The fastest plane in the world. Supersonic aircraft Supersonic aircraft flight speed

Published Tue, 09/29/2015 - 07:20 by russianinterest...

Original taken from Speed, like a dream. Speed ​​as a calling

The 1960s can perhaps be considered the golden years of supersonic aviation. It was at that time that it seemed that just a little more - and squadrons of supersonic aircraft would become the only option for air combat, and supersonic airliners would trace our firmament with their tracks, connecting everything big cities and world capitals. However, it turned out that, as in the case of manned space, man’s journey to high speeds is by no means strewn with roses: passenger aviation remained frozen at around 800 kilometers per hour, and military aircraft hovered around the sound barrier, occasionally daring to briefly fly into the low supersonic region, around Mach 2 or a little more.

What is this connected with? No, not at all because “there is no need to fly fast” or “no one needs this.” Rather, what we are talking about here is that at some point the world began to follow the path of least resistance and considered that scientific and technical progress- this is a self-running cart that is already going downhill, so pushing it additionally is just an unnecessary waste of extra effort.

Let’s ask ourselves a simple question: why is supersonic flight so difficult and expensive? Let's start with the fact that when overcoming an airplane supersonic barrier The nature of the flow around the body of the aircraft changes dramatically: aerodynamic drag increases sharply, kinetic heating of the airframe structure increases, and due to a shift in the aerodynamic focus of the streamlined body, the stability and controllability of the aircraft is lost.

Of course, for the average person and unprepared reader, all these terms sound quite faded and incomprehensible, but if we summarize all this in one phrase, we get: “it’s difficult to fly at supersonic speed.” But, of course, it is by no means impossible. At the same time, in addition to increasing engine power, the creators of supersonic aircraft have to consciously change the appearance of the aircraft - characteristic “swift” straight lines appear in it, sharp angles on the nose and leading edges, which immediately distinguishes a supersonic aircraft even externally from “smooth” ones. "and "sleek" forms of subsonic aircraft.

The nose of the Tu-144 leaned down during takeoff and landing to provide at least minimal visibility to the pilots.

In addition, when optimizing an aircraft for supersonic flight, it develops another unpleasant feature: it becomes poorly suited for subsonic flight and is quite clumsy in takeoff and landing modes, which it still has to carry out at fairly low speeds. The same sharp lines and sweeping shapes that are so good at supersonic give in to the low speeds at which supersonic aircraft inevitably have to move at the beginning and end of their flight. And the sharp noses of supersonic cars also prevent pilots from full review Runway.

Here, as an example, are the nose parts of two Soviet supersonic aircraft that were not implemented in the series - the M-50 of the Myasishchev Design Bureau (in the background) and the T-4 “object 100” of the Sukhoi Design Bureau (nearby).

The efforts of the designers are clearly visible: this is either an attempt to reach a compromise in contours, like the M-50, or a sliding nose, deviating downwards, like the T-4. It is interesting that the T-4 could well have become the first production supersonic aircraft that would fly completely in horizontal supersonic flight without natural visibility through the cockpit canopy: at supersonic, the nose cone completely covered the cockpit and all navigation was carried out only by instruments, in addition, the aircraft had optical periscope. The current level of development of navigation and telemetry means, by the way, makes it possible to abandon the complex design of the movable nose cone of a supersonic aircraft - it can already be lifted and landed only by instruments, or even without the participation of pilots at all.

Identical conditions and tasks give rise to similar designs. The Anglo-French Concorde's nose also moved down during takeoff and landing.

What prevented the USSR from creating, already in 1974, an innovative anti-ship warfare system based on the supersonic T-4, which was so advanced that there were as many as 600 patents in its design alone?

The thing is that by the mid-1970s the Sukhoi Design Bureau did not have its own production capacity to conduct extended state tests of the “100 object”. For this process, what was needed was not an experimental, but a serial plant, for which KAPO (Kazan Aviation Plant) was quite suitable. However, as soon as the decree began to be prepared on the preparation of the Kazan Aviation Plant for the assembly of the pilot batch of T-4, Academician Tupolev, realizing that he was losing the serial plant where the “strategic defect carrier” Tu-22 was produced, came up with an initiative proposal to create its modification Tu-22M, for which, supposedly, it was only necessary to slightly repurpose production. Although, later, the Tu-22M was developed as a completely new aircraft, the decision to transfer the Kazan plant to Sukhoi was not made at the time, and the T-4 eventually ended up in a museum in Monino.

Such a big difference between the Tu-22 and Tu-22M is a legacy of the fight against the T-4.

The issue of the nose cone is not the only compromise that the creators of supersonic aircraft have to make. For many reasons, they end up with both an imperfect supersonic glider and a mediocre subsonic aircraft. Thus, often the conquest of new frontiers in speed and altitude by aviation is associated not only with the use of a more advanced or fundamentally new propulsion system and a new aircraft layout, but also with changes in their geometry in flight. This option was never implemented in the first generation of supersonic vehicles, but it was this idea of ​​a variable-sweep wing that eventually became practically canon in the 1970s. Such changes in wing sweep, while improving the aircraft's performance at high speeds, should not have deteriorated their performance at low speeds, and vice versa.

The Boeing 2707 was supposed to be the first passenger supersonic aircraft with variable sweep wings.

It is interesting that the fate of the Boeing 2707 was ruined not by its design imperfections, but only by a host of political issues. By 1969, as Boeing's 2707 development program entered its final stretch, 26 airlines had ordered 122 2707s from Boeing at a cost of nearly $5 billion. At this point, the Boeing program had already left the design and research phase and construction of two prototypes of the 2707 model had begun. To complete their construction and manufacture test aircraft, the company needed to raise somewhere between 1-2 billion. And the total cost of the program with construction 500 aircraft was approaching $5 billion. Government loans were required. Fundamentally, in another time, Boeing would have found its own funds for this, but the 1960s were not like that.

In the late 1960s, Boeing's production facilities were heavily loaded with the creation of the largest subsonic passenger aircraft in the world - the Boeing 747, which we still fly today. Because of this, model 2707 literally “did not crowd” ahead of the “air cattle carrier” for several years and ended up behind its knobby fuselage. As a result, all available funding and all equipment were used for the production of the 747, and 2707 was financed by Boeing on a residual basis.

Two approaches to passenger aviation - Boeing 747 and Boeing 2707 in one picture.

But the difficulties with the 2707 were much more serious than just technical issues or Boeing's production program. Since 1967, the environmental movement against supersonic passenger transport has been growing in the United States. It was argued that their flights would destroy the ozone layer, and the powerful acoustic shock generated by supersonic flight was considered unacceptable for populated areas. Under pressure from public opinion and then from Congress, President Nixon created a 12-member commission to resolve the issue of financing the SST program, which included the Boeing 2707. But contrary to his expectations, the commission rejects the need for an SST not only for environmental but also for economic reasons. To create the first aircraft, according to their calculations, it was necessary to spend $3 billion, which would only pay off if 300 aircraft were sold. The financial condition of the United States was weakened by the long war in Vietnam and the costs of the lunar race.

Work on the 2707 model was stopped in 1971, after which Boeing tried to continue construction for about a year using its own funds. In addition, private individuals, including students and schoolchildren, also tried to support the “American Dream Plane”, for which more than a million dollars were raised. But this did not save the program. The eventual demise of the program coincided with a downturn in the aerospace industry and the oil crisis, as a result of which Boeing was forced to lay off almost 70,000 of its employees in Seattle, and the Model 2707 became known as “the plane that ate Seattle.”

Goodnight, sweet prince. The cockpit and part of the fuselage of a Boeing 2707 at the Hiller Aviation Museum.

