In the history of human military aircraft development, the F-117 is a unique existence, it is the first "stealth" fighter for mankind. Of course, the so-called "stealth" fighter is not invisible to the naked eye, but relative to the radar system, the aircraft can achieve "stealth", so that in the case of the other side's air defense system is unconscious, the enemy's air defense system or ground targets to carry out surprise attacks. This aircraft that completely changed the mode of war has both the glory created in Panama and Iraq, and the bitterness of being shot down by the Federal Republic of Yugoslavia, but the revolution in stealth technology triggered by it still affects the aviation technology and air force tactical trends of the world's major powers.
(F-117 "Nighthawk")
A bold idea: make an airplane invisible to radar!
In ancient warfare, there were generals who commanded soldiers to cover their bodies with branches, straw, etc., deceive the enemy's spies, and conceal the whereabouts of the troops, which is the earliest and simplest visual invisibility. After mankind entered the industrial age, the army's various camouflage uniforms and camouflage nets became popular, and even battleships and cruisers sailing at sea were spray-painted with various deceptive camouflage to disrupt the enemy's visual reconnaissance. However, the stealth technology of the aircraft can be traced back to the 60s of the last century, and it can be said that it is the latest military stealth technology that was born.
(During World War II, the B-17 bomber often faced the double whammy of German fighters and anti-aircraft guns when performing strategic bombing missions due to its low flight altitude.)
The birth of aircraft stealth technology has a relatively complex background. First of all, at the beginning of the birth of the aircraft, because the main anti-aircraft weapons of various countries are anti-aircraft guns, flying higher and faster has become the key to improving the defense and survivability of aircraft. So we see that during World War II, the US high-altitude bomber flew all the way up, of which the B-17 bomber although the maximum ceiling of up to 10700 meters, but because the aircraft used a non-pressurized open cabin, so when it rose above 10,000 meters, the cabin temperature will drop to -50 ° C, pilots and gunners can not stand it at all.
(B-29 Superfortress bomber)
Therefore, the B-17 generally flew at an altitude of only about 5000 to 6000 meters, in order to ensure the accuracy of the bombing, sometimes even only flew to a height of 3500 meters, which led to the entire bomber cluster must pass through the fire network of the German air defense force when performing the bombing mission, and many B-17 bombers were shot down. Later in the war, during the U.S. bombing of Japan, the new B-29 bomber was used, which could eventually avoid Japanese anti-aircraft fire. Because although the B-29 bomber flies at an altitude of about 12,000 meters, it is equipped with a special fully enclosed pressurized cabin and a turbine exhaust gas heating device, so even at an altitude of -50 ° C, the temperature in its cabin remains above 15 ° C, and the pilot is under normal atmospheric pressure. At that time, the Japanese army, whether it was anti-aircraft guns or fighters, could not pose a threat to the B-29 flying more than 10,000 meters, so we saw the same strategic bombing, the US bombing Japan and bombing Germany, the bomber loss rate was greatly reduced, so that in the later period, the US military did not even carry escort fighters, but directly sent B-29 formations to bomb Japan.
(U-2 aircraft fly at such high altitudes that most fighters cannot reach even today, pictured from the U-2's cockpit outwards.)
However, this "happy time" was soon broken, and after the end of World War II, although the US military had used high-altitude U-2 strategic reconnaissance aircraft for many years to continue to reconnoiter the Soviet Union, everything changed due to the emergence of a new anti-aircraft weapon - anti-aircraft missiles. On May 1, 1960, American pilot Francis Bowers flew a U-2 from peshawar base in Pakistan and flew north to Norway, where he was shot down by a Soviet SA-2 anti-aircraft missile as it passed over the Soviet city of Leningrad (formerly known as St. Petersburg, now Petrograd), and Bowles parachuted and captured.
(U-2 high school reconnaissance aircraft above the clouds)
The advent of anti-aircraft missiles has put pressure on US aircraft that had previously relied on high altitudes and high speeds to frequently invade the airspace of other countries. Although the Americans later developed the more advanced SR-71 "Blackbird" high-altitude high-speed reconnaissance aircraft, but this aircraft also did not have stealth capabilities, and the Soviet Union not only developed the famous MiG-25 specifically to intercept it, but also soon introduced a variety of new anti-aircraft missiles, although the SR-71 Blackbird was never shot down in the years of its service, but its flight was also greatly limited, and its combat effectiveness was far from being comparable to that of the U-2 of that year.
(The full-force SR-71 Blackbird reconnaissance aircraft in the night, which also applies some stealth technology, but mainly high-altitude high-speed)
To this end, the American aviation community began to study a new technology - stealth technology. In fact, on the U-2 and SR-71, the United States has used some stealth technology, but these two aircraft are still mainly considered for flight performance, and stealth technology is only used incidentally. At this time, the US military was determined to develop a new aircraft with stealth as the core goal. This became known as the F-117 Nighthawk stealth fighter, the world's first new aircraft built with stealth technology.
