Aviation of the future: passenger drones, supersonic and biodesign. What is an air pocket? Airplane flight Downdrafts and updraughts

Ordinary piston aircraft with wings and tails are part of the UFO mystery. Although international laws require all aircraft to carry identification marks and tail numbers on their planes, tailfins and fuselages, none of these mysterious aircraft obey the above rules. Usually they are gloomy gray or black and do not have any identification marks. In the flop areas they can often be observed flying at low altitude, with the cockpit always brightly lit, which is not in line with normal night flying practice, as the cockpit light interferes with the pilot's visual observation.

Since 1896, these "pirate" aircraft have been seen in various places around the world. This gives reason to believe that they are interested in our entire planet as a whole. On Monday, July 22, 1968, at about 2 pm, one of these aircraft appeared in a cloudless sky over the San Carlos de Bariloche airport in the vicinity of the city of Bahia Blanca (Argentina). He circled lazily over the airfield at 200 feet, as if preparing for a landing approach.

A large number of witnesses, among whom were pilots, police officers and airport employees, dropped everything and began to observe the unexpected visitor. Of course, the arrival of a plane in broad daylight at a major airport is an event that is unlikely to be of much interest to anyone, but there was something strange about this car. Even very strange.

Subsequently, all the witnesses in their testimony agreed that this aircraft had an unusually long fuselage, and its delta-shaped wings seemed too short to keep a machine of this size in the air. And yet he flew very slowly, so slowly that it was simply incredible how he could stay in the air. One of the fundamental laws of aerodynamics is that the shorter an aircraft's wings are relative to its overall length, the faster it must fly in order to maintain wing lift.

The airport control tower made an attempt to contact this aircraft by radio, but received no answer. Then green signal lights were lit, giving permission to land. However, the giant car continued to circle over the airport. Having reached the end of the 28th runway, the plane suddenly turned 360 degrees around its axis, almost in place. The astonished spectators, watching the maneuvers of the mysterious machine through binoculars from the ground, could not make out any identification marks on its sides, except for three small and one large black squares. None of the airport workers could even identify the type of aircraft, although they were familiar with all existing classes of aircraft from Constellation to U-2, not to mention the fact that they had all the necessary reference books at hand. This plane seemed to be hovering rather than flying, making a small whistling sound. A few minutes later, the car picked up speed and disappeared in a southeasterly direction.

The Argentine authorities have not been able to give at least some explanation for this incident. On July 25, 1968, this story hit the pages of the newspaper LA RAZON, and was later investigated by the Englishwoman Edith Grinet, an employee of the FLYING SOS REVIEW magazine. In 1968, the entire area of ​​the city of Vaia Blanca became the site of extensive UFO sightings. There were reports of both landings and contacts.

A whole formation of unidentified hang-wings has been spotted over the United States and has even received special scrutiny from the unbelieving Air Force. PROJECT BLUE BOOK REPORT 14 states the following in the Unidentified Objects section:

"A cadet of the Naval Aviation School, his wife and several other persons on Sunday, April 20, 1952, were in an open summer cinema for motorists on a session that lasted from 21.15 to 22.40. During the session, they noticed nine groups of objects flying directly above them. In each group consisted of two to nine objects, and one group consisted of twenty objects.These objects flew in a straight course, while changing it with a normal aircraft turn.They resembled ordinary jet aircraft in shape.

The unusual thing about them was that each was surrounded by a red glow emanating from himself. The night was completely cloudless."

A government official from Washington, whose name I understandably do not name, recently told me about an incident that happened to him while living in Long Island in 1957. According to him, he was awakened by the barking and squealing of his dog and Leaving the house, he saw a huge delta-wing aircraft majestically sailing over him in complete silence. The plane was surrounded by some terrible crimson glow. Since he had never seen anything like it, he called the nearest air base and reported what had happened.

The next day, he was called to the air base, where the area security officer asked him for some additional details, saying that they had received similar reports from other people. (Except for a small number of prototypes, hang wing aircraft were a rarity in the fifties.) UFO enthusiasts and the organizations they have created are primarily concerned with collecting information about objects of unusual configuration, such as a disk and flying saucers. However, the Aerial Phenomena Research Organization, having received an intriguing report of a mysterious aircraft, investigated it with all possible care. The witness voluntarily agreed to testify on a lie detector and answer questions from professional psychologists. The name of the witness is Wilhelm Hetzke, a rancher in Calgary, Alberta, Canada. It fully passed the test on the detector. An entire chapter of Jim and Karel Lorenzev's book "UFOs over America" ​​is dedicated to this case.

One morning in October 1965, Wilhelm Hetzke was riding through the grounds of Sickle J Ranch when he suddenly saw what looked like a small plane standing on the ground. It was silvery gray in color with recurved (delta) wings. Driving closer, Hetzke carefully examined the plane. It was about 16 feet long, with a wingspan of 12 feet, and the thickness of the fuselage did not exceed 4-5 feet.

According to Hetzke, the aircraft's skin was unusual, resembling a "waffle surface". A transparent, apparently plastic, canopy covered the cockpit. Through it you could see all sorts of complicated instruments, a fourteen-inch television screen, and two small, glass-like, dented seats. There were no engines, propellers, nozzles to be seen, and no identification marks or even numbers. There were no signs of life either on the plane or around it. Hurrying to work, Hetzke was forced to leave and could not return to this place later.

Hetzke's description of the aircraft contained many more details than we have given here, and most of them were very unusual.

Despite the fact that the object had the most common wings and tailfin, its interior and waffle-like skin speak for themselves. (From numerous reports it follows that UFOs have rough or notched skin. Obviously, this kind of bumpy surface is necessary for sudden braking and reducing the potential speed of the object. The latest aircraft are made with as smooth a surface as is technologically possible.

Even an improperly fitted rivet head can significantly reduce speed.) The aircraft Hetzke discovered was clearly built for very young pilots and flew on a principle unknown to us, requiring neither propellers nor jet blast. (It should also be noted that all gliders have very long wings, while the object Heizke discovered had very short ones.) If you saw such an aircraft flying slowly over you, you probably would not pay much attention to it.

Mysterious cargo planes

Several more types of mysterious aircraft are operating over the territory North America. The gigantic machine, resembling the Flying Boxcar military transport aircraft, frequently appeared over the flask areas, performing maneuvers that were completely impossible for machines of this class. A group of witnesses from the suburbs of Gallipolis, Ohio, told me that they have been watching mysterious flying lights over their hills and fields for thirty years. In addition, without any leading questions from me, they began to talk about "big cargo planes" that fly over the hills a couple of times a month, and "sometimes so low that they would even look to crash into a hill." These cargo planes are multi-engined and painted dull grey. There are no regular military or military routes over Gallipolis. civil aviation. There are no air bases nearby, and planes flying to Charleston Airport (West Virginia) pass much further north. And this is quite understandable, since the reckless courage required when flying over the treacherous mountain range of the Ohio-West Virginia region is not justified in any way.

In his report to the Armed Forces Committee on the Investigation of the UFO Phenomenon (April 5, 1966), engineer Raymond Fowler drew attention to the results of his own investigation conducted by him in the Exeter area (New Hampshire). In particular, he said: “During my first two visits to Carl Dinning Field (from where UFO sightings had been reported earlier), on both occasions I saw a low-flying C-19 Flying Boxcar. It happened on September 11, 1965." In doing my own research, I heard from many people in areas far apart and from air force bases, descriptions of C-19 aircraft.

All witnesses saw these aircraft flying at a very low altitude, which in itself is strange for such a class of aircraft, not to mention the fact that the aerobatics that these aircraft demonstrated is simply impossible for them. For a while, I assumed that the Air Force sent specially equipped aircraft to the flop areas for photography and various tests. But the facts forced me to part with this pleasant hypothesis, replacing it with a very unpleasant one. I came to the conclusion that planes resembling S-19s really operated in the areas of flasks, but, alas, they have absolutely nothing to do with our Air Force.

Small single-engine aircraft have also been frequently seen flying and sniffing over recent UFO sightings. As usual, these aircraft were painted gray and did not have any markings.

Competent witnesses, some of whom had binoculars, saw them over Texas, Florida, and West Virginia. Like large cargo planes, these small machines fly at night with brightly lit cockpits, they are seen in the air on such stormy and rainy nights when no pilot in his right mind would dare to take to the air. There are a lot of facts confirming the love of UFOs for bad weather.

In March 1968, at Point Pleasant, West Virginia, competent observers watched low-lying lights over Highway 62 during an overnight snowstorm. The lights were of the characteristic UFO type. Directly behind these lights followed a small single-seat airplane, seemingly oblivious to the wind and blizzard.

