J-20... The New Generation Fighter II

Serbian aircraft kills during the Kosovo campaign were:
-1 F-117
-1 F-16C
-47 UAVs

The author of that comment in airsuperiority's post advances an interesting theory. But his contention that Serbia was "remarkably effective at downing NATO aircraft" is simply just not true. Being able to down two aircraft doesn't make you air defense system "remarkable", even if one of them was a stealth aircraft. UAVs aren't particularly hard to shoot down, and indeed are often meant for missions where they will probably be lost. NATO had pretty much free reign in the skies over Serbia.

siegecrossbow said:

Song Xiaojun is probably the most patriotic military commentator on CCTV. Remember the whole fiasco when Zhang Zhaozhong claimed, in early 2010, that there was no 5th gen fighter in development and the J-20 was only a 4.5 gen fighter. Poor guy must be eating his words right now.

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Song Xiaojun is probably one of the more knowledgable commentator with very details analysis skills. His comments on the PLA are often not bias to just one party, will make comparisons with other military and give his comments on improvements. I am always happy to see him on the military shows of CCTV and Pheonix TV.

Lobotomizer said:

If they have radar absorbant skin it's awesome. In the US, they have headhache with the f-22 coating. For the JSF, they have radar absorbant skin panel that will cut a lot of works for maintenance.

Composite panel are good if all the structure beneath is composite too, for tails or canard it's ok but for the fuselage, wave hit the metallic structure,wire and engine behind it so it have to absorb radar wave somewhere or reflect it in another direction like the f-117.

The skin look soo smooth on the j-20, i don't know if it's color but it look like big surface are made in one piece or have coated joint(hard for maintenance), not easy to do big panel with multiple bend and curve in metal but far more easy in composite.

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rhino123 said:

What we saw, are pics taken by enthusiats and from quite a distance away from the plane. I do not believe any of them have any massive camera with super tele lens on. Plus Chengdu's weather is not exactly tiptop and extremely clear in winter. Coupled with the fact that when the aircraft flew, light condition, coupled with angles of the shoot would actually hide many details of the aircraft.

Unless anyone of us could actually get to stand very near the aircraft, we would know what the aircraft actually looks like up close and all the fine details.

Of course I am not dismissing the idea that the aircraft could be make of large single piece composite too... either way, it was too early to tell. This might only be a concept whereby the Chinese explored the actual feasibility of the technology and improved on its design for later introduction to the production J-20.

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I remember watching a documentary on the JSF competition, and in the segment about the X-32, they covered how the main wing was a large single piece of some sort of composite. They covered at length the difficulties in manufacturing panel, since in the case of the X-32, it was a major load bearing component aerodynamically, and any structural flaws would be catastrophic.

This was because, as everyone here knows, the X-32 was basically built around that big, thick delta wing. The particular problem the documentary covered was that the Boeing team had to avoid pockets forming inside the sandwiched layers when they "baked" the wing.

If the J-20 is actually covered with big composite panels, that would be quite a feat, as the even Boeing team was never really given a chance to perfect their method for reliably manufacturing flawless composite pieces of that size and for that purpose.

The F-117 would have been almost no help for developing the J-20.

"1. China obtained only parts of the plane (if any) not a complete model.
2. The plane was heavily damaged.
3. Despite its name, the F-117 was a bomber, not a fighter. The J-20 is a fighter and designed for a different role entirely.
4. The F-117 was unable to break the sound barrier, lacked supercruise, lacked advanced AESA radar, lacked thrust vectoring, and air to air combat capabilities...all of which appear in the J-20.
5. The F-117 used "faceted" stealth shaping to evade radar, the J-20 uses a modern "continuous curvature" shaping."

from kyanges :''If the J-20 is actually covered with big composite panels, that would be quite a feat, as the even Boeing team was never really given a chance to perfect their method for reliably manufacturing flawless composite pieces of that size and for that purpose.''

