It is the most expensive aircraft in the world
It is also the only stealth bomber in service in the world today
It was the U.S. Air Force's B-2 bomber
Is it true that the aircraft was developed on The technology of Germany in World War II, and even more so, some claim that it was helped by extraterrestrial technology?
Unfortunately neither.
So how exactly was the B-2 developed, and what are the technical difficulties of this aircraft? Today, let's analyze them one by one.
(B-2 stealth bomber)
1
Unique big bat
The B-2 bombers featured a unique flying wing layout.
The B-2 using this layout had no horizontal tail, not even a vertical tail, and the side profile of the entire aircraft was very flat.
From the top of the fuselage, the plane resembles a giant boomerang, and because the B-2 is painted in pure black, some people call it a "big bat".
The main purpose of this layout is to maximize radar stealth capabilities.
To enhance the radar's stealth capability, it is necessary to minimize the scattering source, or to concentrate the scattered electromagnetic waves in one direction, so that the radar can only receive electromagnetic waves at specific angles.
Under the illumination of radar, the aircraft mainly has several scattering sources that are easy to find, which are: mirror scattering, edge/tip diffraction, cavity scattering and so on.
Mirror scattering mainly occurs on a large area of continuous body skin, edge diffraction mainly appears in the sharp anterior and posterior edges of the wing surface, wingtip angles and other positions, while cavity scattering generally occurs in the intake tract and engine tail nozzle.
At the same time, the vertical tail of the aircraft and other different sides of the main wing, it is also easy to produce a special two-sided reflection area through multiple specular reflections.
To deal with these scattering sources, there is a lot of work that needs to be done.
(edges of the wings parallel to each other)
First of all, the outer surface of the aircraft should be designed as flat as possible, the echo generated by the mirror scattering should be concentrated in one direction, and the vertical tail should be arranged vertically with the fuselage and the main wing surface, or the vertical tail should be simply cancelled to eliminate the two-sided area.
Second, most of the wing edges should be parallel to each other, the echoes generated by the edge framing should be concentrated, and the sharp angle of the wing tips should be reduced as much as possible, weakening the scattering of the tip points.
Third, the intake tract should be designed as an S-shaped to avoid exposing the structurally complex engine intake blades to direct radar waves, so as to reduce cavity scattering.
The flying wing layout used by the B-2 stealth bomber is almost perfect for any of the above.
(B-2 inlet arrangement)
As mentioned earlier, the B-2 is very flattened.
The aircraft did not even have a tail and a flat tail, and the fuselage and wing edges were designed to be the only two parallel directions, which made the B-2's control of mirror scattering and edge diffraction very good.
What is even more unique is that in addition to designing the intake tract as an S-shape, the B-2 also places its opening on the back surface.
In this way, when the aircraft is illuminated by ground radar, the airframe can be used to block the air intake, completely blocking the risk of detection caused by cavity scattering.
Overall, the B-2's stealth design is excellent, and the radar reflection area of such a behemoth at some angles is even smaller than that of a fighter jet.
(B-2 rudder)
But on the other hand, the use of flying wing layout also brought great trouble to the flight control of the B-2 bomber.
Due to the absence of horizontal and vertical tails, the B-2 could only be controlled by rudder on the trailing edge of the wing.
The rudder of the B-2 is actually a set of gear plates that can be cracked, and when the aircraft needs to make a head-up movement, the gear plate on the upper surface of the wing will open to produce a downward torque to "pry" the aircraft, and the opposite is true when doing the downward movement.
If rolling is required, the gear plates on both sides of the wing only need to be differential.
However, the efficiency of this control method is significantly less than that of conventional flat tails and vertical tails.
And due to the influence of the airflow attachment layer on the surface of the wing, the opening angle of the gear plate must exceed at least 5 ° to play the role of flight control.
Therefore, in normal cruise flight, the B-2's control rudder surface is usually open, and it will only be closed to enhance stealth performance when entering a high-threat area.
At the same time, the B-2, which does not have a tail to assume the function of heading stabilization, will lack the return torque when rolling and yawing, which greatly increases the risk of loss of control.
All of these disadvantages add up to make the B-2's flight performance weaker, but this partial design has been exchanged for excellent stealth performance.
After all, the bomber does not need too strong flight performance, in most cases only need to smooth the cruise and then drop ammunition, once attacked by fighters, the bomber no matter how maneuverable it is, I am afraid that it will be doomed.
Therefore, only by reducing the possibility of detection can we better complete the strike mission, which is also the guiding ideology of the B-2 design.
However, the flying wing layout used for the first time also brought other negative effects, such as expensive.
2
B-2, which is more expensive than equal weight gold
In 1997, the first six B-2 bombers were officially delivered to the U.S. Air Force, and the purchase price of these B-2 bombers reached a staggering $2.4 billion.
What is the concept of this price?
The price of gold in 1997 was about $12 to $13 per gram, while the empty weight of a B-2 bomber was 71.7 tons, which means that the price of gold equivalent to the weight of the B-2 was only about $900 million.
One B-2 bomber is equivalent to 2.5 times the price of equal weight gold.
If the B-2 bomber is put today, after taking into account inflation and other factors, the price of a B-2 is about $5 billion, which is enough to purchase nearly 60 F-35 stealth fighter bare aircraft.
Seeing this, I believe that all readers understand how expensive a B-2 is.
So what makes it so expensive?
There are many answers, such as materials, production processes, subsystems, etc., but these are not the most important factors.
What really accounts for the bulk of the B-2's procurement budget is the producer's profits.
According to the relevant data, the cost of a B-2 is about $1.3 billion, which means that of the $2.4 billion purchased, $1.1 billion is the profit of the producer.
