F-22;F-35 stealthier than B-2.

Hmm, I smell a rat! Something tells me they are lying!

Stealth Technology is bases on physics! RCS is a function of reflective angles. If you look at the B-2, it's very flat, which helps the radar flow around it. The F-22 and F-35 on the other hand have many surfaces that could intersect with Radar.

These are the Same People that have been Lieing about Groom Lake since it was built in the 1950's! Do you really want to believe them now?

Side Note: The B-2 and the ATF (F-22) were concieved around the same time.

Tim

Does radar flow? Surely it just bounces? The trick being to 'bounce' it away from rather than towards the scanner dish. Not that I'm disagreeing with you and I think how stealthy an aircraft is depends entirely upon where it is being scanned from, for instance I cannot believe an F-22 is stealthier from the side than a B-2 but I can easily believe it is stealthier from above or below.

Originally posted by waynos
Does radar flow? Surely it just bounces? The trick being to 'bounce' it away from rather than towards the scanner dish. Not that I'm disagreeing with you and I think how stealthy an aircraft is depends entirely upon where it is being scanned from, for instance I cannot believe an F-22 is stealthier from the side than a B-2 but I can easily believe it is stealthier from above or below.

I think (well, its more a vague notion of a guess really ) that it bounces off surfaces, flows along surfaces and scatters off their edges. Someone here is bound to know a helluva lot more about it than me, and can correct me.

edit: Good anology: Look at light reflecting off a table, you can see the table, but the edges (if they are sharp), tend to be lit up just a little more, thats the bounce+flow/scatter effect (I think).

[edit on 3-1-2006 by kilcoo316]

Originally posted by waynos
Does radar flow? Surely it just bounces? The trick being to 'bounce' it away from rather than towards the scanner dish. Not that I'm disagreeing with you and I think how stealthy an aircraft is depends entirely upon where it is being scanned from, for instance I cannot believe an F-22 is stealthier from the side than a B-2 but I can easily believe it is stealthier from above or below.

Radar is made of electromagnetic waves! Yes, electromagnetic waves do flow. They can even fallow the contor of an object is the shape is smooth enough. That is why the B-2 uses a highly blended and curved shape. Under the right conditions, Radar waves will fallow the contor of an aircraft until the meet a gap. that is why the B-2 dosen't have any gaps or seems in its skin.

Tim

Awesome thread guys some very interesting ideas being tossed around hear. I think you maybe on to something ghost and if that was the case that radar could flow maybe wings. My question is control surfaces. you stated that the B-2 has no gaps or seems in its skin. You still get gaps etc from the control surfaces and other moveable surfaces on the plane.

It kind of "flows".

Don't forget eletromagnetic waves are the same as light, and follow the same rules. The waves will refract and spread, however, they cannot turn sharp corners (See the basic physics experiment you would do with light through a pin-hole). So smooth gentle curves will keep the radar "attached" (for want of a better word) to the surface, so instead of multiple wave scattering sharp edges only one or two angles will be sharp enough to scatter the waves.

[Scatter is bad for radar signature BTW]

[edit on 3-1-2006 by kilcoo316]

Originally posted by Canada_EH
You still get gaps etc from the control surfaces and other moveable surfaces on the plane.

Yup, but the gaps are all aligned (as with the serrated edges) so as to scatter all in the one direction if possible.


The control surfaces are a must, there simply is no way of avoiding that - but I guess alot of work has gone into minimising the effect they would have on the RCS (but undoubtedly a large deflection will spike the radar signature).

Right I see, I like the light on a table analogy, very good Thanks for all that then.

Incidentally, there was a programme designed to get rid of control surface gaps back in the 1980's called the mission adaptive wing I think, this was a long time ago and I'm trying to rememebr here but I think a MAW flew on an F-111 testbed where the wing surface was continuous and mechanically warped along the leading and trailing edges instead of having ailerons flaps and LEMD's


edit, here it is from the NASA online Gallery



[edit on 3-1-2006 by waynos]

its was on the F/A-18A i believe that they tested the wing

edit: yup found it on the dryden website. www.nasa.gov...

[edit on 3-1-2006 by Canada_EH]

Never seen the F-18 version before, good stuff Funny thing is though that on that picture it looks like a normal flap at the vback with hinges and everything. Is there a picture which better shows it off I wonder? *decides toi go and have a look*

There should be a place on the site with footage of the F-18 aswell waynos if you want to look for it.

Cheers EH, that was great Though I do notice its not the same thing I was describing but still well worth looking at

Modern radars operate at a high enough frequency that hoping your curves are smooth enough it will "flow over them" is a bit silly I'm afraid.

About RAM, although it has some effect in reducing RCS, it's really not the best choice. Proper shaping to deflect RF in any direction except back at the reciever is the best method to avoid detection. (okay, proper shaping and hiding in ground clutter)

I'd say the original post about the Air Force releasing not only RCSs for the F-22 and the F-35, but also comparitive examples of the B-2 and F-117 is probrably NOT looking at authintic data. We simply do not release that type of information.

Lastly, the reason there have been improvements in stealth design rely most heavily on improved computer processing power. the formulas to determine RCS have existed for decades, but to calculate more and more angles takes up an enormous amount of calculations, especially if you want to consider the same aircraft from multiple aspects. The F-117 looks unweildy because there was a limit to available processing, the B-2 looks much better because we'd learned to do curves, and frankly the overall shape is in fact a little simpler. However, there's a limit to just how far you can reduce your RCS no matter how long you allow the computers to think about it, and the B-2 is about as close as you can get. The F-22 and F-35 can both hope to be pretty stealthy, but to say they're 4 times more so than a B-2 is dubious.