When we talk about current military aircraft, we immediately associate them with the most modern flying vehicles on the global stage, and the 5th generation fighters are the best known. They, and other aircraft, are ahead of most planes built today.
Nowadays we know that there are few units of stealth aircraft, among them we can mention the 5th generation fighters, they are the F-22 Raptor, which was the pioneer among stealth aircraft, or Sealths, also has the North American F- 35, the Russian SU-57 and the Chinese J-20.
However, in addition there are other stealth aircraft, some of them are the very expensive B-2A Spirit bombers and the F-117 Nighthawk (“the one already retired”). In addition to this, we have the Russian UAV S-70, and the Chinese GJ-11 Sharp Sword.
When you hear about aircraft like the ones listed above, you often hear the expression, “Invisible Planes”, but it is worth mentioning that these planes are not literally invisible, we can see them. This term applies to radar coverage.
Early Stealth Technology
To talk about how stealth technology works, we have to go back a few years in history to see the beginnings of the Stealth world.
Since World War I, engineers were already thinking of ways to make it difficult for the enemy to see the aircraft, some tactics were applied throughout the fighting. The Germans, for example, painted their aircraft with a color scheme to make it difficult to identify them.
But in the period of World War II, people began to think and do something more productive for stealth, even due to radar, which was already a reality. So, at the end of the war, the Germans created the plane, or rather, the Ho 229 flying wing (pictured above), an aerial vehicle that was never used in combat, but already had shapes that are now very common in 5th generation aircraft. , its curved design had a meaning and it is believed that it was already focused on inhibiting the coverage of electronic radars.
To learn more about this unique aircraft, click on the link below:
Fun Fact: The German Air Force Flying Wing That Was Ahead of Its Time
What makes aircraft “invisible to radar”?
Because they are strategic aircraft, it is not possible to know much about the technology used to make such action of not identifying the radars possible.
But… We know some things that are common in all existing aircraft:
- The Aerodynamic characteristic: In aircraft it is one of the key points. The reason for deg the aircraft is to decrease the radar signature, which shows the shape that a radar (with electromagnetic waves) is identifying. Another reason for the aircraft's shape is that it dissipates radar waves to multiple sides rather than concentrating them at a single point.
- Absorbing materials: There is a material on aircraft that makes it difficult for the wave emitted by the radar to return to the emitting point, so it is not very clear what is being seen on the radar. These materials even lower the heat signature of the plane's engine output so that nothing is noticeable to radar.
- Non-spare structures: Allied to the shape/geometry of the stealth aircraft, we are careful not to leave anything spare in the structure of the planes. The pitot tube of these aircraft has a diamond-like shape, which makes it difficult for the radar to see. Because they are combat aircraft, unlike common ones, the armament is carried internally and at the exact moment a bay opens, and the bombs, missiles or rockets are released.
- Impedance Matching: Ensures that the entire structure of the aircraft has the same electrical charge distribution, thus making it difficult for radar waves to be able to differentiate the loads between different parts of the aircraft.
- Infrared: Radars can also identify waves in the infrared frequency (heat), easily emitted by aircraft, since engines emit heat in the form of infrared waves. To circumvent this, the gas vents on planes were designed so that there would not be as much hot gas output. Aircraft such as the Nighthawk and the B-2A are an example of this, but they are subsonic, that is, they do not break the sound barrier. In the case of fighters, they are supersonic, but do not need an afterburner to reach supersonic speeds. They have the technology supercruise that allows flights above Mach 1 without having a strong emission of heat from the engines, in addition to saving fuel.
It is also worth explaining a little about the Radar Cross Section (RCS), which is a measure of how identifiable an object is for radars.
So things like, the size of the object, the shape of the object, the material the object is made of make it possible to identify something. Different objects have different values when it comes to RCS, a person has one value, a large plane has another (something around 100), a bird has a value of about 0,5 as it appears very small on the screen of the observer.
The focus of stealth aircraft is to make it possible to approximate the RCS value as closely as possible to that of a bird.
