Text/Journal of Aeronautics
On September 15, 2020, Will Roper, then Assistant Secretary of Air Force Procurement, Technology and Logistics, announced at the online meeting of the Space Network Annual Meeting that the full-size demonstrator of the Next Generation aircraft (NGAD) program has made its first flight; on August 18, 2020, the U.S. Naval Research Association website reported that the U.S. Naval Air Systems Command established the NGAD Office (PMA-230) to accelerate the development of the next generation of carrier-based fighters. In the context of the current great power competition and the great power game, as the US air navy is intensively accelerating the development of the next generation of fighters, the discussion on the evolution of future air combat forms and the development trend of future fighters has become increasingly intense.
Figure 1 Next-generation fighter concept rendering (Source: Flight Global)
Previously, Academician Sun Cong, an expert in the field of aircraft design in China and president of the China Academy of Aeronautics and Astronautics, published a blockbuster article "From the Evolution of Air Combat Winning Mechanism to the Future Development Trend of Fighter Aircraft" in the 8th issue of the Journal of Aeronautics and Astronautics in 2021 (article link: http://hkxb.buaa.edu.cn/CN/10.7527/S1000-6893.2021.25826). Academician Sun Cong has long been engaged in aircraft avionics, stealth technology and aircraft design, and has served as the chief designer of J-XXB/BS, J-15 and Eagle aircraft, and is a new generation leader in China's fighter aircraft development. The article systematically sorts out the evolution of the winning mechanism of air combat, combines the current technological development and layout, and judges the future development trend of fighters. Below, Xiaobian extracted the key content from this paper and shared it with aviation enthusiasts and practitioners.
1 Evolution of the winning mechanism of air combat
First, the era of energy mobility victory
According to the attack mode of fighters, the era of energy mobile air combat includes the era of aircraft guns and the era of tail-attack infrared missiles, and lasted until the end of the 1970s, according to the CSBA's air combat statistics from 1965 to 2002, the sum of the kills caused by these two attack methods accounted for more than 90% of the total number of air combat kills in this era.
Figure 2 Air combat kills statistics, 1965-2022 (Source: CSBA)
After a short period of guns in the air and air combat, air combat quickly entered the era of air artillery. Artillery air combat dominated the air combat mode of the 20th century for more than half a century, spanning two major types of propeller aircraft and jet aircraft. In the era of air artillery and air combat, the game in the information domain and cognitive domain mainly relies on the eyes and brains of pilots, and relies on aircraft platforms and aircraft guns in the action and attack links of the physical domain. Limited by physiological limitations such as the human eye's line of sight distance, range, and brain attention, the opponent is often given the opportunity to sneak up on and out of the blind spot. If the two sides are equally engaged, it can be said that the artillery attack mode is the most demanding attack mode for the energy maneuver of the aircraft platform. The difficulty of this attack also led to a great deal of contingency in artillery and air combat. For example, in the Korean War, the Chinese hero pilot Zhang Jihui, although the flight time on the jet plane was only more than 100 hours, a total flight time of more than 300 hours, but with excellent technology and strong will, he shot down the American ace pilot Davis, who flew more than 3,000 hours, and the latter shot down 11 fighters and 3 bombers in two months.
Figure 3 Schematic diagram of the air battle between Zhang Jihui and Davis
Because air artillery and air warfare relied too much on the high speed of aircraft platforms and space maneuverability, military powers began to develop air-to-air missiles with longer attack ranges and more relaxed attack space-time conditions. In the 1965 Vietnam War, "Operation Rolling Thunder", AIM-7 Sparrow radar-guided missiles and AIM-9 Sidewinder infrared guided missiles were used in air combat on a large scale, but compared with the pre-war predictions of 71% and 65% of the hit probability, respectively, the actual result was only 8% and 15%, far from expectations.
