The myth of stealth
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By any measure, the introduction of stealth into U.S. tactical air-strike forces represents a quantum increase in combat effectiveness and surgical-strike capabilities. However, such unprecedented success as that achieved during the Gulf War brings with it certain dangers. The principal danger is the conviction in the minds of many of this country's decision-makers that stealth renders us invincible. In that regard, stealth is greatly misunderstood by the U.S. taxpayer, and its effectiveness is deliberately overstated by too many government officials—civilian and military—who know better.
The general public should know what stealth really is; but more important, they should know what it is not! To explain what it is not, we must dispel the six myths that surround it: Stealth is purely a phenomenon associated with radar signature. Stealth is a new phenomenon. Stealth cannot be countered. Stealth carries no penalties. Stealth makes platforms invisible to radar. Stealth is passive. More than radar signature
Is radar signature the only aspect of a platform's observability to which stealth techniques can be applied? No, it may be the most important, but it is still only one aspect. All aspects must be addressed if real stealth is to be achieved. There are other aspects of the observability spectrum that are terribly important as well; they include infrared, acoustic, optical, magnetic, electromagnetic and probably others that include fluid wake effects.
? Infrared. Objects passing through a fluid medium generate heat, by virtue of the medium passing over the object's surfaces. This heating is detectable. For an airplane, surface heating occurs in the 8- to 12-micron range of the infrared spectrum. Thus, an existing infrared search-and-track system (IRST) designed for installation in a fighter-interceptor could detect a high-altitude, supersonic bomber at a distance of several hundred miles.
Platforms that develop propulsion through internal-combustion powerplants generate heat that causes their engine and exhaust systems to be detectable in the 3- to 5-micron range. For over 30 years, airborne IRST systems in fighter airplanes have been able to detect another fighter in afterburner at distances of more than 30 miles. IRST systems that operate in the 8- to 12-micron range have enormous potential, especially in the detection of air platforms. When the 8- to 12-micron technology has matured, it may well render moot most other aspects of observability.
? Acoustic. This has been pursued in the field of antisubmarine warfare for over 50 years. Submarines generate acoustic noise with their screws, by their passage through the water and by the sound of their equipment and crews. In the Vietnam War, the U.S. developed and deployed an acoustically stealthy airplane. It was called the "QT-2" (for "quiet airplane"). Even today's drone aircraft employ acoustic stealth.
? Magnetic/electromagnetic. Surface ships and submarines possess enormous magnetic fields because they are made up of thousands of tons of ferrous metal (steel). They also generate an electromagnetic field because of the power-generating machinery on board. These fields are minimized by a process known as "degaussing." For over forty years, antisubmarine aircraft have been targeting submerged submarines by using magnetic anomaly detectors (MAD).
? Wake effects. Submariners have known for years that subs' wakes generate turbulence that can be detected, often for hours after they have passed by. Work in this area has been going on for over 25 years and is still highly classified. However, the same laws of physics apply to airplanes, which also leave a telltale "wake" in the atmosphere.
? Optical. This has been with us ever since spear-throwers discovered the operational benefits of hiding behind trees. Ships wore camouflage paint schemes as early as WW I. It was only in recent years that the pro-active use of lights mounted on and in the airframe could reduce the effects of contrast in tactical airplanes. Using lights in this way had the effect of decreasing the optical detectability of aircraft, since their detectability was directly related to the contrasts in their optical signature against their background. Not surprisingly, F-117s were painted black because they were intended to be deployed exclusively at night.
Much more could be said about the abovementioned aspects, but the point is made. Stealth is not limited to radar.
The optical aspect of observability was saved until last because it is so important. More airplanes have been shot down by enemy gunners using their optical signature than by any other means. That fact will probably not change in the foreseeable future. If this is true, optical stealth should get major emphasis in the design and development of future tactical airplanes.
Stealth is not new
Camouflage is optical stealth in its crudest form. Camouflage has been used in warfare as far back as history has been recorded. The hulls of WW I combat vessels were painted with various shades of camouflage gray to make them hard to see. Airplanes were camouflaged to achieve the same end, but with enemy gunners both in the air and on the ground, the paint schemes had to be a little more sophisticated. Since the sky and the ground have two distinct backgrounds, camouflaging aircraft is more difficult. The principles, however, are the same. The camouflage must make the object blend with the background—just as in nature's classic example of the chameleon.