The year before this incident, in early April 1967, I had been chasing a strange flying fire from an area of ​​old World War II explosives warehouses north of Point Pleasant to the head of a mountain range outside Henderson, West Virginia. I broke off the pursuit and, getting out of the car, joined a group of people standing on the top of one of the hills, when a twin-engine plane suddenly appeared, circled, flew right at us, almost brushing the tops of the trees. As it got closer, the plane shut off its engines, hovering literally over our heads, a completely idiotic maneuver, given the treacherous updrafts that always surround hills and gorges. The cockpit of the aircraft was brightly lit, and the figure of the pilot was clearly distinguished in it. It was about 9 pm, very dark, and the brightly lit cabin looked doubly strange. What kind of pilot is this, who not only decided to fly over the treetops in an extremely dangerous area, but also deliberately stopped the engines and blinded himself by turning on the bright lights in the cockpit?

I jumped in the car and crossed the Ohio River to a small airfield near Gallipolis to see this crazy pilot, since by my calculations there was nowhere else for him to land. There was no one at the airfield, the cars standing there were covered, the engine of none of them was warmed up. Of course, there are certainly private jet owners who like to pinch their nerves with night flights at low altitudes, but there are hardly any among them who would risk their license and life so much by performing such stupid and dangerous tricks over densely populated areas.

Swedish researcher Ek Frenzen, recently digging headlong into the Stockholm newspapers of the thirties, brought together many forgotten fragments of the Scandinavian hat from 1932-1938. He dug up over 90 detailed messages and was kind enough to do the boring job of translating them into English language for us. These messages paint an amazing picture.

Since 1932 big planes unmarked began to appear over northern Sweden, Norway and Finland. All descriptions of these machines indicate that they were gray. They often appeared during terrible snowstorms over cities, railway stations, forts and ships at sea. Often, circling over some object, they turned off their engines. According to the descriptions, many of them were huge multi-engine machines. One group of five witnesses announced sightings of a huge eight-engine aircraft. From many reports it is clear that these machines have repeatedly appeared in threes.

In those years, there were almost no private planes in Scandinavia. The gigantic China Clipper was still being built in the US, and the hulking three-engine Ford, which had just begun production, was used on the many commercial airlines that then existed. In 1926, Admiral Byde and Floyd Bennet flew from Svalbard to the North Pole in a three-engine Fokker.

Their flight was widely covered by the Scandinavian press, and the photo of the Fokker went around all the newspapers.

Six years later, when mysterious planes began to appear over Scandinavia, many witnesses compared them to Baid's Fokker.

The Swedish government took these reports very seriously. In 1934 no less than 24 biplanes of the Swedish Air Force were dispatched to patrol remote and sparsely populated areas of the country, where "flying ghosts" were reported to have appeared. Thorough searches were organized on land, sea and in the air. The operation was carried out in adverse weather conditions, which resulted in the loss of two Swedish aircraft.

I will try to summarize here some of the main cases of this flask.

Sources are the following newspapers: DABENS NEWHETER, STOCKHOLMOTIDNINGEN, VASTERBOTTENSKU RIREN, NORRBOTTENS ALLEMANDA, HUDIKSWALS TIDNINGEN and THE NEW YORK TIMES.

"Piteo. - The parish priest from Landtresk reported that over the past two years he had often seen some mysterious aircraft in the area. Last summer, "flying ghosts" flew over their town twelve times, constantly adhering to the same route and direction - from the south -west to northeast.

Four times the planes appeared at very low altitude, but no identification marks were visible on them.

In one case, the aircraft flew only a few meters above the dome of the parish church. For several seconds, two pilots in the cockpit were clearly visible. The car was a gray monoplane.

The priest did not report this earlier because he thought that the authorities already knew about it from other sources."

Until December 1933 there were extremely few reports published, but the experience of the 1909 flask over New England gives every reason to believe that there were already enough reports of sightings before they made their way to the press.

The first note at our disposal describes a UFO sighting on Christmas Eve: “December 24, 1933 Kalix. The mysterious plane appeared from the sea at about 18:00. Passed over Kalix and disappeared in a westerly direction. A beam of searchlight light directed from the aircraft illuminated the area. On December 27, 1933, the NEW YORK TIMES devoted almost an entire column to the appearance of "mysterious aircraft in a severe blizzard" right over New York City. At 9:30 am on December 26, people throughout Manhattan distinctly heard the sound of an airplane, apparently circling over the city in a blinding blizzard. Radio station NBS noted this case in the latest news, telephone calls with messages fell upon the editorial offices of newspapers. THE TIMES continues:

“Comparison of various reports shows that the pilot flew to 72nd Street, made a circle over Central Park and then headed for the Bronx area (231st Street and Sadwick Avenue). For some time there were no further reports, but at about 2:25 p.m., the sound of an engine was reported from the 155th Street area, near the dam across the Hudson ... All airfields in the Metropolitan District reported that no flights were made and no aircraft landed at them all day through a snow storm."

The planes of 1933 were simply unable to fly in such difficult weather conditions, and it is very doubtful that even now any of the planes could be in the air for five or six hours during a snowstorm. But the plane that appeared over Manhattan did just that, and of course no one ever knew anything about the plane.

In February 1934, exactly the same incident occurred over the capital of Great Britain (see THE NEW YORK TIMES, February 4, 1934).

In Scandinavia, "flying ghosts" immediately after Christmas began to be extremely active. (Remember that the 1909 flag also happened on Christmas week.) There was a report of an unknown aircraft flying back and forth along the Swedish-Norwegian border, and the report came from two places - from Ternaby (Sweden) and from Langmo Vefon (Norway) . On December 28, 1935, the 4th Air Corps of the Swedish Air Force was ordered to fly to Ternaby to investigate the incident.

The mystery took on a tragic twist when Lieutenant Georg Engelhard of the artillery regiment in Gotland skied from Tennas to Storlien, a route that led through wooded areas where flying ghosts were reported to be most frequent. The lieutenant did not arrive at Storlien. Search parties, including Norwegian Air Force aircraft, tried in vain to locate him. On January 4, 1934, a group of three skiers took the alleged Engelhard route and did not return. A new search party was organized already in order to find them.

Even the NEW YORK TIMES has become interested in this overgrown mystery. On January 10, 1934, the Stockholm correspondent of the TIMES reported:

“The Swedish Air Force has already lost two aircraft in its persistent effort to locate the bases of the mysterious aircraft. Everyone's attention is now focused on the fate of Lieutenant Engelhard-Vanberg, who went missing on Christmas Eve, and three skiers who disappeared while trying to find the lieutenant. A spokesman for the Ministry of Defense told reporters that the search for all four missing servicemen has so far yielded no results.

The three missing skiers suddenly appeared on January 12 at the New Style railroad station. The newspapers gave no explanation for their long absence. If they did give an interview to anyone, they have not yet been able to find his publication.

Finally, on January 17, the tent of Lieutenant Engelhard was discovered, and two miles from it, the frozen body of the officer himself. Despite the blizzard raging in the area, the lieutenant left his skis and a fur jacket in a tent and set off on foot into the mountains to meet his death. No further details about this case have been released.

What made the most experienced skier and hunter leave his skis and warm clothes in a tent and go on foot to the mountains through a furious storm? This we will probably never know.

While the unfortunate Engelhard was searched for in the mountains of northern Norway, the flying ghosts continued their flights over the three Scandinavian countries. Approximately one third of all published messages for January-February 1934 fall on Sunday. Swedish officials openly called these cases "Sunday". Several reports of landings of mysterious vehicles came from distant regions. All of them happened on Wednesday.

The prints found in the snow at the landing sites were traces of airplane skis.

In that year, there were many mass sightings of cities and towns for mysterious machines flying over them. Planes often flew during snowstorms, sometimes circled low over the villages, illuminating the ground with powerful searchlights.

We take the liberty of giving a few facts about these incidents, taken from the above-mentioned newspapers;

1. Sunday, December 31, 1933 - Olaf Hellund - "a serious man with a good reputation" - saw "a large gray plane that was larger than any military aircraft he knew." The plane made three circles over the Sorsel railway station at 3.45 am. The car was a monoplane and completely closed, which resembled a passenger plane. It was equipped with floats or skis of some special design... No identifying marks were visible. (It was a full moon, the night was clear.) During the flight over the station, the aircraft engine did not work.

2. Wednesday, January 10, 1934 - At 6 pm, the inhabitants of the city of Tarna noticed a sparkling object at an altitude of 1000 feet. The object turned and headed towards the Arjeplog. After 15 minutes, the inhabitants of Arjeplog, hearing the noise of an aircraft engine, poured out of their homes to look at the plane. Then the plane appeared over Rortrask, north of Norse, and witnesses say that the plane's engine stopped three times while it flew over their town ... The car flew so low that the whole forest was flooded with light.

3. Wednesday, January 10, 1934 Trondheim, Norway. “Two landings of flying ghosts were reported on Wednesday evening in northern Norway. One car landed near the island of Gjeslingen on the Rorvik parallel, the other - in the Namndala area, in a place called Kvala. A report from Gjeslingen says that the inhabitants saw a huge beam of light and heard the noise from the powerful engine. The car landed and remained on the water for about an hour and a half, illuminating the sea around it with a searchlight.

The Norwegian cruiser Eagle was sent to the island, but it arrived too late.