The shape of these stealth planes, as stated above, makes it difficult to see. The incoming wave data is messy and fails to convey anything detailed about what is being tracked.
To provide a more visible example, an F-117 Nighthawk, for example, will appear with a number of 0,00001, which to an observer on the radar screen could be mistaken for a bird, but in the last part of this article we will see that this number can vary both upwards and downwards.
Stealth-planes are not actually invisible at all. They appear on the radar screen with a very low signature, nothing as big as a common plane and for not being sure of what is actually being viewed, they by without having the real identification of the flying object.
Because they have this shape, triangular and with a single wing, especially talking about aircraft like the “retired” F-117 Nighthawk and the B-2A Spirit, their aerodynamics are not very satisfactory for flights and it was necessary to invest more money and technology to compensate for this . So much so that in the F117, for example, we can find a lot of action from the Fly-By-Wire system, allied to a powerful computer that at every moment corrects the flight of the planes, making the piloting of these aircraft a little easier.
Is it possible to identify?
With the advancement of a technology of one part, a second advance to stop that technology is created. Since planes that dissipate radar waves were built, people soon began to think of something to identify them.
The creation of increasingly sensitive radars was necessary for the enemy's strong points to be attacked, it is worth mentioning that in this context, both the US and Russia invested heavily in new radars.
According to a Russian specialist, Aleskei Leonko, Russia already has the capacity to identify invisible aircraft, because according to the specialist the new radars have "a most important feature of these radars is the ability to monitor the area in different frequency bands at the same time".
Most of today's modern radars use an electromagnetic X-band signal, and for these stealth aircraft are successful in missions. However, the Russians have radars with coverage of the X and former L bands, and this could make identification possible, the expert said.
But this is just one Russian side of the story, in modern times there was nothing of great relevance in relation to this topic, but there have been cases of identification and shooting down of stealth aircraft.
Stealth projects from other nations
United States, Russia and China, are the most forward nations in relation to this world. However, other nations are working to have their own stealth aircraft.
See some examples below:
TF-X – From Turkey
Tempest – From the UK
FCAS – Dassault and Airbus project
Invisible Plane shot down
The most famous case, and perhaps the only one, happened in 1999 and involved a classic in the stealth world, the US bomber Lockheed Martin F-117 Nighthawk was shot down by forces from the former Yugoslavia, who fired surface-to-air missiles at the stealth plane and Colonel Zoltan Dani achieved the feat of shooting down the North American plane.
Nighthawk pilot Dale Zelko ejected safely and was rescued. There's something interesting about the story: 12 years after the fact both the Yugoslavian and the American military became friends.
But how did they manage to shoot down the Nighthawk. Well, the Yugoslavian military managed to spy on NATO data and knew that that day there would be an alleged attack by the USA.
Colonel Zoltan Dani was able to tamper with the radar wave frequency signals and thereby located the US plane. Another thing that made the F-117 more visible was the opening of the weapons compartment, which made the aircraft very visible to radars, since the colonel's military was already trying to locate the plane, and when it became more visible, they fired the missiles. land-air.
When asked, the Yugoslavs said: "Sorry, we didn't know it was a stealth plane."
In aviation, we also learn by mistake, and the US military conducted an the F-117's weapons bay doors to make it harder to see.
A summary of everything
Well, from the SR-71, ing through the legendary F-117 and reaching the present day with the F-22 Raptor to the J-20, the leap in technology was huge and will grow even more, as we have already talked about the development of 6th generation, which will bring a new concept of air warfare.
What are the true secrets of the 5th generation, we don't know everything, we know what is ed and shared by websites, experts and the like. Many technologies the countries themselves avoid disclosing, so that enemies cannot exploit the flaws of this system.
The Russians themselves who claim to have such technology to locate these planes still bet on stealth planes, proof of this is the SU-57 and the UAV S-70, both aircraft of great Russian investment for the 21st Century.
But until the 6th generation arrives, and new things come to impress us with such technology and man's intelligence in creating them, we will continue to enjoy these planes from the world of military aviation.
See photos of the main aircraft of this class in combat aviation:
