The following piece first appeared on Warrior Maven, a Military Content Group member website.
100 Aerial combat kills. Zero losses… This fact tells much of the story of the US Air Force’s F-15 Eagle, which continues to surge into the future with new electronic warfare (EW) capabilities, networking technologies, paradigm-changing high-speed computing, and an F-15 EX II 4th-generation “plus” variant moving further into production.
The upgraded F-15 EX jet, first delivered to the Air Force several years ago, introduced a sphere of next-gen types of technical applications to include advanced EW, active electronically scanned array (AESA) radar, ultra-high-speed computer processing, as well as a number of additional adaptations intended to support future combat operations.
The aircraft’s new Eagle Passive Active Warning Survivability System is now entering formal production, according to several recent news reports in The Aviationist and Breaking Defense.
While considered a massively upgraded fourth-gen aircraft balancing itself on an interesting boundary between 4th- and 5th-gen aircraft, the F-15EX is, of course, slightly less stealthy than full 5th-gen platforms such as the F-22 and F-35. However, there are a number of not-yet-seen innovations built into the F-15EX with the aim of making it an impactful asset should it be needed for major power warfare.
There are many elements to this, based in large measure on the broad recognition that the 1980s-era aircraft is, essentially, an entirely different jet than it was decades ago. Elements of the basic airframe structure are similar.
However, the F-15EX is now engineered with a new generation of technologies intended to reshape its tactical significance when it comes to high-end warfare. Many of the innovations woven into the F-15EX also build upon previous upgrade efforts taken up by Boeing to extend the aircraft into the 2040s and beyond.
The F-15EX will fire hypersonic weapons, hit speeds of Mach 2.5, bring new generations of radar and EW, and operate computer processors able to perform 87 billion functions per second. Several years ago, the F-15 was integrated with the fastest jet-computing processor in the world, called the Advanced Display Core Processor II, which, Boeing innovators have explained, does indeed perform 87 billion computing functions per second. The processor was first introduced several years ago.
Interestingly, while the F-15EX is engineered with interfaces and fire control technologies to operate a much wider sphere of weapons, some of the greatest advantages built into the aircraft may reside in the realm of sensing, networking, threat detection systems, and EW. Many of these attributes closely align with the kinds of sensing, computing and EW applications known to be fundamental to 5th-gen assets such as the F-35. Just how comparable is an F-15EX in this respect, as many regard the F-35 advantage as a so-called “flying computer” to reside in the fidelity, range, and integration of its sensing, radar, threat warning, and information sharing systems.
One key indicator may be that the Air Force plans to use the F-15EX as part of crucial Joint Domain Command and Control (JADC2) exercises during the upcoming Northern Edge exercise, as cited by Air Force Magazine. This is quite significant, as sensor-to-shooter multi-domain, multi-mode networking, it is very safe to say, could be described as a massive priority for the Air Force as it seeks to further pivot toward preparations for more expansive, disaggregated yet highly networked warfare intended to leverage a kind of “meshed” warspace wherein artificial intelligence (AI)-enabled sensors and weapons can, as senior Air Force weapons developers like to explain it, operate at the “speed of relevance.”
The concept, as previously described by Air Force European Commander Gen. Jeffrey Harrigian, is a need to connect “any sensor to any shooter,” meaning a highly integrated battlespace could share targeting specifics across unprecedented ranges to execute precision strike operations and stay ahead of an enemy’s decision-making cycle.
Many of the distinct F-15EX attributes reside in the areas of networking, computing, EW, radar, and threat warning systems, yet the new jet does incorporate several potentially paradigm-changing propulsion technologies and attack weapons possibilities. The F-15EX is not only engineered with new levels of “thrust,” but also carries 12 missiles as well as elements of its existing or well-known arsenal, including the AIM-120D, AIM-9X, and standard JDAMS, among others.
While there have been massive software upgrades to the AIM-120D and AIM-9X, enabling improved targeting guidance, jamming countermeasures, and explosives, some of the newer weapons additions could potentially be even more groundbreaking.
The F-15EX will, for example, carry and fire air-launched hypersonic weapons, a decided combat advantage that needs little introduction, as their arrival will naturally transform modern air war when it comes to speed of attack, enemy response time, and stand-off attack range.
