Chinese J-XX/14/20 p.2

Prev. part here: http://forum.keypublishing.co.uk/sho...d.php?t=105427

Now here is a contine thread concerning that J-20.
At start, did anybody get movable LERX information on J-XX/20?

Need to watch it take off video! must see how fast is its take off climb rate.

haven't been on for a while.

well done to china for producing an interesting and exciting new design.

This could be a real kick up the backside for western governments and it even looks good too!

I think it is an achievement by Chinese. Congratulations to them.
Few points:
# Its unveiling/pictures coincides with PAKFA/FGFA deal. Could be just a coincidence.
# PLA is not stopping people from taking pictures. People always blame China that it withholds sensitive information, Look at Wikileaks saga, USA is not any different.
# Its not a copy of any fighter, people need to leave their biases aside.
# It will have a decent range, its fat, will carry large amount of internal fuel. If it is as big as it looks.
# Most realistically its currently powered by AL-31 engine variant, will need IMHO minimum of 160kN+ thrust engine, considering its lumpy frontal cross-section shape.

That's for sure the chinese must be planning a engine with a lot of thurst, if what is said about the size is true.

:cool:

http://paralay.com/TEMP/J20.png

In my opinion an increadably simple landing gear housing doors for a fifth gen. aircraft. Its getting clear how they created the bird in such a short time! Can be dangerous in an emergency situation or full load but sure they already knows it.

Attachment 191292

@ Paralay: Nice. I'd put it more towards 24x15m.


Question: How much "Y" do we see in this design? Remembering the changes the -22 went through on the way from the YF- to the F-. Or the presumed changes for PAKFA on the way to serial model. To me this thing here is very much on the "Y" side of things, maybe almost an "X". I simply don't see that degree of fine tuning of the shape I'd expect from even a prototype. It feels like welding a Maserati nose onto a Land Rover.

Quote:

---

Originally Posted by Corrosion

# It will have a decent range, its fat, will carry large amount of internal fuel. If it is as big as it looks.
# Most realistically its currently powered by AL-31 engine variant, will need IMHO minimum of 160kN+ thrust engine, considering its lumpy frontal cross-section shape.

---

I think it's shear size has surprised quite a few, I was expecting something more 'sleeker', with a smaller frontal nose section. Moreover, the central fuselage section reminds me of the J-8 Finback, long, flat surface to house large engines and fuel.

Quote:

---

Originally Posted by medal64

In my opinion an increadably simple landing gear housing doors for a fifth gen. aircraft. Its getting clear how they created the bird in such a short time! Can be dangerous in an emergency situation or full load but sure they already knows it.

Attachment 191292

---

1. Is this possibly an integrated maintenance door? May be this would explain the size...
2. Judging for the photo this door can be shut once the main landing gears are fully extended. It might be left open only for taxi test purposes...
3. OR...Would it help yaw stabilization at approach?

Quote:

---

Originally Posted by starikki

1. Is this possibly an integrated maintenance door? May be this would explain the size...
2. Judging for the photo this door can be shut once the main landing gears are fully extended. It might be left open only for taxi test purposes...
3. OR...Would it help yaw stabilization at approach?

---

The second option can be a different approach. But against the everything its a simple mechanism when compare with others.

Quote:

---

Originally Posted by Rookh

I think it's shear size has surprised quite a few, I was expecting something more 'sleeker', with a smaller frontal nose section.

---

I think they chose a safer and the most popular path - intakes at the side F-22/F-35 style, and narrowly situated engines, result - very bulky airframe. Raptor's problem is short legs, so they probably tried to find/create some space for fuel and made J-20 longer.

I don't see such long and heavy aircraft to be in the same class as F-22 and T-50 in terms of maneuverability. Also it will need monster engines to SC, but even then DSI intakes will put its limits.

YF-23 and T-50 designers were more original, they were able to create internal bays without bloating the whole design.

Thanks, paralay. By your scale you suggest a roughly 75 foot long aircraft, which is within a foot of what I was guessing by the size comparison with the people standing around it.

I've been trying to fit the notion of the AL-31F into this picture but the scale of the actual engine doesn't seem to fit. These engines seem slightly larger than what I see out there called the AL-31F. The size of the exhaust nozzles fits in between that and the D30. Maybe it's the WS-10A. Maybe it's the WS-15. I just don't trust the notion that it's really the 117S.

Quote:

---

Originally Posted by Distiller

Question: How much "Y" do we see in this design? Remembering the changes the -22 went through on the way from the YF- to the F-. Or the presumed changes for PAKFA on the way to serial model. To me this thing here is very much on the "Y" side of things, maybe almost an "X". I simply don't see that degree of fine tuning of the shape I'd expect from even a prototype. It feels like welding a Maserati nose onto a Land Rover.

