The Evolution of the Air Aggressor

By: Branden Felker
Estimated Reading Time: 18 Minutes

Executive Summary:

Current USAF Aggressor airframes lack the capability to effectively replicate the operational advanced fighter weapon systems fielded by near-peer adversaries China and Russia. Additionally, with only two Air Aggressor squadrons across the USAF, there is a lack of requisite capacity to fully support the advanced air-to-air training requirements of the Combat Air Force. Despite initiatives such as the Air Combat Command Advanced Adversary Air contract awarded in October of 2019 and plans to establish an F-35A Aggressor Squadron at Nellis Air Force Base, the Aggressors will likely still lack the necessary capacity to support a routine and robust advanced air-to-air training environment. These issues highlight a need to not only modernize the current fleet of Aggressor F-16Cs, but to also seek an innovative approach to acquire an affordable, indigenous, advanced replication capability within the USAF. Procurement of a 5th generation fighter-type unmanned aerial system, the Aggressor UAS, developed to augment manned Aggressors with advanced adversary replication would not only solve current capability and capacity shortfalls, but also posture the USAF Aggressors to satisfy future adversary replication requirements.


Both the 2017 National Security Strategy (NSS) and 2018 National Defense Strategy (NDS) call for improved military readiness with a renewed focus on training. However, US Air Force (USAF) Combat Air Force (CAF) air-to-air training lacks effective near-peer adversary threat replication in a live-fly environment. The USAF Aggressors of the 64th Aggressor Squadron stationed at Nellis Air Force Base (AFB) are charged with preparing the CAF through accurate and realistic threat replication training, yet their aircraft are the oldest F-16Cs in Air Combat Command (ACC). Their airframe lacks the capability to effectively replicate the operational advanced fighter weapon systems fielded by near-peer adversaries China and Russia. Additionally, with only two Air Aggressor squadrons across the USAF, there is a lack of requisite capacity to fully support the advanced air-to-air training requirements. The current fleet of Aggressor aircraft must be modernized to increase its 4th Generation fighter replication capabilities, expanded to decrease capacity shortfalls, and ultimately evolved to satisfy replication requirements for both current and future advanced adversary weapon systems.

An ACC initiative to solve the Adversary Air (ADAIR) capacity shortfalls resulted in a $6.4 Billion ADAIR Contract awarded in October of 2019 to seven commercial enterprises. However, the aircraft proposed to fill contract requirements are 3rd and 4th generation fighters and as such, do not possess the airframe characteristics or weapon systems necessary to effectively replicate near-peer adversary fighters. While the USAF has plans to establish an F-35A Aggressor Squadron at Nellis Air Force Base (AFB) to provide a much needed 5th generation replication capability, with only 11 dedicated F-35As, the Aggressors will likely still lack the necessary capacity to support a routine and robust advanced air-to-air training environment. These issues highlight a need for an innovative approach to acquire an affordable, indigenous, advanced replication capability within the USAF. Procurement of a 5th generation fighter-type unmanned aerial system (UAS) developed to augment current Aggressors with advanced adversary replication would not only solve current capability and capacity shortfalls, but also posture the USAF Aggressors to satisfy future adversary replication requirements. Without a critical investment in the USAF Aggressor enterprise, CAF readiness for major combat operations (MCO) against a near-peer adversary will likely be difficult to achieve.

These issues highlight a need for an innovative approach to acquire an affordable, indigenous, advanced replication capability within the USAF.

Adversary and Current Aggressor Capabilities

Force modernization in both the Peoples Liberation Army Air Force (PLAAF) and Russian Aerospace Forces (VKF) over the past 20 years has dramatically increased the capability of adversary fighter weapon systems. Due to this rapid advancement in both technology and capability, the baseline air threat a typical CAF fighter squadron trained against over the past decade is inferior to operational fighters fielded by near-peer adversaries such as the Su-35S, J-10C, J-16, and J-20. While the USAF Weapons School (USAFWS) explores academic solutions to these problem sets and operational test units develop and validate tactical doctrine for emerging threats, the process to incorporate new tactics into readiness training at CAF units could take a matter of years. Additionally, as adversary capabilities meet or exceed those of CAF units, the ability to train against a threat representative adversary becomes increasingly difficult.

