Official Chengdu J-20 Discussion Thread
Aircraft carriers are not a priority for China. J-20 has plenty of combat radius, especially when couple with aerial refuelers. Varyag is for study only, not for operation. Once fusion power is a reality in a few decades, fusion powered fighter planes would have unlimited combat radius.
Let's keep the discussions on the useful side of reality, shall we... regardless of whether or not fusion power becomes practical in the future, it's not here now nor does it promise to be any time soon, so talking about fusion powered aircraft is pointless.
the concerned
Active Member
I still think this points to a strike/aircraft not a fighter something with a range as good if not greater then the SU-34 because the JH-7 isn't excatly going to change the balance its not even as capable as a tornado.
Air Force Brat
Member
Some have mentioned the possibility that it may be a long range interceptor for a denial of assets, ie AWACS, refuellers, carriers,etc, but that line of reasoning generates a little heat on our sister forum. Sino Defense, it does appear that there may be pictures of a second aircraft 2002, which has been long anticipated as it appears the test probe of 2001 has been replaced by an operational probe. Hopefully not an april fools joke. Dr. Songs 2001 thesis has been translated by one of the moderators, and most of the design features as specified in his paper have been incoroporated into the J-20. Dr. Songs paper is quite complimentary of the F-22 to the point of recognizing the outstanding power plants, he suggests that the J-20 would require a great deal of aerodynamic tweaking, to compete with the F-22 in light of less powerfull engines? He talks about the J-20 as an A2A platform, so it will be interesting if indeed this is the second flyable prototype?
It does appear the second prototype 2002 has been rolled out, kind of behind a fence now, so we shall see if they fly it soon. It appears to have the radar installed and the operational pitot, those few changes are all thats been noted so far, lots of discussion on what engines?
No word yet on whether 2002 has flown yet, it seems that we may be under an information blackout, but to my knowledge there has been no official acknowledgement of her roll out either, please correct me if I am wrong?
2002 vid on Sino D of her running up behind the fence, may have a first flight soon, they had the canopy off performing some type of maintenance a day or so ago.
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Haavarla
Active Member
Looks like the second J-20, b/n 2002 are out and doing taxi trials.
Key Publishing Ltd Aviation Forums - View Single Post - J-20 Thread 7
At current time, i could not find any direct link..
Anyway, some small external changes.
The MLG doors have been altered.
And the Air data probe on the nose.
Key Publishing Ltd Aviation Forums - View Single Post - J-20 Thread 7
At current time, i could not find any direct link..
Anyway, some small external changes.
The MLG doors have been altered.
And the Air data probe on the nose.
guessing that might just be a legacy of the fact that this particular stage of testing is over rather than a design change...
Air Force Brat
Member
Yes, Deino has just posted pix of 2001 and 2002 side by side on the Ramp, so hoping we see first flight of 2002 shortly. This on Sino Defense our sister forum, some really good pix. Several of the guys over there noted the gear doors, I'm not too sure they've been changed, but lot of discussion about same, pitot noted.
Air Force Brat
Member
J-20 2002 First Flight
Well its official, the second J-20 prototype, 2002 has flown at the Chendu factory field, Dieno has some interesting comments, and other posters on our sister forum Sino Defense have noted that 2001 has been flown to another airfield. Both aircraft had been sitting at Chengdu together for a week or so. Whether you're a fan or no the J-20 is a significant accomplishment, I have an idea that 2001 will get to the real flight testing away from the limelight, but she has been very succesfull in the public portion of her roll-out. There has been an officiall first flight ceremony with lots of tour buses etc for 2002, so hopefully the wall climbers will continue the unauthorized Chegdu daily airshow coverage for 2002.