---

Much like the T-50, I'd definitely also expect some changes before it enters production - very much an "YF-" rather than "F-". The forward fuselage is not only weird from an aesthetical point of view, it looks like it would significantly restrict visibility over the nose for the pilot, compared to the F-22 and T-50, so that might well change. Other examples are the ventral strakes and engine nozzles, plus any details that may need improvement but which are not obvious on available imagery.

http://i737.photobucket.com/albums/xx11/VVbear/qwqw.jpg
I don't think J20's egines is D30, may be AL-31F or AL-31FN now

Quote:

---

Originally Posted by Trident

Much like the T-50, I'd definitely also expect some changes before it enters production - very much an "YF-" rather than "F-". The forward fuselage is not only weird from an aesthetical point of view, it looks like it would significantly restrict visibility over the nose for the pilot, compared to the F-22 and T-50, so that might well change. Other examples are the ventral strakes and engine nozzles, plus any details that may need improvement but which are not obvious on available imagery.

---

Hmmm, I would think with that bubble canopy visibility would be fairly superb.

Quote:

---

Originally Posted by Epsilon

I think they chose a safer and the most popular path - intakes at the side F-22/F-35 style, and narrowly situated engines, result - very bulky airframe. Raptor's problem is short legs, so they probably tried to find/create some space for fuel and made J-20 longer.

I don't see such long and heavy aircraft to be in the same class as F-22 and T-50 in terms of maneuverability. Also it will need monster engines to SC, but even then DSI intakes will put its limits.

YF-23 and T-50 designers were more original, they were able to create internal bays without bloating the whole design.

---

May be The reason some think it is "bloating the whole design" because they choose to use an upper wing mounted on top of fuselage. by contrast F-22/-35/T-50 all have mid mounted wing. also. notice the landing gear strut attachment location. should give some indication where they have their main load bearing structure laid out. This thing's structure reminds of X-32 actually...

also, remember, doesn't matter how much lift one's fighter's body can generate. the lift-over-drag is still better on a pure wing. :-).
with its Canard-LEX-Delta combo this thing may have deceptively smaller on paper -wing loading.

Quote:

---

Originally Posted by starikki

1. Is this possibly an integrated maintenance door? May be this would explain the size...
2. Judging for the photo this door can be shut once the main landing gears are fully extended. It might be left open only for taxi test purposes...
3. OR...Would it help yaw stabilization at approach?

---

1) yes.
2) yes.
3) no. more like flutter.

Quote:

---

Originally Posted by Epsilon

...

---

see my reply in blue


I think they chose a safer and the most popular path - intakes at the side F-22/F-35 style, and narrowly situated engines, result - very bulky airframe. Raptor's problem is short legs, so they probably tried to find/create some space for fuel and made J-20 longer.

I think they were juggling the choices between lifting body type aka T-50 and the canard/lex/delta combo they were trying to do. Mr. Song's original paper talked about this problem. basically the choice is that a flattened blended wing-fuselage can not realistically mount the canard up and above the main wing.
One thing one does not do often is to get inside of the chief aerodynamicist's head on a particular project. what his reasonings are initially and see the final product. this might be an exception.

I don't see such long and heavy aircraft to be in the same class as F-22 and T-50 in terms of maneuverability. Also it will need monster engines to SC, but even then DSI intakes will put its limits.

I think you may be surprised. you still hasn't see its actual weight class. human eyes are deceptive.

YF-23 and T-50 designers were more original, they were able to create internal bays without bloating the whole design.

if I remember correctly (or not), original YF-23 had problems fitting in larger bays that AF wanted. I do not know whether they will be successful in that regard if they choose to kept the development going.

Interesting, some of the newest pics make the aircraft look a bit like the Swedish Draken but with canards.

-----JT-----

Quote:

---

Originally Posted by MadRat

Thanks, paralay. By your scale you suggest a roughly 75 foot long aircraft, which is within a foot of what I was guessing by the size comparison with the people standing around it.

I've been trying to fit the notion of the AL-31F into this picture but the scale of the actual engine doesn't seem to fit. These engines seem slightly larger than what I see out there called the AL-31F. The size of the exhaust nozzles fits in between that and the D30. Maybe it's the WS-10A. Maybe it's the WS-15. I just don't trust the notion that it's really the 117S.