An air-fired missile traveling at 5 times the speed of sound would certainly hit an air or ground target operating hundreds of miles away in a matter of minutes, all but eliminating an enemy’s ability to respond in time. The Air Force has now also armed its F-15E with the well-known StormBreaker weapon, a first-of-its-kind air-dropped bomb able to find, track, and destroy moving targets from distances as far as 40 nautical miles in all weather conditions. Not only does the StormBreaker utilize a two-way data link enabling it to adjust course in flight according to a target’s movements, but the weapon is engineered with an often-discussed tri-mode seeker. The “tri-mode” targeting and sensing technology draws upon millimeter wave, infrared, and laser targeting guidance to track and eliminate targets.
The Raytheon-built StormBreaker can also operate as a certain kind of countermeasure to an extent, given that its seeker can adapt to switch targeting modes in the event that one method of guidance is jammed, blocked, or thwarted by an enemy. This builds in a key element of redundancy, particularly because the StormBreaker was developed with inertial measurement, GPS, and radio datalinks such as LINK 16. The multiple modes of guidance and navigation could, therefore, ensure that the weapon continues on to its target in the event that GPS guidance is jammed, denied, or taken away by an enemy.
For instance, should a group of enemy fighters seek to maneuver under heavy cloud cover or during a sandstorm or blizzard, laser-spot targeting or even GPS could be quite challenging. Millimeter wave, however, is an all-weather targeting guidance system able to move through or overcome line-of-sight challenges that can cause laser beam attenuation. Infrared targeting could also, for instance, find the heat signature emitting from an enemy armored vehicle and strike through certain weather conditions as well.
Perhaps in part for this reason, Millimeter Wave technology is increasingly being woven into weapons guidance systems. Millimeter Wave is defined as small wavelengths with frequency ranges between 30 and 300 GHz where a total of around 250 GHz bandwidths are available, according to ScienceDirect. As with other kinds of radar, the higher the frequency, the more precisely configured the return signal, a technical phenomenon that can enable a munition to alter course upon detecting movement or position changes.
“The small wavelengths of mmWave frequencies enable large numbers of antenna elements to be deployed in the same form factor thereby providing high spatial processing gains,” as stated in a 2017 publication called “mmWave Massive MIMO, a Paradigm for 5G.” (Mumatz, Rodriguez, Dai)
The Air Force’s upcoming Northern Edge exercise in Alaska is intended to test the boundaries of modern warfare by replicating a wide sphere of advanced threats to include enemy aircraft, air defenses, and even space-generate attacks upon air assets.
The service plans to field several new F-15EX Eagle II aircraft as part of its exercise, a wargame intended to place a special focus upon combat networking, such as the now well-known Joint All Domain Command and Control program. An essay in Air Force Magazine quotes senior Air Force officials explaining that the F-15EX will indeed be featured as part of the JADC2 portions of the Northern Edge wargame.
To what extent can an F-15EX contribute to or enhance JADC2? While considered an upgraded 4th-gen operating just below the threshold of its 5th-gen counterpart, the new F-15EX’s presence may raise the question as to whether its contribution could rival that of a 5th-gen aircraft given the technological sophistication of its sensing, computing, and weaponry?
Computing, threat detection, and electronic warfare may all present instances wherein the emerging F-15EX Eagle II could impact any kind of combat-sphere networking operation.
The aircraft is now engineered with an EW system called Eagle Passive/Active Warning and Survivability System (EPAWSS), a technology engineered to operate in both active or passive mode to perform both offensive and defensive missions. Some of its mission scope includes an ability to find a “line-of-bearing” and jam or disable enemy radio communications by detecting an electronic signature of enemy systems or even approaching weapons. In passive mode, an EW system can, in effect, “listen” for enemy signatures without emitting any kind of detectable electronic signal. This brings great tactical relevance as any kind of outgoing electromagnetic signal can expose or reveal an aircraft’s position, therefore making it more vulnerable. At the same time, having an ability to operate in active mode is also critical as it can enable the aircraft to disable ground-firing systems, air attacks, or even enemy drones.
EPAWSS replaced a 1980s legacy system called the Tactical Electronic Warfare suite. Interestingly, a report last year from the Air Force Test Center writes, “EPAWSS takes advantage of today’s computing, receiver and transmitter technologies to provide quicker, smarter response to threats, getting better actionable information to the pilot,” Ed Sabat, Project Development Lead and Civilian Director of Operations, 772nd Test Squadron, said in the Air Force report.
The service report further specifies that EPAWSS can succeed in detecting RF and IR (infrared) threats by “acquiring accurate targeting information prior to threat engagement.”
