In the mid-60s of the last century, residents of American megalopolises repeatedly appealed to the city administration with complaints about strange phenomena taking place in the sky. In completely cloudless weather, thunder suddenly sounded in the sky and, rapidly dying down, disappeared without a trace.
As time went. The mysterious thunder continued to periodically frighten ordinary Americans. Finally, on July 10, 1967, after sporadic complaints escalated into mass grievances, the US Air Force issued an official statement, which reported that strange thunder appeared as a result of flights of the Lockheed SR -71 supersonic strategic reconnaissance aircraft.
This story continued with several dozen lawsuits by American citizens, in which they demanded from the Air Force to compensate for the damage caused during the flights. The amount that the military had to pay by court order amounted to 35 thousand dollars, however, in the thirty-year history of the fastest and one of the most expensive military aircraft to operate, the SR -71 is a small drop in the sea of victories and defeats.
History of creation, or wanted the best, but it turned out, as always
The first flight of the "Blackbird" or "Blackbird", as the US military nicknamed the SR -71 for its appearance, took place on December 22, 1964. The new supersonic reconnaissance aircraft were intended for use by the US Air Force, which at that time did not have a worthy rival to the new generation A-12 supersonic reconnaissance aircraft, which was in service with the CIA.
At that time, the A -12 was the fastest aircraft in the world - about 3300 km / h and had one of the highest ceilings with a maximum height of 28.5 km. Initially, the CIA planned to use the A-12 for reconnaissance over the territory of the Soviet Union and Cuba, however, plans had to be changed due to an event that occurred on May 1, 1960, when the predecessor of the Titanium Goose (as the A-12 was called) U-2 was shot down Soviet anti-aircraft missile system. The CIA decided not to risk expensive aircraft and used satellites for reconnaissance in the USSR and Cuba, and sent the A-12 to Japan and North Vietnam.
A-12
The A-12 chief designer Clarence "Kelly" Johnson considered this distribution of intelligence forces unfair, and beginning in 1958, he began to negotiate closely with the Air Force high command to create a more advanced military aircraft that could combine the functions of a reconnaissance and bomber.
Four years later, the United States Air Force finally assessed the possible benefits that they could get with the A-12 or its possible prototype in service and gave its consent. By then, Johnson and his team had been working on two new models, the R-12 and RS-12, for over a year. A few months later, the mock-ups were ready and Johnson presented them to be torn apart by the Air Force command. General Li Mei, who arrived for the presentation, was extremely displeased. He stated that the RS -12 was nothing more than a repetition of North American Aviation's projected XB-70 Valkyrie, a modification of the RS-70.
Perhaps, the reason for this statement was: firstly, the combat purpose of both aircraft - reconnaissance bombers, secondly, the ability to refuel in the air for both models, and thirdly, the maximum speed, both of which are three times faster sound. In all other respects, the planes are absolutely not alike either in size, shape or technical characteristics.
1) Length RS -12 - 32, 74 m / Length Valkyrie - 56, 6 m.
2) Wingspan RS -12 - 16, 94 m / Wingspan Valkyrie - 32 m
3) The maximum speed of RS -12 (at that time it was assumed) - more than 3300 km / h / The maximum speed of the Valkyrie - 3200 km / h.
Johnson could not convince General May. Moreover, the dispute became so serious that US Secretary of Defense Robert McNamar had to intervene. Without taking sides, he simply ordered to stop the development of both aircraft. If there were someone else in Johnson's place, then perhaps the projects would have remained just projects. However, Hall Hibbard, Johnson's leader and project leader for the first Stealth F-117, once said about him: "This damn Swede can literally see the air." Perhaps Johnson saw the air better now, and therefore decided to use his last chance.
He simply changed the RS acronym from Reconnaissance Strike to Reconnaissance Strategic. Thus, having changed the combat purpose of his aircraft, no one could blame him for duplicating the Valkyrie, and he continued the development of the RS -12.
