JSF Stealth Coat Cost (for 65 YEARS?!) Phew.....

[neiyold]

'The accuracies built into F-35 from the start are a major plus point,' adds Cronshaw."

Cannot praise this statement enough! Following the F35 even a little and one becomes aware of the incredibly pervasive DFMM going into this product. Fascinating.

Good thread, thanks.

[Prinz_Eugn]

"Lockheed officials avoided the need to use stealthy appliqués and coatings by curing the substance into the composite skin of the aircraft, according to Tom Burbage, executive vice president of F-35 program integration for the company. It “makes this airplane extremely rugged. "You literally have to damage the airplane to reduce the signature,” he said in an interview with AVIATION WEEK.

So new LO technology consists in banging the aircraft to reduce RCS????
Thats new and innovating!


Bill Sweetman please return your forgiven!

Haha! Didn't even catch that.

"I think you know what I meant..."

[cfg]

Good catch. To degrade, of course

[munny]

These coatings are also designed in a way that the small reflection from the front face of the absorber is cancelled by a residual reflection from the structure beneath it. This is not an easy procedure, and it makes RAM design much more tricky than most people believe.

That was fascinating information….thanks.

The mesh holds up half of the waves for long enough so that when they escape, their phases are the opposite of the other half which bounce off the face, thus they cancel each other out.

Is the length of time it holds them for static or is it adjustable depending on the frequency of the incoming waves detected by receivers on the aircraft?

If it does indeed alter the timing, how does it handle multiple frequencies hitting it at the same time? Its been said that the PAK FA will have X-band radars in the nose and L-band on the wing lead edges, I wonder how that changes things.

[Beazz]

These coatings are also designed in a way that the small reflection from the front face of the absorber is cancelled by a residual reflection from the structure beneath it. This is not an easy procedure, and it makes RAM design much more tricky than most people believe.

That was fascinating information….thanks.

The mesh holds up half of the waves for long enough so that when they escape, their phases are the opposite of the other half which bounce off the face, thus they cancel each other out.

Is the length of time it holds them for static or is it adjustable depending on the frequency of the incoming waves detected by receivers on the aircraft?

If it does indeed alter the timing, how does it handle multiple frequencies hitting it at the same time? Its been said that the PAK FA will have X-band radars in the nose and L-band on the wing lead edges, I wonder how that changes things.

LOL>. Not that I'd know those answers, but don't seem like anyone that did know would be likely to be posting the *hows* of this on here eh? I'm sure our Chinese and Russian pals would love to know as well.

Beazz

[munny]

Well LM was happy to divulge how the basics of it work in the first place. I'm guessing that this system is used by everyone but the true secret is how to build machines which can cut the mesh so accurately.
Was wondering if there were any other tidbits of public information floating around. I know Spaz is the absolute master of providing sources of information.

[spazsinbad]

Spaz is no spy. Google it. Or as I prefer 'Gargle' it. With patience you will be amazed what you might find.

[spazsinbad]

munny, (having a few minutes) here are some clues via WickedPedia:

http://en.wikipedia.org/wiki/Stealth_technology

"Radar absorbent material
Radar absorbent material (RAM), often as paints, are used especially on the edges of metal surfaces. While the material and thickness of RAM coatings is classified, the material seeks to absorb radiated energy from a ground or air based radar station into the coating and convert it to heat rather than reflect it back."
______________________

http://en.wikipedia.org/wiki/Radar_absorbent_material

"Radar absorbent material, or RAM, is a class of materials used in stealth technology to disguise a vehicle or structure from radar detection. A material's absorbency at a given frequency of radar wave depends upon its composition. RAM cannot perfectly absorb radar at any frequency, but any given composition does have greater absorbancy at some frequencies than others; there is no one RAM that is suited to absorption of all radar frequencies. A common misunderstanding is that RAM makes an object invisible to radar. A radar absorbent material can significantly reduce an object's radar cross section in specific radar frequencies, but it does not result in "invisibility" on any frequency."
&
"Foam absorber
Foam absorber is used as lining of anechoic chambers for electromagnetic radiation measurements[citation needed]. This material typically consists of a fireproofed urethane foam loaded with carbon black, and cut into long pyramids. The length from base to tip of the pyramid structure is chosen based on the lowest expected frequency and the amount of absorption required. For low frequency damping, this distance is often 24 inches, while high frequency panels are as short as 3-4 inches. Panels of RAM are installed with the tips pointing inward to the chamber. Pyramidal RAM attenuates signal by two effects: scattering and absorption. Scattering can occur both coherently, when reflected waves are in-phase but directed away from the receiver, or incoherently where waves are picked up by the receiver but are out of phase and thus have lower signal strength. This incoherent scattering also occurs within the foam structure, with the suspended carbon particles promoting destructive interference. Internal scattering can result in as much as 10dB of attenuation. Meanwhile, the pyramid shapes are cut at angles that maximize the number of bounces a wave makes within the structure. With each bounce, the wave loses energy to the foam material and thus exits with lower signal strength.[4] Other foam absorbers are available in flat sheets, using an increasing gradient of carbon loadings in different layers."