In general, the requirements of energy maneuvering on the aircraft platform are to have a faster speed to quickly approach or detach from the opponent, a higher lift limit to increase the height and energy advantage, a better climb rate to stabilize the interception or get rid of the opponent in the vertical plane, excellent roll agility and turning maneuverability to obtain or prevent the opponent from getting the opportunity to fire.
Second, the era of information mobility and victory
With the rapid development of electronics, communications, computers and other technologies, fighters have made great progress in airborne radar, data links, navigation, flight control, weapons, etc., and air combat has entered the era of information mobility victory. The emergence of stealth technology has greatly subverted the huge gap between stealth platforms and non-stealth platforms in information acquisition, and the confrontation between stealth aircraft has intensified the mobility and game of information acquisition, processing, fusion, transmission, and use. The improvement of the radar performance multiple of the aircraft in the information domain and the expansion of the multiple of the missile range in the physical domain have made the air battle really enter the over-the-horizon, and "the enemy discovers first, the enemy launches first, and the enemy hits first" has become the winning mechanism in the era of information mobility. In information maneuvering, first discovery and first identification of the opponent is the primary condition for the start of the air combat kill chain, and it is also the reason for the fierce game between the two sides in the information field.
The F-15C aircraft is equipped with an AN/APG-63(V)2 pulse Doppler radar with a detection range of more than 125 km for targets per square meter; the AIM-54 Undead Bird air-to-air missile has a maximum range of more than 200 km; and drawing lessons learned from over-the-horizon attacks in the Vietnam War that cannot be reliably identified during over-the-horizon attacks, the F-15 uses technology that automatically detects the target type from the target's echo signal (extracting signal characteristics from the compressors and turbine blades of the opponent's engine), Thus possessing the ability to identify non-cooperative targets. The combined advances of these technologies will theoretically lead to air combat confrontations at a distance of more than 100 kilometers, but in fact, since the 1980s, an air war between military powers has never occurred.
With the gradual improvement of the ground air defense system, the ground threat faced by the third-generation aircraft has become more and more severe, in order to solve the problem of penetration, the US military as early as the 1970s (if not counting the SR-71 "Blackbird") began the research and development of the stealth aircraft F-117, and put into actual combat in the Gulf War, and achieved huge benefits. The application of stealth technology has greatly undermined the balance of the game between the offensive and defensive sides in the information domain, which is why since the end of the 1980s, all combat aircraft developed by the US military in high-threat environments have basically have stealth capabilities or characteristics.
Figure 4 F-117
The F-22, which was born for air superiority, defined the 4S standards of the fourth generation of aircraft: stealth, super patrol, ultra-high maneuvering, super avionics, and formed a crushing advantage over the third generation of aircraft. In the 2006 "Northern Blade" exercise, the F-22 achieved an impressive result of 144:0 against the third-generation aircraft. Many views attribute the F-22's enormous superiority to information warfare capabilities composed of high-stealth and high-power active phased array radars. In fact, this only accounts for two of the 4S's. Compared with the third-generation F-22, it also builds an unparalleled performance advantage in the physical domain, thus realizing the double kill and comprehensive upgrade of the third-generation machine in the information domain and the physical domain, which is the significance of the other two Ss.
Figure 5 The discovery of the first enemy is the primary need for information mobility
F-22 in the supersonic cruise state to launch missiles, can greatly increase the power range of the missile, F-22 supersonic large stabilizer overload provides it with excellent offensive and defensive conversion capabilities, so that it can quickly U-turn without losing speed, and use the supercruising speed to quickly consume the power range of the incoming missile. Combining attack and defense, the F-22 has formed an unbreakable and unavoidable distance advantage over the third-generation aircraft.