The Invisible Nighthawk
Unlike other fighter jets, as an epoch-making product, the F-117 reveals this characteristic that is incompatible with common sense, which is the fundamental reason why this aircraft is unforgettable. An American colonel test pilot who flew the F-117 once wrote in his memoirs that from an aerodynamic point of view, the F-117 does not look like anything that can fly. This statement is probably the voice of most people when they first saw the F-117 stealth fighter.
(The ground-ready F-117 Nighthawk fighter has an angular appearance that is hard to forget and will not be confused with any other aircraft.)
The F-117 Nighthawk was the world's first fighter designed with "stealth" as its primary goal, since stealth actually consists of three aspects, namely radar stealth, infrared stealth, and optical stealth. Therefore, F-117 can be said to be enough in these three aspects, and some technical indicators may not be surpassed even today's F-22 and F-35. This is also the most unique part of the F-117 fighter.
First of all, due to the continuous development of modern radar technology, not only ground air defense radar has been widely deployed by various countries, but also airborne early warning aircraft have become important high-altitude radar stations. As early as the end of the 1960s, the Soviet Union developed and equipped its own first-generation Tu-126 "Moss" early warning aircraft, in the Third India-Pakistani War in 1971, the Indian Air Force's MiG-21 fighter was able to achieve one-sided victory over the Pakistani F-104 fighter, and even went deep into pakistani territory for 100 kilometers to carry out precision strikes on Pakistani military targets.
(The Soviet Air Force's first-generation Tu-126 AWACS aircraft was scarce and strictly confidential, but it did participate in the Indo-Pakistani War of 1971.)
Similarly, the early warning aircraft, because of their condescending position, have a strong detection capability for fighters, and can detect incoming fighters hundreds of kilometers away and alert their own air defense forces and fighters. If the size of the AWACS aircraft is large enough, it can also carry a large number of aviation command equipment and personnel, and it can be directly used to direct its own fighters for air defense and attack operations, which has been verified in the Indo-Pakistani War in 1971.
The stealth aircraft not only needs to avoid ground radar, but also needs to avoid the radar reconnaissance of the airborne early warning aircraft, so its omnidirectional radar stealth capability is the top priority to consider. According to the official figures given by the United States, the radar reflection area (RCS) of the F-117 is only 0.001 square meters, while the fifth generation of the US F-22 fighter is 0.01 square meters, and the F-35 is 0.02 ~ 0.05 square meters, which is obviously not as thorough as the F-117.
(The F-117 is an aircraft designed and built entirely with "stealth first" requirements, and in a sense, it can also be seen as a technical verification aircraft.)
The F-117 fighter is a very distinctive aircraft from the appearance, because the aircraft is contrary to the smooth and smooth shape design of modern aircraft, but adopts the pyramid shape design, all aircraft skins are flat design, and through the repeated irradiation of radar verification, and then to achieve the best tilt angle. In order to maximize stealth as much as possible, the F-117 adopted a lower monoplane design, the entire belly was designed as a flat and smooth piece, and there was no external hanging point, the whole aircraft was designed with only 1 bomb bay, and 2 hanging points were designed in the bomb bay, which could carry 2 2000 lb (907 kg) laser-guided bombs for precision strikes. Although theoretically the F-117's magazine can also carry air-to-air missiles on air-to-air combat missions. However, in order to achieve complete radio silence stealth, the F-117 simply did not even have an airborne radar installed, but only installed an infrared/optical/laser three-in-one sighting device, so in fact the F-117 does not have the ability to use air-to-air missiles for air combat.
(The F-117 sacrificed a lot to take care of stealth performance, including weapons carrying capabilities and air combat capabilities.)
In order to achieve maximum stealth capability, the cockpit of the F-117 even uses a pyramid design, and the cockpit windshield is a five-piece metal coated glass, thus completely eliminating the "hole effect" of the cockpit, but due to the care of the stealth design, the F-117 pilot vision is very bad, and the aircraft can be said to be quite difficult to fly. Not only that, but all the skins of the aircraft use a disjointed graphic design, so the aerodynamic performance of the aircraft is very poor, so that the shape of the aircraft is now called "static unstable" aircraft, because the air flow will have uncontrollable changes in the performance of the aircraft, and it was impossible to successfully lift off in the early days. It was only because the United States developed a digital flight control system in the 1970s that the aircraft's onboard flight control computer could automatically maneuver the aircraft to maintain its attitude, so as to ensure that the F-117 could fly safely. But even so, the F-117 is still one of the most dangerous aircraft in the world, with only 42 aircraft produced, and many of them crashed due to improper operation, resulting in the early retirement of the US military, which is also the most tragic price paid for stealth.