[spazsinbad]

New stealth tricks in store for F-35? By Stephen Trimble on July 16, 2009

http://www.flightglobal.com/blogs/the-d ... re-fo.html

"Aerospace blogger and journalist Dave Majumdar, a contributor to The DEW Line, has interviewed Lockheed Martin and F-35 program officials in advance of roll-out of CF-1, the first prototype of the naval variant.

Debuting on the July 28 is the US Navy's first all-aspect stealth aircraft, the F-35C.

Designed to meet the stringent requirements for a "very long range, very low observable, first day of war strike aircraft", the "F-35 has all-aspect stealth", said Steve Weatherspoon, Lockheed Martin's Deputy Test Verification officer for the F-35 Integrated Test Force.

The naval variant "was designed from the beginning to operate in the maritime environment", said Steve O'Bryan, a Lockheed Martin Vice President for Business Development. According to O'Bryan, the aircraft's radar absorbent coatings were designed to be able to withstand daily exposure to the high temperatures, salt water, and chemicals encountered onboard an aircraft carrier. O'Bryan adds that the new coatings will be "resilient" enough that the aircraft's radar cross section will not suffer when it is scratched, chipped, or cracked "during day-to day operations in a naval environment". This should greatly reduce the maintenance burden for the Navy, he said.

Craig Williams, head of Business Development for the F-35C at Lockheed Martin, explains that the new coatings are "less ornate" than previous incarnations of radar absorbent materials (RAM). The new compounds dispense with the "silver paint" primers found in previous designs, "completely eliminating" the hazardous and difficult substance.

In order to validate the performance of the new low-observable (LO) materials, Williams explained that "coupons" of the compound are being tested "on the beach" and "at sea" for "days, weeks, months, and years at a time". The new coatings have also been tested in a specially designed chamber where they have been exposed to "salt fog" and gases such as sulfur dioxide, which would be encountered under operational conditions.

To ensure that the LO seal of the aircraft is not routinely broken, Williams explains that "natural openings" are utilized for maintenance as often as possible. These "natural openings" include the wheel wells and the weapons bays among others. Where access is not possible through these openings, access panels are provided. O'Bryan points out the baseline requirements for the JSF program mandate that the jet be "twice as reliable as a late model F-16 or F/A-18", which should substantially reduce the need to break open the LO seals under operation conditions.

Furthermore, "everything faced during F-22 operations has been improved upon", Williams said, reflecting upon the "lessons learned" from that program. Recently, he added that he had attended a meeting where JSF program officials met with their F-22 counterparts. According to Williams, the verdict from the F-22 officials was that "every possible lesson learned" from the Raptor had been incorporated into the Lightning II."

[garrya]

F-35 skin

[marauder2048]

Can you post the entire presentation?

[charlielima223]

Wasn't the F-22 suppossed to get F-35 coatings on certain parts of the jet to reduce maintenance costs?

[hornetfinn]

Very interesting. It's easy to see the evolution of the stealth coating in these pictures. F-22 coating seems to be rather thick and is definitely much more difficult to work with. It would be interesting to see how F-22 coating looks like now...

[spazsinbad]

USING this URL one may find info on the topic "Some F-35 coatings applied to F-22" or similar:

search.php?st=0&sk=t&sd=d&sr=posts&keywords=Majumdar+Raptor+Coatings&fid%5B%5D=65&ch=-1

This one is perhaps more detailed: viewtopic.php?f=22&t=15391&p=194449&hilit=Majumdar+Raptor+Coatings#p194449
_________________________________

Most recent info: viewtopic.php?f=22&t=15391&p=364737&hilit=Diamond+recoat#p364737

[quicksilver]

Although stated generically, what doesn’t get enough emphasis are the differences in degree of difficulty between the older technology LO and the newer. This translates to ‘time and effort’ necessary to keep jets LO mission ready. Service maintainers with the most previous experience in LO (USAF) generally see F-35 as a revelation; those with less or none (eg, the Navy and Marine Corps) see it as ‘another maintenance requirement’ that they didn’t have before. Credible people I speak to say the quantifiable difference between the old stuff and the new is an an order of magnitude less.