SwingKidTo understand the problem of quoting absolute figures I did a scan.
A 3-D-modell looks much more interesting, which itself differs by flight-configuration and atmospheric conditions. I think it is enough to get a first idea. 🙂
It’s a good illustration. For those unfamiliar with the decibel scale, this diagram shows a maximum RCS of about 6.3 square meters (+8 dBsm) to the side, minimum of about 0.0003 square meters (-35 dBsm), frontal RCS 0.016 square meters, “median value” around 0.01 square meters (calibrated assuming 0 dB = 1 square meter) – in short, a variation of 21000 times, depending ONLY on which direction we are looking at the aircraft. What meaning can it have, to quote any single number as this aircraft’s “RCS”? What meaning can it have, to “reduce” that RCS “by 1/14”? Is it a reduction of the maximum value, the average value, or the frontal value?
If it’s a “hotspot” solution, then it’s probably just reducing the largest “spikes” at the sides, but leaving the frontal RCS perhaps relatively unchanged. To design and manufacture a real “reduced RCS” aircraft requires more than hotspot solutions or even software simulations – it’s necessary that the measured RCS match the simulated RCS for such simulations to have any value. But the measured RCS is extremely “random” and difficult to predict, and the smaller the radar wavelength used to detect the aircraft, the more spurious “spikes” and “dips” there will be in the RCS pattern. The only hope is to have extremely fine manufacturing tolerances, so that the simulation and measurement models match as perfectly as possible. Then if there is a “spike” or other disparity between the designed and measured RCS, there is some hope that the cause of it can be discovered in simulation and fixed. So Russia has two challenges – first it must construct a facility for controllably measuring RCS from different angles, and second, it must improve manufacturing tolerances so that the simulations and measurements match. Only then it will have the tools for building stealthy aircraft.
Until then, Russia is stuck using active jammers to hide its aircraft, and using “hot-spot” solutions to keep the RCS “spikes” from exceeding the capabilities of the jammers to hide them. This is a completely different goal than Western “RCS reduction”, which is to reduce dependence on active jamming. Either way, the quoted numerical accomplishments are demonstrably meaningless without much more information.
-SK
SwingKidThere have been several articles in Avweek etc from a Russian bureau who have worked on RCS reduction.
There have been several articles about the MiG-1.44’s smaller RCS than F-22. :rolleyes:
I can send you the article if you want.
Sure!
They said that they had cut the RCS on the Tu-160 to 1/6th, the Su-47 Berkut 1/10th, and the Kh-101 to 1/14th compared to the unmodified design provided by the OKB.
These are interesting numbers but they don’t actually mean anything. Radar cross section is like the “glint” from a shiny car. From one angle, the entire windshield is reflecting the sun. From another angle, it’s dark. Simply rotating any typical object by as much as 1 degree can easily cause its RCS to fluctuate by the 8-11 dB factors quoted above or more. Is that all they did? How did they know the aspect they were looking at from the “before” and “after” tests were exactly the same? One source will say the MiG-21 has a 3 sqm RCS, another will say 2, another will say 10 – and they’ll all be correct, because the real RCS is “2-10, depending on aspect and frequency”. As long as you use the same measurement standard (e.g. max-aspect RCS vs 10 GHz radar), you can make meaningful comparisons. But RCS without such qualifiers is as meaningful as missile range without knowing shooter and target velocities, aspects and altitudes. And the manufacturer will always take advantage of that to “spin” the numbers in own favor.
This is not strictly a Russian problem, the Americans do this even worse, with “bird-” and “insect-size” RCS that leaves internet analysts measuring beetle diameters. “Well, we didn’t tell you which insect…” But at least the Americans have a coherent design strategy…
Separately, they worked on the Su-35 cutting its RCS to 1/10th with minor modifications, including developing an aerosol based RAM for treating munitions hotspots.
The reduction of “spikes” can be accomplished with minor modifications, but this is just another example of the “cheating with numbers” I described above. Let’s illustrate with an example.
This Russian RCS firm is handed a Tu-160 for RCS reduction. They notice that from a certain angle, the RCS pattern has a big “spike”, or hotspot. At this particular angle and frequency, the RCS is 100 square meters. The apply minor modifications and “hotspot” treatments to eliminate the spike. Now the RCS pattern is smoother, let’s say 15 square meters from every direction.
Now the RCS company says “we reduced the RCS by a factor of 6!” But they never tell you, together with this figure, what was the original RCS.