The F-15EX also incorporates additional networking innovations to include the transition from hydromechanical flight controls to “fly-by-wire,” Boeing developers told Warrior as far back as several years ago. Fly-by-wire technology is, of course, greatly enabled by faster computer processing, something the F-15EX incorporates with its Advanced Display Core Processor, a technology that performs 87 billion computing functions per second. As part of the computing and electronics upgrades, the F-15EX Eagle II integrates a 10-inch by 19-inch digital touchscreen data display.
The F-15EX emerging computer technology is also being leveraged to support an F-35-esque Mission Data Files system, a threat library of information incorporating threat-specific data. The system, described by Boeing experts as of particular relevance to electronic warfare, can draw upon incoming sensor information, bounce it off a database of known threats, and identify particular enemy targets such as a Russian enemy fighter jet.
Does all of this mean that an F-15EX could successfully compensate for the lack of stealth with these kinds of weapons guidance technologies, much longer attack ranges, increased sensor sensitivity and fidelity, high-speed computing, and threat warning detection? Is there any way the advanced F-15EX could actually compete with a Chinese J-20 or Russian Su-57? The answers to this may not be fully clear and full of a host of differently interpreted variables. If an F-15EX had the long-range sensors, varied guidance systems, advanced computing, threat library identification data, and vastly improved weapons reach, could it destroy enemy air defenses or 5th-gen platforms without having to engage itself in close proximity?
Should an F-15EX operate with the sensing, AI-enabled computing, threat identification and radar technology, and long-range weapons guidance systems in any way comparable to existing 5th-gen aircraft, then there certainly may be an argument for deploying the F-15EX in a major power warfare scenario amid an attack campaign aimed at establishing air superiority against an advanced rival. After all, part of the rationale for F-35 superiority is based upon the notion that it is designed to find and kill multiple enemy aircraft and air defenses before it is even seen. Could this be possible for a non-stealthy F-15EX Eagle II? Perhaps. Yet arguably not at the same time, as stealth is considered by many to be an indispensable attribute when it comes to countering advanced air defenses.
This may be the thinking on the part of advocates. However, many 5th-gen advocates are likely to insist that only a true, stealthy 5th-gen aircraft could succeed in those kinds of advanced, ultra-high-threat great power war scenarios. Some have gone so far as to suggest that an advanced 4th-gen aircraft might linger in a kind of liminal zone, meaning it may be far too advanced for counterinsurgency, yet not capable of engaging the most high-end great power threats.
Fifth-gen advocates also make a case for what’s called “cost-benefit,” meaning that even if a single F-35 is more expensive per aircraft than other options, far fewer F-35s can, it is argued, perform the mission of multiple 4th-gen aircraft, therefore saving money.
These, it seems, maybe the most fundamental and pressing questions informing ongoing debates about funding, threat indicators, cost value, and other factors as they contribute to planning regarding air fleet asset configuration. The debate is not likely to go away, and its resolution may depend in large measure on how each aircraft performs. Perhaps, ultimately, a combination of both aircraft would be optimal? Such thinking may eventually carry the day; the question is, what is the mix of numbers between them? TBD.
F-35 vs. F-15EX
The F-35 and F-15EX are so different in so many respects that comparing them might not make sense.
Yet, the two aircraft have been analyzed in relation to one another for years, given the ongoing debates about whether it makes sense to add a 4th-generation “plus” plane in more significant numbers and reduce the size of the F-35 buy.
Just several years, debate, analysis, and even controversy likely reverberated through the halls at the Pentagon regarding the wisdom of the F-15EX, a 4th-gen ++ aircraft intended as an advanced, multi-role fighter designed to expand lethality, sensing, and targeting beyond previous variants of the aircraft.
Like the F-35, the F-15EX does have cutting edge and highly sensitive Advanced Electronically Scanned Array radar technology as well as advanced high-speed computing. However, the aircraft is extremely different and less capable than an F-35 in a number of key respects.
Perhaps of greatest significance, the F-15EX is not stealthy.
Lack of stealth is likely to prove extremely problematic in high-threat enemy territory. The most advanced and rapidly emerging Russian and Chinese-built air defenses are now much more likely to operate with the ability to detect even stealth aircraft to some degree.
This is an emerging reality that continues to present something of a predicament for US weapons developers seeking to preserve air supremacy against major power rivals. Russian media claims that its upgraded S-400 and S-500 air defense systems can detect and destroy stealth aircraft may have yet to be verified in some measurable way, and there is, of course, a massive margin of difference between merely “detecting” something in some capacity and actually being able to shoot it down.
Chinese HQ-9 air defenses, reported to have appeared in areas around the South China Sea, are a fast-growing and serious threat as well.