Live-fly training conducted against replicated adversaries relies on accurate replication of weapon systems and airframe characteristics. The replication categories relevant to fighter aircraft are the fire-control radar (FCR), infra-red search and track system (IRSTS), data link, helmet-mounted display (HMD), radar cross section (RCS), electronic attack (EA), and maneuverability. Effective replication requires an aircraft achieve an as capable or better performance than the adversary aircraft in each corresponding replication category. Figure 1 depicts an open source comparison of advanced adversary fighter characteristics and how they compare to current Aggressor F-16C capabilities. These adversary capabilities drive the establishment of the following replication benchmark: active-electronically-scanned-array (AESA) FCR, IRSTS, data link, HMD, integrated EA, maximum RCS of .5m2, 50,000ft operating ceiling, maximum speed of Mach 2.0, and maximum loading of 9.0 Gs.

OTH, Emerging Security Environment, Multi-Domain OperationsFigure 1. Open Source Comparison of Aggressor and Adversary Fighter Characteristics

While not all Aggressor aircraft need to meet the benchmark in each category, the Aggressor fleet should be able to field requisite quantities of each capability to meet training objectives. For instance, replication of a “high fast flyer” profile is not a capability every Aggressor airframe must be able to do, but the Aggressor fleet should be able to field the ability to fly Mach 2.0 at 50,000ft when required by the training scenario. Conversely, the requirement to detect and target air threats at appropriate ranges is a capability each Aggressor should be able to employ. When replicating advanced adversary fighters, an AESA FCR is required and should be fielded on every Aggressor airframe.

Shortfalls in reaching the replication benchmark result in missed training opportunities for CAF operators and reduced effectiveness of live-fly training. Additionally, training conducted against replication shortfalls can drive false lessons learned and skew the validity of operational readiness assessments. Units that regularly train against the aforementioned adversary fighters, such as the USAF Weapons School, Red Flag and other Large Force Exercise (LFE) participants, and both operational and developmental test units are most at risk of the negative impact to training. However, as these advanced adversary threats appear in the Designed Operational Capability (DOC) Statements of CAF units, the impact of replication shortfalls will be felt CAF-wide.

Modernizing Current Aggressors

The USAF Air Aggressors have skillfully developed adversary tactics and replication methods for the aforementioned adversary fighters, but due to their benchmark deficit, Aggressor pilots have reached the limit of what the F-16C airframe, in its current configuration, can effectively replicate. The 64th Aggressor Squadron at Nellis Air Force Base currently operates F-16C Block 25 and 32 aircraft, and as previously mentioned, they are the oldest F-16s in ACC. As such, they fall short of the replication benchmark in several categories. Fortunately, several aircraft modernizations are available for the F-16C that would greatly enhance the Aggressors’ ability to effectively replicate modern adversary fighters and reach the benchmark in several categories. Unfortunately, the USAF has not allocated funding for most of the available modernizations.

The FCR installed on Aggressor F-16Cs is the APG-68, a mechanically-scanned-array radar with limited processing capability when compared to a passive electronically-scanned array (PESA) or AESA FCR. At an estimated cost of $3.2 million per FCR, the APG-83, a fully integrated AESA FCR, has been developed and successfully installed on F-16Cs around the world. While the Air National Guard has begun installation of the AESA FCR on its 72 F-16Cs, USAF assigned F-16Cs, including the Aggressors, have not received them. Additionally, unlike the vast majority of both CAF and modern adversary fighter aircraft, USAF Aggressors lack the capability of an HMD. While the legacy APG-68 does contain several radar modes for within-visual-range (WVR) maneuvering, the lack of an HMD reduces an Aggressor pilot’s ability to both visually acquire a target and efficiently cue weapons against it.

Another weapon system USAF F-16Cs lack is an IRSTS. Without an IRSTS, Aggressor pilots are unable to effectively replicate infra-red (IR) detection of targets and the ability to employ IR weapons is degraded. This is a significant replication limitation when opposing 5th generation assets. While IRSTS solutions exist for F-16C integration in podded form, the F-15C is currently the only USAF fighter platform that carries an IRSTS. Additionally, only half of the 64 AGRS F-16Cs are equipped with a data link capability. Data link aids in target identification, weapons employment, and increased situational awareness during an air-to-air engagement. As adversary tactics and targeting techniques continue to advance, an integrated data link is not only required for replication capabilities, it is critical to ensure basic airmanship and safety are maintained when operating in an LFE scenario. Overall, when compared to target acquisition systems of adversary fighters, Aggressor F-16Cs operate at a deficit due to a lack of a modern FCR, an IRSTS, an integrated helmet, and comprehensive data link.

