Media reports indicate the U.S. Air Force and Navy are beginning to fund programs to develop “6th Generation Fighters” designed to replace the F-22 Raptor in the Air Force and F/A-18 in the Navy beginning in the early 2030s. Given that developing, testing and fielding advanced combat aircraft over the past several decades requires 15-20 years, it’s not too early to begin developing the next system. However, recent CSBA analysis of almost 1,500 air combat victory claims achieved over the past five decades strongly suggests advances in electronic sensors, communications technology and guided weapons may have fundamentally transformed the nature of air combat. If correct, this has significant implications for how the services should approach the design and development of future air to air combat systems. Just to be clear, this is not about current production systems such as the F-35, but what systems should be developed to follow them.

Air Combat in Historical Perspective: The Gun Era

Air-to-air combat developed rapidly in World War I. First generation aviators quickly learned the most effective techniques for winning dogfights, and leading aces on both sides codified these techniques into rules and guidelines. The central purpose of these rules was to enable pilots to achieve what modern combat pilots call superior situational awareness (SA). This results when a pilot has a better understanding of the position of all relevant aircraft and their activities in the combat area than an opponent. The ultimate expression of SA is to move into position to attack an opponent without being detected, launch an attack and escape before his wingmen can respond.

For about 50 years, the human eye was the primary air-to-air sensor and the machine gun and automatic cannon the air-to-air weapons of necessity. As an air-to-air sensor, human vision has a relatively short effective range of about two nautical miles. Aircraft can be seen farther away if the highly sensitive central vision is focused on them, but with central vision limited to a cone roughly 2 degrees wide, pilots searching for opposing aircraft without some sort of cue to narrow their search are unlikely to detect them until the less acute peripheral vision is able to resolve them at about 2 nm. The effective range of aerial gunnery grew from about 50 yards during World War I to about 500 yards by the early 1960s, but pilots were still required to maneuver their aircraft into a small portion of the sky to employ their weapons. Against an unalerted opponent, the attacker simply had to ensure he was within range and had the target “in his sight.” Against an alerted and maneuvering opponent, achieving hits required the attacker not only to be in range, but also to maneuver in the same plane as the target and to allow sufficient lead to account for the distance the target would travel during the bullet's time of flight. The difficulties and time required in attaining a good firing solution against a maneuvering target, combined with the decrease in SA due to the need to fully concentrate on the target, caused many of the great aces of World War II to shun maneuvering combat as a high-risk, low-payoff activity. Instead, they strove to achieve quick surprise attacks, break away, assess the situation, and re-attack if possible.

The Missile Era

By the mid-1960s, new aerial weapons and sensors appeared in conflicts in Southeast Asia, South Asia, and the Middle East. The new weapons included both infrared (IR) and radar-guided missiles, while the new sensors were largely air-to-air radars. IR missiles allowed attacks within a 30-degree cone behind the target at ranges approaching the 2 nautical mile effective visual search radius. Radar-guided missiles, in theory, allowed attacks from any aspect (front, side, or rear) and beyond visual range (BVR). Air-to-air radars were capable of detecting and tracking targets at 15 nm or more. While the early missiles and radars had serious limitations and were unreliable, they offered substantial advantages over guns and the human eye. CSBA compiled a database of over 1,450 air-to-air victories in conflicts over the past fifty years. Advances in air-to-air sensor and weapon capabilities are illustrated in the accompanying figure. Over time, guns were displaced by rear-aspect-only IR missiles, which were in turn replaced by all-aspect missiles, and finally, long range BVR missiles have come to dominate modern air-to-air engagements.

These trends suggest that over the past five decades, advances in radar and other sensor technologies, missile capabilities, and communication technologies allowed pilots to search effectively much larger volumes of sky and engage targets at ever-increasing range. Furthermore, detailed analysis of air combat engagements during Operation Desert Storm indicates that more than twenty years ago, most air combat engagements were initiated before the aircraft were within visual range with a commensurate decrease in the frequency of maneuvering combat. This suggests that aircrew SA is no longer primarily linked to what they can physically see through the cockpit canopy, but to what they glean from cockpit displays of sensor output and information passed from offboard sources such as nearby friendly aircraft.

This transformation appears to have steadily reduced the utility of some attributes traditionally associated with fighter aircraft (e.g., extreme speed and maneuverability) while increasing the value of attributes not usually associated with fighter aircraft (e.g., network connectivity, sensor and weapon payload and range). Aircraft performance attributes essential for success in air-to-air combat during the gun and early missile eras such as high speed, good acceleration, and maneuverability are likely much less useful now that aircraft can be detected and engaged from dozens of miles away.

At the same time, nontraditional attributes such as minimal radar and IR signature; space, payload, and cooling capacity; power for large-aperture long-range sensors; and very-long-range weapons seem to be of increased importance. The need for greatly increased unrefueled combat radius in the face of emerging threats to theater bases and aerial refueling operations also appears to be growing in importance as potential adversaries field forces specifically designed to counter short-range fighter-centric aerial power projection concepts the U.S. has repeatedly used over the past two decades in numerous conflicts. Both supersonic speed and high maneuverability place significant constraints on aircraft designers and force tradeoffs in aircraft design that limit the incorporation of many of the nontraditional, but increasingly important attributes listed above.

The trends identified suggest it may be appropriate to cast a much wider net in the development of future air combat operational concepts, sensors, weapons, and platforms, to include examining “radical” departures from traditional fighter concepts. For example, with the value of both speed and maneuverability already much reduced, it is possible the next “fighter” may be a large subsonic stealthy aircraft with attributes normally associated with “bombers”. These could include broad-band/all-aspect stealth, far greater endurance, and large payload capacity both to carry large numbers of longer-range air-to-air weapons and contain large power and cooling systems needed to support large-aperture sensors. In short, there could be a convergence in future “bombers” and “fighters” around a common platform that could yield substantial increases in operational effectiveness while saving tens of billions of dollars in development and procurement costs.