What motivated the creators of supersonic cars? The situation with military customers is generally clear. Warriors always needed a plane that would fly higher and faster. Supersonic flight speed made it possible not only to reach enemy territory faster, but also to increase the flight ceiling of such an aircraft to an altitude of 20-25 kilometers, which was important for reconnaissance aircraft and bombers. At high speeds, as we remember, the lifting force of the wing also increases, due to which the flight could take place in a more rarefied atmosphere, and, as a result, at a higher altitude.

In the 1960s, before the advent of anti-aircraft missile systems capable of hitting targets at high altitudes, the main principle of using bombers was to fly to the target at the highest possible altitude and speed. Of course, current air defense systems cover this kind of niche for the use of supersonic aircraft (for example, the S-400 complex can shoot down targets directly in space, at an altitude of 185 kilometers and at their own speed of 4.8 km/s, essentially being a missile defense system , not air defense). However, in actions against ground, surface and air targets, supersonic speed is quite in demand and is still present in long-term military plans for both Russian and Western aircraft. It’s just that the implementation of a rather complex supersonic flight is difficult to compatible with the task of stealth and stealth that they have been trying to instill in bombers and fighters over the past 30 years, due to which you have to choose, as they say, one thing - either hide or break through.

However, does Russia now have a reliable weapon against American AUGs? So, not to get within 300 kilometers of them to launch the Onyxes by some inconspicuous but vulnerable vessel? The T-4 had a coherent concept of its own style of destroying an aircraft carrier group, but does Russia have it now? I think not - just as there are still no hypersonic missiles X-33 and X-45.

American bomber XB-70 Valkyrie. It was with them that the MiG-25 was supposed to fight.

Where the future of military aircraft will turn is an open question.

I want to say a few more words about civil supersonic aircraft.

Their operation made it possible not only to significantly reduce flight time on long-distance flights, but also to use unloaded airspace at high altitudes (about 18 km), while the main airspace used by airliners (altitudes 9-12 km) was already even in the 1960s significantly busy. Also, supersonic aircraft flew along straight routes (outside airways and corridors). And this is not to mention the most basic: saving time for ordinary passengers, which amounted to about half the flight time during, for example, a Europe-USA flight.

At the same time, I repeat once again - the project of supersonic aircraft, both military and civilian, is by no means impossible from a practical point of view or in any way unrealistic from an economic point of view.

We just took a wrong turn at one time and rolled the cart of progress not uphill, but along the easiest and most pleasant path - down and downhill. Even today, supersonic passenger aircraft projects are being developed for the same segment for which another innovative concept was made: the Augusta-Westland AW609 tiltrotor. This segment is the segment of business transportation for wealthy clients, when the plane carries not five thousand passengers in brutal conditions, but a dozen people in conditions of maximum efficiency and maximum comfort. Meet Aerio AS2. If you're lucky, it will fly in the near future, in 2021:

I think everything is already quite serious there - both the partnership with Airbus and the announced investments of 3 billion dollars allow us to consider the project not a “decoy”, but a serious application. In short, “a respectable gentleman - for respectable gentlemen.” And not for any beggars who allowed the world at the end of the twentieth century to turn onto an easy and convenient path.

However, I already wrote about this, I will not repeat it. Now it's nothing more than the past:

Now we live in a different world. In a world without supersonic aviation for everyone. However, this is not the worst loss.

The exploration of the sky has been an unattainable dream for mankind for many centuries. After the expanses were finally conquered, the aircraft became more and more sophisticated and durable. A significant achievement in this field was the invention of supersonic military and passenger aircraft. One of these airliners was the Tu-244, the features and characteristics of which we will consider further. Unfortunately, this project did not develop into mass production, like most similar developments. Funds are currently being sought to resume development of this project or similar aircraft.

How did it all begin?

Aviation began to develop rapidly after the Second World War. Various projects of aircraft with jet engines were developed, which were supposed to replace conventional power units. An important point the creation of supersonic airliners was not about achieving the speed of sound, but about overcoming this barrier, since aerodynamic laws change at such speeds.

Similar technologies began to be used en masse in the fifties of the last century. Among the serial modifications we can note domestic MiGs, American North American fighters, Delta Dagger, French Concordes and many others. In passenger aviation, the introduction of supersonic speeds was much slower. The Tu-244 is an aircraft that could not only compete in this industry, but become a world leader in it.

Development and creation

The first experimental civil aircraft capable of breaking the sound barrier appeared in the second half of the sixties of the 20th century. From then until now, only two models have been put into mass production: the Tu-144 and the French Concorde. The airliners were typical aircraft for ultra-long flights. The operation of these machines ceased to be relevant in two thousand and three. Currently, supersonic airliners are not used to transport passengers.

There have been attempts to create new modifications of civilian jet airliners, but most of them remained under development or were closed altogether. Such long-term projects include the Tu-244 supersonic passenger aircraft.

It was supposed to replace its predecessor and have improved characteristics borrowed from prototypes - Concorde and some American aircraft. The project was fully developed by the Tupolev design bureau; in 1973, the aircraft under development received the name Tu-244.

Purpose

The main objective of the project being developed was the creation of a supersonic jet aircraft capable of transporting passengers safely, quickly and over long distances. Moreover, the device had to be significantly superior in all respects to conventional jet aircraft. The designers placed a special emphasis on speed.

In other aspects, supersonic aircraft were inferior to their counterparts. Firstly, transportation was not economically profitable. Secondly, flight safety was lower. By the way, the serial production and use in civil aviation of the predecessor of the Tu-244 was discontinued precisely for the second reason. During the first year of operation, the Tu-144 suffered several accidents that led to the death of the crew. The new project was supposed to eliminate the shortcomings.

Tu-244 (aircraft): technical characteristics

The final model of the airliner in question was supposed to have the following tactical and technical indicators:

1. The crew piloting the aircraft includes three pilots.
2. Passenger capacity varied from 250 to 300 people.
3. The estimated cruising speed is 2175 kilometers per hour, which is twice the sound barrier.
4. Power plants - four motors with turbine fans.
5. The flight range is from seven to nine and a half thousand kilometers.
6. The carrying capacity is three hundred tons.
7. Length / height - 88 / 15 meters.
8. Working surface area - 965 sq. m.
9. The wingspan is forty-five meters.

If we compare the speed indicator, the projected Tu-244 passenger aircraft, the history of which is quite interesting, has become a little slower than its direct competitors. However, due to this, the designers wanted to increase capacity and increase the economic benefits of operating the machine.

Future prospects

The development of a new project, the result of which was supposed to be a supersonic passenger aircraft Tu-244, dragged on for many years. A lot of changes and improvements were made to the design. However, even after the collapse of the USSR, the Tupolev Design Bureau continued to work in the given direction. In 1993, detailed information about the project was even presented.

Nevertheless, the economic crisis of the nineties had a negative impact on this area. There was no official message about the closure of developments, nor any active actions. The project was on the verge of being frozen. Specialists from the United States are joining the work, negotiations with whom have been ongoing for a long time. To continue research, two aircraft of the one hundred and forty-fourth series were converted into flying laboratories.

What's next?

The supersonic Tu-244 (the aircraft whose photo is presented below) unexpectedly disappeared from the design documentation as an object of research. It was adopted in two thousand and twelve and assumed that the first hundred units of passenger airliners would enter service no later than 2025. This leapfrog with documentation raised a number of questions and misunderstandings. In addition, several other interesting and promising developments have disappeared from this program.

This prospect was seen in a negative way. Facts indicated that the project was frozen or closed completely. However, there was no official confirmation or denial about this. Given the instability of the economy, a lot of assumptions can be made in a subjective configuration, but the facts speak for themselves.

Realities of today: Tu-244 (aircraft)

History of creation of this aircraft was stated above. How are things going now? Considering all that has been said, it can be assumed that the project in question is currently at least hanging in the air, if not completely covered. There is no official submission of a statement about the fate of the development, as well as the reasons for the reduction and suspension of the project. It is quite possible that the main problem is insufficient funding, economic inadequacy or obsolescence. Alternatively, all three of these factors together may be present.