The RS -12 was transformed into the SR -71 by accident. In a speech in July 1964, the President of the United States (Johnson's namesake) Lyndon Johnson, speaking of the aircraft RS -12, mixed up the letters and pronounced SR -12. Incidentally, this was not the only oversight of the president in his speeches regarding aircraft. In February of the same year, Johnson read the name A-11 instead of the AMI (Advanced Manned Interceptor) abbreviation, which later became the official name.
Clarence Johnson took the 71 as an indication that his model of the scout is the next step after the Valkyrie project. This is how the Lockheed SR -71 ("Blackbird") was born.
In fact, the SR -71 was the prototype of two other aircraft designed by Johnson - the A-12 and YF-12, which simultaneously combined the functions of an interceptor and a reconnaissance aircraft. It was the YF-12 that became the model that Johnson eventually began to build on. Compared to the YF-12, it increased the dimensions of the SR -71: its length was 32.7 meters instead of 32 m, and the height was 5.44 meters instead of 5.56. In the entire history of world military and civil aviation, the SR -71 is one of the most long planes. It is rare to find a model whose length reached at least 30 meters. But, despite this, thanks to its record speed and one of the highest altitude ceilings - 25, 9 km, SR -71 joined the ranks of the first generation stealth aircraft - Stealth.
Johnson also increased the maximum take-off weight, instead of 57.6 tons, as in the YF-12, the SR -71 began to weigh 78 tons at takeoff. The phrase “we wanted the best, but it turned out as always” related to this parameter. It was not easy to lift such a mass into the air, so Johnson decided to use an air refueling system using a specially converted KC-135 Q tanker aircraft. The scout flew into the air with a minimum amount of fuel, which greatly facilitated it. Refueling was carried out at an altitude of 7.5 km. Only then could the SR -71 go on a mission. Without refueling, it could hold out in the air, just like the previous models for 1.5 hours, however, it covered 5230 km during this time - 1200 km more than the A -12 and YF -12. One refueling flight cost the US Air Force $ 8 million, which soon caused the military command, following the example of the CIA with the A-12, to “scream” about the cost of the SR -71 flights.
The fact is that on December 28, 1968, the program for the production and development of the A-12 reconnaissance aircraft was closed. The Lockheed Corporation cited the high operating cost of the Titanium Goose as the main reason (there is no data on the cost of one A-12 flight). Moreover, there was no point in continuing its production, while the more advanced SR -71 had been in service for two years. At that time, the CIA had already given all of its A-12s to the Air Force and in return received spy satellites with the most modern photographic equipment. Looking ahead, let's say that one of the reasons why the surviving SR -71s began to be decommissioned between 1989 and 1998 was the high cost of operation. Over the 34 years of the SR -71's existence, the US Air Force has spent more than $ 1 billion on flights of 31 aircraft. It didn't work out to save money.
Finally, the most important difference and unrivaled advantage so far is the supersonic speed SR -71 - 3529, 56 km / h. This figure is three times the speed of sound in air. A-12 and YF-12 lost over 200 km / h to the Blackbird. In this regard, Johnson's planes made a revolution. After all, the world's first supersonic aircraft appeared in 1954, just eight years before the A-12 or SR-71. The maximum speed that he could develop barely exceeded the speed of sound - 1390 km / h. In 1990, thanks to their speed, the Blackbirds avoided the usual "conservation" in museums and hangars of military bases, since NASA showed considerable interest in them, where several copies were transferred.
On the SR-71, scientists and designers from NASA conducted aerodynamic research under the AST (Advanced Supersonic Technology) and SCAR (Supersonic Cruise Aircraft Research) programs.
The minimum level of hypersonic speed is about 6,000 km / h
Everything was uneasy in the sky
High speed not only solved the tasks set by Johnson, but also created many difficulties in the operation of the "Blackbird". At a speed of Mach 3 (Mach number = 1 speed of sound, i.e. 1390 km / h), the friction against the air was so great that the titanium skin of the aircraft was heated up to 300 ºС. However, Johnson solved this problem as well. The minimum cooling was provided by the black paint of the case, made on a ferrite base (ferrite - iron or an iron alloy). It performed a double function: firstly, it dissipated the heat entering the surface of the aircraft, and secondly, it reduced the aircraft's radar signature. In order to reduce visibility, ferrite paint is very often used in military aviation.
