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Chengdu J-10 Multirole Fighter Air Craft News & Discussions

i'm trying to convince endians from years.

Composites add quality, finish, reduce joints and in circumstances can reduce weight and increase production rate (if used extensively)

If its their aircraft... composites enable visual stealth.. active cancellation.. and have anti-gravity properties.
If its a Pakistani or Chinese aircraft.. composites are expensive.. fragile.. and add nothing to the airframe.
PDF's laws of relative perception number 3345.
 
Composites have nothing to do with RCS.

Looks like they do - I had to look into this for my own education but I will share so we are all enlightened:

Eurofighter Technology and Performance : Structure
Eurofighter benefits from advances over the past twenty years in the fields of metallurgy, polymer science and composites. Over 80% of the airframe is comprised of modern materials. This brings advantages not only in terms of the strength to weight ratio but also has implications for stealth.

https://netfiles.uiuc.edu/mragheb/w...Systems/Radar Signatures of Wind Turbines.pdf
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http://ftp.rta.nato.int/public/PubFullText/RTO/MP/RTO-MP-069(II)/MP-069(II)-(SM1)-11.pdf
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and US military innovation since the Cold War: creation without destruction
By Harvey M. Sapolsky, Benjamin H. Friedman, Brendan Rittenhouse Green
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As far as how much composites effect the RCS of a fighter the answer is a little bit but “not too much”….

“The fact that stealth aircrafts are made from composites has already taken a deep hold in aviation folklore. After all , Such, At least is the popular theory. What may prove surprising is that the use of composites is not one of the most significant RCS reduction measures.”



“The role played by composites in reducing RCS is a more subtle one”


Source : (“Stealth war planes” by Doug Richardson)
Doug Richardson trained as an electronic engineer in the aerospace industry. He has been the defense editor of the aviation journal “Flight international”, Editor of German journal “Military technology” , Editor of “defense material” and technical editor of “Armanda international”. Currently he is the editor of “Jane's Missiles & Rockets “.

Stealth Warplanes - Doug Richardson - Google Books
 
This is taking us off topic but thought a bit clarification could be in order (objective better educating myself).

In my opinion better composite material would reduce the Radar signature of J-10 but would not reduce its RCS.

As RCS =Radar Cross-section, it deals with the shape and dimensions of a surface and the angles regardless of what the surface is made up of.

Radar signature is a totally different thing. Based on dimensions, angles between adjoining surfaces + the material of the surface determine the resulting radar signature of an object.

For example, if you have a spherical object, no matter what that sphere is made up of, the dimensions as in radius and diameter of that sphere would remain the same, as these are mere measurements. You take a measuring tape/scale and measure it, the results would be the same regardless of the sphere being made of wood or glass.

Now if you put same shaped spherical objects (same measurements) under a beam of light, one made of wood and the other of glass, the glass sphere would reflect more light than one made of wood.

Similar principle works when, radar beams strike an object and are reflected back. If the object is made up of more radar reflective material the higher signature you get back.
Now if an object with bad dimensions (angles between adjoining surfaces prone to more radar beams reflecting back to radar) and bigger size is made up of a more reflective material, then the Radar Signature would be even bigger than one made of less reflective surface.

Eurofighter benefits from advances over the past twenty years in the fields of metallurgy, polymer science and composites. Over 80% of the airframe is comprised of modern materials. This brings advantages not only in terms of the strength to weight ratio but also has implications for stealth.
What this translates into is Based on dimensions, angles between adjoining surfaces + the material of the surface determine the resulting radar signature of an object.
The Idea here is to reduce Radar signature, be it with reduction in RCS or less radar reflective materials or combination of both.

Don’t know if the following statements have been paraphrased by the posters above, or put as they appear in the original script.

“The fact that stealth aircrafts are made from composites has already taken a deep hold in aviation folklore. After all , Such, At least is the popular theory. What may prove surprising is that the use of composites is not one of the most significant RCS reduction measures.”


“The role played by composites in reducing RCS is a more subtle one”
 
Looks like they do

Yes they do..
but saying composites alone does not.
Whether the composites are shaped to diffract em waves? etc
the word composite by its own covers a while range of materials that may have nothing to do with RCS.
for eg.. Many if not all of Rutan's designs use composites that have more to do with weight saving than RCS.
 
Inshallah once we get the fc-20's where do you guys think they will be stationed? close to indian border perhaps as it will be a front line fighter ?
 
Inshallah once we get the fc-20's where do you guys think they will be stationed? close to indian border perhaps as it will be a front line fighter ?

Hi,

Front line fighters close to the border are dead meat---that is why when the iaf based their su30 sqdrn's in jammu kasmir---it was a matter of some relief---.
 
Inshallah once we get the fc-20's where do you guys think they will be stationed? close to indian border perhaps as it will be a front line fighter ?

I think PAF Base Mianwali is an excellent place. (Not too close and not too far!)

img-3.gif


Right now this place does not station any good aircrafts

Here is the list:
K-8P
F-7P, FT-7P
F-7P, FT-7P
Alouette III
 
I think PAF Base Mianwali is an excellent place. (Not too close and not too far!)

img-3.gif


Right now this place does not station any good aircrafts

Here is the list:
K-8P
F-7P, FT-7P
F-7P, FT-7P
Alouette III

Yea it will be interesting to see where they will be placed anyhow .. first we have to get them ;)
 
Looks like they do - I had to look into this for my own education but I will share so we are all enlightened:

Eurofighter Technology and Performance : Structure
When the word 'composite' is used in discussing RCS control measures, it is safe to assume that the 'composite' in question have been specifically formulated for RCS control measures.

The F-22 has far less 'composite' than popularly believed...

F-22 Materials and Processes
The overall percentage of composites in the F-22 (approximately 25%) is historically high, though not unprecedented. However, the extensive application of Resin Transfer Molding (RTM) technology and high temperature bismaleimide (BMI) composite materials directly resulted in the high weight/performance efficiency the Raptor demonstrates.

Technically speaking, concrete and plywood are composites (gross), stainless steel is a composite (molecular), and water is a composite (atomic). Most of the things in this world, if not the universe, are composites.

My advice is that while it is not technically wrong to casually use the word 'composite' in these discussions, one should take caution and point out the proper context of 'composite' when appropriate. If the subject under discussion is about weight saving measures, then point out that context, if the subject is about RCS controls, then point out the composite is ferrite particles embedded and is applied on the outer surfaces of the body.
 
Composites have nothing to do with RCS.

that's not true. RCS isn't judged by just composites, that's a fact, but composites having nothing to
do with RCS is not correct.

the amount of composite material used in the airframe does have a lot to with RCS.
an airframe that has extensive composites will have a lesser RCS than that which has an all-metal airframe
or which uses metals more than composites, because composites reflect lesser radar waves than a
metal airframe in its place, so use of these DOES have something to do with RCS, but a lot more matters anyway
 
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