Not so long ago (2014) in the means mass media information leaked about the possible resumption of the Tu-244 project. However official version Again, no action was taken on this issue. For the sake of objectivity, it is worth noting that foreign developments of passenger supersonic airliners are also far from complete, many of them are closed or are under big question. I would like to believe that this grandiose machine will be built according to all modern standards in the near future.

A little about the predecessor

Development of TU-144 by decision of the Council of Ministers Soviet Union began in nineteen sixty-nine. Construction of a supersonic civil aircraft started at MMZ "Experience". The estimated flight range of the airliner should be three and a half thousand kilometers. To improve aerodynamics, the aircraft received a modified wing planform and an increased area.

The length of the fuselage is designed to accommodate internal accommodation of one hundred and fifty passengers. Two pairs of engines were placed under each wing. The jet aircraft made its first flight in 1971. The factory test program included about two hundred and thirty flights.

Comparative characteristics

The supersonic Tu-244 is an aircraft whose dimensions are somewhat larger than those of its predecessor. It has distinctive parameters in other tactical and technical meanings. For comparison, consider the performance of the Tu-144 airliner:

• crew - four people;
• capacity - one and a half hundred passengers;
• length / height - 67 / 12.5 meters;
• thrust with afterburner - 17,500 kg/s;
• maximum weight - one hundred eighty tons;
• cruising speed is 2,200 kilometers per hour;
• practical ceiling - eighteen thousand meters;
• maximum range - six and a half thousand kilometers.

The main external difference between the new aircraft (Tu-244) and its predecessor was supposed to be a change in the design of the curved nose.

The cardinal feature of the two hundred and forty-fourth project from its prototype under the symbol “144” is the absence of a downward deflecting nose. The cabin glazing is minimally equipped. This solution is designed to provide the necessary visibility during the flight, and takeoff and landing, regardless of weather conditions, are controlled by an electronic vision optics unit.

It is worth noting that modern environmental requirements for civil airliners significantly impede the creation of a supersonic aircraft of this class, since its operation a priori becomes economically detrimental. Developments have been undertaken to create a supersonic business class aircraft capable of breaking the supersonic barrier. However, the Tu-444 project was also suspended. Its advantages over its competitors are its relative low cost compared to the Tu-244 airliner, as well as the solution to technical issues related to environmental requirements for modern aircraft. For reference: the supersonic airliner in question was presented to the general public in France (1993, Le Bourget air show).

Finally

If all Soviet initiatives in aviation had been finalized and implemented, it is quite possible that this industry would have made a huge leap forward. However, economic, political and other problems significantly slow down this process. One of the most prominent representatives in the world of supersonic civil aviation was to be the Tu-244 airliner. Unfortunately, for a number of reasons, the project is still in development or in a “suspended” state. I would like to hope that there will be people who will finance the project, and this will ultimately lead to the creation of not only the fastest passenger aircraft, but also the transport of the future, characterized by efficiency, capacity and safety.

“Turn on supersonic!”

Supersonic passenger aircraft - what do we know about them? At least that they were created relatively long ago. But, for various reasons, they were not used for as long and not as often as they could have. And today, they exist only as design models.

Why is that? What is the peculiarity and “secret” of supersonic sound? Who created this technology? And also – what will be the future of supersonic aircraft in the world, and of course – in Russia? We will try to answer all these questions.

"Farewell flight"

So, fifteen years have passed since the last three functioning supersonic passenger aircraft made their last flights, after which they were written off. This was back in 2003. Then, on October 24, they all together “said goodbye to the sky.” The last time we flew at low altitude, over the capital of Great Britain.

Then we landed at London Heathrow Airport. These were Concorde-type aircraft owned by the aviation company British Airways. And with such a “farewell flight” they ended a very short history of passenger transportation at speeds exceeding sound...

That's what you might have thought a few years ago. But now it is already possible to say with confidence. This is the finale of only the first stage of this story. And probably all its bright pages are yet to come.

Today - preparation, tomorrow - flight

Today, many companies and aircraft designers are thinking about the prospects of supersonic passenger aviation. Some are making plans to revive it. Others are already preparing for this with all their might.

After all, if it could exist and function effectively just a few decades ago, today, with technologies that have seriously stepped forward, it is quite possible not only to revive it, but also to solve a number of problems that forced leading airlines to abandon it.

And the prospects are too tempting. The possibility of flying, say, from London to Tokyo in five hours seems very interesting. Cross the distance from Sydney to Los Angeles in six hours? And get from Paris to New York in three and a half? With passenger aircraft, which are capable of flying at higher speeds than sound travels, this is not at all difficult.

But, of course, before its triumphant “return” to the airspace, scientists, engineers, designers, and many others still have a lot of work to do. It's not just about restoring what once was by offering a new model. Not at all.

The goal is to solve many problems associated with passenger supersonic aviation. Creation of aircraft that will not only demonstrate the capabilities and power of the countries that built them. But they will also turn out to be really effective. So much so as to occupy a worthy niche in aviation.

The history of "supersonic" Part 1. What happened in the beginning...

Where did it all begin? In fact, from simple passenger aviation. And he has been like this for more than a century. Its design began in the 1910s in Europe. When the masters of the most developed countries the world created the first aircraft, the main purpose of which was to transport passengers over various distances. That is, a flight with many people on board.

The first among them is the French Bleriot XXIV Limousine. It belonged to the aircraft manufacturing company Bleriot Aeronautique. However, it was used mainly for the amusement of those who paid for pleasure “walks”-flights on it. Two years after its creation, an analogue appears in Russia.

It was the S-21 Grand. It was designed on the basis of the Russian Knight, a heavy bomber created by Igor Sikorsky. And the construction of this passenger aircraft was carried out by workers of the Baltic Carriage Plant.

Well, after that, progress could no longer be stopped. Aviation developed rapidly. And the passenger one, in particular. At first there were flights between specific cities. Then the planes were able to cover distances between states. Finally, aircraft began to cross oceans and fly from one continent to another.

Evolving technologies and everything large quantity innovations allowed aviation to travel very quickly. Much sooner than trains or ships. And for her there were practically no barriers. There was no need to change from one transport to another, not only, say, when traveling to some particularly distant “end of the world”.

Even when it is necessary to cross land and water at once. Nothing stopped the planes. And this is natural, because they fly over everything - continents, oceans, countries...

But time was passing quickly, the world was changing. Of course, the aviation industry also developed. Airplanes over the next few decades, right up to the 1950s, changed so much when compared with those that flew back in the early 1920s and 30s that they became something completely different, special.

And so, in the middle of the twentieth century, the development of the jet engine began at a very rapid pace, even in comparison with the previous twenty to thirty years.

A small informational digression. Or - a little physics

Advanced developments have allowed aircraft to “accelerate” to speeds greater than the speed at which sound travels. Of course, first of all, this was applied in military aviation. After all, we are talking about the twentieth century. Which, sad as it may be to realize, was a century of conflicts, two world wars, the “cold” struggle between the USSR and the USA...

And almost every new technology, created by the leading states of the world, was primarily considered from the point of view of how it could be used in defense or attack.

So, airplanes could now fly at unprecedented speeds. Faster than sound. What is its specificity?

First of all, it is obvious that this is a speed that exceeds the speed at which sound travels. But, remembering the basic laws of physics, we can say that in different conditions, it may differ. And “exceeds” is a very loose concept.

And that’s why there is a special standard. Supersonic speed is one that exceeds sound speed up to five times, taking into account the fact that depending on temperature and other environmental factors, it can change.

For example - if we take normal atmospheric pressure at sea level, then in this case the speed of sound will be equal to an impressive figure - 1191 km/h. That is, 331 meters are covered in a second.
But what is especially important when designing supersonic aircraft is that as you gain altitude, the temperature decreases. This means the speed with which sound travels is quite significant.

So let's say, if you rise to a height of 20 thousand meters, then here it will already be 295 meters per second. But there is another important point.