4. Sunday, January 21, 1934 - "On Sunday, at 6 pm, many residents of Bengtoforsen (Scotland) saw a very bright light in the sky.

It was about the size of a full moon and moved at high speed. The sound of a running engine was clearly audible... In Indal, west of Bengtoforsen, the light appeared at the beginning of the seventh. Many people watched as the fire swirled over the village for ten minutes, and then disappeared in a westerly direction.

Much to the annoyance of the Swedish military authorities, these mysterious machines liked to circle over railway stations and forts, especially over Fort Boden, without leaving other important strategic objects without attention. Many observed only a blinding beam from the light, and our old friend "spotlight" began to appear in one message after another.

When a large gray plane began to circle over the Norwegian ship "Tordenkskiold" off the coast of Tromso on Tuesday, January 23, 1934, it, flying at low altitude, searched the deck with a powerful searchlight. Captain Sigvard Olsen said the pilot was clearly visible in the brightly lit cockpit. He was wearing a helmet with large flying goggles.

But the real flop began on Saturday, January 6, when a significant number of sightings were recorded simultaneously across Sweden. Then the peaks of the flop were: Monday January 8th, Wednesday January 10th, Saturday January 20th, Sunday January 21st, Tuesday January 23rd, Thursday January 25th, Tuesday February 6th and Sunday February 11th.

The number of published reports decreased sharply when representatives of the army and counterintelligence were sent to the areas of the most frequent sightings for a thorough investigation. The military ministries of Sweden, Norway and Finland already had their own, and very gloomy, point of view on the whole thing.

Territorial air space their countries were violated in the most flagrant manner, and not by one or two aircraft, but by a whole air armada acting with suspicious persistence. These aircraft were larger than any combat vehicles, they could operate in any weather over any, even the most dangerous, mountainous territory. Such a global operation certainly required the presence of well-equipped bases with a large number of technical personnel, with a well-thought-out supply system for fuel and other necessary equipment, such as warehouses with spare parts, food, a repair base, etc. But despite the thorough searches undertaken by the armed forces of the three states, nothing resembling such a base, of course, was found.

Aircraft carriers in 1934 were still in their infancy and could produce and receive only a small number of small biplanes.

In 1942, the US Navy slightly modernized the Hornet aircraft carrier in order to deliver General Doolittle's B-25 twin-engine bombers closer to the coast of Japan (The author is mistaken: in 1942, James Doolittle, who commanded the famous flight over Tokyo, was not a general, but a lieutenant colonel. - approx. per.).

These bombers took off with great difficulty from an aircraft carrier and made a purely symbolic raid on Tokyo, but they could no longer land on an aircraft carrier and were forced to fly to the unoccupied part of mainland China.

In 1934, Hitler was still gaining strength, and the Luftwaffe simply did not exist yet.

The Soviet Union had no aircraft and, more importantly, no reason for such senseless demarches over Scandinavia. After all, there was a huge risk of causing an unprecedented international scandal. If at least one of these aircraft crashed or was captured and its belonging to some foreign power was proved, then the actions of the entire armada could not be regarded otherwise than as the beginning of hostilities.

Based on some information, probably known only to the New York Times, this newspaper suggested that the Japanese were to blame for the entire Scandinavian history. But none of the Scandinavian newspapers, despite the large number of speculations discussed, even hinted at Japan. And the justice of this is quite obvious - Japan, which at that time was resolving its problems in China, had neither the opportunity nor the reasons for carrying out such an operation.

At the very beginning of the flask, Swedish newspapers entertained themselves with a completely frivolous conclusion about liquor smugglers delivering liquor to the Scandinavian countries. It makes no sense to refute it, we only note that even the official investigation left no stone unturned from him ...

As in the days of the 1896-1897 and 1909 flops, the 1934 flop included occasional low-altitude flights of objects familiar to people in principle, and hundreds of high-altitude flights of mysterious lights, which, it seemed, were they were controlled, judging by the maneuvers they performed. The mysterious planes were "hard" objects and were used to support the actions of a much larger number of "soft" objects, which for some reason deployed their operations in northern latitudes. Witnesses reported seeing aircraft carrying red, green and white lights. When these glittering lights were seen at high altitudes, it was suggested that the planes were flying to connect with flying ghosts hiding somewhere much higher.

The mysterious planes could perform amazing maneuvers. They turned off their engines, sometimes at an altitude of not more than 100 feet, and without any visible energy made three or four circles over an object.

Try to perform such a maneuver on an ordinary plane, and you will end your life under its wreckage. On April 30, 1934, Major General Reutersvärd, commander of the district in Norland (Sweden), issued the following statement to the press:

"A comparison of all the reports leaves no shadow of doubt about the illegal aerial inspection of our secret strategic areas. Many reports from quite reliable people give an almost detailed description of these mysterious machines, and in each case one common detail attracts attention: on one of these machines, no identification marks were seen ... It is absolutely impossible to explain all these cases with fantasy or hallucination. And then the questions arise: “who are they?”, “and why are they violating our airspace?”.

If all the courses of the flying ghosts of 1934 are mapped, then their route seems to become clear. It seems that from day to day they flew in a huge arc with fanatical constancy. Flying south from northern Norway, they passed over Sweden and turned north again over Finland. If we make a full circle from this arc, then its upper part will fall on the area of ​​the sparsely populated island of Svalbard in the Arctic Ocean, and the western part will fall on the northern tip of the island of Greenland. Incidentally, there have been a lot of interesting observations over Greenland. (In Chapter 1, we discussed a case in which a string of unidentified objects were detected by radar while flying over Greenland.) Hundreds of reports of UFO sightings come from the Arctic regions and thus seem to confirm the very popular theory that flying saucers come from holes over the North Pole. The Aerial Phenomena Research Organization holds the advanced theory that objects enter from space into the Earth's polar regions to bypass the intense radioactive belt concentrated above the temperate regions.

Radio signals from eternity

During flights over Scandinavia of flying ghosts, mysterious radio signals were received throughout Sweden and Norway. This issue has also been widely discussed in the press. On January 11, 1934, one of the newspapers of the city of Umeå (Sweden) noted the following:

“Officers at the Air Force headquarters believe that the mysterious planes have radio transmitters and radio navigation devices on board ... It is certain that these machines are representatives of some extraordinary organization.”

“The radio listeners of the city of Umeå intercepted on their receivers the conversations of the flying ghosts, from which it can be concluded that their intelligence service is at the highest level ... The radio conversations took place in the wake of the popular music program of the city of Umeå, and their topic was a discussion of the rendezvous point of several flying ghosts. At the end of the negotiations, the time for the next contact was named. (Correspondents investigating a 1956-1957 UFO contact claim by one Howard Menger of New Jersey allegedly found a strange radio transmitter on his farm. This transmitter did not emit its own signals, but used signals “stolen” from a local radio station. Swedish reports suggest that someone in Umeå in 1934 used the same equipment when the "output" of an ordinary radio station was used as a power source for "pirate" signals.) January 25, 1934 named Halmar Hedstrom caught on his receiver the following message, transmitted on short waves: “The sea is calm, the temperature is two degrees Celsius. You must land on the water and catch what we have been talking about. Be in touch again at 19.45. The message also included data on wind direction, location coordinates and other information. Although all the conversations were in Swedish, Hedstrom couldn't remember much.

Another radio amateur from the city of Hedesund picked up a similar message on the same day. An additional message was also intercepted at the indicated time - 19.45.

Some messages were received on a wave of 900 m, others - in the range of 230-275 m.

The vast majority of sightings in 1934, regardless of location, took place around 6 p.m. In March, the flop began to decline, but periodic reports were received throughout the thirties.

"Reports of mysterious lights seen in the sky are coming in from various places. A reporter from the Norwegian Telegraph Agency collected some of these reports while traveling around the Sixth District. Nearly all sightings were reported by residents to the police, whose representative gave a detailed report to the correspondent. A report of an observation was also received mysterious lights in the vicinity of Tromso on Tuesday evening.

The flying ghosts returned to Scandinavia in 1936, exactly following the well-trodden routes of 1934. Once again, their appearance was accompanied by mysterious radio signals. The NEW YORK TIMES correspondent, who in 1934 tried to blame everything that happened on Japan, this time blamed Germany for transmitting the mysterious radio signals. But again, as in 1934, the Scandinavian press did not attach any importance to these fabrications.

As the brightly shining object chased across the Midwestern prairie behind. by a train in 1937, The NEW YORK TIMES, August 15, citing astronomers, attributed the incident to the influence of the planet Venus.

It need hardly be said that the inhabitants of northern Scandinavia are very familiar with the northern lights and other ordinary astronomical and atmospheric phenomena. It is doubtful that they paid particular attention to anything they thought could have a natural explanation.

We have at our disposal two messages from different parts of Europe that deserve to be included in this book. On Thursday, February 11, 1937, the Norwegian fishing trawler "Fram" left Kvalovik at about 9 pm. Bypassing the mountainous cape that separates the harbor of Kvalovik from the ocean, the crew of the trawler noticed a large seaplane sitting on the water.