Regarding EA, Aggressor aircraft are equipped with some of the most advanced jamming capabilities available in the CAF. Currently, the 64 AGRS F-16Cs are capable of carrying the Angry Kitten, ACaP, and ALQ-188 jamming pods. These pods provide the ability to saturate the air-to-air environment with both radar disruption (noise) and radar deception signals. While the Aggressor EA pods are advanced, limited integration with aircraft avionics prevents full maximization of EA capabilities. Finally, as depicted in Figure 1, the F-16C has a nominal RCS of approximately 5m2. When replicating advanced 4th and 5th generation fighters, the unrealistic increase in contact range of the Aggressor F-16C results in degraded training for CAF operators. Unfortunately, there are limited opportunities to improve the replication capabilities of the F-16C in these two categories.

Due to the deficiencies in the ability to effectively replicate advanced adversary fighters, Aggressor F-16Cs must be modernized to meet the benchmark in four categories. The specific system modernizations the USAF should fund for the Aggressor F-16C fleet should be, in order of priority: AESA radar, data link, IRSTS pod, and an HMD. Although the Aggressors are currently funded for an incremental hardware and software modification, of the modernization items listed, the 64 AGRS F-16Cs will only receive the data link capability. It is worth noting that a piecemeal approach to modernization, while better than the status quo, should not be viewed as a linear improvement of replication capability. In other words, the combination of capabilities working together to improve the replication pilot’s understanding of the environment and the ability to perceive and act on advantageous engagements is what ultimately increases advanced adversary replication. In the absence of a comprehensive approach to Aggressor modernization, the USAF has looked to alternative methods at improving CAF readiness.

The specific system modernizations the USAF should fund for the Aggressor F-16C fleet should be, in order of priority: AESA radar, data link, IRSTS pod, and an HMD.

ADAIR and the LRIP F-35A

As previously mentioned, Air Combat Command (ACC) awarded a $6.4 Billion ADAIR Contract to a group of seven companies. Unfortunately, the vast majority of the aircraft proposed to fill the joint contract do not meet the benchmark previously established for replication of advanced adversary fighters. In most cases, the aircraft operate at a capability and performance deficit even in comparison to current F-16C Aggressors. While the quantity of ADAIR aircraft available to fulfill CAF red-air training requirements will provide much needed reprieve to CAF units and allow them to re-focus on blue-air training requirements, a deficit will remain in capable adversary aircraft to replicate advanced adversary fighters.

In May of 2019, the USAF announced the reactivation of the 65th Aggressor Squadron at Nellis AFB with 11 Low Rate Initial Production (LRIP) F-35A aircraft. Then Secretary of the AF, Heather Wilson, stated, “This move will allow us to repurpose early production F-35s to help train Airmen for the high-end fight.” The aircraft are scheduled to arrive at Nellis AFB in early 2022, and upon arrival, these aircraft will be able to close the existing technology gap and provide near-peer adversary training to CAF operators. Aside from maximum speed, the F-35A meets the established replication benchmark in each category and will indigenously provide the Nellis AFB Aggressors with an ability to fulfill the advanced adversary fighter training requirements. With this move, F-35A units assigned to Nellis AFB that currently augment adversary training requirements will be able to re-focus on their primary mission sets. Additionally, CAF units participating in Nellis based LFEs, USAF Weapons School squadrons, and priority testing missions will benefit from increased Aggressor replication capabilities.

However, before the Aggressor F-35A aircraft can be delivered, the USAF must fill the requirements of a limitation imposed by the 2020 Defense Authorization Bill. The bill prevents the transfer of the LRIP F-35As to Nellis AFB until the USAF provides Congress with a plan to modernize the organic aggressor fleet. Specifically, Sec. 149 of the bill speaks to Air Force Aggressor Squadron Modernization and states, “The Secretary of the Air Force may not transfer any low-rate initial production F–35 aircraft for use as aggressor aircraft until the Chief of Staff of the Air Force submits to the congressional defense committees a comprehensive plan and report on the strategy for modernizing its organic aggressor fleet.” Specific contents of this report are to include, “An analysis of the cost and timelines associated with modernizing the current Air Force aggressor squadrons to include upgrading aircraft’s radar, infrared search-and-track systems, radar warning receiver, tactical data link, threat-representative jamming pods, and other upgrades necessary to provide a realistic advanced adversary threat.” While this bill does not call current Aggressor fleet upgrades into action, it does emphasize the importance this issue has received at the highest levels of the US government.