At 25 thousand meters above sea level, the temperature begins to rise, since this is no longer the lower layer of the atmosphere. And so it goes on. Or rather, higher. Let's say at an altitude of 50,000 meters it will be even hotter. Consequently, the speed of sound there increases even more.

I wonder - for how long? Having risen 30 kilometers above sea level, you find yourself in a “zone” where sound travels at a speed of 318 meters per second. And at 50,000 meters, respectively – 330 m/s.

About the Mach number

By the way, it is interesting that to simplify the understanding of the features of flight and work in such conditions, the Mach number is used in aviation. general description such, can be reduced to the following conclusions. It expresses the speed of sound that occurs under given conditions, at a particular altitude, at a given temperature and air density.

For example, the flight speed, which is equal to two Mach numbers, at an altitude of ten kilometers above the ground, under normal conditions, will be equal to 2,157 km/h. And at sea level - 2,383 km/h.

The history of "supersonic" Part 2. Overcoming barriers

By the way, for the first time a pilot from the USA, Chuck Yeager, achieved flight speeds of more than Mach 1. This happened in 1947. Then he “accelerated” his plane, flying at an altitude of 12.2 thousand meters above the ground, to a speed of 1066 km/h. This is how the first supersonic flight took place on earth.

Already in the 1950s, work began on the design and preparation for mass production of passenger aircraft capable of flying at speeds faster than sound. They are led by scientists and aircraft designers from the most powerful countries in the world. And they manage to succeed.

That same Concorde, a model that will finally be abandoned in 2003, was created in 1969. This is a joint British-French development. The symbolically chosen name is “Concorde”, from French, translated as “concord”.

It was one of two existing types of supersonic passenger aircraft. Well, the creation of the second (or rather, chronologically, the first) is the merit of the aircraft designers of the USSR. The Soviet equivalent of the Concorde is called the Tu-144. It was designed in the 1960s and made its first flight on December 31, 1968, a year before the British-French model.

To this day, no other types of supersonic passenger aircraft have been implemented. Both the Concorde and the Tu-144 flew thanks to turbojet engines, which were specially rebuilt in order to operate at supersonic speed for a long time.

The Soviet analogue of the Concorde was operated for a significantly shorter period. Already in 1977 it was abandoned. The plane flew at an average speed of 2,300 kilometers per hour and could carry up to 140 passengers at a time. But at the same time, the price of a ticket for such a “supersonic” flight was two, two and a half, or even three times more than for an ordinary one.

Of course, such things were not in great demand among Soviet citizens. And maintaining the Tu-144 was not easy and expensive. That’s why they were abandoned so quickly in the USSR.

Concordes lasted longer, although tickets for the flights they flew were also expensive. And the demand was not great either. But still, despite this, they continued to be exploited, both in Great Britain and in France.

If you recalculate the cost of a Concorde ticket in the 1970s at today's exchange rate, it will be about two tens of thousands of dollars. For a one way ticket. One can understand why the demand for them was somewhat less than for flights using aircraft that do not reach supersonic speeds.

Concorde could carry from 92 to 120 passengers at a time. He flew at a speed of more than 2 thousand km/h and covered the distance from Paris to New York in three and a half hours.

Several decades passed like this. Until 2003.

One of the reasons for the refusal to operate this model was a plane crash that occurred in 2000. At that time, there were 113 people on board the crashed Concorde. They all died.

Later, an international crisis began in the field of passenger air transportation. Its cause is the terrorist attacks that occurred on September 11, 2001, in the United States.

Moreover, on top of that, the warranty period for the Concorde is ending. Airbus airline. All this together made the further operation of supersonic passenger aircraft extremely unprofitable. And in 2003, all Concordes were written off one by one, both in France and in the UK.

Hopes

After this, there were still hopes for a quick “return” of supersonic passenger aircraft. Aircraft designers talked about creating special engines that would save fuel, despite the flight speed. We talked about improving the quality and optimizing the main avionics systems on such aircraft.

But, in 2006 and 2008, new regulations of the International Civil Aviation Organization were issued. They defined the latter (by the way, they are valid also on this moment) standards for permissible aircraft noise during flight.

And supersonic planes, as you know, did not have the right to fly over populated areas, that’s why. After all, they produced strong noise pops (also due to the physical characteristics of the flight) when they moved at maximum speeds.

This was the reason that the “planning” of the “revival” of supersonic passenger aviation was somewhat slowed down. However, in fact, after the introduction of this requirement, aircraft designers began to think about how to solve this problem. After all, it also took place before, it’s just that the “ban” focused attention on it – the “noise problem”.

What about today?

But ten years have passed since the last “ban”. And planning smoothly turned into design. Today, several companies and government organizations are engaged in the creation of passenger supersonic aircraft.

Which ones exactly? Russian: Central Aerohydrodynamic Institute (the same one that is named after Zhukovsky), Tupolev and Sukhoi companies. Russian aircraft designers have an invaluable advantage.

The experience of Soviet designers and creators of the Tu-144. However, it is better to talk about domestic developments in this area separately and in more detail, which is what we propose to do next.

But it’s not just the Russians who are creating a new generation of supersonic passenger aircraft. This is also a European concern - Airbus, and the French company Dassault. Among the companies in the United States of America that are working in this direction are Boeing and, of course, Lockheed Martin. In the country rising sun The main organization designing such an aircraft is the Aerospace Exploration Agency.

And this list is by no means complete. It is important to clarify that the overwhelming majority of professional aircraft designers working in this field are divided into two groups. Regardless of country of origin.

Some believe that it is in no way possible to create a “quiet” supersonic passenger aircraft at the current level of technological development of mankind.

Therefore, the only way out is to design a “simply fast” airliner. It, in turn, will go to supersonic speed in those places where this is allowed. And when flying, for example, over populated areas, return to subsonic.

Such “jumps,” according to this group of scientists and designers, will reduce flight time to the minimum possible, and not violate the requirements for noise effects.

Others, on the contrary, are full of determination. They believe that it is possible to fight the cause of the noise now. And they made a lot of effort to prove that it is quite possible to build a supersonic airliner that flies quietly in the very coming years.

And a little more fun physics

So, when flying at a speed of more than Mach 1.2, the airframe of the aircraft generates shock waves. They are strongest in the tail and nose areas, as well as some other parts of the aircraft, such as the edges of the air intakes.

What is a shock wave? This is an area where air density, pressure and temperature experience sudden changes. They occur when moving at high speeds, faster than sound speed.

To people who are standing on the ground, despite the distance, it seems that some kind of explosion is happening. Of course, we are talking about those who are in relative proximity - under the place where the plane flies. That is why supersonic aircraft flights over cities were banned.

It is precisely such shock waves that representatives of the “second camp” of scientists and designers are fighting against, who believe in the possibility of leveling out this noise.

If we go into detail, the reason for this is literally a “collision” with air at a very high speed. At the wave front there is a sharp and strong increase in pressure. At the same time, immediately after it, there is a drop in pressure, and then a transition to a normal pressure indicator (the same as it was before the “collision”).

However, a classification of wave types has already been carried out and potentially optimal solutions have been found. All that remains is to complete the work in this direction and make the necessary adjustments to the aircraft designs, or create them from scratch, taking into account these amendments.

In particular, NASA specialists came to realize the need for structural changes in order to reform the characteristics of the flight as a whole.

Namely, changing the specificity of shock waves, as far as possible at the current technological level. What is achieved by restructuring the wave, through specific design changes. As a result, the standard wave is considered as an N-type, and the one that occurs during flight, taking into account the innovations proposed by experts, as an S-type.

And with the latter, the “explosive” effect of pressure changes is significantly reduced, and people located below, for example, in a city, if an airplane flies over them, even when they hear such an effect, it is only like a “distant slam of a car door.”