In WW II, the Luftwaffe put radar-absorbing carbon material in the leading edge of one of its bomber's wings to make acquisition by British radar more difficult. Still later, the U-2 was developed as a stealthy airplane as were the B-1B bomber and the SR-71 reconnaissance airplane. So stealth is not new; not by a long shot—not even radar stealth.
Can stealth be countered?
Yes. Several countries are already hard at work developing counter-stealth technology. Of course, the simplest way to counter radar stealth is to decrease the frequency and thereby increase the wavelength of radar. Regardless of the size of an airplane, it will act as a dipole antenna to a certain radar frequency whose wavelength is a multiple of the airplane's natural radar return. That is why the F-117s were clearly visible to the air-search radar of an old British destroyer on patrol in the Persian Gulf.
The same principle applies to the highly touted B-2 bomber. The laws of physics apply, despite ballyhoo and public relations "smoke and mirrors." The question of designing a search radar with a variable frequency and a spectrum-survey capability has been considered. Unfortunately, such equipment is very expensive to buy as well as labor-intensive to operate. The cost to configure/reconfigure an entire class of ships or model of aircraft would be prohibitive for most users. In the final analysis, all stealth really does is reduce detection range.
Penalties
Are there penalties associated with the use of stealth? Of course there are, and they are enormous!
Most of the penalties fall in the aircraft-performance category. For example, external stores on stealth aircraft had to be eliminated almost entirely. Fuel tanks and weapons suspended from the bottom of the airplane acted like radar corner reflectors; therefore, all weapons and extra fuel had to be carried internally. This had an enormous effect on the design of the airplane and on its "natural" radar signature, and it also produced drag polars that substantially reduced an airframe's maximum speed as well as its ability to turn and to accelerate. During the weapons-release phase, the F-117 has to open its weapons-bay doors. While in this configuration, however briefly, the F-117's radar signature (and, therefore, its vulnerability) increases dramatically. This is one of the most significant penalties of stealth. Stealth design efforts
? Acoustic. Sound suppression of air vehicles is most concerned with quieting the powerplant. In the case of propeller-driven drones, the effort involves a quiet propeller design and muting the exhaust system. In the case of jet-powered aircraft, the effort focuses on exhaust-gas noise suppression. Sound suppression in submarines is done through external anechoic coatings and by shock-mounting noisy internal equipment such as generators.
? Infrared. For air vehicles, IR emanations in the 3- to 5-micron range are suppressed by using cooling air and shrouding around hot parts of the machine (usually the powerplant). In submarines, IR emanations come principally from fluid efflux, either from powerplant-related operations or jettisoned ship-related products such as garbage and human waste.
? Magnetic stealth. Can only be achieved through degaussing that requires dedicated ship time on a dedicated range. The effects are not always as permanent as intended, and there is no simple fix once the ship is ?in the field.? In aircraft, the problem doesn?t exist simply because of the limitations of magnetic measuring detectors. If the hunter got close enough to a target aircraft to detect its magnetic emanations, the aircraft would be well inside the detection range of other sensors and also the hunter?s own minimum weapons envelope.
? Optical. Aside from what we know about camouflage, the most promising optical stealth technology is that dealing with the elimination of contrast by the use of lighting. In the latter stages of the Vietnam War, serious efforts were made to enhance the combat effectiveness of U.S. tactical aircraft through the medium of optical stealth. The classic example was a ground test conducted at Miramar, California, in which a Phantom II was configured with a series of strategically located white lights. The test showed rather dramatically that when contrast is reduced, so is the optical signature. For a number of reasons, follow-up tests to this initial development effort were never pursued; however, the results of tests conducted a few years ago showed great promise. The drawback of optical stealth is the same proximity problem that faces the magnetic detectors.