Deciding that the plane had crashed, the captain of the trawler changed course and headed towards it. The green and red signal lights on the wings of the car were clearly visible, but as the ship began to approach, the lights suddenly went out. At the same moment, the plane was enveloped in clouds of smoke and disappeared.

At noon the next day, on Friday, February 12, 1937, an unknown aircraft, having appeared over the capital of Austria, Vienna, began to circle over the city. The unusualness of this case was widely noted by the European press. Obviously, there were some reasons to doubt the origin of this aircraft.

Scandinavia: 1946

On June 10, 1946, an object resembling a German V-2 rocket passed over Finland. In the following two weeks, UFO-type lights, cylindrical objects and unidentified winged vehicles were seen by thousands of people in Sweden and Norway. The vast majority of observations were concentrated in cold, sparsely populated northern regions both countries. The European press paid due attention to them - "ghost rockets" replaced the flying ghosts of 1934. They were seen far to the south, over Greece and over the mountains of Switzerland, where they flew confidently over gorges and canyons. They were intercepted by radar and photographed. (One such photograph, depicting an arrow-shaped streak of light, was published by the London Morning Post on September 6, 1946.) The speed of these objects has been measured and ranged from 400 to 1000 miles per hour.

Some of the objects seemed to be exploding in mid-air, some of them ejecting shards of metal that looked like normal slag.

British and Scandinavian newspapers openly accused the Soviet Union of testing new types of combat missiles in northern European airspace. Moscow categorically denied this fact. In September bright green balloons were spotted over Portugal. "A huge projectile with a fiery tail" swept over Casablanca. A huge flaming sphere whistled through the sky over Oslo and exploded with a terrifying roar. On Wednesday, July 3, 1946, a mysterious explosion rocked a small town in the center of Scotland, shattering windows and killing one person (apparently by shell shock). No one could explain the cause of this explosion. Swedish authorities have collected more than 2,000 reports of "ghost rockets". Although this flask received very little coverage in the American press, General James Doolittle flew to Stockholm to participate in the investigation. London was also shocked by a series of explosions, the origin of which no one could explain.

At the end of August 1946, the lid slammed shut. On August 22, the London DAILY TELEGRAPH newspaper reported: "In order to prevent the leakage of technical information about the launch of rockets flying over Denmark, the Danish government asked correspondents not to indicate those areas of the country where these rockets were seen ... ". On August 31, 1946, the correspondent of the DAILY TELEGRAPH in Oslo reported:

"Starting from Wednesday, Norwegian newspapers stopped any discussion about missile flights over Scandinavia. Today, the Norwegian General Staff issued a memorandum for the press, demanding that no information be published in the press about the appearance of missiles over Norwegian territory and that all reports on this topic be sent to the Intelligence Directorate of the General Staff …

In Sweden, it is also forbidden to mention in the press about flights and explosions of missiles over the country's territory.

In a short 50 years, we have gone from mysterious inventions to espionage and smuggling, and then came to the Russian secret weapon. Since none of these explanations can be taken seriously, and the phenomenon continues to be observed, we seem to be left with the only acceptable hypothesis: the arrival of aliens from outer space on Earth. For a long time, members of the Fortian Society, admirers and followers of the late Charles Fort, have been fueling this hypothesis with their irresponsible publications. They have not yet been asked a question, and they already have an answer ready for anything. Their thought works in this direction: in 1945 we dropped atomic bombs on Japan. The energy of atomic explosions was recorded in space by the instruments of some alien super-civilization.

This super-civilization was terribly shocked by the fact that such a nonentity as a man discovered the secret of atomic energy. To investigate this sad fact, an expedition to Earth was organized. However, some superintelligent navigator made a small mistake and instead of bringing the spacecraft to the affected Japan, he flew to Scandinavia.

It's a pity if that's the case.

Mysterious helicopters

Thousands of observations for the period 1896-1938. ghost airships and mysterious planes lead us to the next inevitable conclusion; the true substance of a phenomenon is such that it can shape itself into any desired form it chooses. And that raises a very important question: Do these things really exist? Or are all the thousands of messages nothing more than examples of mass hysteria, correspondent jokes and misinterpretations of natural phenomena?

It is impossible to have two points of view. Either the overwhelming percentage of reports must be recognized as true, or everything is pure nonsense.

If I were to write a book, say, about the Civil War, I would use the same sources, i.e. old newspapers, historical documents, letters from participants in the events, and as a result, the book I created would be accepted by scientists and historians with little or no no questions at all. But flying saucers are so discredited by all sorts of amateur theories and fans of the alien version that skeptics, who easily find obvious nonsense in all their hypotheses, get reason to say the same about all other UFO data.

If the farmer of the sixties of the last century, who participated in the battles civil war, left behind a bunch of crumpled letters, where he describes the events he experienced, historians, like tigers, rush to these letters to repeatedly quote them in their scholarly writings. But if the same farmer saw some unusual object over California in 1875 and reported it in a letter to the local newspaper, then why can't this letter be considered a historical document today? No, skeptics will find fault with every word of such a letter, and if there is nothing to complain about, they will question the author's sanity.

It is my firm opinion that we should stop asking the question: "Could such things really be?", and start asking another: "What can this all mean?".

The gullible can get caught up in stories about amazing spaceships from distant galaxies, and everything will become clear to them. But what will they say about the numerous stories associated with seemingly completely ordinary planes and helicopters? Yes, there are also ghost helicopters!

On Tuesday, October 11, 1968, a bright flying fire danced over drinking water tanks in New Jersey. There had been enough strange observations in that area before, but this case was doubly strange. A few minutes after the blinding bright object disappeared, a whole formation of mysterious helicopters appeared.

"This thing blinded me so much that I could not find my car," one of the witnesses to the incident, police sergeant Ben Thompson, told Dr. Berthold Schwartz. “I had the impression that I was looking straight into the spotlight to see the nests of reflective lamps ... After that, I saw absolutely nothing for about twenty minutes.”

Approximately 15 minutes after the blinding object disappeared, a detachment of helicopters appeared and began to circle at low altitude. A little above them appeared a group of ten or twelve jets. Hundreds of cars filled with stunned spectators drove up to the spot. They, of course, saw helicopters, but not in such numbers. Police Sergeant Robert Gordon described his confusion as follows: “In all my life I have never seen seven helicopters in the air at once ... And I have been living here for forty years.”

Science writer Lloyd Mellen investigated the case. He made inquiries at all nearby Air Force bases, airports, and even the Pentagon. No one knew anything about these helicopters and planes. The Civil Aviation Bureau was as surprised as the others. No one has been able to lift the veil of secrecy. I don't really believe that this was the Air Force's reaction to the appearance of a sparkling object above the tanks. Firstly, because no one directly reported this to the Air Force, and secondly, because there never was such a large detachment of helicopters at the nearby McKire and Stewart airbases, and if they were, then, given their slowness, it is unlikely that after 15 minutes they would have appeared over the scene. Of course, we must not forget that the existing opinion about the shameless lies of representatives of the Air Force about everything related to UFOs may not be without foundation.

New Jersey residents claim to have seen these helicopters and jets. So they are all lying? But what's the point of such a lie? And if this is true, then where, from where and why did these cars fly? And who controlled them?

The North Vietnamese have a negligible number of aircraft and even fewer helicopters. Nevertheless, at the end of June 1968, a whole array of some strange lights appeared over the Ben Hai River, and one of the mysterious helicopters, as reported, was even shot down. Newsweek Vietnam correspondent Robert Stoke was at the scene. Here is his message (NEWSWEEK, July 1, 1968):

"Captain William Bates was on radio duty at Regimental Headquarters in the village of Dong Ha. At 11 p.m., the Marine forward watch radioed that their observer had detected thirteen yellow-white lights with an electronic telescope, floating in a westerly direction at an altitude of 500 to 1000 feet above the Ben Hai River, which flows in the middle of the demilitarized zone.Bates immediately contacted the command to find out if there were any planes or helicopters in the observation area.Having received a negative answer, the captain contacted the Alpha 2 anti-aircraft radar station, the northernmost military unit 1 Corps Less than a minute later, an answer came from the station about strange glare in all 360 degrees of all-round visibility.

Around 1:00 a.m. Air Force and Marine Corps planes were already over Da Nang and began pursuing unidentified objects. After 45 minutes, the Marine Corps pilot reported the destruction of the helicopter. However, when a reconnaissance aircraft equipped with infrared equipment passed over these areas, it did not find burning debris anywhere.

In June, these objects were intercepted almost every night by radar over the demilitarized zone. And it was never possible to identify, and there is hardly any reason to consider them really Vietnamese aircraft or helicopters. If this were the case, it would be surprising why the North Vietnamese suddenly stopped using them, since after June 1968 they did not appear again.

A few weeks after this series of incidents, mysterious helicopters appeared over the state of Maryland. At about 8:20 p.m. on Tuesday, August 19, 1968, an oval object girdled in the center with red and white glittering lights hovered over Rosecroft Restreck near Phelps Cons, Maryland. One of the many witnesses, Geese I. Donovan, stated that she also saw at least seven helicopters circling the site. “I noticed this,” she said, “because I have never seen so many helicopters in the air.”