Oh and for you Sweetman fans, this airplane has been out there and whether or not they have radar or this or that, there really is little doubt that they are prototypes, and the lack of changes in 2002 indicate that they are fairly confident of their overall design. Its public debut indicates that this is a flagship, and I believe that they will make every attempt to field this aircraft ASAP, but in what quantities and with what capabilities? It is an important statement and a great PR success for the PLAAF. Cheers Brat
Well its official, the second J-20 prototype, 2002 has flown at the Chendu factory field, Dieno has some interesting comments, and other posters on our sister forum Sino Defense have noted that 2001 has been flown to another airfield. Both aircraft had been sitting at Chengdu together for a week or so. Whether you're a fan or no the J-20 is a significant accomplishment, I have an idea that 2001 will get to the real flight testing away from the limelight, but she has been very succesfull in the public portion of her roll-out. There has been an officiall first flight ceremony with lots of tour buses etc for 2002, so hopefully the wall climbers will continue the unauthorized Chegdu daily airshow coverage for 2002.
Oh and for you Sweetman fans, this airplane has been out there and whether or not they have radar or this or that, there really is little doubt that they are prototypes, and the lack of changes in 2002 indicate that they are fairly confident of their overall design. Its public debut indicates that this is a flagship, and I believe that they will make every attempt to field this aircraft ASAP, but in what quantities and with what capabilities? It is an important statement and a great PR success for the PLAAF. Cheers Brat
Just a follow on question to Air Force Brat. Your statement relative to the "overall design", were you alluding to the outside final configuration of the aircraft? Maybe I don't quite understand what you meant by that statement? IMHO, overall design means everything that is included with the aircraft. Just needs your clarification, thanks.
Air Force Brat
Member
Primarily configuration, and overall planform, if you are able to access Dr. Songs paper, it appears that they have stayed true to his thesis of the aft mounted delta, and distant coupled canards, with the twin vert stabs outboard and canted outward. There is still much to be done in regard to powerplants, and I believe that the intention was to have TVC, although those may not be absolutely necessary, now that production of the Raptor has been discontinued. In fact Dr. Song makes it very clear that the J-20 must be able to recover from post stall manuevering if the TVC were to fail. So to be clear, you are correct in that there remains much to be done with fitment of radar, flight control system, etc,etc. My point is that the basic airframe is delivering on their design objectives, and appears to fly very well, although if you check my posts on Sino D, I note there there has been no apparent supersonic or post stall flight testing. In fact if you note the F-22 and F-35, nailing down the basic airframe and adding equipment and capability later, seem to be the new norm. IMHO, Cheers As an aside the fact that we have all these pix and videos from Chengdu, speaks to how pleased they are, if things were not going well that conduit of information would have been closed long before now.
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all it means, and I have said this elsewhere, is that the lack of external change means that they are comfortable with the final external config
that has nothing to do with internal changes - anyone who thinks that the internal fitouts etc are gold knows bugger all about aircraft or platform engineering.
this is not a gold article no matter what the enthusiasts might argue. I suspect that the chinese, just like JSF have done systems development off platform on other aircraft (like catbird), to speed it up.
Air Force Brat
Member
Thank you gf, thats what I was trying to say, and the Airfield where 2001 has been taken has much tighter security, Siegecrossbow, one of the Sino D mods has stated the wall climbers are afraid to have cameras or even cell phones out. As I pointed out, the original intent was to have TVC, and those powerplants are simply not at a place developmentally where they could power the prototype. They are likely not going to power the early-production aircraft either in my humble opinion. This aircraft also has an exceptionally complex flight control system due to its configuration, but as I stated, it does seem to fly well, but its unlikely to have the post stall supermanueverability that quite frankly seems to be going "out of style" and as you noted, many of the systems are in fact being developed on other platforms.
a30challanger
New Member
Looks like if the Euro Fighter and the mig29 had a baby it would give to birth to j-20
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Not sure if anyones posted this video yet
[nomedia="http://www.youtube.com/watch?v=6JgdMxYtM48"]最新æ¼20 (J20):　Latest Combat Maneuver Tests on 2012.03.20 - YouTube[/nomedia]
There's one thing i must ask about this video, the sequence at 0:30, when the pilots moving the flaps etc, on the horizontal stabilisers there appears to be 2 independant flaps.
Is that normal for a 21st century aircraft? May seem a silly question to ask, but i can't think of any other i've seen which operates like that, and then, why do it? What aerodynamic properties would that bring to the table?