Shape is also important

In addition, for example, Japanese aviation designers, not so long ago, in mid-2015, created an unmanned glider model D-SEND 2. Its shape is designed in a special way, allowing to significantly reduce the intensity and number of shock waves that occur when the device flies at supersonic speed.

The effectiveness of the innovations proposed in this way by Japanese scientists was proven during tests of D-SEND 2. These were carried out in Sweden in July 2015. The course of the event was quite interesting.

The glider, which was not equipped with engines, was raised to a height of 30.5 kilometers. By using hot air balloon. Then he was thrown down. During the fall, he “accelerated” to a speed of Mach 1.39. The length of D-SEND 2 itself is 7.9 meters.

After the tests, Japanese aircraft designers were able to confidently declare that the intensity of the shock waves when their brainchild flies at a speed exceeding the speed of sound propagation is two times less than that of the Concorde.

What are the features of D-SEND 2? First of all, its nose is not axisymmetric. The keel is shifted towards it, and at the same time, the horizontal tail unit is installed as all-moving. It is also located at a negative angle to the longitudinal axis. And at the same time, the tail tips are located lower than the attachment point.

The wing, smoothly connected to the fuselage, is made with normal sweep, but stepped.

According to approximately the same scheme, now, as of November 2018, the supersonic passenger AS2 is being designed. Professionals from Lockheed Martin are working on it. The customer is NASA.

Also, the Russian SDS/SPS project is now at the stage of improving its form. It is planned that it will be created with an emphasis on reducing the intensity of shock waves.

Certification and... another certification

It is important to understand that some projects of passenger supersonic aircraft will be implemented in the early 2020s. At the same time, the rules established by the International Civil Aviation Organization in 2006 and 2008 will still be in force.

This means that if before that time there is no serious technological breakthrough in the field of “quiet supersonic”, then it is likely that aircraft will be created that will reach speeds above one Mach only in zones where this is permitted.

And after that, when the necessary technologies do appear, in such a scenario, many new tests will have to be carried out. In order for aircraft to obtain permission to fly over populated areas. But these are only speculations about the future; today it is very difficult to say anything for sure on this matter.

Question of price

Another problem mentioned earlier is the high cost. Of course, today, many engines have already been created that are much more economical than those that were used twenty or thirty years ago.

In particular, those that can provide aircraft movement at supersonic speed are now being designed, but at the same time do not “eat up” as much fuel as the Tu-144 or Concorde.

How? First of all, this is the use of ceramic composite materials, which reduce temperatures, and this is especially important in hot zones of power plants.

In addition, the introduction of another, third, air circuit - in addition to the external and internal ones. Leveling the rigid coupling of a turbine with a fan, inside an aircraft engine, etc.

But nevertheless, even thanks to all these innovations, it cannot be said that supersonic flight, in today’s realities, is economical. Therefore, in order for it to become accessible and attractive to the general public, work to improve engines is extremely important.

Perhaps the current solution would be a complete redesign of the design, experts say.

By the way, it will also not be possible to reduce the cost by increasing the number of passengers per flight. Because those aircraft that are being designed today (meaning, of course, supersonic aircraft) are designed to transport a small number of people - from eight to forty-five.

New engine- solution to the problem

Among the latest innovations in this area, it is worth noting the innovative jet turbofan power plant created this year, 2018, by GE Aviation. In October it was introduced under the name Affinity.

This engine is planned to be installed on the mentioned AS2 passenger model. There are no significant technological “new products” in this type of power plants. But at the same time, it combines the features of jet engines with high and low bypass ratios. Which makes the model very interesting for installation on a supersonic aircraft.

Among other things, the creators of the engine claim that during testing it will prove its ergonomics. The fuel consumption of the power plant will be approximately equal to that which can be recorded for standard airliner engines currently in operation.

That is, this is a claim that the power plant of a supersonic aircraft will consume approximately the same amount of fuel as a conventional airliner that is not capable of accelerating to speeds above Mach one.

How this will turn out is still difficult to explain. Since the design features of the engine are not currently being disclosed by its creators.

What could they be - Russian supersonic airliners?

Of course, today there are many specific projects for supersonic passenger aircraft. However, not all are close to implementation. Let's look at the most promising ones.

So, Russian aircraft manufacturers who inherited the experience of Soviet masters deserve special attention. As mentioned earlier, today, within the walls of TsAGI named after Zhukovsky, according to its employees, the creation of the concept of a new generation supersonic passenger aircraft has almost been completed.

IN official description The model provided by the press service of the institute mentions that this is a “light, administrative” aircraft, “with a low level of sonic boom.” The design is carried out by specialists, employees of this institution.

Also, in a message from the TsAGI press service it is mentioned that thanks to the special layout of the aircraft body and the special nozzle on which the noise suppression system is installed, this model will demonstrate the latest achievements in the technological development of the Russian aircraft industry.

By the way, it is important to mention that among the most promising TsAGI projects, in addition to what has been described, is a new configuration of passenger airliners called the “flying wing.” It implements several particularly relevant improvements. Specifically, it makes it possible to improve aerodynamics, reduce fuel consumption, etc. But for non-supersonic aircraft.

Among other things, this institute has repeatedly presented finished projects that have attracted the attention of aviation enthusiasts from all over the world. Let’s say, one of the latest, a model of a supersonic business jet, capable of traveling up to 7,000 kilometers without refueling, and reaching a speed of 1.8 thousand km/h. This was presented at the exhibition “Gidroaviasalon-2018”.

“...design is going on all over the world!”

In addition to the Russian ones mentioned above, the following models are also the most promising. American AS2 (capable of speeds up to Mach 1.5). Spanish S-512 (speed limit - Mach 1.6). And also, currently at the design stage in the USA, Boom, from Boom Technologies (well, it will be able to fly at a maximum speed of Mach 2.2).

There is also the X-59, which is being created for NASA by Lockheed Martin. But it will be a flying scientific laboratory, not a passenger plane. And no one has planned to put it into mass production yet.

The plans of Boom Technologies are interesting. Employees of this company say that they will try to reduce the cost of flights on the supersonic airliners created by the company as much as possible. For example, they can give an approximate price for a flight from London to New York. This is about 5000 US dollars.

For comparison, this is how much a ticket for a flight from English capital to “New” York, on a regular or “subsonic” plane, in business class. That is, the price of a flight on an airliner capable of flying at speeds greater than Mach 1.2 will be approximately equal to the cost of an expensive ticket on an airplane that could not make the same fast flight.

However, Boom Technologies bet that it will not be possible to create a “quiet” supersonic passenger airliner in the near future. Therefore, their Boom will fly at the maximum speed it can develop only over water. And when you are above land, switch to a smaller one.

Given that the Boom will be 52 meters long, it will be able to carry up to 45 passengers at a time. According to the plans of the company designing the aircraft, the first flight of this new product should occur in 2025.

What is known so far about another promising project– AS2? It will be able to carry significantly fewer people - only eight to twelve people per flight. In this case, the length of the liner will be 51.8 meters.

Over water, it is planned to be able to fly at a speed of Mach 1.4-1.6, and over land - 1.2. By the way, in the latter case, due to its special shape, the plane, in principle, will not generate shock waves. For the first time, this model should take to the air in the summer of 2023. In October of the same year, the aircraft will make its first flight across the Atlantic.

This event will be timed to coincide with a memorable date - the twentieth anniversary of the day the Concordes last flew over London.

Moreover, the Spanish S-512 will take to the skies for the first time no later than the end of 2021. And deliveries of this model to customers will begin in 2023. The maximum speed of this aircraft is Mach 1.6. It can accommodate 22 passengers on board. The maximum flight range is 11.5 thousand km.

The client is the head of everything!

As you can see, some companies are trying very hard to complete the design and begin creating aircraft as quickly as possible. For whom are they willing to rush in such a hurry? Let's try to explain.

