Stealthy glass or what?

I wondered what the F-22's canopy (am I spelling it right: the glass above the pilot's head) is made out of and if it contributes to the plane's stealthiness. I know that the windows of the russian bomber TU-160 don't let radioelectricall emissions through them for the porpuse of stealthiness and that is tech from some years ago.
So is there any info on the subject at all or it's still classified?

good question...never actually crossed my mind...will research it tho

I found this on globalsecurity.org Just do a google search for F-22 canopy.


The F-22's cockpit is one of the very first "all-glass" cockpits for tactical fighters � there are no traditional round dial, standby or dedicated gauges. It accommodates the largest range of pilots (the central 99 percent of the Air Force pilot population) of any tactical aircraft. It is the first baseline "night vision goggle" compatible cockpit, and it has designed-in growth capability for helmet-mounted systems. The canopy is the largest piece of polycarbonate formed in the world with the largest Zone 1 (highest quality) optics for compatibility with helmet-mounted systems. While functionality is critical, the F-22's cockpit design also ensures pilot safety with an improved version of the proven ACES II ejection seat and a new pilot personal equipment and life support ensemble.

hope this helps

the term 'glass cockpit' refers to the instrument disaplys not the canopy (which is the correct term). I'm afraid I don't know about the F/A-22 canopy either but at a guess I would say that it is some special glass or at least treated or coated glass.

Its probably made with a crystaline structure, because tthat best dissapates radar energy in an appropriate way according to the needs of a stealthy airplane. That is why carbon composites are used with stealth, so try to find a glass that usses carbon for structure. It may be that the canopy is designed so that RAM is not needed there, the F-22 only has some areas of RAM while most of the plane usses shaping to decrease the RCS.

The canopy is the largest piece of polycarbonate formed in the world with the largest Zone 1 (highest quality) optics for compatibility with helmet-mounted systems.

Let me expand on that....


Canopy
The F-22's canopy is approximately 140 inches long, 45 inches wide, 27 inches tall and weighs approximately 360 pounds. It is a rotate/translate design, which means that it comes down, slides forward and locks in place with pins. It is a much more complex piece of equipment than it would appear to be.

The F-22 canopy's transparency (made by Sierracin) features the largest piece of monolithic polycarbonate material being formed today. It has no canopy bow and offers the pilot superior optics (Zone 1 quality) throughout (not just in the area near the HUD) and it offers the requisite stealth features.

The canopy is resistant to chemical/biological and environmental agents, and has been successfully tested to withstand the impact of a four-pound bird at 350 knots. It also protects the pilot from lightning strikes.

The 3/4-inch polycarbonate transparency is actually made of two 3/8-inch thick sheets that are heated and fusion bonded (the sheets actually meld to become a single-piece article) and then drape forged. The F-16's canopy, for comparison, is made up of laminated sheets. A laminated canopy generally offers better bird-strike protection and because of the lower altitude where the F-16 operates, this is an advantage. However, lamination also adds weight as well as reduced optics.

There is no chance of a post-ejection canopy-seat-pilot collision as the canopy (with frame) weighs slightly more on one side than the other. When the canopy is jettisoned, the weight differential is enough to make it slice nearly 90 degrees to the right as it clears the aircraft.

www.edwards.af.mil/articles98/ docs_html/splash/apr98/cover/cockpit.htm - 23k


[edit on 9-10-2004 by Fastmover01]

Ok, heres what ive found:

The canopy of the F-22s cockpit has a thing layer of gold on it to keep emissions from entering or leaving the cockpit.

source

Also interesting to note is the F-16 had RCS reducing methods incorporated into its canopy:

Have Glass is the code name for a series of RCS reduction measures for the F-16 fighter. Its primary aspect is the addition of an indium-tin-oxide layer to the gold tinted cockpit canopy. This is reflective to radar frequencies, while it may seem odd, adding a radar reflective coating actually reduces the plane's visibility to radar. An ordinary canopy would let radar signals straight through where they would strike the many edges and corners inside and bounce back strongly to the source, the reflective layer dissipates these signals instead. Overall, Have Glass reduces an F-16's RCS (radar-cross section) by some 15 percent.

source

Hope that helps.

Thank you that was very helpful
I'm not very fast at searching so the links are very wellcome

Originally posted by waynos
the term 'glass cockpit' refers to the instrument disaplys not the canopy (which is the correct term).

thanx I wasn't sure that I got the word right and as for the Glass Cockpit - I do know what it means but I don't remember mentioning it

Gold hmmm...

That post is very speculative but I didn't really expect that there is deteiled info on the tech...the exact technologies and methods will remain a previlege to only a few scienties and engineers

PS: hope some day to have that previlege

Originally posted by vorazechul
I know that the windows of the russian bomber TU-160 don't let radioelectricall emissions through them for the porpuse of stealthiness and that is tech from some years ago.

That coating in them might be for preventing blinding of crew from flash of nuclear explosion. I have one book in which it was that Bone has that kind of coating... and Blackjack is pretty much same concept.
And they aren't real stealth planes, they just use methods to decrease RCS in parts where it can be done easily.


At least Nighthawk might have some kind of coating in glass...
and it wouldn't be usefull to have stealth plane if pilot's head still "shows" on radar.

At least colorful reflections generally hints to coatings.

But I think shaping can be used to decrease RCS of canopy same way like shaping is used for other parts of plane.

Originally posted by vorazechul
Thank you that was very helpful
I'm not very fast at searching so the links are very wellcome

Originally posted by waynos
the term 'glass cockpit' refers to the instrument disaplys not the canopy (which is the correct term).

thanx I wasn't sure that I got the word right and as for the Glass Cockpit - I do know what it means but I don't remember mentioning it

Your welcome, it was fast mover who mentioned glass cockpit and as you asked about the canopy specifically I thought it would help if I spelled out the difference.

That coating in them might be for preventing blinding of crew from flash of nuclear explosion. I have one book in which it was that Bone has that kind of coating... and Blackjack is pretty much same concept.

Good idea but I'm sure about that coating. And I think it was because the monitors inside the cocpit aren't LCD but normal ones and they sure radiate alots of energy

At least Nighthawk might have some kind of coating in glass...
and it wouldn't be usefull to have stealth plane if pilot's head still "shows" on radar.

Would be interresting to have a lock on the pilots head...and what about the radar signature: "Hey my radar is picking up something...I think it's an Ivan"

[edit on 10-10-2004 by vorazechul]

[edit on 10-10-2004 by vorazechul]

I'm not 100% sure what gives it the gold color, but several aircraft have canopies made of this material (the F-16C and F-117 for instance). It absorbs RADAR energy, and contributes to the aircraft's stealthiness. Since most aircraft are designed with some consideration towards stealth, they are becoming commonplace. Most people don't realize that all modern military aircraft are designed to be as stealthy as possible. The aircraft that are designed from the ground up to evade RADAR completely are the ones typically dubbed "stealth," - but think of this - a B-1 has a smaller RADAR return than a UPS truck lol.

Originally posted by Migsaremytoys
I'm not 100% sure what gives it the gold color

The answer is GOLD as with the B-2 the canopy has a very thin layer of gold coating it to electro-magnetic emission from passing through.

There is a great site where they have a 360 degree interactive view of the interior of the B-2 (only one of it kind every allowed) and they explain about the layer being only a few atoms thick so that it is still transparent.