? Fluid wake effects. For both aircraft and submarines, the phenomenon of fluid wake effects represents an aspect of observability that could have serious implications. Unfortunately, (or fortunately, depending on whether one is the hunter or the hunted), it represents an enormous technological challenge and is also shrouded in secrecy.
Invisible? Only temporarily
An expression from WW II antisubmarine warfare refers to a "flaming datum." This is the location of a burning ship that has been struck by a submarine weapon. The counterattack against the offending submarine uses as a "datum" the location of the burning ship and the time of the attack.
Knowing the submarine's speed and the range of its torpedoes well defines the search area. Most of the more than 700 German U-boats sunk in WW II were destroyed after the flaming datum had been established. When the F-117 opens its weapons bays, it automatically increases its radar signature. The bays are open only for a short time, but it's long enough for enemy radar to get a lock on the fighter's position and allow the enemy to take countermeasures.
The moment the F-117 opens its weapons-bay doors is the modern-day equivalent of the flaming datum. Once seen, how-ever briefly, the F-117's presence has been announced. Air defenses, knowing the F-117's speed limitations, can quickly mount a counterstrategy that, given modern weapons systems, can find it and destroy it.
Low altitude isn't the cure
First designed purely for high-altitude operation, the B-2 bomber was modified to operate at lower altitudes. The resulting increase in structural weight and the added weight incurred by the addition of gust-load-alleviation systems has produced a tactical airplane that is ridiculously vulnerable. The B-2's maximum speed at sea level, for example, is so low that virtually any tactical airplane (of Korean War vintage or later) can easily run it into the ground.
Modern tactical aviators have always thought there was a haven at extremely low altitudes and high speeds. When in trouble, it was worthwhile to head for the tall grass during egress from a highly defended target area. Regardless of weapons and platforms, a target going 700 knots at 50 feet off the ground is difficult to shoot down. In the highly touted B-2, we now have a tactical airplane that costs over two billion dollars and is "dead meat" once it has been detected at low altitude. A burst of 20-millimeter gunfire from a Korean War F-86, for example, cannot be affected one iota by all of the multimillion-dollar electronic and electro-optical countermeasures that the B-2 carries. The B-2 is probably the most technology-intensive aircraft ever built. It certainly does not, however, possess the important ingredients of all successful tactical aircraft: survivability and graceful degradation of battle-damaged weapons systems. From a cost-effectiveness standpoint, one should ask what the relative merits might be to have the same interdiction mission attempted by a careful mix of more conventional, less expensive aircraft, including the low-flying, low-tech A-6s of the Persian Gulf War. That is, if we still had any—but that's yet another story.
Radar signatures
B-52 bomber: 60 square meters
B-1A bomber: 6 square meters B-1B bomber: 0.6 square meters
B-2 Stealth bomber: less than 0.06 square meters An airplane's stealth can be measured by how much radar energy it reflects. Known as "radar cross-section" (RCS), this measurement is determined by the plane's size, shape and material composition. These drawings show how the RCS, measured in square meters, has been progressively reduced through four generations of American bombers.
Although the F-22's design employs surface-shaping technologies similar to the B-2's to reduce radar signature, the principal differences between the two airplanes lie in surface coating and active defense systems (courtesy of Lockheed / Martin F-22 team photo via Air Force Magazine). Passive or active stealth
A few words need to be said about the passive aspect of stealth technology: it is not just passive. Unfortunately, the active aspect of stealth is still shrouded in secrecy—especially as it relates to the B-2 program. Suffice it to say that incoming radar energy is "modified" in such a way as to tell the source of the radar that there is no target.
Summary
As tactical aviation approaches its first century, aircraft designers will have to weigh the relative merits and the tradeoffs involved in striking the proper balance between stealth and aircraft performance. The tradeoffs probably won't be exactly the same for unmanned systems, such as a stealthy Tomahawk missile or a reconnaissance drone. Infrared detection systems in the 8- to 12-micron range seem to offer the greatest promise at this juncture. Technology in the development of new theater air-defense systems is advancing in parallel with stealth technology. There is no technical reason to suspect that either will jump substantially ahead of the other.
As a bottom line, it is probably safe to say that there is no such thing as an invisible airplane. And if it isn't invisible, it certainly ought to be equipped to fight its way into and out of a highly defended target area.