So, during 2017, for example, the volume of air passenger traffic amounted to four billion people. Moreover, 650 million of them flew long distances, spending from 3.7 to thirteen hours on the way. Next - 72 million out of 650, moreover, they flew first or business class.

It is these 72,000,000 people, on average, that those companies that are engaged in the creation of supersonic passenger aircraft are counting on. The logic is simple - it is possible that many of them will not mind paying a little more for a ticket, provided that the flight will be approximately twice as fast.

But, even despite all the prospects, many experts reasonably believe that the active progress of supersonic aviation, created for the transport of passengers, may begin after 2025.

This opinion is confirmed by the fact that the mentioned “flying” laboratory X-59 will first take to the air only in 2021. Why?

Research and Outlook

The main purpose of its flights, which will take place over several years, will be to collect information. The fact is that this aircraft must fly over various populated areas at supersonic speed. Residents of these settlements have already expressed their consent to conduct tests.

And after the laboratory plane completes its next “experimental flight”, people living in those populated areas over which it flew should talk about the “impressions” that they received during the time when the airliner was above their heads. And especially clearly express how the noise was perceived. Did it affect their livelihoods, etc.

The data collected in this way will be transmitted to the Federal Aviation Administration in the United States. And after their detailed analysis by specialists, a ban on flights may be possible. supersonic airliners over populated land areas will be cancelled. But in any case, this will not happen before 2025.

In the meantime, we can watch the creation of these innovative aircraft, which will soon mark the birth of a new era of supersonic passenger aviation with their flights!

Exactly 15 years ago, the last three supersonic passenger aircraft Concorde of the British airline British Airways made a farewell flight. On that day, October 24, 2003, these planes, flying at low altitude over London, landed at Heathrow, ending the short history of supersonic passenger aviation. However, today aircraft designers around the world are again thinking about the possibility of fast flights - from Paris to New York in 3.5 hours, from Sydney to Los Angeles in 6 hours, from London to Tokyo in 5 hours. But before supersonic aircraft return to international passenger routes, developers will have to solve many problems, among which one of the most important is reducing the noise of fast aircraft.

A short history of fast flights

Passenger aviation began to take shape in the 1910s, when the first airplanes specifically designed to transport people by air appeared. The very first of them was the French Bleriot XXIV Limousine from Bleriot Aeronautique. It was used for pleasure air rides. Two years later, the S-21 Grand appeared in Russia, created on the basis of the Russian Knight heavy bomber by Igor Sikorsky. It was built at the Russian-Baltic Carriage Plant. Then aviation began to develop by leaps and bounds: first flights began between cities, then between countries, and then between continents. Airplanes made it possible to get to your destination faster than by train or ship.

In the 1950s, progress in the development of jet engines accelerated significantly, and supersonic flight became available to military aircraft, albeit briefly. Supersonic speed is usually called movement up to five times faster than the speed of sound, which varies depending on the propagation medium and its temperature. At normal atmospheric pressure at sea level, sound travels at a speed of 331 meters per second, or 1191 kilometers per hour. As you gain altitude, the density and temperature of the air decrease, and the speed of sound decreases. For example, at an altitude of 20 thousand meters it is already about 295 meters per second. But already at an altitude of about 25 thousand meters and as it rises to more than 50 thousand meters, the temperature of the atmosphere begins to gradually increase compared to the lower layers, and with it the local speed of sound increases.

The increase in temperature at these altitudes is explained, among other things, by the high concentration of ozone in the air, which forms the ozone shield and absorbs part of the solar energy. As a result, the speed of sound at an altitude of 30 thousand meters above the sea is about 318 meters per second, and at an altitude of 50 thousand - almost 330 meters per second. In aviation, Mach number is widely used to measure flight speed. In simple terms, it expresses the local speed of sound for a specific altitude, density and air temperature. Thus, the speed of a conventional flight, equal to two Mach numbers, at sea level will be 2383 kilometers per hour, and at an altitude of 10 thousand meters - 2157 kilometers per hour. For the first time, American pilot Chuck Yeager broke the sound barrier at a speed of Mach 1.04 (1066 kilometers per hour) at an altitude of 12.2 thousand meters in 1947. This was an important step towards the development of supersonic flights.

In the 1950s, aircraft designers in several countries around the world began working on designs for supersonic passenger aircraft. As a result, the French Concorde and the Soviet Tu-144 appeared in the 1970s. These were the first and so far the only passenger supersonic aircraft in the world. Both types of aircraft used conventional turbojet engines optimized for long work in supersonic flight mode. Tu-144 were in service until 1977. The planes flew at a speed of 2.3 thousand kilometers per hour and could carry up to 140 passengers. However, tickets for their flights cost on average 2.5–3 times more than usual. Low demand for fast but expensive flights, as well as general difficulties in operating and maintaining the Tu-144, led to their removal from passenger flights. However, the aircraft were used for some time in test flights, including under a contract with NASA.

Concorde served much longer - until 2003. Flights on French airliners were also expensive and were not very popular, but France and Great Britain continued to operate them. The cost of one ticket for such a flight was, in terms of today's prices, about 20 thousand dollars. The French Concorde flew at a speed of just over two thousand kilometers per hour. The plane could cover the distance from Paris to New York in 3.5 hours. Depending on configuration, Concorde could carry from 92 to 120 people.

The Concorde story ended unexpectedly and quickly. In 2000, the Concorde plane crash occurred, in which 113 people died. A year later, a crisis began in passenger air travel caused by the terrorist attacks of September 11, 2001 (two planes with passengers hijacked by terrorists crashed into the towers of the World War II shopping center in New York, another, the third, fell into the Pentagon building in Arlington County, and the fourth fell in a field near Shanksville in Pennsylvania). Then the warranty period for Concorde aircraft, which was handled by Airbus, expired. All these factors together made the operation of supersonic passenger aircraft extremely unprofitable, and in the summer and autumn of 2003 airlines Air France and British Airways took turns decommissioning all Concordes.

After the closure of the Concorde program in 2003, there was still hope for the return of supersonic passenger aircraft to service. Designers hoped for new efficient engines, aerodynamic calculations and computer-aided design systems that could make supersonic flights economically affordable. But in 2006 and 2008, the International Civil Aviation Organization adopted new aircraft noise standards that prohibited, among other things, all supersonic flights over populated land areas in Peaceful time. This ban does not apply to air corridors specifically designated for military aviation. Work on projects for new supersonic aircraft has slowed down, but today they have begun to gain momentum again.

Quiet supersonic

Today, several enterprises and government organizations in the world are developing supersonic passenger aircraft. Such projects, in particular, are carried out by the Russian companies Sukhoi and Tupolev, the Zhukovsky Central Aerohydrodynamic Institute, the French Dassault, the Japan Aerospace Exploration Agency, the European concern Airbus, the American Lockheed Martin and Boeing, as well as several startups, including Aerion and Boom Technologies. In general, designers were divided into two camps. Representatives of the first of them believe that it will not be possible to develop a “quiet” supersonic aircraft that matches the noise level of subsonic airliners in the near future, which means that it is necessary to build a fast passenger aircraft that will switch to supersonic where it is allowed. This approach, the designers from the first camp believe, will still reduce the flight time from one point to another.

Designers from the second camp primarily focused on combating shock waves. When flying at supersonic speed, an aircraft's airframe generates many shock waves, the most significant of which occur in the nose and tail area. In addition, shock waves typically occur at the leading and trailing edges of the wing, at the leading edges of the tail, at the swirler areas and at the edges of the air intakes. A shock wave is a region in which the pressure, density and temperature of a medium experience a sudden and strong jump. By observers on the ground, such waves are perceived as a loud bang or even an explosion - it is because of this that supersonic flights over populated land are prohibited.