Such a huge amount of money was separated by Northrop Grumman and Boeing, and the most profitable of them was Northrop Grumman, who undertook the design work and guided the central fuselage, cockpit and other parts.
Even of the $1.3 billion cost, only about $600 million is manufacturing costs, while the remaining $700 million is a research and development cost that is evenly distributed to each aircraft.
(B-2 Rough Structure Perspective)
Such a high cost has reduced the number of B-2 purchases from the initial forecast of 133 to 21, and the reduction in the number of purchases has further increased the research and development costs that each B-2 needs to be shared equally, forming a vicious circle.
The only 22 B-2 bombers were so rare that they even had their own name like warships.
However, such a precious bomber was also scrapped, seriously injured, and slightly injured because of the accident.
They are the 12th Kansas Phantom and the 11th Washington Phantom, respectively, while the minor injuries to which one have not been made public.
The Kansas Phantom crashed on February 23, 2008, just 17 seconds after takeoff due to a failure of an atmospheric data sensor.
The Washington Phantom had an engine fire in February 2010, but the Air Force decided to repair it because the damage to the airframe was not serious.
In the early morning of September 14 last year, another B-2 bomber crashed off the runway in an accident while landing, but fortunately did not cause major damage.
3
B-2 design copied from Germany?
The advancement of the B-2 once made many military fans lament that this is the product of extraterrestrial technology, but this is not the case, and the development of the flying wing layout actually has a very clear historical context.
The early wing layout of the aircraft, most famously the HO229 bomber prototype, which first flew in Germany in 1944.
The aircraft, designed by the Horton brothers, has a fuselage length of nearly 7.5 meters and a wingspan of nearly 16.8 meters, powered by two turbojet engines, and is expected to fly at a maximum speed of mach 0.9 at high subsonic speeds.
After the Allies won World War II, these strangely shaped aircraft were basically captured by the US military, and it is for this reason that there is a claim that the B-2 borrowed the design of the HO229.
Is this really the case?
（HO229）
In fact, this claim is a complete rumor.
Northrop Grumman, which produced and designed the B-2 stealth bomber, developed the flying wing layout earlier than the HO229.
As early as the end of the 1930s, Northrop Grumman began to develop the flying wing layout aircraft, and manufactured the first flying wing layout aircraft in the United States, the N-1M.
The N-1M wing layout demonstrator also made its maiden flight on 3 July 1940 and showed good performance.
Such success led the U.S. military to become increasingly interested in flying wing layout aircraft.
(N-1M)
Finally, in November 1941, the U.S. Army Air Force, the predecessor of the U.S. Air Force, invested in Northrop to develop a truly military-valuable flying wing layout bomber, the XB-35.
Although it first flew later than the German HO229 and used traditional piston propeller power, it was much larger than the latter, with an XB-35 fuselage length of 11.43 meters and a wingspan of 52.43 meters.
The XB-35 bomber can be said to be the real predecessor of the B-2, and before the XB-35, Northrop's journey to develop the flying wing layout bomber is enough to prove that the B-2 has no connection with the German HO229.
（XB-35）
4
Can't B-2 be surpassed?
To this day, the B-2 is still the only stealth bomber in the world today with a flying wing layout, and can't this bomber really be surpassed?
Admittedly, designing an aircraft with a flying wing layout is challenging.
Although the idea of flying wing layout was proposed earlier, Boris Cheranowski of the former Soviet Union built the first aircraft with flying wing layout as early as 1924.
However, due to the problems in flight control of the flight wing layout mentioned above, until the invention of fly-by-wire flight control, the accident rate of this aircraft was very high.
Therefore, the manufacture of a mature and usable flying wing layout bomber requires a long period of scientific research accumulation, which is why countries around the world have not yet developed a second flying wing stealth bomber.
However, the B-2 bomber was not completely flawless.
Because the bomber was designed and built in an older age, its avionics system was less compatible, and the ability to use other munitions developed subsequently would often require major changes.
The original B-2 could only use all kinds of virtually unpowered free-fall bombs, such as the JDAM Jet Dam joint guided attack bomb, the GBU-37 ground-penetrating bomb, and even the B-61 tactical nuclear bomb.
Although these bombs also have precise guidance capabilities, they require the B-2 to rely on stealth ability to sneak into the air over the target and drop it.
(B-2 Mount Solution)
In the past, when air defense and anti-stealth technology were still relatively backward, this trick was still relatively easy to use, but with the development of anti-stealth radar and other equipment in various countries, such tactics were not feasible.
After all, no matter how good the B-2's stealth performance, it is impossible to drop bombs in the air in a powerful air defense network without being detected.
Therefore, in the subsequent improvement and upgrading, the B-2 is also specially equipped with the fire control module of the JASSM cruise missile, which officially has the ability to strike outside the defense zone.
However, the range of JASSM is only 500 kilometers, and today, when the fifth-generation aircraft and anti-stealth radars of various countries are in service, the range of 500 kilometers is not enough.
However, the B-2 has not yet obtained the launch capability of a new generation of LARSM missiles due to the poor compatibility of avionics systems.
(B-21 Imaginary)
Therefore, the United States also proposed a development plan for the next generation of stealth bombers, that is, the B-21 stealth bomber.
Since there is no need to cross the Arctic route for nuclear deterrence missions, the B-21 bomber developed for east Asian conditions has been greatly reduced in size and weight, and the combat radius will be reduced to about 4,000 kilometers.
However, the B-21 has very high information and digital capabilities, and its design indicators include the ability to command drones, and the B-21 can even launch air-to-air missiles for self-defense air combat under the guidance of other fighters or drones.
The mainland has also invested a lot of resources in the development of a new generation of stealth bombers, and there is evidence that the mainland's flying wing layout stealth bombers have also entered the manufacturing stage, let's wait and see!