Maybe our Air Force is secretly hunting for flying saucers in helicopters, not finding anything better? We do, of course, use fighter jets frequently, albeit unsuccessfully, to chase unidentified objects, but neither I nor many Air Force officers with whom I have spoken have even heard of the use of helicopters for this purpose, not even by word of mouth.

Helicopters - very expensive cars and difficult to manage. It is for these reasons that the World War II prediction that "helicopters will be in every garage" did not come true. UFO hunting operations require several helicopters to be constantly on standby for immediate departure. I've been snooping around many of our air bases and have not found even a hint of this kind of operation.

I have come to the conclusion that the unidentified helicopters are in the same category as the flying ghosts of 1934 and the tiny plane in Calgary.

They are part of the whole UFO phenomenon, not proof of our hunt for unidentified objects.

Are there really flying saucers?

Since 1982, thousands of UFO photographs have been taken. Many of them recorded vague spots and streaks of light, but many were clearly "solid" objects, similar to machines of some kind with portholes, hatches and other clearly distinguishable parts. And here another problem arises. With a negligible exception, no two UFO images are the same. I have received hundreds of photographs in the mail and collected hundreds of others during my travels. Since photographs are so easily counterfeited, I have usually avoided taking too much care of both the photographs themselves and their authors. However, I myself took two very similar photographs in two different areas.

Over the past three years, I have interviewed thousands of eyewitnesses in person, by phone, and by mail. At the same time, many of those who gave descriptions of sparkling, changing "soft" objects said the same thing. But I have rarely heard two independent witnesses describe in one word what they saw as a "solid" object. I have heard of tiny saw-sounding objects circling over mines in Ohio, and giant gondola-shaped machines with many rows of windows hovering over the Kaitatini Mountains in northern New Jersey. And it seems that there were as many different forms of objects as there were witnesses. However, I reassure myself time and time again that the witnesses were reliable and simply told honestly what they saw.

And if we take as a basis that the witnesses are telling the truth, then we can safely assume that UFOs appear in billions of different sizes and shapes. Or they don't have any shape at all. And that brings us back to the old psychological warfare gambit. If there are continuous contradictions in the description of objects, then few people will take this phenomenon seriously, but if people, say, in Brazil, Iowa and Australia begin to give the same testimony, then this can immediately alert both scientists and the military.

PROJECT BLUE BOOK REPORT 14 tried to solve this problem. Air Force specialists put 434 unidentified object reports into a computer in an attempt to get a basic model. They received 12 basic types of objects. Of the thousands of reports that are available, 1,200 or 1,200,000 different types of UFOs can be obtained with equal success. And those 12 types of objects that are described in REPORT 14 were not observed at all after 1955.

Then maybe there are no types of UFOs at all?

Our catalog of UFO types today contains flying cubes, triangles, hexagons, cones, spheres, objects shaped like giant metal insects and flying jellyfish. We have UFOs with wheels, wings, antennae, bulging domes, flat portholes, and none at all. We have objects of all colors of the spectrum. There are gigantic "cigars" with multiple portholes that spew blue fire from their tails. ("Flying saucer base," the proponents of the alien version assure us.) We have wheelless cars driving through desert areas a few inches above the ground. We also have unmarked piston and jet aircraft and unidentified helicopters roaming over the flask areas. In other words, we have everything but the basic model, which would appear regularly in different years and in different places. And all this forces us to make two inevitable conclusions to choose from:

1. All witnesses are either wrong or lying.

2. Some unknown super-civilization produces thousands of different types of flying machines and sends them to our planet.

The governments of all countries of the world stubbornly adhere to the first conclusion, UFO enthusiasts - the second.

As for me, I do not adhere to either one or the other. Moreover, I suggest a third alternative. I believe that some "solid" objects definitely only exist as a temporary transmog. They are disco and cigar-shaped. They leave distinct traces on the ground after landing.

Witnesses touched them and even went inside. These "hard" objects are nothing more than baits, just like the airships and planes of yesterday, the purpose of which is to cover and ensure the operation of a huge number of "soft" objects. Therefore, for me, the main interest are "soft" objects.

They are the key to unraveling the whole mystery.

There are countless reports of objects changing size and shape right before the eyes of witnesses, or splitting into several small objects, each of which flew off in a different direction. In some cases, the reverse process took place: several small objects were combined into one large one, which then calmly continued its flight.

Many times witnesses have said to me in a mysterious low voice, “You know, I don't think the things I saw were machines. I have a strong impression that they are alive.”

Researchers such as John Bessor and Ivan T. Sanderson have openly discussed the possibility that some UFOs are indeed living beings. Of course, there is no direct evidence, this statement can be challenged, like any other. Make your own choice. Each point of view has its own strengths, but after analyzing all the data, none of them can be adopted without very legitimate doubts.

Passed the sound barrier :-) ...

Before jumping into conversations on the topic, let's bring some clarity to the question of the accuracy of concepts (what I like :-)). There are two terms in common use today: sound barrier and supersonic barrier. They sound similar, but still not the same. However, there is no point in diluting it with particular rigor: in fact, this is one and the same thing. The definition of the sound barrier is used most often by people who are more knowledgeable and closer to aviation. And the second definition is usually all the rest.

I think that from the point of view of physics (and the Russian language :-)) it is more correct to say the sound barrier. There is simple logic here. After all, there is the concept of the speed of sound, but there is no fixed concept of the speed of supersonic, strictly speaking. Looking ahead a little, I’ll say that when an aircraft flies at supersonic, it has already passed this barrier, and when it passes (overcomes) it, then it passes a certain threshold value of speed equal to the speed of sound (and not supersonic).

Something like that:-). Moreover, the first concept is used much less frequently than the second. This is apparently because the word supersonic sounds more exotic and attractive. And in supersonic flight, the exotic is certainly present and, of course, attracts many. However, not all people who savor the words " supersonic barrier' really understand what it is. More than once I was convinced of this, looking at the forums, reading articles, even watching TV.

This question is actually rather complicated from the point of view of physics. But we, of course, will not climb into complexity. We will just try, as usual, to clarify the situation using the principle of "explaining aerodynamics on the fingers" :-).

So, to the barrier (sonic :-))!… Aircraft in flight, acting on such an elastic medium as air, becomes a powerful source of sound waves. I think everyone knows what sound waves are in the air :-).

Sound waves (tuning fork).

This is an alternation of areas of compression and rarefaction, propagating in different directions from the sound source. Approximately like circles on the water, which are also just waves (but not sound :-)). It is these areas, acting on the eardrum, that allow us to hear all the sounds of this world, from human whispers to the roar of jet engines.

An example of sound waves.

The points of propagation of sound waves can be various nodes of the aircraft. For example, an engine (its sound is known to anyone :-)), or body parts (for example, the bow), which, condensing the air in front of it when moving, create a certain type of pressure (compression) wave running forward.

All these sound waves propagate in the air at the speed of sound we already know. That is, if the plane is subsonic, and even flies at low speed, then they seem to run away from it. As a result, when such an aircraft approaches, we first hear its sound, and then it flies itself.

I will make a reservation, however, that this is true if the plane does not fly very high. After all, the speed of sound is not the speed of light :-). Its magnitude is not so great and sound waves need time to reach the listener. Therefore, the sequence of sound appearance for the listener and the aircraft, if it flies at high altitude, may change.

And since the sound is not so fast, then with an increase in its own speed, the plane begins to catch up with the waves emitted by it. That is, if he was motionless, then the waves would diverge from him in the form concentric circles like circles on the water from a thrown stone. And since the plane is moving, then in the sector of these circles, corresponding to the direction of flight, the boundaries of the waves (their fronts) begin to approach each other.

Subsonic motion of the body.

Accordingly, the gap between the aircraft (its nose) and the front of the very first (head) wave (that is, this is the area where gradual, to a certain extent, braking oncoming flow when meeting with the nose of the aircraft (wing, tail) and, as a result, increase in pressure and temperature) begins to decrease and the faster, the greater the flight speed.

There comes a moment when this gap practically disappears (or becomes minimal), turning into a special kind of area, which is called shock wave. This happens when the flight speed reaches the speed of sound, that is, the aircraft moves at the same speed as the waves emitted by it. The Mach number in this case is equal to one (M=1).

Sound movement of the body (M=1).

shock wave, is a very narrow area of ​​the medium (of the order of 10 -4 mm), when passing through which there is no longer a gradual, but a sharp (jump-like) change in the parameters of this medium - speed, pressure, temperature, density. In our case, the speed drops, pressure, temperature and density increase. Hence the name - the shock wave.

Somewhat simplistically, I would say this about all this. It is impossible to slow down the supersonic flow sharply, but it has to be done, because there is no longer the possibility of gradual deceleration to the speed of the flow just in front of the nose of the aircraft, as at moderate subsonic speeds. It seems to stumble upon a section of subsonic in front of the nose of the aircraft (or the toe of the wing) and collapses into a narrow jump, transferring to it the great energy of movement that it possesses.