Blackbird engine - Pratt & Whitney J58-P4. Length - 5.7 m. Weight - 3.2 tons
The main "conditioner" in the SR-71 design was the special JP-7 fuel, which was developed for the US supersonic aviation. Due to its constant circulation from the fuel tanks, through the skin of the aircraft, to the engines, the body of the Blackbird was constantly cooled, and the fuel had time to heat up to 320 ºС during this time. True, the technical advantages of the JP-7 were little justified by its consumption. At cruising speed, two Pratt & Whitney J58 reconnaissance engines consumed about 600 kg / min.
At first, the circulation system was the main headache for engineers. JP-7 fuel could easily leak through even the smallest leaks. And there were more than enough of them in the hydraulic and fuel systems. By the summer of 1965, the problem with fuel leakage had finally been resolved, but this was just the beginning of the Blackbird's chain of failures.
On January 25, 1966, the first SR -71 crashed. The scout flew at an altitude of 24 390 m at a speed of Mach 3, at which point the plane lost control due to a failure of the air intake control system. Pilot Bill Weaver successfully ejected despite the ejection seat remaining in the plane. On the SR -71, Johnson installed new ejection seats that allowed pilots to safely exit the cockpit at an altitude of 30 m and a speed of Mach 3. Perhaps it was a fluke, he was simply thrown out of the cockpit by a stream of air. Weaver's partner Jim Sauer also managed to eject, but he could not survive.
Air intake - a structural element of an aircraft that serves to take in ambient air and then supply it to various internal systems. The air from the air intake can serve as a heat carrier, an oxidizer for fuel, creating a supply of compressed air, etc.
Air intake "Blackbird"
Bill Weaver did most of the testing of the Blackbird. For him, this was not the only disaster, as well as for his partners. On January 10, 1967, the SR -71 underwent speed runs along the runway. For greater complexity, the strip was wetted in advance to enhance the sliding effect. Having landed on the runway at a speed of 370 km / h, pilot Art Peterson was unable to release the brake parachute. It should be noted that the speed of separation from the lane for the SR -71 is 400 km / h. Of course, conventional brakes could not stop the reconnaissance aircraft on a wet surface, and the SR -71 continued to move along the runway at the same speed. As soon as he stepped onto the dry section of the track, all chassis tires burst from the heat. The bare chassis discs began to strike sparks, causing the magnesium alloy wheel hubs to catch fire. Considering that magnesium alloys ignite at temperatures from 400 to 650 ° C, then approximately the same temperature was in the area of the chassis during braking. The plane stopped only when it passed the entire runway and hit the ground of a dried lake with its nose. Peterson survived, however, suffered numerous burns.
The failure of the braking parachute turned out to be an isolated case, but the magnesium bushings repeatedly led to the fire of the Blackbird. Ultimately, the engineers replaced the magnesium alloy with aluminum.
The last accident in the test program occurred again due to the failure of the air intake. On December 18, 1969, the SR -71 crew worked out the onboard electronic warfare system. As soon as the scout reached maximum speed, the pilots heard a strong bang. The aircraft began to lose control and gave a sharp roll. 11 seconds after the clap, the crew commander gave the order to eject. The plane crashed, and it was not possible to find out the exact cause of the accident. However, experts assumed that the disaster was due to the failure of the air intake. The sharp roll that the plane gave after the clap could only be explained by the uneven distribution of engine thrust. And this happens if the air intake fails. The problem with not starting the air intake was inherent in all aircraft of the A -12, YF -12 and SR -71 series. In the end, Johnson made the decision to replace the manual control of the air intakes with an automatic one.
In 1968-1969. there were three more disasters with SR -71. The reasons were: the failure of the electric generator (the battery, which could provide the aircraft with 30 minutes of flight, was not enough), the ignition of the engine and the ignition of the fuel tank (after the fragments of the wheel disks pierced it). The planes went out of order and another serious flaw appeared on the surface of the project: firstly, there was a catastrophic lack of spare parts, and secondly, the repair of one aircraft would hit the US Air Force's "pocket" hard. It is known that the cost of maintaining one squadron of SR-71 was equal to the cost of maintaining two air wings of tactical fighters in flight condition - this is approximately $ 28 million.
