Chengdu J-20 5th Generation Aircraft News & Discussions

[Su33KUB]

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.

thanks, by the way two of my favorite aircraft are F-14 and F-111, but i love MiG-23 and MiG-29, and from China the J-8 is my favorite Saludos

 

[LKJ86]

Via @空军发布 from Weibo

 

[LKJ86]

Via @captain笨小航 from Weibo

 

[LKJ86]

Via @酒色财气吕洞宾 from Weibo

 

[LKJ86]

Via @空天砺剑 from Weibo

 

[LKJ86]

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Via CCTV 1 and @沉默的山羊 from Weibo

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[LJQC]

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.

My bet is that similar to how a F-16 utilises differential horizontal stabilisers to help with roll maneuver, the J-20 uses differential vertical stabilisers to increase roll control efficiency while at the same time uses it as an ARI (Aileron-Rudder Interconnect) to minimize side-slip.

Here you can find the F-16 FLCS block diagram for both analog and digital one (DFLCS): http://i.imgur.com/9XKCGrD.png, https://archive.org/details/DTIC_ADA189675/page/n39

Note that how pitch control output is mixed with roll control output. And also the section of Aileron-Rudder Interconnect where rudder deflection (automatically controlled by FLCS) syncs with aileron deflection and it increases as Angle of Attack (AOA) increases. The ARI is designed to minimize side-slip and make the jet roll around its velocity vector so that best roll performance can be attained.

 

[seven7seven]

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.

 

[KungFuLee]

I do not get what you are trying to say.

If you think what I said is incorrect, please do point it out directly instead of sending me a cryptic youtube video.

 

[LKJ86]

https://twitter.com/x/status/1189182904703672322

 

[LKJ86]

Via @白龙_龙腾四海 from Weibo

 

[Deino]

J-20A + WS-10C

(Image via 桜小路才華/@10969YUKIKAZE at Twitter)

PS: via https://lt.cjdby.net/forum

 

[bahadur999]

J-20A + WS-10C

(Image via 桜小路才華/@10969YUKIKAZE at Twitter)

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PS: via https://lt.cjdby.net/forum

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Do you think the J-20 will go 'mass-production' in its current form? or will they make a J-20B after fixing/upgrading it and then proceed?
I find it unusual that this picture unveils this exposed-version of the J-20 - not something other countries should see if the PLA seeks to fight with it later...

 

[Ultima Thule]

Do you think the J-20 will go 'mass-production' in its current form? or will they make a J-20B after fixing/upgrading it and then proceed?
I find it unusual that this picture unveils this exposed-version of the J-20 - not something other countries should see if the PLA seeks to fight with it later...

its already in production

 

[bahadur999]

its already in production

Production - Yes
Mass-production - Not yet.
J-20 is still deployed in one Air Brigade (I count combat brigades, not Test Brigades) which i am sure it is not fully equipped yet...
The question in when the J-20 will go mass-production and on what technical conditions.