[nomedia="http://www.youtube.com/watch?v=6JgdMxYtM48"]最新æ¼20 (J20):　Latest Combat Maneuver Tests on 2012.03.20 - YouTube[/nomedia]
There's one thing i must ask about this video, the sequence at 0:30, when the pilots moving the flaps etc, on the horizontal stabilisers there appears to be 2 independant flaps.
Is that normal for a 21st century aircraft? May seem a silly question to ask, but i can't think of any other i've seen which operates like that, and then, why do it? What aerodynamic properties would that bring to the table?
Haavarla
Active Member
Rob@
This is how the modern FBW or FCS work these days.
The Su-35S and T-50 has the same function.
The rudders act as airbrake(both points inwards), and the Elevators and carnards independed movments help trim(less drag from control surfaces) and increase the roll response time.
This is how the modern FBW or FCS work these days.
The Su-35S and T-50 has the same function.
The rudders act as airbrake(both points inwards), and the Elevators and carnards independed movments help trim(less drag from control surfaces) and increase the roll response time.
Air Force Brat
Member
An outstanding observation Rob and something that lots of folks miss, those are more properly referred to as flaperons, which are inboard, the next control surface on each side outboard are elavons. Their function is the key to their name, as while they are flaps, and ailerons in the traditional sense, they also perform the pitch function of elevators. This is somewhat archaic tech as the aft mounted deltas of the Convairs, 102 and 106 had flaperons and elevons. In addition as you have noted the J-20 has distant coupled canards, which also perform the pitch funtion and in fact may be the primary pitch control in landing and takeoff. You have in fact hit on the Flight Control System, which is quite an engineering achievement in and of itself, and in fact is the key to the J-20s overall manueverability. The aft mounted delta main wing has made this neccesary in order to have full roll and pitch control and as Haavarla has noted, the all flying verts are canted outward and also aid in the pitch control. Cheers Brat
Chinese now have three stealth fighter programs. Apparently a dude named Noshir Gowadia sold US stealth secrets to China Noshir Gowadia father of Chinese stealth technology | Defence Aviation
Air Force Brat
Member
2011 ;and 2012 have flown, and now we are looking at 2013? this airplane is coming along nicely, and has some very profound engineering changes to "clean it up". I think we may be a little out of touch on DT??
https://medium.com/war-is-boring/chinas-building-stealth-fighters-faster-and-faster-665e6e41db0f
6th J-20 prototype has flown, number 2015 apparently only shows minor differences from the earlier more radically different prototype 2011 with a housing for an IR sensor, more LO orientated outlets and supposedly a new coating.
The only real difference for this prototype is slightly different tail surfaces. After all, 6 prototypes in you'd think the final design is becoming more set in stone.
The article ends saying the WS-15 engine is still in development.
6th J-20 prototype has flown, number 2015 apparently only shows minor differences from the earlier more radically different prototype 2011 with a housing for an IR sensor, more LO orientated outlets and supposedly a new coating.
The only real difference for this prototype is slightly different tail surfaces. After all, 6 prototypes in you'd think the final design is becoming more set in stone.
The article ends saying the WS-15 engine is still in development.
Air Force Brat
Member
Yes apparently the tail stings have been redesigned as you have noted, and its likely according to Dieno that they are entering the LRIP phase. The WS-15 may be some time coming yet, as the intakes of 2011 were reduced and reshaped, likely to optimize the airflows for AL-31FN that seems to be currently powering the J-20. Delft on the Sino Defense forum has noted that the J-15 and other Flankers are built in "batches" rather than the more typical "assembly line" type of production facility that many of us are more familiar with, I would imagine that Chengdu will also produce the J-20 in small batches???
So we do now have six flying prototypes, and I would imagine that flight test will move right along? President Xi has "clamped down" on alleged security leaks so we just don't see the lovely pix and videos that we did when 2001 was first rolled out and flown, very sad indeed, I was rather excited that maybe some things would change in China, I find the frosty new attitude very disappointing??