The effect of an explosion or a very loud bang is produced by so-called N-type shock waves, which are formed when a bomb explodes or on the glider of a supersonic fighter. On a graph of pressure and density growth, such waves resemble the letter N of the Latin alphabet due to a sharp increase in pressure at the wave front with a sharp drop in pressure after it and subsequent normalization. In laboratory experiments, researchers at the Japan Aerospace Exploration Agency found that changing the shape of the airframe can smooth out the peaks in the shock wave graph, turning it into an S-type wave. Such a wave has a smooth pressure drop that is not as significant as that of an N-wave. NASA experts believe that S-waves will be perceived by observers as a distant slam of a car door.

N-wave (red) before aerodynamic optimization of a supersonic glider and a similarity to the S-wave after optimization

In 2015, Japanese designers assembled the D-SEND 2 unmanned glider, whose aerodynamic shape was designed to reduce the number of shock waves generated on it and their intensity. In July 2015, the developers tested the airframe at the Esrange missile test site in Sweden and noted a significant reduction in the number of shock waves generated on the surface of the new airframe. During the test, D-SEND 2, not equipped with engines, was dropped from a balloon from a height of 30.5 thousand meters. During the fall, the 7.9-meter-long glider picked up a speed of Mach 1.39 and flew past tethered balloons equipped with microphones located at different heights. At the same time, the researchers measured not only the intensity and number of shock waves, but also analyzed the influence of the state of the atmosphere on their early occurrence.

According to the Japanese agency, the sonic boom from aircraft comparable in size to the supersonic passenger planes Concorde and designed according to the D-SEND 2 design, when flying at supersonic speeds, will be half as intense as before. The Japanese D-SEND 2 differs from the gliders of conventional modern aircraft in the non-axisymmetric arrangement of the nose. The keel of the vehicle is shifted towards the bow, and the horizontal tail unit is all-moving and has a negative installation angle relative to the longitudinal axis of the airframe, that is, the tips of the empennage are located below the attachment point, and not above, as usual. The glider wing has a normal sweep, but is stepped: it smoothly mates with the fuselage, and part of its leading edge is located at an acute angle to the fuselage, but closer to the trailing edge this angle increases sharply.

According to a similar scheme, a supersonic American startup Aerion is currently being created and is being developed by Lockheed Martin for NASA. The Russian (Supersonic Business Aircraft/Supersonic Passenger Aircraft) is also being designed with an emphasis on reducing the number and intensity of shock waves. Some of the fast passenger aircraft projects are planned to be completed in the first half of the 2020s, but aviation regulations will not yet be revised by then. This means that the new aircraft will initially perform supersonic flights only over water. The fact is that in order to lift the restrictions on supersonic flights over populated land, developers will have to conduct many tests and submit their results to aviation authorities, including the US Federal Aviation Administration and the European Aviation Safety Agency.

S-512/Spike Aerospace

New engines

Another serious obstacle to the creation of a serial passenger supersonic aircraft is the engines. Designers today have already found many ways to make turbojet engines more economical than they were ten to twenty years ago. This includes the use of gearboxes that remove the rigid coupling of the fan and turbine in the engine, and the use of ceramic composite materials that allow optimizing the temperature balance in the hot zone of the power plant, and even the introduction of an additional third air circuit in addition to the already existing two, internal and external. In the field of creating economical subsonic engines, designers have already achieved amazing results, and ongoing new developments promise significant savings. You can read more about promising research in our material.

But, despite all these developments, it is still difficult to call supersonic flight economical. For example, a promising supersonic passenger aircraft from the startup Boom Technologies will receive three turbofan engines of the JT8D family from Pratt & Whitney or the J79 from GE Aviation. In cruising flight, the specific fuel consumption of these engines is about 740 grams per kilogram-force per hour. In this case, the J79 engine can be equipped with an afterburner, which increases fuel consumption to two kilograms per kilogram-force per hour. This consumption is comparable to the fuel consumption of engines, for example, of the Su-27 fighter, whose tasks are significantly different from transporting passengers.

For comparison, the specific fuel consumption of the world's only serial turbofan engines D-27, installed on the Ukrainian An-70 transport aircraft, is only 140 grams per kilogram-force per hour. The American CFM56 engine, a “classic” of Boeing and Airbus airliners, has a specific fuel consumption of 545 grams per kilogram-force per hour. This means that without a major redesign of jet aircraft engines, supersonic flights will not become cheap enough to become widespread, and will only be in demand in business aviation - high fuel consumption leads to higher ticket prices. It will also not be possible to reduce the high cost of supersonic air transportation by volume - the aircraft being designed today are designed to carry from 8 to 45 passengers. Conventional planes can accommodate more than a hundred people.

However, in early October of this year, GE Aviation projected a new Affinity turbofan jet engine. These power plants are planned to be installed on Aerion's promising AS2 supersonic passenger aircraft. The new power plant structurally combines the features of jet engines with a low bypass ratio for combat aircraft and power plants with a high bypass ratio for passenger aircraft. At the same time, there are no new or breakthrough technologies in Affinity. GE Aviation classifies the new engine as a power plant with a medium bypass ratio.

The engine is based on a modified gas generator from the CFM56 turbofan engine, which in turn is structurally based on the gas generator from the F101, the power plant for the B-1B Lancer supersonic bomber. The power plant will receive an upgraded electronic digital engine control system with full responsibility. The developers did not disclose any details about the design of the promising engine. However, GE Aviation expects that the specific fuel consumption of the Affinity engines will not be much higher than or even comparable to the fuel consumption of modern turbofan engines of conventional subsonic passenger aircraft. How this can be achieved for supersonic flight is not clear.

Boom / Boom Technologies

Projects

Despite the many projects of supersonic passenger aircraft in the world (including even the unrealized project of converting the Tu-160 strategic bomber into a supersonic passenger airliner proposed by Russian President Vladimir Putin), the AS2 of the American startup Aerion, S-512, can be considered the closest to flight testing and small-scale production Spanish Spike Aerospace and Boom American Boom Technologies. The first is planned to fly at Mach 1.5, the second at Mach 1.6, and the third at Mach 2.2. The X-59 aircraft, created by Lockheed Martin for NASA, will be a technology demonstrator and a flying laboratory; there are no plans to launch it into production.

Boom Technologies has already announced that they will try to make flights on supersonic aircraft very cheap. For example, the cost of a flight on the route New York - London was estimated by Boom Technologies at five thousand dollars. This is how much it costs today to fly on this route in business class on a regular subsonic airliner. The Boom airliner will fly at subsonic speed over populated land and switch to supersonic speed over the ocean. The aircraft, with a length of 52 meters and a wingspan of 18 meters, will be able to carry up to 45 passengers. By the end of 2018, Boom Technologies plans to select one of several new aircraft projects for implementation in metal. The first flight of the airliner is planned for 2025. The company postponed these deadlines; Boom was originally scheduled to fly in 2023.

According to preliminary calculations, the length of the AS2 aircraft, designed for 8-12 passengers, will be 51.8 meters, and the wingspan will be 18.6 meters. The maximum take-off weight of the supersonic aircraft will be 54.8 tons. AS2 will fly over water at a cruising speed of Mach 1.4-1.6, slowing to Mach 1.2 over land. The somewhat lower flight speed over land, coupled with the special aerodynamic shape of the airframe, will, as the developers expect, almost completely avoid the formation of shock waves. The aircraft's flight range at a speed of Mach 1.4 will be 7.8 thousand kilometers and 10 thousand kilometers at a speed of Mach 0.95. The first flight of the aircraft is planned for the summer of 2023, and the first transatlantic flight will take place in October of the same year. Its developers will mark the 20th anniversary of the last flight of Concorde.

Finally, Spike Aerospace plans to begin flight testing a full prototype of the S-512 no later than 2021. Deliveries of the first production aircraft to customers are scheduled for 2023. According to the project, the S-512 will be able to carry up to 22 passengers at speeds up to Mach 1.6. The flight range of this aircraft will be 11.5 thousand kilometers. Since October last year, Spike Aerospace has launched several scaled-down models of supersonic aircraft. Their purpose is to test the design solutions and effectiveness of flight control elements. All three promising passenger aircraft are being created with an emphasis on a special aerodynamic shape that will reduce the intensity of shock waves generated during supersonic flight.