Richardson looks at the layout of the Tu-160 and estimates the RCS should be around 15 square meters. He has no way of predicting “spikes”, this is just an average estimate.
Now I come along and say “the original Tu-160 RCS is 15 square meters, because Richardson said so, and the Russians reduced it by a factor of six. Now it’s 2.5 m! All accomplished with minor “hotspot” treatments!”
The thing about RCS is very small things can contribute very large amounts to the RCS. By treating these hotspots, you can significantly reduce RCS. Not to the level of stealth aircraft, clearly, but potentially significant.
Agreed, but I call this “glint reduction” instead of “RCS reduction”. The reflection of the sun from the windshield is not considered part of the normal appearance of the automobile.
A corner reflector is not “glint”. It contributes to general RCS in a wide range of directions. There is no way to compensate for this with “hotspot” treatments. Real RCS reduction can only be built into the airplane from the paper design, not added as an afterthought. And the RCS figures in western sources like Richardson are NOT talking about spurious glint. Mix these numbers in with Russian RCS reduction claims at own risk.
-SK
SwingKidIts not always possible to tell RCS by eye.
An electromagneticist begs to differ. 😉
The main benefit came from coating the first row of bliscs.
What’s a “blisc”?
http://www.dvd-nakupi.com/slikefilmi/Blisc.htm
:confused:
This and special coating of cockpit-glass are very effective methods to better RCS.
Yefim Gordon’s book shows some black paint on the engine intakes of a single test Tu-160, but there’s no evidence this has been applied to the other operational bombers. It probably proved useless, since RAM accounts for very little RCS reduction on aircraft – RAM tests on MiG-23 and Su-25 also amounted to nothing – anechoic chambers are covered with think jagged spikes of carbon-soaked sponge, not with black paint. RAM coating only becomes a factor when the dominant RCS caused by the aircraft’s shape has been reduced to ridiculous levels. What good is coated “cockpit glass” when the cockpit is not even visible from below? Russia has no facilities for design and test of RCS model shapes, all they can do is fly the full-scale experiment over a SAM radar and hope for the best. Good to satisfy the paymasters that work is being done, but such a method will never produce results.
Richardson gives an original value of 15 qm for Tu-160 and B-1A was 10 qm,
when I remember well.
The reduced Tu-160 comes to 2,5 qm and is better than a MiG-21 by that.
A clean B-1B is 0,75 qm.
What is the source for the “reduced” Tu-160? 15 divided by 6? Gordon claims the “reduced” MiG-29M has RCS of 10 m^2.
When the Russians start mounting airplanes on poles in the Kazakhstan desert, then they’ll be working on RCS reduction. Until then all talk of Russian RCS reduction is nothing serious.
-SK
SwingKidHere’s the ramp at Krasnodar….
Argh!! When were you in Krasnodar? Do you have a city map you’d be willing to part with? 😮 I lost mine.
-SK
SwingKidWow. I’m so flattered to have been mistaken for a Dane, I want to express gratitude, rather than defend myself! 🙂
Fighter pilots are human beings. I and others have enjoyed the privilege of working with some who were a great inspiration, and others who were.. less so. However, the honour of an officer has a living content that stands taller than individual personality, and true professionalism needs no defense from sarcastic internet humor. If anything I have written is false, then at its chosen moment, the truth shall naturally impose itself upon me and all other cynics, without any need for argument. Until then, I can only laugh at the trappings of modern warfare:
“A good friend once told me that death smiles at us all – All a man can do is, smile back…”
:rolleyes:
Best regards to men of honour.
-SK
SwingKidI can’t find the quote – but I read that the Tu-160 actually has a LOWER frontal cross-section due to the slim fuselage.
On the B-1, the cockpit is positioned on top of the nosewheel bay – hence the hump-backed fuselage and therefore a greater cross sectional area.
:rolleyes:
The only time-wasters in aviation more meaningless than American claims about missiles are Russian claims about RCS. Tu-160 is as much a flying Disneyland of corner reflectors as the MiG-1.44.
Anyone seen a photo showing just the front doors open ??
I’ve seen one that appears to show the opposite – Kh-55SM launch with only the rear doors open. Unfortunately from the angle it’s hard to be sure if the front doors are really closed, or just obscured by the engine nacelles.
Hope this helps,
-SK
SwingKidGripen in my opinion would be the best choice, or Eurofighter.
Important is to take an European product!!!
What defense would a Serbian Gripen or Eurofighter provide, that is worth the cost of upgrading from existing MiG-29? All three are capable of killing MiG-21s and UAVs with ease, and all three are easy pickings for F-22.