By the way, it can also be said vice versa that the aircraft transfers part of its energy to the formation of shock waves in order to slow down the supersonic flow.

Supersonic motion of the body.

There is another name for the shock wave. Moving along with the aircraft in space, it is, in fact, the front of a sharp change in the above parameters of the environment (that is, the air flow). And this is the essence of the shock wave.

shock wave and a shock wave, in general, are equal definitions, but in aerodynamics the first is more commonly used.

The shock wave (or shock wave) can be almost perpendicular to the direction of flight, in which case they take an approximately circular shape in space and are called straight lines. This usually happens in modes close to M=1.

Modes of body movement. ! - subsonic, 2 - M=1, supersonic, 4 - shock wave (shock).

At numbers M > 1, they are already at an angle to the direction of flight. That is, the plane is already overtaking its own sound. In this case, they are called oblique and in space they take the form of a cone, which, by the way, is called the Mach cone, after the scientist who studied supersonic flows (he mentioned him in one of).

Mach cone.

The shape of this cone (its “slimness”, so to speak) just depends on the number M and is related to it by the relation: M = 1 / sin α, where α is the angle between the axis of the cone and its generatrix. And the conical surface touches the fronts of all sound waves, the source of which was the aircraft, and which it “overtook”, reaching supersonic speed.

Besides shock waves may also be affiliated, when they are adjacent to the surface of a body moving at supersonic speed or retreated if they do not touch the body.

Types of shock waves in supersonic flow around bodies of various shapes.

Usually, shocks become attached if the supersonic flow flows around any pointed surfaces. For an aircraft, for example, this can be a pointed nose, a PVD, a sharp edge of an air intake. At the same time, they say “jump sits”, for example, on the nose.

And the receding shock can be obtained when flowing around rounded surfaces, for example, the front rounded edge of a thick aerodynamic wing profile.

Various components of the aircraft body create a rather complex shock wave system in flight. However, the most intense of them are two. One head on the bow and the second tail on the elements of the tail unit. At some distance from the aircraft, the intermediate jumps either overtake the head one and merge with it, or the tail one overtakes them.

The shock waves on the aircraft model when blowing in a wind tunnel (M=2).

As a result, two jumps remain, which, in general, are perceived by the earthly observer as one due to the small size of the aircraft compared to the flight altitude and, accordingly, a short time interval between them.

The intensity (in other words, energy) of the shock wave (compression shock) depends on various parameters (the speed of the aircraft, its design features, environmental conditions, etc.) and is determined by the pressure drop at its front.

As the distance from the top of the Mach cone, that is, from the aircraft, as a source of perturbations, the shock wave weakens, gradually turns into an ordinary sound wave and eventually completely disappears.

And on what degree of intensity it will have shock wave(or shockwave) that reaches the ground depends on the effect it can produce there. It's no secret that the well-known Concorde flew supersonic only over the Atlantic, and military supersonic aircraft go supersonic at high altitudes or in areas where there are no settlements (at least it seems like they should do it :-)).

These restrictions are very justified. For me, for example, the very definition of a shock wave is associated with an explosion. And the things that a sufficiently intense shock wave can do may well be up to it. At least the glass from the windows can fly out easily. There is enough evidence of this (especially in the history of Soviet aviation, when it was quite numerous and the flights were intense). But you can do worse things. You just have to fly lower :-) ...

However, for the most part, what remains of shock waves when they reach the ground is no longer dangerous. Just an outside observer on the ground can at the same time hear a sound similar to a roar or explosion. It is with this fact that one common and rather persistent misconception is associated.

People who are not too experienced in aviation science, hearing such a sound, say that this plane overcame sound barrier (supersonic barrier). Actually it is not. This statement has nothing to do with reality for at least two reasons.

Shock wave (compression shock).

Firstly, if a person on the ground hears a booming roar high in the sky, then this only means (I repeat :-)) that his ears have reached shock wave front(or shock wave) from an airplane flying somewhere. This plane is already flying at supersonic speed, and not just switched to it.

And if the same person could suddenly be a few kilometers ahead of the aircraft, then he would again hear the same sound from the same aircraft, because he would be affected by the same shock wave moving along with the aircraft.

It moves at supersonic speeds, and therefore approaches silently. And after it has had its not always pleasant effect on the eardrums (well, when only on them :-)) and safely passes on, the rumble of running engines becomes audible.

Approximate aircraft flight pattern for various values ​​of the M number on the example of the Saab 35 "Draken" fighter. The language, unfortunately, is German, but the scheme is generally understandable.

Moreover, the transition to supersonic itself is not accompanied by any one-time “booms”, pops, explosions, etc. On a modern supersonic aircraft, the pilot most often learns about such a transition only from the readings of the instruments. In this case, however, a certain process occurs, but it is practically not noticeable to him, subject to certain piloting rules.

But that's not all :-). I'll say more. in the form of just some kind of tangible, heavy, difficult-to-cross obstacle, against which the plane rests and which needs to be “pierced” (I have heard such judgments :-)) does not exist.

Strictly speaking, there is no barrier at all. Once upon a time, at the dawn of the development of high speeds in aviation, this concept was formed rather as a psychological belief about the difficulty of switching to supersonic speed and flying at it. There were even statements that it was impossible at all, especially since the prerequisites for such beliefs and statements were quite specific.

However, first things first…

In aerodynamics, there is another term that quite accurately describes the process of interaction with the air flow of a body moving in this flow and striving to switch to supersonic. This is wave crisis. It is he who does some of the bad things that are traditionally associated with the concept sound barrier.

So something about the crisis :-). Any aircraft consists of parts, the air flow around which in flight may not be the same. Take, for example, a wing, or rather an ordinary classic subsonic profile.

From the basics of knowledge about how the lifting force is formed, we are well aware that the flow velocity in the adjacent layer of the upper curved surface of the profile is different. Where the profile is more convex it is greater than the total flow velocity, then when the profile flattens it decreases.

When the wing moves in the flow at speeds close to the speed of sound, there may come a moment when, for example, in such a convex region, the speed of the air layer, which is already greater than the total flow speed, becomes sonic and even supersonic.

Local shock that occurs on transonic during a wave crisis.

Further along the profile, this speed decreases and at some point again becomes subsonic. But, as we said above, the supersonic flow cannot quickly slow down, so the occurrence of shock wave.

Such shocks appear in different parts of the streamlined surfaces, and initially they are quite weak, but their number can be large, and with an increase in the total flow velocity, supersonic zones increase, the shocks “strengthen” and move towards the trailing edge of the airfoil. Later, the same shock waves appear on the bottom surface of the profile.

Full supersonic flow around the wing airfoil.

What is the risk of all this? But what. First- is significant increase in aerodynamic drag in the range of transonic speeds (about M=1, more or less). This resistance grows due to a sharp increase in one of its components - wave resistance. The same one that we did not take into account when considering flights at subsonic speeds.

For the formation of numerous shock waves (or shock waves) during the deceleration of a supersonic flow, as I said above, energy is spent, and it is taken from the kinetic energy of the aircraft. That is, the plane simply slows down (and very noticeably!). That's what it is wave resistance.

Moreover, shock waves, due to the sharp deceleration of the flow in them, contribute to the separation of the boundary layer after itself and its transformation from laminar to turbulent. This further increases the aerodynamic drag.

Airfoil flow at various M numbers. Shocks, local supersonic zones, turbulent zones.

Second. Due to the appearance of local supersonic zones on the wing profile and their further shift to the tail section of the profile with an increase in the flow velocity and, thereby, a change in the pressure distribution pattern on the profile, the point of application of aerodynamic forces (pressure center) also shifts to the trailing edge. As a result, there appears diving moment relative to the center of mass of the aircraft, causing it to lower its nose.

What does all this result in ... Due to the rather sharp increase in aerodynamic drag, the aircraft needs a significant engine power reserve to overcome the transonic zone and reach, so to speak, real supersonic.

A sharp increase in aerodynamic drag on transonic (wave crisis) due to an increase in wave drag. Cd is the drag coefficient.

Further. Due to the occurrence of a diving moment, difficulties arise in pitch control. In addition, due to the disorder and unevenness of the processes associated with the emergence of local supersonic zones with shock waves, too difficult to manage. For example, on a roll, due to different processes on the left and right planes.

Yes, plus the occurrence of vibrations, often quite strong due to local turbulence.

In general, a complete set of pleasures, which bears the name wave crisis. But, true, all of them take place (there were, specific :-)) when using typical subsonic aircraft (with a thick profile of a straight wing) in order to achieve supersonic speeds.

Initially, when there was not enough knowledge yet, and the processes of reaching supersonics were not comprehensively studied, this very set was considered almost fatally insurmountable and was called sound barrier(or supersonic barrier, if you want to:-)).