In 2017, air passenger travel worldwide totaled four billion people, of which 650 million traveled long flights length from 3.7 to 13 thousand kilometers. 72 million long-haul passengers flew first and business class. It is these 72 million people that developers of supersonic passenger planes are targeting first, believing that they will gladly pay a little more money for the opportunity to spend about half as much time in the air as usual. However, supersonic passenger aviation will most likely begin to actively develop after 2025. The fact is that research flights of the X-59 laboratory will begin only in 2021 and will last several years.

Research results obtained during X-59 flights, including over settlements- volunteers (their residents agreed to have supersonic planes fly over them on weekdays; after the flights, observers will tell researchers about their perception of noise), it is planned to submit it to the US Federal Aviation Administration. It is expected that on their basis it may revise the ban on supersonic flights over populated land, but this will not happen before 2025.

Vasily Sychev

The speed of a sound wave is not constant even if the considered medium of sound propagation is air. The speed of sound at a fixed air temperature and atmospheric pressure changes with increasing altitude above sea level.

As altitude increases, the speed of sound decreases. The conventional reference point for the value is zero sea level. So, the speed at which a sound wave travels along the water surface is equal to 340.29 m/s, provided the ambient air temperature is 15 0 C and the atmospheric pressure is 760 mm. Hg So, airplanes flying at speeds higher than the speed of sound are called supersonic.

First achievement of supersonic speed

Supersonic aircraft are aircraft based on their physical ability to travel at speeds higher than sound waves. In our usual kilometers per hour, this figure is roughly equal to 1200 km/h.

Even airplanes from the Second World War with piston internal combustion engines and propellers creating an air flow during a dive already reached a speed of 1000 km/h. True, according to the stories of the pilots, at these moments the plane began to shake terribly due to strong vibration. The feeling was that the wings could simply come off the fuselage of the plane.

Subsequently, when creating supersonic aircraft, design engineers took into account the effect of air flow on the design of aircraft when reaching the speed of sound.

Overcoming the supersonic barrier by airplane

When an airplane moves among air masses, it literally cuts through the air in all directions, creating a noise effect and waves of air pressure diverging in all directions. When the aircraft reaches the speed of sound, a moment occurs when the sound wave is not able to overtake the aircraft. Because of this, a shock wave appears in front of the front of the aircraft in the form of a dense barrier of air.

The layer of air that appears in front of the aircraft at the moment the aircraft reaches the speed of sound creates a sharp increase in resistance, which is the source of changes in the stability characteristics of the aircraft.

When an airplane flies, sound waves travel from it in all directions at the speed of sound. When the plane reaches speed M=1, that is, the speed of sound, sound waves accumulate in front of it and form a layer of compacted air. At speeds above the speed of sound, these waves form a shock wave that reaches the ground. The shock wave is perceived as a sonic boom, acoustically perceived by the human ear below on the earth's surface as a dull explosion.

This effect can be constantly observed during supersonic aircraft exercises by civilians in the flight area.

Another interesting physical phenomenon during the flight of supersonic aircraft is the visual advance of aircraft by their own sound. The sound is observed with some delay behind the tail of the aircraft.

Mach number in aviation

The theory with a confirming experimental process of the formation of shock waves was demonstrated long before the first flight of a supersonic aircraft by the Austrian physicist Ernst Mach (1838 - 1916). The quantity expressing the ratio of the speed of the aircraft to the speed of the sound wave is called today in honor of the scientist - Mach.

As we have already mentioned in the water part, the speed of sound in the air is affected by meteorological conditions such as pressure, humidity and air temperature. The temperature, depending on the altitude of the aircraft, varies from +50 on the surface of the Earth to -50 in the layers of the stratosphere. Therefore, at different altitudes, to achieve supersonic speeds, local weather conditions must be taken into account.

For comparison, above the zero sea level, the speed of sound is 1240 km/h, while at an altitude of more than 13 thousand km. this speed is reduced to 1060 km/h.

If we take the ratio of the speed of the aircraft to the speed of sound as M, then with a value of M>1, it will always be supersonic speed.

Aircraft with subsonic speed have a value of M = 0.8. A range of Mach values ​​from 0.8 to 1.2 sets the transonic speed. But hypersonic aircraft have a Mach number of more than 5. Among the famous Russian military supersonic aircraft, we can distinguish the SU-27 - an interceptor fighter, the Tu-22M - a missile-carrying bomber. Among the American ones, the SR-71 is a reconnaissance aircraft. The first supersonic aircraft in mass production was the American F-100 fighter in 1953.

A model of the space shuttle during testing in a supersonic wind tunnel. A special shadow photography technique made it possible to capture where the shock waves originate.

The first supersonic aircraft

Over the 30 years from 1940 to 1970, the speed of aircraft increased several times. The first flight at transonic speed was made on October 14, 1947 on an American Bell XS-1 aircraft in the state of California over an air base.

The Bell XS-1 jet was piloted by US Air Force Captain Chuck Yeage. He managed to accelerate the device to a speed of 1066 km/h. This test provided a significant piece of data to further push the development of supersonic aircraft.

Supersonic aircraft wing design

Lift and drag increase with speed, so the wings become smaller, thinner and swept in shape, improving streamlining.

In aircraft adapted for supersonic flight, the wings, unlike conventional subsonic aircraft, extended at an acute angle back, resembling an arrowhead. Externally, the wings formed a triangle in a single plane with its acute angled apex at the front of the aircraft. The triangular geometry of the wing made it possible to control the aircraft predictably at the moment of crossing the sound barrier and, as a result, to avoid vibrations.

There are models that used wings with variable geometry. At the time of takeoff and landing, the angle of the wing relative to the aircraft was 90 degrees, that is, perpendicular. This is necessary to create maximum lift at the time of takeoff and landing, that is, at the moment when the speed decreases and the lift at an acute angle with unchanged geometry reaches its critical minimum. As speed increases, the wing geometry changes to a maximum acute angle at the base of the triangle.

Record-breaking aircraft

During the race for record speeds in the sky, the rocket-powered Bell-X15 reached a record speed of 6.72 or 7,200 km/h in 1967. This record could not be broken after a long time.

And only in 2004, the NASA X-43 unmanned hypersonic aerial vehicle, which was developed to fly at hypersonic speeds, was able to accelerate to a record 11,850 km/h during its third flight.

The first two flights ended unsuccessfully. To date, this is the highest aircraft speed figure.

Supersonic car testing

This Thrust SSC supersonic jet car is powered by 2 aircraft engines. In 1997, he became the first land-based vehicle breaking the sound barrier. As with supersonic flight, a shock wave appears in front of the car.

The approach of a car is silent, because all the noise created is concentrated in the shock wave following it.

Supersonic aircraft in civil aviation

As for civil supersonic aircraft, there are only 2 known production aircraft that operate regular flights: the Soviet TU-144 and the French Concorde. TU-144 made its debut flight in 1968. These devices were designed for long-distance transatlantic flights. Flight times were significantly reduced in comparison with subsonic devices by increasing the flight altitude to 18 km, where the aircraft used an uncongested air corridor and avoided cloud loading.

The first civilian supersonic aircraft of the USSR TU-144 completed its flights in 1978 due to their unprofitability. The final point in the decision to refuse to operate it on regular flights was made due to the disaster of a prototype TU-144D during its testing. Although it is worth noting that outside of civil aviation, the TU-144 aircraft continued to be used for urgent mail and cargo delivery from Moscow to Khabarovsk until 1991.

Meanwhile, despite expensive tickets, the French supersonic aircraft Concorde continued to provide air travel services to its European customers until 2003. But in the end, despite the richer social class of European residents, the question of unprofitability was still inevitable.