Fig. 6 The inescapable zone between the F-22 and the typical third-generation aircraft (dynamic dimension)
In general, due to the rapid progress of sensor technology and missile technology, the scope of air combat has been significantly expanded, and the era of information-mobile air combat has pursued the winning principle of "discovery of the enemy first, launch of the enemy first, and hit by the enemy first", and the effectiveness of air combat has been doubled with the support of system operations. The emergence of stealth technology immediately broke the game balance between the offensive and defensive sides in the information field, but the F-22, which was born for the air superiority, did achieve a comprehensive upgrade of the third-generation aircraft in the information domain and the physical domain. This shows that information mobility is by no means a rejection and denial of energy mobility, on the contrary, energy mobility has completed the expansion and sublimation in another form, and together with information superiority, it has jointly built the winning ability in the era of information air combat.
2 Mechanism of victory in future air combat
From the perspective of the development law of aviation technology in the 20th century, the development of fighter aircraft is rapidly evolving in the direction of complex air combat systems, with the spurt development of incremental technologies and variable technologies such as autonomy, artificial intelligence, unmanned, computing, communications, etc., aviation platforms will achieve a deeper degree of interconnection and a wider range of synergistic energy, which directly stimulates the research and application of complex air combat systems.
Imagine such an air combat scenario similar to the thought experiment in 203X: two high stealth fighters of Country A are on air patrol missions, and suddenly guided by the ground command and control center and ground early warning radar, they come forward to intercept the air assault formation of Country B. Country A fighter in the appropriate distance radar to start the sudden detection, but found a total of 10 targets in front of and behind the 2 formations, because the distance between the two sides is in rapid proximity, in the case of the A country fighter radar can not accurately identify the target, the 2 pilots have no time to think too much, after the coordination of target allocation, each selected two targets, to each target to launch two missiles. In the process of guidance, the radar alarm suddenly received the opponent's radar guidance signal, but it was impossible to determine which formation in front and behind launched the missile, and in a hurry, it abandoned the middle section of guidance and turned away.
In fact, this is a broad 2V2 air combat scenario, in addition to 2 manned high stealth fighters, B country also has 4 unmanned loyal wingman, 2 long-range front air nodes, and 2 decoy/detection/dexterity interference trinity of air patrol air patrols a total of 8 low-cost/consumable drones. This air battle scenario is not far away, and we can find clues from the current technological layout of the US military.
In 2016, the U.S. Air Force officially released a public version of the Air Superiority 2030 Flight Plan, which clearly stated that in order to continue to maintain cross-generation air superiority, the U.S. Air Force needs to quickly build a new generation of air combat systems and the next generation of air superiority fighter PCA. In August 2020, the U.S. Naval Air Systems Command established the NGAD Office to accelerate the development of the next generation of carrier-based fighters. Judging from the current technical layout of the US military, the US military is taking the "next generation of air domination" as the starting point, taking the point and area, focusing on many key dimensions such as the communication architecture, the accusation architecture, and the functional architecture of the future air combat system, conducting comprehensive technical research and verification, and accelerating the construction of a complex air combat system with distribution, high survival, strong killing, dynamic, elastic, and efficient.
Figure 7 The technical layout of the US Department of Defense, Air Force/Navy, etc. around the future complex combat systems
From the current technical layout of the US military and the discussion and judgment of the academic community, the future air war is bound to be the confrontation of the air combat system, at least the US military is shaping a new model of air combat system confrontation, and accelerating the development and construction of related capabilities. Its core concept is: with the next-generation fighter platform such as PCA as the core node, by combining a small number of high-end platforms such as PCA and a large number of low-cost, consumable, modular, and strongly autonomous unmanned wingman/cruiser, etc., to build a native air combat system. In the future, the core pursuit of confrontation between air combat systems is to identify and recognize the relationship between multiple nodes of the opponent, system architecture and complex killing link at the same time, prevent the opponent from identifying and recognizing the system architecture and killing link of the opponent, and seek the closed-loop function of delaying, destroying and interrupting the opponent in the whole killing chain link, and the air combat will enter the era of cognitive mobility victory.