In addition to the necessary radar stealth, the F-117 also fully considered the necessary significance of infrared and optical stealth, for which the aircraft used the F404-GE-F1D2 non-afterburner turbofan engine originally designed for the U.S. Navy A-12 stealth attack aircraft, in order to fully stealth performance, the air intake of the aircraft was designed on the back of the aircraft, while a fine wire mesh was designed on the air intake, which although the air intake efficiency loss was up to 30%, but it perfectly shielded the intake tract and engine fan blades. The RCS of the engine was so small that it was completely negligible, but because of this design, the engine intake loss was too large, and neither the subsequent F-22, F-35, nor the Russian Su-57 aircraft of the US military used this design.
In order to reduce the infrared characteristics of the aircraft, the F-117 also uses a unique harmonica-type jet port, and its spout is sprayed upwards, which makes it more difficult to detect the F-117 infrared from below. At the same time, the F-117 also designed 11 vertical deflectors in the nozzle, and designed a special conduit in the front of the fuselage to pressurize the cold air, mix with the engine gas and spray it. According to tests, the tail vent gas temperature of the F-117 fighter is only 66 ° C, while the fourth generation fighters such as the F-15 and F-16 usually have an engine nozzle temperature of more than 800 ° C. Even today, most infrared-seeking anti-aircraft missiles cannot capture such tiny infrared features as the F-117.
The air intakes of the F-117 engines are arranged with a fine wire mesh (red circle); there is no radar, and there is a set of photoelectric integrated reconnaissance and aiming system under the cockpit (yellow circle).
Moreover, due to its poor flight performance (the F-117 is limited by its aerodynamic appearance and cannot be supersonic flight without an afterburner engine), the F-117, although it is named "fighter", does not actually have any "combat" capabilities, so the aircraft can usually only be operated at night or at dusk and other dim weather conditions, using night and bad line of sight to provide optical shelter for itself. However, coincidentally, the first-generation radar absorbing material sprayed by the F-117 also happened to be a dark gray and black color, so it was objectively conducive to the F-117's nocturnal activity ("Nighthawk" lived up to its name).
A path of sadness and joy to the war
After the F-117 stealth fighter was successfully developed and equipped with the U.S. Military, the U.S. Air Force immediately rushed to put it into combat testing, and the opportunity soon came. In the "just cause" military operation of the US invasion of Panama in 1989, the F-117 fighter jet made its first appearance and dropped 907 kilograms of laser-guided bombs at the Panama Defense Force barracks in the first wave of air raids, and the Panamanian army immediately became a mess and was quickly defeated by the US army. However, because Panama was originally only a small country, the number of soldiers was weak, and it was impossible to truly test the performance of the F-117 aircraft. Soon, the last major war in the Cold War gave the F-117 another stage to show itself.
(The combination of the B-2 and F-117, before the F-22 entered service, was the world's most powerful stealth air power.)
In 1990, Iraqi military strongman Saddam Hussein suddenly sent troops to neighboring Kuwait and soon occupied this small, wealthy neighbor. After that, under the authorization of the United Nations, the United States organized a multinational force of up to 540,000 troops, stationed in Saudi Arabia in a huge way, ready to compete with Iraq, and the famous Gulf War broke out.
And Iraq is by no means comparable to the small country of Panama. In the Iran-Iraq War of 1980-1988, Iraq relied on the export of oil in exchange for dollars, and purchased advanced weapons on a large scale in Europe, the Soviet Union and other countries. Before the 1991 Gulf War, the iraqi regular army had a total strength of more than 500,000 troops, and was equipped with advanced mirage F1, MiG-29, MiG-25 and other advanced fighter jets, while the Iraqi army was also equipped with T-72M1 tanks, BMP-1 infantry fighting vehicles, and a large number of advanced european-made artillery, anti-aircraft missiles and other weapons.
The Iraqi army has also established a network of radar and anti-aircraft missile firepower large enough to cover the whole country, and any aircraft that dares to step into Iraqi airspace will be hit hard by this network. Not only that, the Iraqi Air Force even modified a Il-76 early warning aircraft on its own, and they adapted the French Sea Tiger radar to a Il-76 and converted it into the iraqi air force's first and only early warning aircraft. With air-to-ground coordination and a large arsenal of advanced European and Soviet anti-aircraft missiles, Iraq was indeed a formidable adversary to the F-117.