“The HQ-9 is capable of engaging multiple aircraft, including combat aircraft. It resembles the Russian S-300 system but China is assessed to have developed variants of the system with a longer range, potentially up to 230 kilometers,” a DW report writes.
A Jet Without a Mission?
Considering these factors, some are likely to wonder if the F-15EX is an aircraft without a clearly defined mission.
Does the aircraft linger in a certain kind of liminal uncertainty, meaning that it might be overqualified for most uncontested environments yet insufficient to counter the highest threat or most contested environments, such as those containing Russian or Chinese air defenses?
The F-15EX is, at least in terms of its external configuration, modeled upon 1980s engineering, yet it does contain quantum-like improvements in computing, radar range and sensitivity, avionics, sensing, and weaponry.
However, it simply is not stealthy – and that fact simply won’t change.
Its construction, configuration, coating, and external shape do not resemble the stealthy exterior of an F-22 or F-35, and it does not appear to have an internal weapons bay. As a 4th-Gen 1980s airframe, the F-15EX is not as flat, sloped, or rounded as a fifth-generation plane and is most likely not built with a mind to seams, bolts, and other attachments specific to procedures needed to construct a stealth aircraft.
The F-15EX also has a protruding cockpit, much like the original variants, and some sharp edges, likely to generate a stronger radar return signal.
Just several years, debate, analysis, and even controversy likely reverberated through the halls at the Pentagon regarding the wisdom of the F-15EX, a 4th-gen ++ aircraft intended as an advanced, multi-role fighter designed to expand lethality, sensing, and targeting beyond previous variants of the aircraft.
F-15EX: Worth the Budget Dollars?
While the F-15EX did incorporate several cutting-edge innovations and expanded air-combat capacity for US Air Force fourth-generation aircraft, some questioned the rationale for the plane for several critical reasons related to today’s threat environment.
Perhaps most of all, the aircraft simply may not be stealthy enough to survive against Russian or Chinese air defenses, many of which have been massively upgraded in recent years.
Russian media, for instance, often writes that its advanced S-500 air defense system can detect some stealth aircraft, a claim which may or may not be true.
What is known is that advanced air defenses operate with next-generation computer processing, digital networking between systems, and an ability to hit aircraft at longer ranges on a greater number of frequencies.
The US Air Force has been upgrading the F-15 for many years, giving it Advanced Electronically Scanned Array radar and new generations of sensing and computing. Yet, all of its many innovations may prove less relevant if the aircraft cannot operate against sophisticated great power rivals. However, even if the F-15EX is primarily capable of performing missions in a less-contested environment, it does fly with a large and very lethal payload.
On this point, an essay from several years ago in the EurAsian Times says the F-15EX operates with as many as 12 air-to-air missiles and can carry 13.6 tons of payload.
F-15EX Against Russian & Chinese Air Defenses
At the same time, if the aircraft is not stealthy enough to operate against the most advanced air defenses, is it truly worth the expense?
This is also likely a question that continues to receive attention among weapons developers because if the F-15EX is only capable in permissive environments, it may be somewhat of an advanced aircraft without a clear mission.
Many other less-expensive and upgraded aircraft can function in a “bomb truck” type of capacity, which raises questions about the utility or mission concept of the F-15EX.
The Mass Option
There is yet another key factor that might help explain the rationale for the F-15EX, and it pertains to the question of “mass” or major warfare.
For instance, should there be a massive air-war engagement between the US and Russia or China, there will clearly be a place for a 4th-gen “Plus” type of aircraft able to win against enemy 4th-gen.
The Chinese, for instance, have hundreds of J-10s, and the Russians operate hundreds of Su-27s and Su-30s, aircraft that would likely need to be engaged and destroyed in any kind of massive air war involving large numbers of planes.
Clearly, Russian and Chinese 5th-generation aircraft need to be destroyed, yet a large-scale or protracted engagement would also present the need to eliminate both Russia and China’s large fleet of 4th-generation aircraft. This is a mission for which the F-15EX might be exceptionally well suited.
Does this mean the F-15EX is worth the cost?
Available data suggest the F-15EX costs roughly $80 million per plane. Cost savings advantages associated with the F-15EX, when compared to buying larger numbers of F-35s, may not make sense, given that the price-per-plane of the F-35 is slated to drop to $89 million.
Given all these factors, one might wonder if the F-15EX lingers in a certain kind of liminal uncertainty. It might be overqualified for most uncontested environments yet insufficient to counter the highest threat or most contested environments, such as those containing Russian or Chinese air defenses.