Figure 8 In the future, complex air combat systems with unmanned coordination as the core feature
The design of air combat systems in the cognitive mobility era belongs to the category of complex system design. Different from the traditional single system, complex systems are more through distributed control, system autonomous decision-making, local visibility, flexible layering, collaborative cooperation, inter-system interaction and the pursuit of the minimum constraints to complete the design goals. Therefore, new methods and means need to be sought to design complex systems to generate and manage emergent behaviors to meet the application needs of cognitive mobile air combat. The overall goal of the future air combat system design is: from the communication architecture, the accusation architecture, the functional architecture and the physical architecture and many other levels, the following generation of air superiority combat aircraft as a strong node, through a variety of existing /unmanned nodes of extensive information interaction and different degrees of autonomous decision-making operation, to achieve the rapid, efficient, accurate, parallel closed-loop of the kill chain, in the efficiency, robustness, adaptability, elasticity and accuracy and many other dimensions to achieve the emergence of capabilities. Autonomous and artificial intelligence technologies are necessary to implement complex air combat systems.
It should be noted that the emergence of the next generation of air combat forms is by no means a negation and abandonment of the previous generation of air combat forms, on the contrary, it is the inheritance and expansion of the previous generation of air combat forms. Defeating the opponent by competing for the comprehensive advantage of the "trinity" maneuver of the information domain, the cognitive domain and the physical domain has always been the guiding ideology of the air combat victory mechanism.
Figure 9 Air-air confrontation runs through the information domain/cognitive domain/physical domain
3 Discussion of several relationships
First, equal emphasis is placed on capacity and scale
The ability, scale and combination of equipment are the most core factors in the design of equipment structure, and they are also indispensable constraints that must be considered at the beginning of the design of a type of equipment. In 2009, Air Force Lieutenant Colonel W. Bush Locke systematically sorted out and analyzed the training data in the Red Flag Military Exercise, and extracted the law of the impact of the numerical superiority of fighters on the exchange ratio of air combat. The conclusion shows that after the ratio of the number of aircraft participating in the battle between the two sides reached 2:1, the air loss ratio of the SU-27 and F-15C showed an inflection point and rose rapidly. When the ratio of aircraft to aircraft was between 0.1:1 and 2:1, the air loss ratio of the SU-27 and F-15C was extremely flat, almost fixed at 3.5:1, and when the ratio of the number of aircraft participating in the battle was less than 0.1, the loss ratio decreased rapidly (the loss of the F-15C increased rapidly). Judging from the historical data of air combat in World War II and the training data of the Red Flag Military Exercise, when the fighters of the two sides are in the same generation of confrontation, the impact of numerical superiority on belligerent-level air combat is extremely obvious. As the degree of coordination between aircraft in the battle layer continues to increase, the impact of numerical superiority on the outcome of the engagement will continue to increase.
Figure 10 "Red Flag Exercise": Su-27 vs. F-15C swap ratio
In 2015, the RAND Corporation released a study on the U.S.-China Military Scorecard, which comprehensively compared U.S. and Chinese military capabilities for 10 missions, including airfield strikes, air superiority, and anti-ship operations. Among them, when comparing the air superiority forces between China and the United States, the size of the US military needs to obtain and control air superiority over Taiwan is analyzed (see figure below). Studies have shown that in the most severe cases, the US military needs to dispatch 7 air wings from bases on Guam or other bases at the same distance to achieve continuous control over the Taiwan Sea. In fact, the requirements for long-range regional control and the defense of long national borders have a strong demand for the size of the fighter jets of each military power. Consider a 7-day, 24-hour zone control mission where the defenders need to maintain a sustained presence of aircraft of sufficient size to withstand an influx of attacks from the attackers. The results of the air battle are not only strongly linked to the scale of the above-mentioned combat layers, but even fought in the case of fierce attacks on the airfield, which is difficult to detect. Therefore, the scale requirement is one of the core constraints that must be considered in the equipment demonstration stage.