(F-117 belly details, magazine and upturned engine tail vents are clearly visible)
However, the F-117 did not disappoint in the face of such a strong and tight air defense network, in the 38-day "Desert Storm" operation, the F-117 fighter was the only aircraft that the coalition forces were able to fly to the Iraqi capital Baghdad for air strike missions, and in the entire Gulf War, no F-117 aircraft was found or attacked by Iraq, and the total number of F-117 fighters deployed in the Gulf accounted for only 4% of the total number of all coalition aircraft sorties, but it destroyed 40% of the total number of aircraft dispatched by the coalition forces. All kinds of targets, and almost all of the high-value targets were destroyed by the F-117, which fully demonstrated the subversive significance of stealth aircraft for future air combat in the Gulf War, and because of this, the USAF stepped up the development of subsequent F-22 fighters.
But as the saying goes, often walk by the river, which can not get wet shoes. After 20 years on the pitch, the F-117 finally saw the only defeat of its service career. In the 1999 Yugoslav War in Kosovo, an F-117 stealth fighter was finally shot down by the Serbs using old-fashioned SA-3 anti-aircraft missiles while on a bombing mission, but then NATO sent a powerful search and rescue force to successfully rescue Dale Zelko, the American pilot of the F-117 fighter, which saved some face for this defeat.
(F-117 Nighthawk fighter jet shot down by The Federal Republic of Yugoslavia)
Rumors of the F-117 being shot down are still widely debated, but the official account of the Federal Republic of Yugoslavia is that the Confederate Army used old-fashioned mipo radar to successfully capture the whereabouts of the F-117 fighter jet. In fact, the early human air-to-air warning radar usually uses the meter wave radar, the meter wave radar detection distance is long, not susceptible to meteorological and electronic interference, but the disadvantage is that the detection accuracy is low, can not guide the target for air defense weapons, and the size is bulky, easy to be attacked. However, due to the long wavelength of the meter-wave radar, the radio waves of the meter-wave radar will not be refracted to other directions like other centimeter waves when they contact the stealth aircraft, but will be bounced back in the same way. Therefore, the mipo radar has a good anti-stealth function, and the Yugoslav air defense forces have taken advantage of the old mipo radar to grasp the time and path of the F-117 every time it enters and exits the yugoslav sky, and then set up an ambush on its own place to shoot down the F-117 in one fell swoop.
Tactics and technology are just as important as the stealth fighters that continue to evolve
With the F-117 shot down, the U.S. military believed that F-117 secrets had been leaked, so it quickly retired the aircraft from active service and replaced it with updated F-22 and F-35 fighter jets. At present, the three major powers of China, the United States and Russia have developed and equipped themselves with new stealth fighters, also known as "fifth-generation fighters". For the foreseeable time, the full stealth of fighters has been an important development direction for modern fighters.
(F-22 and F-35 formation flights, the U.S. military's second-generation stealth fighter, has far outperformed the F-117 in performance.)
At present, the US military's F-22, F-35 and other fighters, including Russia's Su-57 fighters, have been briefly deployed on the Syrian battlefield. The US and Russian aircraft even "practiced their skills" over Syria, for which the Pilot of the Russian Su-35 fighter even exposed the images of the US F-22 fighter jet taken by himself flying the Su-35 fighter using the IRST device on social media websites. This also shows that under certain conditions, stealth aircraft still have their own weaknesses that need to be improved and compensated.
Common sense says that there is no perfect weapon, and stealth fighters usually carry a small amount of weapons and equipment in order to fully achieve the design goal of low detectability. Because the attached weapons and ammunition will increase the radar reflection area of the aircraft, the fifth-generation fighters can generally only use the built-in bomb bay when performing stealth combat tasks, which is to learn from the successful experience of the F-117 fighter. At the same time, the stealth aircraft developed now have appropriately relaxed the pursuit of stealth performance, no longer pursuing the ultimate like the F-117, and at the same time have a very high standard for other performance of the aircraft, such as range, payload, and especially air combat capabilities, which can be seen from the F-22 fighter's "big killing" in the previous red flag exercises and Alaska air defense exercises.
(Although only 195 were produced, the F-22 is still one of the most powerful fighters today, and the F-117 is also a "successor".)
In summary, any weapon can not stand alone, there must be a suitable and efficient combat system to cooperate with it, F-117 was shot down to a large extent is actually NATO itself lax, the US Air Force takes it for granted that the Federal Republic of Yugoslavia can not shoot down its own advanced stealth aircraft, so F-117 even at the same time every day to take the same flight route to bomb the Federal Republic of Yugoslavia, which let the Confederate Army feel the law, thus successfully ambushing the indispensable F-117 fighter. From this point, it is not difficult to see that even in the case of technical existence and crushing, reasonable tactics can still produce miracle effects.
Although the F-117 stealth fighter has been retired for more than a decade, the research and development of stealth fighters in various countries will not stop. Instead, it will continue to evolve, like a cycle of spears and shields.