Those "Blackbirds", which successfully passed flight tests, were subjected to the most thorough technical inspection. After landing, each flying unit underwent about 650 checks. In particular, it took two technicians several hours to check the air intakes, engines and bypass devices after the flight.
During the tests, which took place until 1970, when the SR -71 was in service for four years, Lockheed suffered heavy losses, both technical and human. However, military service for the Blackbirds was just beginning.
Blackbirds on a mission
Approximately 1300 meters are required for the SR -71 on the runway for the takeoff run at a speed of 400 km / h. 2.5 minutes after the scout takes off from the ground, at a speed of 680 km / h, he gains an altitude of 7.5 km. So far, the SR -71 remains at this height, only increasing the speed to Mach 0.9. At this moment, the air tanker KC-135 Q is refueling the Blackbird. As soon as the tanks are full, the pilot switches the reconnaissance control to the autopilot, since the plane should begin to climb at a speed of 860 km / h, no less, no more. At an altitude of 24 km and a speed of Mach 3, the pilots again switch to manual control. This is how each mission begins.
The main points of reconnaissance for the SR -71 were: Vietnam, North Korea, the Middle East, Cuba, and yet, despite warnings from the Air Force command, the Soviet Union in the Kola Peninsula area.
When the Blackbirds began to be sent to North Vietnam in 1968, the Vietnam War between the north and south of the country (1955 - 1975) was in full swing on its territory. From 1965 to 1973, there was a period of full-scale US military intervention. This was the largest military mission for the SR -71.
The Blackbirds were equipped with their own reconnaissance equipment. They were equipped with an automatic autonomous astroinertial navigation system, which, being guided by the stars, made it possible to accurately calculate the location of the aircraft even during the day. A similar navigation system was later used in the Soviet T-4 bomber-missile carrier, which was being designed at that time. The exact correspondence of the flight to a given route on the SR -71 could be verified using an air data calculator and an on-board computer.
In the very process of reconnaissance, the SR -71 could use several aerial cameras, a side-looking radar system (radar) and equipment capable of operating in the infrared range (thermal imaging devices). A panoramic aerial camera was also located in the forward instrument compartment. Such reconnaissance equipment allowed the "Blackbird" for 1 hour of flight at an altitude of 24 km to survey the territory of 155 thousand km 2. This is slightly less than half of the territory of modern Vietnam. As far as photographic equipment is concerned, in one sortie, the scout filmed several hundred ground objects. For example, in November 1970 in Vietnam, before the failed operation of the US military "Falling Rain" to free prisoners from the Son Tai camp, the Blackbird managed to photograph the place where the prisoners were supposedly kept.
North Vietnamese artillery repeatedly tried to shoot down SR -71, according to some estimates, several hundred artillery missiles were fired at the reconnaissance officer, however, not a single launch was successful. Experts believed that the electronic warfare system, which suppressed the radio signal at the Vietnamese launch complex, allowed the Blackbird to escape the shelling. The same unsuccessful shelling was once subjected to SR -71 over the territory of the DPRK.
However, the Air Force nevertheless lost several SR -71s during reconnaissance missions, however, in all cases, weather conditions were the cause of the accident. One such incident occurred on May 10, 1970, when the Blackbird crashed over Thailand, where US military bases were located during the Vietnam War. The SR -71 had just refueled and ran into a thunderstorm front. The pilot began to lift the aircraft above the clouds, as a result of which he exceeded the allowable limit on the pitch angle (i.e., the angle of the aircraft's nose upward), the thrust of the engines dropped, and the aircraft lost control. The ejection seats did their job again, the crew safely left the plane.
