J-20... The New Generation Fighter II

[vesicles]

I had a similar question for the experts. Do all aircraft require afterburner to take off? What is the significance of the J-20 taking off without afterburner?

I don't think all aircrafts need afterburners to take off. Most jets, other than fighters, don't even have afterburners (I think).

 

[duskylim]

It is with great satisfaction that I finally saw the pictures of the J-20 in flight. Especially those with high resolution displaying the aircraft's full lower plan-form.

Without any doubt, we can clearly see the plane's CAC lineage.

From the canard-delta layout, to the strakes (chines?) and the DSI-bump, all these bear the hallmarks of Chengdu's design.

It was a surprise for me to hear the rumor that the engines were indigenous WS-10G's.

Equally surprising was how closely the forward part of the aircraft resembled that of the F-22, including the one-piece canopy, the rhomboid nose and the trapezoidal intakes.

Compared to the T-50 PAKFA prototype, which clearly resembles a member Su-27/30/3x family modified (one might say 'squished') into a stealth aircraft, Chengdu's design does not resemble any of it's previous aircraft, and if I'm not mistaken, is CAC's 1st twin-engined fighter.

The plan-form showed us just how sleek this fighter is, with the length vs span (fineness ratio) larger than any of the competing designs - she was designed for speed.

It also revealed the forward swept intakes and size and and surprising length of the DSI bump - I had no idea they projected that far forwards of the intake's lip.

I was expecting a much shorter, stubbier bump, - given the previous DSI's on the JF-17 and J-10B.

I look forward with anticipation to the next series of test flights - hopefully with the landing gear up this time.

 

[challenge]

challenge, you need to stop posting stuff from wforum on here. I mean, haven't you learned your lesson yet? Every time you post something you found on there here you get laughed at.

Anyhow, going back to the J-20, what's everyone's thought on the bomb bays? Do you think they're actually doors or are they simply panels attached together and holding place for doors. It seems like the fit is a bit tight for actual doors, no? If they're indeed doors then that's an almost beyond belief manufacturing job.

you only wanted the good news?kill the messenger that bring the bad news?is that what you want?

 

[rhino123]

Re: J-20... The New Generation Fighter

Hi Everyone,

I am new here. I join this forum because there are many good professional analysis here.
Here are a few things puzzling me. I watched the takeoff video over and over again. I noticed following facts:
1. It takes less than 15 sec to take off. (speed 0 to wheel leave the ground)
2. The takeoff speed seems low.
3. The takeoff distance seems quite short. Some Chinese claims that it's only about 200m. I don't believe that. Let me take 300m for the time being.

4. There is absolutely no flame been seen at the nozzle. Not even a little redness.

Let's discuss 1-3 first.
I pull out my calculator, if I take 300m as the takeoff distance, I got 144km/h take off speed. There is no way for that beast to take off at this speed!
So I assume the take off speed was 230km/h, I got 480m of takeoff distance, which seems much longer than what we saw.
The truth may be between, but no matter how you slice it, the takeoff is damn impressive!
Anyone figure out or knows the real takeoff speed and distance?

Let discuss point 4.
When I first saw the picture of J-20, I thought the designer simply give up on the IR stealth. Now I am not sure. Any comments?

All points 1 to 3 are given from eye witnesses, many of which are not professional or are they too well verse in military aircraft, thus they couldn't really be taken into account. To settle my curiosity, could you give me a formula in which you receive the 144km/h figure?

And there is no way we would know how fast the plane required before it reach the point of taking off, because obviously it is not travelling at constant speed.

(PS. Can you guys ignored Challenge post in future? He posts nothing but rubbish and would never admit it when others pointed that out.)

 

[siegecrossbow]

you only wanted the good news?kill the messenger that bring the bad news?is that what you want?

We are perfectly fine with bad news if it is competently analyzed and more importantly, not a proven hoax.

 

[dingyibvs]

I got a few questions abou the airframe of the J-20:

1) how many hardpints could J-20 have? from a few photos showing he bottom of the plane, it seems that J-20's internal weapons bay is not too big (the area between the landing gears)...

