversation with a lot of fantasy and little technical detail, I think you should first look for people respect each other and later try to make it people learn otherwise it is to be honest kinder garden level photo album of J-20

You don't get it, exactly as at the SDF: Again you are lecturing ad nauseum on irrelevant things and complain about YOUR point of view and then you feel offended. To tell us water is wet and the sky is blue is also not wrong, but it is irrelevant when the question was "what maneuver that J-20 was executing on the pic"?

Therefore I have nothing against discussions, quite to the contrary, but if a simple question is given and one certain member constantly goes off by his own ex-curses in avionics, then this is off. In fact I only noticed a certain detail and the question - not even mine - was "what maneuver that J-20 was executing on the pic"? Not again a long story about the difference of a V-tail, regular rudders and so on and if you prefer the Secretprojects forum, just go ahead.

 

[Fsjal]

My simple question was indeed about what maneuver the J-20 was doing in that twitter picture, and when talking about how I've never seen such an asymmetrical tail position, what I meant was I've never seen a tail position in which the vertical stabilizers are facing the same direction but one is in a slightly different angle than the other. I am fully aware of how vertical stabilizers work, and I am fully aware of what a slanted-angle all-moving V-tail is, I was simply asking about the J-20 in the twitter pic and what maneuver it was executing to have its tail position be in an asymmetrical way.

 

[Su33KUB]

My simple question was indeed about what maneuver the J-20 was doing in that twitter picture, and when talking about how I've never seen such an asymmetrical tail position, what I meant was I've never seen a tail position in which the vertical stabilizers are facing the same direction but one is in a slightly different angle than the other. I am fully aware of how vertical stabilizers work, and I am fully aware of what a slanted-angle all-moving V-tail is, I was simply asking about the J-20 in the twitter pic and what maneuver it was executing to have its tail position be in an asymmetrical way.

they are asymmetric for a law of vectors remember V tails are rudders and tailerons simple like that you do not understand that law, if you really understand how they work you will know the rudder and taileron are basicaly pitch and yaw, the J-20 was doing pitch and yaw at the same time there is a law of vectors, there is nothing special about it, when they do symmetric deflections each force cancels out or enforce each other but since each vector also does not only have a direction but a magnitude you can have different results if you have asymmetric deflections like the one on the picture

figure 3.3 explains it on regular aircraft 3.3A is rudder and elevator , 3.3b is V tail doing the same

In the picture you mention J-20 is turning but it is turning with a little picht, in few words a tighter turn, all V tails can do that from propeller aircraft with V tails to jet aircraft with V tails like Su-57, F-35 or F-18

the reason that picture is confusing is because V tails do yaw but also pitch, and they can do both at the same time, that asymmetric deflection of both tails represent a turn but by giving more deflection to one tail that is also adding lift, so the sums of both vectors is mostly yaw, basically turning but a little pitch is also playing, it is not new but normal behavior of V tails. To see where the aircraft is going you have to sum the vectors

However i was silenced just because people are ignorant and arrogant and if you are trying to help lies and pride count more here than science and truth

 

[ozranger]

The video captures J-20's maneuverability at the best angle as I believe. It was recorded on the PLAAF Open Day, Changchun.

https://www.bilibili.com/video/av71969161?from=search&seid=6507727793430084722

Another one which might be even better
https://www.bilibili.com/video/av71778647?from=search&seid=6507727793430084722

 

[lcloo]

When I was studying laws, one of the points that make a judge making decisions in a court was the intention of the offender. Regardless of the degree of actions or damages done, the sentence would be based on whether the offender's intention is malicious or un-intentional, as in planned murder, or accidental killing.

I think we all know some of the posters' intentions --- malicious, negative or contributory and positive.

 

[LKJ86]

Via CCTV 1 and @沉默的山羊 from Weibo

 

[LKJ86]

Via @MinorLogan from Weibo

 

[serenity]

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Via CCTV 1 and @沉默的山羊 from Weibo

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Do you have a link to the CCTV one with J-20? I missed it and cannot find.

 

[Deino]

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Via CCTV 1 and @沉默的山羊 from Weibo

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Is this an older report (or just now published) from the arrival of the fist J-20s at the 172nd Brigade or is it another event?

My simple question was indeed about what maneuver the J-20 was doing in that twitter picture, and when talking about how I've never seen such an asymmetrical tail position, what I meant was I've never seen a tail position in which the vertical stabilizers are facing the same direction but one is in a slightly different angle than the other. I am fully aware of how vertical stabilizers work, and I am fully aware of what a slanted-angle all-moving V-tail is, I was simply asking about the J-20 in the twitter pic and what maneuver it was executing to have its tail position be in an asymmetrical way.

