Thanks! I thought it made its first taxi tests in October and flew fisrt only about in December!
J-20 5th Gen Fighter Thread VIII
- Thread starter Blitzo
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Thanks! I thought it made its first taxi tests in October and flew fisrt only about in December!
Hard to say if they got the milestones confused.
Can someone recount/summarise the development differences in the J-20 200X series and 20XX series of prototype airframes? I've tried reading through the ancient threads but there are literally thousands of pages spanning quite a few years.
This is coming from the recent J-36 news on the 2nd prototype's flight. While not perfectly accurate, I am searching for information on J-20s development and see how it matches up to its next-gen successor ion both milestones and scope of changes.
As we know, the J-36's 2nd prototype changed its ventral inlet type, landing gear design and engine exhaust/nozzle design, but its said that these are less significant aerodynamic changes than between the J-20 200X and 20XX series, is this true? I can only see some inlet "edge" geometry changes between the earlier and later J-20 prototypes (and canopy design as well, I guess).
This is coming from the recent J-36 news on the 2nd prototype's flight. While not perfectly accurate, I am searching for information on J-20s development and see how it matches up to its next-gen successor ion both milestones and scope of changes.
As we know, the J-36's 2nd prototype changed its ventral inlet type, landing gear design and engine exhaust/nozzle design, but its said that these are less significant aerodynamic changes than between the J-20 200X and 20XX series, is this true? I can only see some inlet "edge" geometry changes between the earlier and later J-20 prototypes (and canopy design as well, I guess).
Shape of intake, tail sting, cropped canards/vertical slabs, addition of EOTS, adding internal support frame to canopy and detonation cords, changing engine from AL-31 to WS-10 and addition of jagged nozzles.
I forgot about that and also the massive flap actuators. Both were temporary measures until flight control has been improved.
I see, thanks for the summary.
I'm by no means an expert in aircraft design, but from my layperson view these listed changes seem less significant than changing inlet type and exhaust design (including the amount of observable mass removed) that the J-36 publicly seen 2nd prototype has just showed. Changing the shape of a DSI inlet (I know later production J-20s also had changes to the underlying DSI bump) should be less significant than changing the type of inlet altogether, for example. If I am wrong, please correct me on this.
The J-36 2nd prototype has shown non-trivial aerodynamic changes, including even fundamentals of its flight control system if they're switching from trench exhausts (unknown TVC type and capability) to 2D TVC. This is not something usually seen on designs nearing maturity. However, several subsystems like what seems to be (buried) EOTS are already installed 1st prototype, which suggests a more advanced developmental stage than the J-20 200X series since there's no reason to test these later subsystems if the fundamentals aren't sorted out yet.
Despite the more advanced numbering of 36011 (implying the 2nd airframe of the 2nd series) of the J-36 publicly seen 1st prototype, it seems like greater changes are being made than in the J-20's 200X series. This isn't unexpected given 6th-gen is novel for everyone worldwide, but it does suggest that a 2030s IOC is unlikely. It took some 7 years for the J-20 to go from the 200X series to IOC, so we shouldn't expect J-36 IOC until around 2032 (by this most vague of extrapolations).
Well you also have to consider that the Chinese aviation industry is significantly more mature now than it was when J-20 prototypes first surfaced. So the baseline capability has been improved which means in theory the same milestones could be reached faster. That said yes this will take a while, this is a difficult task. I'm not sure why you say a 2030s IOC is unlikely, even if you added a few more years to your 2032 date that's still mid-2030s. I think the people who said IOC by 2030 or even earlier were clearly too optimistic and/or underestimating the challenges but I think your take is also pretty obviously too pessimistic. I would be very surprised if IOC hasn't happened by 2040.
The most impactful changes for J-20 from 200X to 201X were the removal of the LERXes in front of the canards, the added camber over the inlets, and the change in the main LERX shape into a sharp rather than curved profile. These all modified the aerodynamics of the plane, probably not insignificantly. The DSI bump geometry also changed from 200X to 201x and while we don’t know for sure the added hexagonal bleed panels on the inlet sides suggest there were other added mechanisms to how the inlets operate and behave. Most significantly though when 201X came out the big shrimps said that the entire internal design of the plane was redone from scratch. We can surmise something to this effect by observing the external panels and vents on the plane, which follow mostly different arrangements from the 200X series.
These are all much more significant changes than what we’ve been able to observe on the new J-36, as best as we can tell so far with the current pictures available. IF the J-36 matches this level of changes though, it employed these changes after less than a year from first flight, while that timeline was 3* years for the J-20.
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