J-20... The New Generation Fighter

Engineer said:

Most likely not, since the rudders are canted and would produce unwanted pitching moment.

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The aircraft uses fly-by-wire. Its computers must be well able to compensate for that unwanted pitching moment by deflecting the elevators.

A control law that maintains zero pitch-rate would prevent the rudder from turning against each other in the first place.

Courtesy of hhg of CDF

If it would be a programmed feature for landing than it wouldn't prevent it, and it would be easy for fbw to control pitch moment trough regulation of elevator deflection.

Engineer said:

A control law that maintains zero pitch-rate would prevent the rudder from turning against each other in the first place.

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It's still possible to maintain control of pitch by additionally using the canard or maybe thrust vectoring. How feasible would this be is the question.

vesicles said:

But they did! Note that officially they are not saying anything. Only yesterday they were denying the existence of the project at all. How can they announce anything when they tell people J-20 doesn't even exist?

All the flight test things have been strictly speculation by pepole like us, not even experts. All the experts are expecting test flights within this year, not the next few days So if anything, we have ourselves to blame. It only mean we still cannot predict what the Chinese govn't will do. That's the only coming out of this.

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Being AWOL last year you probably missed the announcement of such a 4/5th gen program by a PLAAF General. He went on to think they could start to be inducted in 2018. So if we use the American F22 program as a guideline, logic dictates that this 4/5th gen plane would have to be making an appearance pretty soon. That is if it wasnt just "hot air" on the part of the General.

Hui Tong admit that the second J20 prototype uses not only a chinese engine, but an improved version of FWS10. Fantastic news!! If they can test a new plane with an indigenous engine now, in 5-7 years (when the plane will be in mass production), probably they won't need 117S at all because they will mass produce a domestic engine. Maybe we can finally start to have faith in chinese aerospace industry. Let's consider were china was ten years ago and where is now, if this momentum in mainteined you can guess where it will be a decade from now!

PS People's daily comment (heading) on US-China relationship and China military development , title says all

I have a question on the plane wing: I've read that the wing surface is small, and the plane is very long, to facilitate supercruise. In theory these two aspect of J20 wouldn't reduce the stability of the plane at low speed? One of the strength of F22 in dogfight seems that is a plane that goes on stall rarely, maybe this is why J20 engineer opted for canards, to compensate this disavantage? Thx

Man the new J20 must be very huge...look at those people under her wing, looked so tiny...It's much larger than the J10 too.

bladerunner said:

Being AWOL last year you probably missed the announcement of such a 4/5th gen program by a PLAAF General. He went on to think they could start to be inducted in 2018. So if we use the American F22 program as a guideline, logic dictates that this 4/5th gen plane would have to be making an appearance pretty soon. That is if it wasnt just "hot air" on the part of the General.

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It would be unwise to use the F-22 program as a guideline -- the political, economic and requirements are way different for PLAAF and PRC. But even if we did use the F-22 as a guide, it doesn't mean J-20 necessarily has to make an "appearance" -- most likely its already had its first flight a few months ago.

The General did say it would enter service between 2017-2019. Do you also remember that CCTV later retracted the statement and that the 4th/5th generation fighter was really just an "upgraded J-10"? It obviously means that some in the PLAAF weren't very happy with the General's open-ness.

Why would a high ranking commander just let out hot air on state news on such an important project, with so many details...