Via the SDF:

If you like the photo, the actual roll can be found in this video at 0:11

https://twitter.com/x/status/1185854184400146432

 

[Su33KUB]

Is this an older report (or just now published) from the arrival of the fist J-20s at the 172nd Brigade or is it another event?

thanks it is a roll, i was thinking it was a roll, but i doubted since is difficult to calculate the vector sum, but the wings trailing edges flaps of that picture are asymmetrically deflected and the aircraft is vertical well a bit diagonal hinting a climb or roll, but any way thanks, you have showed me you are fair Saludos

 

[FuturePAF]

Does the J-20 have a Pelican tail or just a modified four poster?

 

[gambit]

My simple question was indeed about what maneuver the J-20 was doing in that twitter picture, and when talking about how I've never seen such an asymmetrical tail position, what I meant was I've never seen a tail position in which the vertical stabilizers are facing the same direction but one is in a slightly different angle than the other. I am fully aware of how vertical stabilizers work, and I am fully aware of what a slanted-angle all-moving V-tail is, I was simply asking about the J-20 in the twitter pic and what maneuver it was executing to have its tail position be in an asymmetrical way.

Your question maybe simple but the answer is not. The answer involves the foundation of avionics architectures itself. If I post my explanation which will involved an F-18 and supporting sources, it will be deemed too long and boring and will be deleted because someone whines about it. The reality is that the Chinese members of this forum are not interested in the technical details of the J-20 because -- irony abounds -- an American have better answers than they can.

 

[KungFuLee]

When I was studying laws, one of the points that make a judge making decisions in a court was the intention of the offender. Regardless of the degree of actions or damages done, the sentence would be based on whether the offender's intention is malicious or un-intentional, as in planned murder, or accidental killing.

I think we all know some of the posters' intentions --- malicious, negative or contributory and positive.

Maybe off topic, but what you said does not make sense as a Law Graduate

Malice and the Malice aforethought are two separate things, one is intention, the other is premeditation, and both are distinct from Mens Rea and Actus Reus, all those term are related to a different thing.

Case in point, While Malice is a factor on charging someone murder from manslaughter, however, one still need to proof a guilty mind and a guilty acts (Mens Rea and Actus Reus) to present to make a case, be it murder or manslaughter. However, you do not need to proof premeditation or as you said "Plan" to found one guilty for murder.

Also, sentence is ALWAYS depends on the degree of action and damages. Ie. Killing a adult aged female will have a different sentence of killing an adult aged male, and will have a different sentencing guideline than killing a adult aged pregnant female, or killing a young child. Although those are the same definition of "Homicide". Also the degree of damage done would also be counted into consideration during sentencing.

Again, this may be out of topic, I just want to say this...

 

[gambit]

thanks it is a roll, i was thinking it was a roll, but i doubted since is difficult to calculate the vector sum, but the wings trailing edges flaps of that picture are asymmetrically deflected and the aircraft is vertical well a bit diagonal hinting a climb or roll, but any way thanks, you have showed me you are fair Saludos

It was a typical aileron roll for airshow. An aileron roll is the most simple of rolls. In simpler aircrafts, like the Cessna 152 I trained on while in high school prior to the USAF, an aileron roll requires three actions: control (or yoke) to either with starboard or port, slight throttle increase, and slight rudder. In flight, every time you make a maneuver, you lose a bit of airspeed, hence the slight increase in throttle.

In avionics, flight control surface deflection is the result of the algorithm of command, airspeed, altitude, gyroscope, and accelerometer. The slower the airspeed, the greater the VISIBILITY of that deflection. So for the J-20 video, the fact that we can see the port vertical stab's high deflection at timestamp 00:10 mean airspeed just above stall, not cruise. After all, it was an airshow and airshow's airspace are designed to be limited.

The FLCC received a cockpit command. The Central Air Data Computer (CADC) sends airspeed and altitude data to the FLCC. The three rate gyros (pitch, roll, and yaw) sends their data to the FLCC, and the two accelerometers sends their data to the FLCC. Then the FLCC calculate the rate and final angle of displacement for the flight control surfaces. The higher the airspeed, the less surface deflection. Conversely, the lower the airspeed, the higher the deflection. So for us to see the deflection at timestamp 00:10, it means airshow airspeed. As the J-20 continues its aileron roll, the jet's AOA, to me, indicates a slight pitch askew (diagonal), further evidence of a lower airspeed than usual. The asymmetrical deflection of the various flight control surfaces is evidence of a computerized flight controls system (FLCS). Not necessarily all fly-by-wire, but for starter, at least a computerized FLCS. For the J-20, the public was informed of a FBW-FLCS.

 

[LKJ86]

Via www.top81cn.cn