When trying to overcome the speed of sound on conventional piston aircraft, there were many tragic cases. Strong vibration sometimes led to the destruction of the structure. The aircraft did not have enough power for the required acceleration. In level flight, it was impossible due to an effect of the same nature as wave crisis.

Therefore, a dive was used for acceleration. But it could very well be fatal. The dive moment that appeared during a wave crisis made the dive protracted, and sometimes there was no way out of it. Indeed, in order to restore control and eliminate the wave crisis, it was necessary to extinguish the speed. But to do this in a dive is extremely difficult (if not impossible).

Dragging into a dive from level flight is considered one of the main causes of the disaster in the USSR on May 27, 1943 of the famous experimental BI-1 fighter with a liquid-propellant rocket engine. Tests were carried out for the maximum flight speed, and according to the designers, the speed achieved was more than 800 km / h. Then there was a delay in the peak, from which the plane did not come out.

Experimental fighter BI-1.

Nowadays wave crisis already well enough studied and overcome sound barrier(if it is required :-)) is not difficult. On aircraft that are designed to fly at sufficiently high speeds, certain design solutions and restrictions are applied to facilitate their flight operation.

As is known, the wave crisis begins at numbers M close to unity. Therefore, almost all jet subsonic liners (passenger, in particular) have a flight limitation on the number M. Usually it is in the region of 0.8-0.9M. The pilot is instructed to follow this. In addition, on many aircraft, when the limit level is reached, after which the airspeed must be reduced.

Almost all aircraft flying at speeds of at least 800 km/h and above have swept wing(at least on the leading edge :-)). It allows you to push back the start of the offensive wave crisis up to speeds corresponding to M=0.85-0.95.

Arrow wing. Fundamental action.

The reason for this effect can be explained quite simply. On a straight wing, an air flow with a speed V runs almost at a right angle, and on a swept wing (sweep angle χ) at a certain slip angle β. The velocity V can be vectorially decomposed into two streams: Vτ and Vn .

The flow Vτ does not affect the pressure distribution on the wing, but it does the flow Vn, which determines the carrying properties of the wing. And it is obviously less in magnitude of the total flow V. Therefore, on the swept wing, the onset of a wave crisis and the growth wave resistance occurs noticeably later than on a straight wing at the same freestream velocity.

Experimental fighter E-2A (the predecessor of the MIG-21). Typical swept wing.

One of the modifications of the swept wing was the wing with supercritical profile(mentioned him). It also allows you to move the beginning of the wave crisis at high speeds, in addition, it allows you to increase efficiency, which is important for passenger liners.

SuperJet 100. Supercritical swept wing.

If the aircraft is intended to transit sound barrier(passing and wave crisis too :-)) and supersonic flight, then it usually always differs in certain design features. In particular, it usually has thin profile of the wing and plumage with sharp edges(including diamond-shaped or triangular) and a certain shape of the wing in plan (for example, triangular or trapezoidal with an influx, etc.).

Supersonic MIG-21. Follower E-2A. A typical triangular wing.

MIG-25. An example of a typical aircraft designed for supersonic flight. Thin profiles of the wing and plumage, sharp edges. Trapezoidal wing. profile

Passing the notorious sound barrier, that is, such aircraft carry out the transition to supersonic speed on afterburning engine operation due to the increase in aerodynamic resistance, and, of course, in order to quickly slip through the zone wave crisis. And the very moment of this transition is most often not felt in any way (I repeat :-)) neither by the pilot (he can only reduce the sound pressure level in the cockpit), nor by an outside observer, if, of course, he could observe this :-).

However, here it is worth mentioning one more misconception, connected with outside observers. Surely many have seen this kind of photographs, the captions under which say that this is the moment of overcoming the plane sound barrier so to speak, visually.

Prandtl-Gloert effect. Not related to passing the sound barrier.

First of all, we already know that there is no sound barrier, as such, and the transition to supersonic itself is not accompanied by anything so extraordinary (including clap or explosion).

Secondly. What we saw in the photo is the so-called Prandtl-Gloert effect. I already wrote about him. It is in no way directly related to the transition to supersonic. It's just that at high speeds (subsonic, by the way :-)) the plane, moving a certain mass of air in front of it, creates some rarefaction area. Immediately after the passage, this area begins to fill with air from the nearby space with natural an increase in volume and a sharp drop in temperature.

If a air humidity is sufficient and the temperature falls below the dew point of the ambient air, then moisture condensation from water vapor in the form of fog, which we see. As soon as conditions are restored to the original, this fog immediately disappears. This whole process is rather short.

Such a process at high transonic speeds can be facilitated by local surges I, sometimes helping to form something similar to a gentle cone around the aircraft.

High speeds favor this phenomenon, however, if the air humidity is sufficient, then it can occur (and occurs) at rather low speeds. For example, above the surface of water bodies. By the way, most beautiful photos of this nature were made on board an aircraft carrier, that is, in sufficiently humid air.

That's how it works. The shots, of course, are cool, the spectacle is spectacular :-), but this is not at all what it is most often called. nothing to do with it (and supersonic barrier too:-)). And this is good, I think, otherwise the observers who take this kind of photo and video might not be good. shock wave, do you know:-)…

In conclusion, one video (I have already used it before), the authors of which show the effect of a shock wave from an aircraft flying at low altitude at supersonic speed. There is, of course, a certain exaggeration there :-), but the general principle is clear. And again, it's amazing :-)

And that's all for today. Thank you for reading the article to the end :-). Until we meet again…

Photos are clickable.

The video was made using the Schlieren method for studying shock waves.

NASA has released footage of a T-38 Talon training aircraft flying at supersonic speed against the background of the Sun. It was made using the Schlieren method to study shock waves generated at the edges of an aircraft airframe. Pictures and videos of shock waves are needed by NASA specialists for research conducted as part of a project to develop a "quiet" supersonic aircraft.

The Schlieren method is one of the main methods for studying air flows in the design and testing of new aircraft.

This method of photography makes it possible to detect optical inhomogeneities in transparent refractive media. Schlieren photography uses special lenses with a cut-off aperture.

In such cameras, direct rays pass through the lens and are concentrated on the cut-off diaphragm, which is also called the Foucault knife. In this case, the reflected and scattered light is not focused by the lens on the knife and falls on the camera matrix. Due to this, the attenuated light scattered and reflected by refractions in the air is not lost in direct rays.

The shock waves are clearly visible in the published video. They are areas in which the pressure and temperature of the medium experience a sharp and strong jump. Shock waves are perceived by an observer on the ground as an explosion or as a very loud bang, depending on the distance to the supersonic object.

The sound of the explosion from shock waves is called sonic boom, and it is he who is one of the main obstacles in the development of supersonic passenger aviation. Currently, aviation regulations prohibit supersonic flights aircraft over populated parts of the land.

Aviation authorities may allow supersonic flights over populated areas of land if the perceived noise level of passenger aircraft does not exceed 75 decibels. In order to make the existence of civil supersonic aviation possible, developers are now looking for different technical ways to make new aircraft "quiet".

When flying at supersonic speeds, an aircraft generates a lot of shock waves. They usually occur at the tip of the nose cone, on the leading and trailing edges of the wing, on the leading edges of the tail assembly, in the areas of the swirlers of the flow and on the edges of the air intakes.

One way to reduce the perceived noise level is to change the aerodynamic design of the aircraft.

In particular, it is believed that the redesign of some elements of the airframe will make it possible to avoid sharp pressure surges at the front of the shock wave and sharp drops in pressure in its rear part, followed by normalization.

A shock wave with sharp jumps is called an N-wave, since on the graph it resembles this particular letter of the Latin alphabet. It is these shock waves that are perceived as an explosion. The new aerodynamic design of the aircraft will have to generate S-waves with a smooth and not as significant pressure drop as that of the N-wave. It is assumed that S-waves will be perceived as a soft pulsation.

The development of a technology demonstrator for a “quiet” supersonic aircraft as part of the QueSST project is being carried out by the American company Lockheed Martin. The work is carried out by order of NASA. In June of this year, the preliminary design of the aircraft was completed.

It is planned that the first flight of the demonstrator will take place in 2021. The "quiet" supersonic aircraft will be made single-engine. Its length will be 28.7 meters. He will receive a glider, the fuselage and wing of which outwardly resemble an inverted aircraft. The QueSST will be equipped with a conventional vertical keel and horizontal rudders for maneuvering at low flight speeds.

At the top of the keel, a small T-tail will be installed, which will "break" shock waves from the bow and cockpit canopy. The nose of the aircraft will be significantly lengthened to reduce drag and reduce airframe drops where shock waves can form during supersonic flight.

QueSST technology involves the development of such an aerodynamic design of the aircraft, on the edges of which the smallest possible number of shock waves would be formed. In this case, those waves that will still be formed should be much less intense.

Small unmanned aerial vehicles are becoming more common every year - they are used in filming TV shows and music videos, for patrolling territories, or just for fun. Drones do not require special permission, and their cost is constantly decreasing. As a result, the aviation authorities of some countries decided to study whether these devices pose a danger to passenger aircraft. The results of the first studies turned out to be contradictory, but in general, regulators came to the conclusion that flights of private drones should be taken under control.