"Rufus I know the fanboys here are motivated primarily by national pride and hate the thought that their country is behind the curve on such a key military technology,
At Roll out of the Rafale C or D for Discreet, the EM and IR reduction work was obvious and already well advertised, nothing to do with marketing, what you are doing is called revisonism."
stupid website design. sorry about the multi-post, my bad.
Slim Pickinz especially the ones with civilian and military experience directly in the current topic of debate?
Well when i will read something noticeable for being not only level but accurate i'll let you know, you have no idea wehat my experience is, pretending is one thing, i'm still waiting for you to demonstrate otherwise than by calling people names and flaming...
That's 90% of you pretending to know about it then.
For your info it already does, the fact tha tyou don't know it yet is another issue...
Slim Pickinz I'm sorry to burst your bubble, but thats the truth. Backed up with hundreds of pages of comments on the subject.
You dont, you just indicated that you are still unaware, next time you have the opportunity, ask one of the Rafale pilots what they think of them.
>>>>>
Rufus Wingman, there are far too many errors in your recent post for me to spend the time required to correct them.
Please DO because you keep writing and prove little...
This is certainly NOT a minimal effort.
Had you known your basics you would comprehend the FACT that a straight inlet have a better pressure recovery characteristic than a curved one, there also are resonance issues created in the S-shapes due to the high transonic airflow.
If the compressor blades have to stay subsonic, it doesn't mean that compressive waves doesn't occur in the inlets expecially when they are of this type; Pitot, since it have to happen to slow down the airflow before it reaches the compressor blades.
This, with only a diffuser to provoc a mild shock on their leading edge, making the 1.5 shock, which helps and give a 0.2 Mach margin.
The presence of S-shaped glove requieres a high degree of computation too.
As a matter of FACT, Typhoon designers didn't have CATIA nor ONERA and Saint Cyr advanced aerodynamic simulation and tunneling facilities to help them with this, and Typhoon suffers from high-frequency vibrations due to a marginal inlet design.
You totaly forget that aerodynamics doesn't suffer approximation and in the case of US twin fin design it shows big time.
Rufus As I said before there was an awareness outside the US that it was possible to reduce the RCS of aircraft. The Rafale did ultimately receive some measures to that end, but they were extremely limited.
Not ultimately, but well before DESIGN STAGE.
And more to the point, there are feature there that you keep ignoring and are well known to reduce RCS, it's all a matter of compromise and even US V.L.O fighters does compromise.
F/A-18 is designed angularly like the F-22, Rafale uses souple curves like YF-23, from the from it shares a very similar cross section, similar to B2, nEUROn or XB-47.
Since the invention of radar, the Karman wing/fuselage junction is known to reduce radar return, so does the mid-fuselage mounted wing.
The single fin is for this type of aircraft, a compromise to aerodynamics, performances and cost, it was chosen over the twin fin configuration from 1982 in order to save weight and reduce cost.
Rufus Gee, you don't think trying to advertise the plan that way had something to do with marketing? lol
= From F-404 to M88 the difference in IR signature is enormous.
Then there was the little matter of the RAM paint used on C01, it was further developed with visual stealth in mind.
The features such as serrated area and RAM are not an after thaught they need to be developed in an anechoidal chamber for optimisation in particular their position on the airframe, which is what they did.
Rufus I give the French credit for knowing how to market a plane,
When we see all the fantasise we can read about F-35 we think we're just amateurs because you see, trying to pass this for a dogfighter or an Air Superiority fighter takes some degree of mickey taking, and then some, only a simple look at its design features and aerodynamics tells me it is FAR from being that performant in this role...
Rufus A totally conventional 4th generation aircraft, with a modest effort at RCS reduction... but from France!
Totaly conventional? LOL!
This is Dwight Looi lowest possible level of analysis...
If you knew your aeros (he don't), and a little more about stealth you wouldn't be calling Rafale conventional but advanced.
Please elaborate (if you can).
Rufus Where did I say it was? I never said that simply HAVING a canted tail meant that an aircraft was stealthy, only that no aircraft with significant RCS reduction work would have a vertical tail. You can't turn around people's statements and pretend they work both ways. It is true how I said it.