2) from comparing J-20 with F-22, J-20 has the canards as well as movable tails while F-22 has no canard and fixed tails. It seems that J-20 is the only plane out of the 3 stealth fighters with canards and with the smallest wings. So how would all these affect manueverability either positively or negatively?

3) I seem to remember seeing photos of J-20 with a tint of green in its cockpit. So what is that? Is that the holographic (spelling?) HUD?

4) the landing gears seem to be much bulkier than other heavy fighters like Su-27, especially looking from the front. Is this because the stealth plane is much heavier than convetional fighters?

5) Someone asked earlier about the possibility of only changing the nozzle of the engine instead of changing the whole engine. And no one has commented on that yet. So is it possible for them to haul the plane to a place change the nozzle of the plane? So there is actually only one plane with the same engine, only different nozzle? I personally don't think this idea is a little far fetched, but I don't know.

Thanks

Don't know about the first 4, but for 5, it's possible, but it wouldn't be a very effective allocation of resources to design new nozzles for an engine that you don't plan to use. If you've got money and time to burn, then that's fine, but I don't think China can afford the time or money.

Hi Everyone,

I am new here. I join this forum because there are many good professional analysis here.
Here are a few things puzzling me. I watched the takeoff video over and over again. I noticed following facts:
1. It takes less than 15 sec to take off. (speed 0 to wheel leave the ground)
2. The takeoff speed seems low.
3. The takeoff distance seems quite short. Some Chinese claims that it's only about 200m. I don't believe that. Let me take 300m for the time being.

4. There is absolutely no flame been seen at the nozzle. Not even a little redness.

Let's discuss 1-3 first.
I pull out my calculator, if I take 300m as the takeoff distance, I got 144km/h take off speed. There is no way for that beast to take off at this speed!
So I assume the take off speed was 230km/h, I got 480m of takeoff distance, which seems much longer than what we saw.
The truth may be between, but no matter how you slice it, the takeoff is damn impressive!
Anyone figure out or knows the real takeoff speed and distance?

Let discuss point 4.
When I first saw the picture of J-20, I thought the designer simply give up on the IR stealth. Now I am not sure. Any comments?

I don't think your math is right. Just knowing final velocity doesn't give you take off distance, you'll need to know the acceleration as well. I don't think the takeoff showed anything regarding IR stealth, as taking off without afterburners is pretty common.

you only wanted the good news?kill the messenger that bring the bad news?is that what you want?

If by bad news you mean bad quality news then yes, I'd like to kill the messenger who consistently brings them to me

 

[Blitzo]

Lol darn it. I go away on holiday for three days and then this thing flies... Sigh.

Congrats to CAC, PLAAF anc China, and anyone else who wants to feel congragulated.
J-20 ftw (two days late)

 

[kyanges]

Lol darn it. I go away on holiday for three days and then this thing flies... Sigh.

Congrats to CAC, PLAAF anc China, and anyone else who wants to feel congragulated.
J-20 ftw (two days late)

Thanks for the congratulations. .

 

[Quickie]

I think it is pretty clear that there are two J-20 prototypes out there, each one using different engines so the PLAAF can see which performs better. For example

and a couple of more showing the same:

Could those engines in fact be the AL-31F also used on the J-11 and the WS-10A used on the J-11B?

It seems to me now there really are 2 prototypes. See the white line (in parallel with the front edge of the tail/rudder) and the star? You'll notise that the distance between the line and the nearest point of the star is different for the 2 prototypes pictured with different nozzles. It's easier to see it if you compare that to the distance between the front edge of the rudder and the line. Have to check out on this with the number 2001 as well. That said, I'm assuming one of the image is not flipped to its mirror image.

 

[vesicles]

It seems to me now there really are 2 prototypes. See the white line (in parallel with the front edge of the tail/rudder) and the star? You'll notise that the distance between the line and the nearest point of the star is different for the 2 prototypes pictured with different nozzles. It's easier to see it if you compare that to the distance between the front edge of the rudder and the line. Have to check out on this with the number 2001 as well. That said, I'm assuming one of the image is not flipped to its mirror image.

If you are talking about the first two photos, the angles of the tails in those photos are different. The tail in the first photos is more straight while the tail in the second pic is tilted. So the difference in distance between the line and star may be an optical illusion.