In July 2015, a Lufthansa plane landing at Warsaw Airport almost collided with a multicopter flying at a distance of less than a hundred meters from it. In April 2016 the pilots passenger aircraft British Airways, which landed at London airport, reported to the dispatchers about the collision with the drone during the landing approach. Later, however, the investigation concluded that there was no drone, and what the pilots took for it was most likely an ordinary package lifted by the wind from the ground. However, already in July 2017, at the British Gatwick airport, the plane almost collided with a drone, after which the controllers were forced to close one runway for landing and redirect five flights to reserve lanes.

According to the British research organization UK Airprox Board, in 2016 in the UK there were 71 cases of dangerous proximity of passenger aircraft with drones. In aviation, a close proximity is considered to be an aircraft approaching another aircraft at a distance of less than 150 meters. Since the beginning of this year, there have already been 64 cases of drones approaching aircraft in the UK. In the United States, aviation authorities registered just under 200 cases of dangerous proximity last year. At the same time, the aviation authorities still have a poor idea of ​​how dangerous small drones can be for passenger aircraft. Some experts have previously suggested that a collision with a drone for a passenger liner would be no more dangerous than a regular collision with birds.

According to Aviation Week & Space Technology, since 1998, 219 people have died worldwide due to mid-air collisions with birds, and a significant number of them flew in small private jets. At the same time, airlines around the world spend a total of $625-650 million annually to repair damage to passenger aircraft due to bird strikes. By the way, in general, passenger liners are considered resistant to direct hit by birds. During the development and testing of new aircraft, special checks are even carried out - the aircraft is fired upon with the carcasses of various birds (ducks, geese, chickens) to determine its resistance to such damage. Checking the engines for throwing birds into them is generally mandatory.

In mid-March last year, researchers from the American George Mason University, in which they announced that the threat of drones to aviation is greatly exaggerated. They studied the statistics of aircraft strikes with birds from 1990 to 2014, including episodes that ended in human casualties. As a result, scientists came to the conclusion that the real probability of a dangerous collision of a drone with an aircraft is not so great: only one case in 187 million years should end in a large-scale catastrophe.

To try to determine whether drones are indeed a threat to passenger aircraft, two independent studies were commissioned in 2016 by aviation authorities in the European Union and the UK. The engineers who conduct these studies bombard various aircraft fragments with drones of various designs or their parts in order to cause real damage that passenger aircraft can receive in a collision. In parallel, mathematical modeling of such collisions is carried out. Research is carried out in several stages, the first of which has already been completed, and the results are presented to customers. As expected, after the completion of the work, the aviation authorities will develop new rules for the registration and operation of drones by private individuals.

Drone crashes into the windshield of a passenger plane during testing in the UK

Today at different countries There are no unified rules for flying drones. For example, in the UK it is not required to register and license drones weighing less than 20 kilograms. At the same time, these devices must perform flights in the line of sight of the operator. Private drones with cameras cannot fly up to people, buildings and cars at a distance closer than 50 meters. In Italy, there are practically no special rules for drones, except for one thing - drones cannot be flown by a large crowd of people. And in Ireland, for example, all drones weighing more than one kilogram must be registered with the country's Civil Aviation Authority. By the way, in the European Union, Ireland is one of the ardent supporters of tightening the rules for the use of drones.

Meanwhile, while in Europe they plan to tighten the screws, in the United States, on the contrary, they intend to make drone flights more free. So, at the beginning of this year, the US Federal Aviation Administration concluded that light consumer quadrocopters do not pose a big threat to aircraft, although their flights near airports are unacceptable. In February, US companies 3DR, Autodesk and Atkins have already received permission to operate drone flights at the world's busiest airport - International airport Hartsfield-Jackson Atlanta, which annually passes through itself about a hundred million passengers. Here, quadcopters were used to produce high-resolution 3D maps of the airport. They flew in the line of sight of the operator and under the control of air traffic controllers.

The results of the study were first published by a working group of the European Aviation Safety Agency in October last year. These researchers concluded that amateur drones do not pose a serious threat to passenger aircraft. The members of the working group during their work focused on studying the consequences of air collisions between passenger aircraft and drones weighing up to 25 kilograms. For the study, drones were divided into four categories: large (weighing more than 3.5 kilograms), medium (up to 1.5 kilograms), small (up to 0.5 kilograms) and “harmless” (up to 250 grams). For each category, experts determined the degree of danger, which was assessed on a five-point scale: 1-2 - high, 3-5 - low. Devices that received four or five points were considered safe.

To determine the degree of danger, the researchers used data on the flight altitudes of vehicles by category, took into account the likelihood of their appearance in the same airspace with aircraft, as well as the results of computer and full-scale tests of the collision of drones and airliners. In addition, the individual degree of danger was assessed for each unmanned vehicle according to four points: damage to the hull, threat to the life of passengers, threat to the life of the crew, threat of violation of the flight schedule. To simplify the assessment, the researchers conducted calculations for aircraft flying at a speed of 340 knots (630 kilometers per hour) at an altitude of three thousand meters or more and at a speed of 250 knots at a lower altitude.

Based on the results of all calculations, the participants of the European working group came to the conclusion that small drones at an altitude of up to three thousand meters practically do not pose a threat to passenger aircraft. The fact is that such devices to a great height, where they can collide with an aircraft, are extremely rare. In addition, they have a very small mass. Medium drones, according to experts, do not pose a serious threat to airliners. Only if a device weighing 1.5 kilograms (most amateur drones have such a mass) collides with an aircraft at an altitude of more than three thousand meters, can it threaten flight safety. Large devices are recognized as dangerous for passenger aircraft at all flight altitudes.

According to the results of full-scale tests, it turned out that in the event of a collision with drones, the windshields of the airliners, nose cones, wing leading edges, and engines can receive the most damage. In general, the damage from drones weighing up to 1.5 kilograms can be comparable to the damage from birds that aircraft regularly encounter in the air. Now, European experts are preparing for an expanded study. This time, the damage that drones can cause to the engines of passenger aircraft will be studied, as well as the likelihood of batteries falling into technological holes.

By the way, earlier scientists from the Virginia Polytechnic University conducted computer simulations of situations in which various drones fall into a working aircraft engine. The researchers concluded that vehicles weighing more than 3.6 kilograms pose a serious danger to engines. Once in the engine, they will destroy the fan blades and collapse themselves. Then the fragments of the fan blades and the drone will fall into the external air circuit, from where they will be thrown out, as well as into the internal circuit - the compressor, the combustion chamber and the turbine zone. The speed of debris inside the engine can reach 1150 kilometers per hour. Thus, in a collision during takeoff with a drone weighing 3.6 kilograms, the engine will completely stop working in less than a second.

Meanwhile, the results of the British study were summed up in the middle of this year - in July, the company QinetiQ, which carried out the work, handed over the report to the National Air Traffic Control Service of Great Britain. The study, conducted by a British company, used a specially designed air gun that fired drones and their parts at predetermined speeds at the front of decommissioned planes and helicopters. For shooting, quadrocopters weighing 0.4, 1.2 and 4 kilograms, as well as aircraft-type drones weighing up to 3.5 kilograms, were used. Based on the results of the shooting, experts came to the conclusion that any drones are dangerous for light aircraft and helicopters that do not have a special certificate of protection against bird strikes.

Bird-proof passenger aircraft can be seriously damaged by drones when flying at cruising speeds that range from 700 to 890 kilometers per hour. The researchers attributed the destruction of the windshields in a collision with heavy parts of the drones - metal body parts, a camera and a battery - to serious damage. These parts, breaking through the windshield, can fly into the cockpit, damage the control panels and injure the pilots. Dangerous for the liners were considered devices weighing from two to four kilograms. It should be noted that cruising speed passenger planes are already developing at a high altitude (usually about ten thousand meters), which amateur drones are simply unable to climb.

According to QinetiQ, drones weighing four kilograms can be dangerous for passenger aircraft at low flight speeds, such as when landing. At the same time, the severity of damage to the aircraft largely depends on the design of the drone. So, during the tests, it turned out that drones with a camera placed on a suspension under the body have a small chance of breaking through the windshield of a passenger aircraft. The fact is that in a collision with glass, the camera on the suspension will first hit, and then the body of the drone. In this case, the camera and its suspension will play the role of a kind of shock absorber, taking on part of the impact energy. The UK aviation authorities, who are pushing for a drastic tightening of drone regulations, are expected to order an additional study.

Some of the drones that are being mass-produced today already have the geofencing function. This means that the device is constantly updating the database of areas closed to drone flights. In such a zone, the drone simply will not take off. However, in addition to serial devices, there are home-made drones that can fly into the airspace of airports. And there are quite a few of them. In general, so far not a single case of a collision between an aircraft and a drone has been registered, but this is just a matter of time. And even if small drones do not pose a serious threat to passenger aircraft, they can still have a negative impact on aviation, increasing the already considerable costs for companies to repair liners.

Vasily Sychev