Former Blackbird pilot
Intelligence missions in the Middle East during the eighteen-day Yom Kippur War (the war between Israel on the one side and Egypt and Syria on the other) and in Cuba were single and successful. In particular, the reconnaissance operation in Cuba was to provide the American command with confirmation or refutation of information about the strengthening of the USSR's military presence in Cuba. If this information was confirmed, the "cold war" could develop into a real international scandal, since according to the agreement signed between Khrushchev and Kennedy, it was forbidden to supply strike weapons to Cuba. SR -71 made two sorties, during which images were obtained, refuting rumors about the supply of fighter-bombers MiG-23BN and MiG-27 to Cuba.
The Blackbirds' cameras, capable of shooting within a radius of 150 km, allowed US military intelligence to photograph the coastal zone of the Kola Peninsula without violating Soviet airspace. However, once the not very agile SR -71 still went too far. On May 27, 1987 SR -71 entered Soviet airspace in the Arctic region. The command of the Soviet Air Force sent a MiG-31 fighter-interceptor to intercept. With a speed of 3000 km / h and a practical ceiling height of 20.6 km, the Soviet aircraft successfully drove the Blackbird into neutral waters. Shortly before this incident, two MiG-31 aircraft also intercepted SR -71, but this time in neutral territory. Then the American intelligence officer failed the mission and flew to the base. Some experts believe that it was the MiG-31 that forced the Air Force to abandon the SR -71. It is difficult to say how plausible this version is, however, there is reason to believe so. The Soviet Krug anti-aircraft missile system, which could easily reach the Blackbird at maximum height, could also have caused the departure of the SR -71.
MiG-31
Anti-aircraft missile system "Krug"
The photographic equipment of the Blackbirds was, indeed, effective, however, it was powerless in cloudy weather. Poor visibility could not only be the cause of the failed mission, but also the cause of the accident. During the rainy season, when the sky was overcast, pilots had to maneuver in search of an open view. The loss of altitude on a heavy aircraft did not have the best effect on its piloting. It is for this reason that the US Air Force abandoned the idea of sending the SR -71 to reconnaissance in Europe.
Before landing the SR -71, the pilots turn on the autopilot. When the aircraft's speed reaches 750 km / h, the descent begins. According to the plan, at the moment when the plane starts to approach landing, the flight speed should drop to 450 km / h, and when touching the runway - 270 km / h. As soon as the contact occurs, the pilots release the braking parachute, with which the SR -71 overcomes 1100 m. Then, when the aircraft's speed significantly decreases, the parachute is fired and the Blackbird continues braking with the main brakes. This is how each flight ends.
Retired Blackbirds
At the end of the 1980s, the first wave of resolution of the issue of withdrawing the Blackbirds from the US Air Force began. There were plenty of reasons: a large number of accidents, high operating costs, shortage and costly spare parts, and, finally, vulnerability to the aforementioned Soviet weapons. In the fall of 1989, the final decision was made to remove the SR -71 from service. Opponents of such a decision argued that there was no alternative to SR -71, and the spy satellites advocated in Congress and in the Air Force themselves did not justify themselves either at a price that was several times higher than the cost of the Blackbirds, or in efficiency. how the SR -71s could conduct more extensive reconnaissance.
Almost all the aircraft were transferred to museums, several copies remained inactive at the bases, several aircraft were transferred to NASA and the Pentagon for use.
At that time, the irreplaceable reconnaissance officers of the SR -71 Air Force could not leave just like that, and in the mid-90s the military nevertheless decided to partially return to the use of "Blackbirds". In 1994, the DPRK began testing nuclear weapons. The Senate sounded the alarm and asked Lockheed to resume SR-71 flights, since there was nothing to conduct reconnaissance. The company's management agreed, but demanded $ 100 million. After an agreement was reached, several Blackbirds rejoined the US Air Force. A year later, the Senate re-allocated the same amount to keep the SR -71 aircraft in flight condition. Flights continued until 1998. However, in 1998, the Blackbirds were finally removed from service. According to reports from news agencies, it can be judged that unmanned reconnaissance aircraft and spy satellites have replaced the SR -71, however, information about them is kept secret.
Such was the story of the creation, victory and defeat of the fastest manned aircraft in the world, the Lockheed SR -71 ("Blackbird").