Figure 11 Troops Required to Achieve Air Attrition Victory in attack and non-attack bases (measured by the number of air wings)
Second, the trade-off between specialization and multi-purpose
In a research report released by the Center for Strategic and Budget Evaluation in 2018, it was pointed out that the equipment structure development of the U.S. Naval Aviation Corps reflects such a law: the pursuit of effectiveness in confrontation between major powers and the pursuit of efficiency in peacetime. With the advent of the era of great power competition, the Center for Strategic and Budgetary Evaluation has proposed three aviation equipment structures for the U.S. Navy for 2040, namely traditional, balanced, and dedicated mission structures. The evaluation results show that the special mission equipment structure scheme can deliver more firepower at a longer distance and with higher survivability, which is an effective solution to support the game of major powers.
Judging from the current development layout of the US air force and navy, especially in the project arrangement of the combat equipment structure, this characteristic is indeed presented. The U.S. Air Force's PCA focuses on air superiority missions, while the B-21 focuses on long-range penetration depth strikes. In December 2020, the U.S. Navy and others jointly issued a maritime strategy document entitled "Maritime Superiority: Winning with Integrated Global Naval Power", which pointed out that the Navy's next-generation aircraft will bear heavy responsibility in air defense and anti-missile warfare, and the joint strike fighter F-35C will assume the primary responsibility in power projection and strike tasks under the support of MQ-25 unmanned tankers. From the perspective of equipment construction, the U.S. Air Navy has different positions in the positioning of equipment according to its own role in the concept of joint operations and combined with the unique needs of its own services, but has chosen a relatively dedicated mission-type equipment structure path: give full play to the equipment potential of special equipment in the implementation of matching tasks in harsh environments, and achieve overall optimal performance through global coordination and integrated command operations.
Third, digital engineering and rapid procurement and innovation
In June 2018, the U.S. Department of Defense officially released the "Department of Defense Digital Engineering Strategy" to the public. The core idea is to use models and data that can be continuously transmitted across disciplines and fields in the whole life cycle to carry out scientific research activities such as systematic demonstration, design, trial testing and identification. In 2019, The Air Force's Assistant Secretary for Procurement, Technology and Logistics, Mr. Roper, proposed the concept of "Digital 100 Series", which aims to upgrade fighters every four years through the comprehensive use of digital engineering, agile software development and modular open system architecture "Trinity" tools to achieve rapid iterative research and development. In order to adapt to the digital project, the US Department of Defense has also continuously promoted the acquisition reform strategy. In January 2020, the U.S. Department of Defense officially issued Directive 5000.02, "Operation of the Adaptive Acquisition Framework", which strives to achieve flexible, rapid, and agile capability integration, rapid prototyping, and rapid deployment. At this point, in view of the ability development in the digital age and the acquisition of agile, flexible and innovative adaptive capabilities, the US military strives to grasp with both hands, both hands must be hard, with the intention of constantly confusing the opponent while completely opening up the gap with the opponent in time, rhythm and ability.
After more than a century of air combat practice, mankind has experienced two eras of air combat, energy maneuvering to win, information maneuver to win the two eras, with the rapid development of autonomy, artificial intelligence and many other incremental and variable technologies, the future of air combat will quickly enter the era of cognitive maneuver victory, with unmanned coordination as the core feature of complex air combat systems confrontation will be the main mode of future air combat. The core pursuit of cognitive mobile air combat is to identify and recognize the relationship, system architecture and complex killing link between multiple nodes of the opponent, prevent the opponent from identifying and recognizing the system architecture and killing link of the opponent, and seek to delay, destroy and interrupt the closed-loop function of the opponent in the whole killing chain link. Based on the needs of the times under the competition of major powers and the game of great powers, based on the mission positioning under the concept of future joint operations, and based on technological changes in the digital era, the next generation of fighters will be the core backbone nodes of a complex air combat system that focuses on air superiority and scale in the equipment structure, has rapid response at the mission level, and can win cognitive mobile air combat at the combat level.