U2 and F-12 and SR-71 were perfectly detectable by radar BOTH ground based and airborne, the Russian never had any problems intercepting them.
Rufus Give your engineers some credit, if there had in fact been a "race for stealth" they would have produced something useful by now.
They did you simply chose to ignore it.
Rufus Europe tinkered with conventional designs, while the US built multiple generations of fully operational stealth aircraft.
Correction here: The only fully operational stealth aircraft the US built was the F-117, the rest were still not in the same ballpark.
As for SR-71 it was more of a prototype built in a slightly larger number.
Europe priority, at least that of France was in developing its basic and then more advanced technologies, stealth technologies were ready at Dassault-Aviation for a full scale UCAV as early as 2003.
This was the sole reason for DGA to give the budget to them first for the Grand Duc programe, then look for European partners after Michelle Aliot-Marie decided to open it to them after an agreement at Eurosatory between Dassault and EADS, on UAV/UCAV partnership.
This is our history boys, and it is well advertised by the Europpean press, go and dig it.
The fact that you can come up with this tells me a lot on how much of an aviation enthusiast you are, i got comments on Rafale from some US test-pilots which contrasts with yours in many ways.
First they know what they are talking about, no disrespect, then they appreciate design features for what they are regardless of nationality.
Endly they all well complimentary of Rafale design and none would dare using the word conventional, quiet the contrary.
Now if you have any number of flight hours in aircrafts such as the Tiger II or F/A-18s i'd listen to you opinion but at the way you write about it i think you don't even fly a paraglider... Sorry.
Rufus That Rand report, as I already explained to you, is not even attempting to officially define terms. It made arbitrary distinctions between aircraft for the purpose of keeping things simple for the reader. They explained that quite clearly.
Yes they did and design features still eludes you.
Rufus Even IF it had been their intention to define levels of RCS reduction and rank aircraft... Rand is in no way "official." They are a third party group that produces commissioned studies.
Commisioned on the ground of their capabilties on behalf of the US Air Force, vs your opinion i know what to believe, more to it in this same report it is clear that they also mention systems and as the last article i posted, the notion of Observability goes further than just EM signature management.
This report was published one year before the contract for AN/APG-79 was signed, meaning that the F/A-18 they mentions as R.O wasn't full equiped with what ALSO makes a F-22 V.L.O today, a LPI radar worth mentioning.
Rufus Now you are trying to reinvent history.
This is your forumers habbit, not mine.
I know my aerospacial history and YES Frnace did have to rebuild her aerospacial industry and not only it, ALL her industries after WWII...
Rufus Your pride is a heck of a lot bigger than your knowledge wingman.
Im afraid you mystake me for one of your other forumers here...
Rufus The F-117's emergence will forever mark one of the key turning points in aviation history.
So dont come up with U2 and SR-71 as "stealth", they had various degree of radar signature developed in them but certainly not that of YF-117...
Alternative thinking based on knowlege of FACT surely, please inform yourself, technologies in Europe aren't developed backward.
Rufus Rand is not "official."
Their work IS it is sponsored for the USAF with USAF and USN datas, which is more than you can claim for yourself.
Rufus That report was not "work on defining levels of observability."
But it DID and to an extend showing that my points were perfectly valid...
The only reason they were is because the subject is still classified so trying to imply it is not a base from which we can make reasonable assumptions is wrong...
The quoted ALL the features making V.L.O and L.O and as a matter of FACT most of them are in the explaination i given along my previous posts.
Rufus That is why they wrote that disclaimer.
NO; the disclaimer is there to indicate that they did so because they canot disclose more sensitive informations to the public, not that they are not doing a good job of categorising the aircraft they mention.
This RAND repport is WAY more specific than yourself, you keep bringing the stealth issue to V.L.O only and EM signature management only, this is plain wrong.
Rufus So? The Rafale doesn't have it now.
Rufus Lol, correcting this could be a multi-page post in itself...
LOL!
Please fell FREE to write, what i can see is that you have no clue and i have tons of archives to throw at you guys...
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