---

:rolleyes:

Quote:

---

Originally Posted by paralay

:rolleyes:

---

good drawing. but I think the tail is a little off. it should be angled instead of straight.

http://www.aviationweek.com/aw/gener...20Tests&next=0

China's J-20 Stealth Fighter In Taxi Tests

Dec 30, 2010




By Bill Sweetman
Washington


The J-20 is a single-seat, twin-engine aircraft, bigger and heavier than the Sukhoi T-50 and the F-22. Comparison with ground-service vehicles points to an overall length of 75 ft. and a wingspan of 45 ft. or more, which would suggest a takeoff weight in the 75,000-80,000-lb. class with no external load. That in turn implies a generous internal fuel capacity. The overall length is close to that of the 1960s General Dynamics F-111, which carries 34,000 lb. of fuel.

All the more credence to my assertion its optimized for transonic and low mach speeds. Unless they have some D-30 class engine on it, this is no high mach cruiser like the T-50 and F-22.

Quote:

---

Originally Posted by KYL

The J-20 is a single-seat, twin-engine aircraft, bigger and heavier than the Sukhoi T-50 and the F-22. Comparison with ground-service vehicles points to an overall length of 75 ft. and a wingspan of 45 ft. or more, which would suggest a takeoff weight in the 75,000-80,000-lb. class with no external load. That in turn implies a generous internal fuel capacity. The overall length is close to that of the 1960s General Dynamics F-111, which carries 34,000 lb. of fuel.

---

This, combined with the front-aspect-emphasized RCS reduction, makes me wonder if this is NOT a "stealth fighter", but rather a "stand-off missile platform" with good penetration-strike capabilities... something like a newer, more stealthy Su-34 or F-111*.

We should be wary of trying to force-fit this aircraft into a pre-conception based on what the US and Russia have/are building... this is designed for Chinese needs.

High among these needs are the ability to penetrate the highly-defended airspace of Taiwan and destroy its command/communication/network centers and its missile sites... and to attack USN carrier groups coming to the aid of Taiwan.





* in its original F-111A/F-111B dual-version concept, but modern electronics allow the roles to be combined into one version.

Quote:

---

Originally Posted by Bager1968

This, combined with the front-aspect-emphasized RCS reduction, makes me wonder if this is NOT a "stealth fighter", but rather a "stand-off missile platform" with good penetration-strike capabilities... something like a newer, more stealthy Su-34 or F-111*.

We should be wary of trying to force-fit this aircraft into a pre-conception based on what the US and Russia have/are building... this is designed for Chinese needs.

High among these needs are the ability to penetrate the highly-defended airspace of Taiwan and destroy its command/communication/network centers and its missile sites... and to attack USN carrier groups coming to the aid of Taiwan.





* in its original F-111A/F-111B dual-version concept, but modern electronics allow the roles to be combined into one version.

---

Why would they need to penetrate the airspace of Taiwan to destroy their communication networks...a missile barrage would do it much better than any fighter can.

Another thing to consider is suitable air to air missiles for the aircraft whilst the PiLi-12 BVR missile is probably suitable for internal carriage the standard WVR missile fielded by China the PiLi-8 is hardly suitable with its huge fins:

http://www.sinodefence.com/airforce/...ges/pl8_01.jpg

The PiLi-9 is probably more suitable with its smaller fins but its an export weapon with inferior performance to the PiLi-8. I highly doubt they would integrate the Russian R-73 so that leads me to the conclusion that they have something new in the pipeline.

Quote:

---

Originally Posted by i.e.

s

if I remember correctly (or not), original YF-23 had problems fitting in larger bays that AF wanted. I do not know whether they will be successful in that regard if they choose to kept the development going.

---

The YF-23 had a far larger main bay than YF-22 (and F-22). The only problem was the sidewinder bay which is part of ther reason the F-23 had a longer fuselage.

Quote:

---

Originally Posted by Fedaykin

Another thing to consider is suitable air to air missiles for the aircraft whilst the PiLi-12 BVR missile is probably suitable for internal carriage the standard WVR missile fielded by China the PiLi-8 is hardly suitable with its huge fins:

http://www.sinodefence.com/airforce/...ges/pl8_01.jpg

The PiLi-9 is probably more suitable with its smaller fins but its an export weapon with inferior performance to the PiLi-8. I highly doubt they would integrate the Russian R-73 so that leads me to the conclusion that they have something new in the pipeline.

---

Ahem...

PL-10... test round fired 2 years ago. PL-21 test round supposedly fired (ground launch) March 2010.

I completely agree on the view that the J-20 has a different overall role compared to the F-22. The J-20 more likely can be described as a "air-to-ground" dominance fighter for the pacific region. Coupled with small, internally fitting anti ship missiles, it could be a formidable opponent for any navy operating in the region, and a very real threat to the american carrier forces operating inside the 2nd island chain! It can be thus viewed as a successor of the JH-7A, while still beeing able to hold its own against 5th gen fighters (or avoid them!) and shoot down Gen 4 or 4.5 fighters on its way the ground targets!