European products are for fighting coalition wars on other continents. Serbia would not benefit from such games.
-SK
SwingKidOk let’s not discuss if there will be wars in the future or not.
There is no sense to make decisions about purchasing weapons without a plan to use them. At least, a coherent and visible plan makes a better deterrent against potential aggressors than no such plan, and thus even reduces the probability of war while preparing for it. Iraq’s efforts to prove its harmlessness led to invasion. North Korea’s threats of violence have protected it for 50 years.
To deter NATO airstrikes, accept some free F-16s of any version, then import the S-300.
To deter low-flying air raids by weaker neighbours, retain the 4 MiG-29s. No upgrade is necessary until Croatia deploys radar-guided AAMs.
To deter invasions, buy Ka-52. To deter insurgents, buy Su-25.
Buying Gripens is asking for trouble. It sends a message to all neighbours that neither US nor Russia are providing intelligence support.
-SK
SwingKidAre you sure that letter from the F-15C-pilot is authentic? I´m not.
It was provided as such by a USAF test pilot of 19 years experience previously acquainted with the author, who endorsed it with “these are our typical thoughts during real missions.” Certain details in the account have also been confirmed accurate by other sources.
To be fair, it probably started out as an e-mail intended for a very different audience than the general public, for which Rosenkranz had the advantage of knowing he would be writing for.
Nevertheless your surprised reaction really surprises me… Now I don’t want to offend you with other examples; my intention was only to be cynical, not controversial. Maybe things are different in Europe?
-SK
SwingKid“Morals and Ethics”: Fighter pilot vs. UCAV example 1.
SONOFABITCH! I gotta get me some!
…
“Cxxx” later critique my comm as incorrect 3-1 terminology… EAT ME!
…
Later report confirmed both pilots ejected safely. Not that neither Boxer nor I would’ve felt bad if they morted.
Should be news for the dead pilot…
-SK
SwingKidI just hope the big ones will defend the need to have a man in the loop; a human decision maker with a moral and ethical foundation.
You don’t know enough fighter pilots. :rolleyes:
I’ll take Skynet, thanks… 😀
-SK
SwingKidI read it in the Toronto Star last week but also heard it from a “friend of a friend” in the industry months ago. The EH-101 has established a reputation in Canada as a maintenance nightmare. Pretty ironic after all the years of fighting to buy them.
-SK
SwingKidThere was a good “briefing”-style article about it in an old issue of World Air Power Journal (possibly vol. 9 Summer 1992?). If I remember correctly,
Successes:
– Excellent ECCM
– Excellent digital communication systems (including satellite link), overcame compatibility problems between Air Force, PVO, Navy and Army radios by carrying all of them
Shortcomings:
– Insufficient detection range (200 km vs fighters)
– Terrible crew facilities; high noise levels and no toilet
– Non-turbofan engines reduce maximum loiter time
– Aerial refueling tested but discovered aerodynamically impossible
One confusing claim was that the radar processing was done on board the A-50, whereas the E-3 must transmit its radar data back to a ground station for processing. Other sources all seem to report this the other way around. :confused:
It was also claimed that some of the shortcomings were addressed with the fleet-wide “A-50U” upgrade, but no specific information provided, except that the capabilites are still not considered to equal E-3.
One of my books has a photo of what appears to be an A-50 radar operator sitting at his station, but it isn’t very good and there doesn’t seem to be much to learn from it (except maybe that Russians don’t use a light-stick user interface as they do on Western AWACS).
Possibly a useful aircraft for controlling Su-27 and MiG-29 operations over land, but I imagine aerial-refuelled MiG-31s could patrol the coastline watching for cruise missiles without help.
-SK
SwingKidI suspect the Luc display is nothing more advanced than a larger array of lights.
In that photo you can still see an earlier version of the Vyuga pod control panel in the lower left.
The “Luch” display is separate from the Vyuga pod control panel seen in the cockpit. The Su-17M4 for example can be fitted with either the TV screen, the KKR reconnaissance display, or the “Luch” indicator in the same upper-right corner of the cockpit, but not at the same time. The cockpit display has to be fitted on the ground according to the mission. Thus, “flex” payloads combining both ARMs and other weapons were not an option.
-SK
SwingKidIf you don’t know the difference between instructions per second and clock speed, then this discussion is pointless.
I’m bailing out too, over the PRF-less “yes each pulse” rebuttal. Nice to know that while hanging in a parachute after getting suckered in, at least we’re in good company. 😉
-SK
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