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the x32 was designed 10 yrs ago... and now we see huge composite panel on airliner like 787, a350 and a380, it's certain that they don't have to resist the stress of a fighter jet but as to be almost a bulletproof technology now if FAA certify these aircraft... Some China company like Chengdu are supplier of composite components on these aircraft so why not...

example of components:

''BEIJING, June 02, 2005 -- Boeing today announced agreements with Chinese suppliers worth an estimated US$600 million for production of commercial airplane parts and components.

The 787 Dreamliner highlighted the announcement. Chengdu Aircraft Industrial (Group) Co. Ltd., will work on the 787 composite rudder, Hafei Aviation Industry Co., will build the 787 wing-to-body fairing panels and Shenyang Aircraft Corporation will provide the 787 vertical fin leading edge assembly.

Other contracts or agreements include BHA Aero Composite Parts Co. Ltd. building the interior panels for the 777 control cabin, as well as the wing-to-body fairing panels and tail cone for the Next-Generation 737. CAC also will provide the 737 forward entry door and the 737 automatic over-wing exit door.''

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The only salvageable parts of the F 117 would be the RAM coating as the electronics and airframe were destroyed. Even if Chinese agents had acquired RAM samples the RAM itself has several issues which would make it incompatible on the J-20

The F 117 used a heavy ferric based RAM that limited it to subsonic speeds and required long airstrips for takeoff.

The video of the flight of the J-20 shows that it takes off in around 300 meters without afterburner.

either


A. China has super advanced engines that can lift an estimated 70,000 pound bird in short distances without afterburner.
or
B. China had to invent dramatically lighter RAM to coat the J-20 with

either way Chinese engineers had to invent either new RAM or engine technology for the J-20.

Another problem with this type of painted on RAM is that it is easily damaged even by rain. This problem is also seen on the f 22. On many photos we see people on the J-20 to replace braking chutes. This would severely damage the J-20's RAM if it was based on the F 117 type of RAM or even if China had F-22 style RAM. The only stealth fighter that has solved this problem would be the F-35 with its integrated RAM.

A. China has invented integrated RAM like the F-35
or
B. U.S has operational F-35s that China or another country has shot down allowing them study that as well.

Guess which ones more likely.

here are my sources

( f 117 RAM )

( J-20 first flight)

( F-35 RAM )

( most non-biased article I could find)

Picture of F-117 wreckage in Serbia

Do you think this F-117 debris held important stealth technology secrets? Or does it look like a pile of junk to you too?



"U.S. Doubts ’99 Jet Debris Gave China Stealth Edge


An American F-117 aircraft was shot down over Serbia in 1999.
(Photo credit: Vladimir Dimitrijevic Tanjug/Associated Press)"

Re: Picture of F-117 wreckage in Serbia

Martian said:

Do you think this F-117 debris held important stealth technology secrets? Or does it look like a pile of junk to you too?

Please, Log in or Register to view URLs content!

"U.S. Doubts ’99 Jet Debris Gave China Stealth Edge

An American F-117 aircraft was shot down over Serbia in 1999.
(Photo credit: Vladimir Dimitrijevic Tanjug/Associated Press)"

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It is a pile of junk, though F-117's design limitation spawned from the limited computer power of the CAD design of its time and its mission profile. It is unknown, however, that how much of the RAM coating survived the heat and physical shock without significant chemical change that'd render it worthless to research and re-engineering.

Not to mention how did such samples survived the 5 JDAMs that the USAF dropped onto Chinese embassy...

Though I inclined to believe that J-20 would be using an improved formula of the RAM material to make it economical and serviceable.

The engine skeptics will have to eat their words soon enough. Another news article by China's aviation news paper chronicling the struggle to create a reliable, first class engine. This news story is interesting since it is about a female engine designer. She was responsible for system design of the Taihang Engine (unknown variant but said to be "newest" in the article), which has been approved.

one factor why J-20 was slightly bigger may be the engine, the russian and China inability produce compact high T:W ratio ,high thrust jet engine.
J-10 has to undergoes redesign ,since AL-31F for example was 23% heavier than PW F-101 engine .result fuselage is longer than lavi