While the replication capability of the F-35A is sufficient, the planned allocation of aircraft for the 65 AGRS may pose a quantity limitation. With only 11 F-35As, the robust advanced adversary training requirements of Nellis AFB may still prevent the Aggressors from indigenously fulfilling all the advanced adversary training requirements. Furthermore, it is expected that China will eventually produce between 100 and 200 of their most advanced manned fighter, the J-20, by the mid-2020s. CAF operators should expect to face this stealth threat, augmented by hundreds of 4th+ generation J-10Cs and J-16s, should MCO ever commence against China. The 11 F-35A Aggressors will alone not be able to effectively replicate the type of training scenario expected for MCO against these projected numbers of advanced adversary fighters. This potential future training deficit presents an opportunity for an innovative approach to fulfill both the Congressional mandate to modernize the USAF’s organic Aggressor fleet as well as address both Aggressor capability and capacity shortfalls.

A Future Capability – The Aggressor UAS

Despite the addition of the LRIP F-35As to the current fleet of F-16C Aggressors, an innovative approach must be sought to evolve the USAF Aggressor enterprise and provide effective threat-representative live-fly training to the CAF. In addition to current 5th generation aircraft in production in Russia and China, both nations are also conducting research and development related to 5th generation unmanned aircraft. These efforts seek to challenge the competitive advantage the joint force currently holds over its adversaries and will eventually drive additional advanced replication requirements for CAF air-to-air training. In a response to the technologies emerging from adversary nations and to maintain the ability to replicate current and future operational capabilities of near-peer adversaries, the USAF needs to invest in a similar capability for its Aggressor fleet, the Aggressor UAS.

Fortunately, tactical UAS efforts are underway in the US and Australia that could serve as the backbone for the development of an affordable, indigenous, 5th generation UAS platform. Boeing has partnered with the Australian Air Force to develop the Airpower Teaming System (ATS). The ATS is designed to enhance and multiply the capabilities of current airpower assets and provide allied forces a distinct advantage over adversaries. Specifically, the ATS will “integrate sensor packages onboard to support intelligence, surveillance and reconnaissance, tactical early warning missions and more.” In addition to the affordable nature of the ATS, concepts that can be applied to the Aggressor UAS are its ability to utilize artificial intelligence (AI) to fly independently or in support of manned aircraft and its ability to integrate onboard sensors that can share collected information through data link capabilities. Additionally, the ATS proposes an ability to “plug and play” different components or sensors into the nose section compartment, granting maximum flexibility for application across multiple mission sets. Each of these capabilities would greatly benefit the development of the Aggressor UAS.

Kratos Unmanned Aerial Systems, a California-based company, has two tactical UAS programs under development. The UTAP-22 Mako is a small-scale platform that will provide an affordable UAV capable of flying in contested environments alongside established manned weapon systems. It is configured with radio, data link, EA, and defensive counter-measure capabilities. Additionally, it has a flexible internal and external design configuration allowing for different payload integration for different mission sets. Kratos has also developed the XQ-58A Valkyrie for the USAF’s Low Cost Attritable Aircraft (LCAA) program. Kratos asserts “the XQ-58A delivers a combination of long-range, high-speed, and maneuverability, along with the capability to deliver a mix of lethal weapons from its internal bomb bay and wing stations.” With an estimated cost around $3 million per aircraft, the LCAA is far more affordable than the approximately $100 million a 5th generation manned fighter costs. While the Valkyrie is a subsonic UAV, its maneuverability in conjunction with the EA and defensive countermeasure capabilities could be applied to the Aggressor UAS.

Whether the USAF invests in currently available UAS capabilities or opts to develop a separate program of record for the Aggressor UAS development, integration of an Aggressor UAS with current and future manned Aggressors will revolutionize the Aggressor enterprise. It will not only satisfy current near-peer adversary fighter training requirements but provide an opportunity to fill future replication requirements. The Aggressor UAS program would include the UAS vehicle as depicted in Figure 2, associated payloads, a networked ground station, a robust communications link, and support functions such as maintenance and mission planning capabilities. The Aggressor UAS program would focus on maximizing replication of beyond-visual-range capabilities and the program requirements should mirror the established replication benchmark. Additional design requirements above the established benchmark would include the following attributes: internally integrated EA, passive detection capabilities, Link-16 and Multi-Function Advanced Data Link (MADL) compatibility, dispensable counter-measures, and the ability to operate independently, in concert with other UAS vehicles, or individually from cockpit-like controls located in the ground-station.

OTH, Emerging Security Environment, Multi-Domain OperationsFigure 2. Author’s Rendition of the Aggressor UAS Concept

To maximize cost savings and increase flexibility, the Aggressor UAS program would not seek to incorporate all the sensor and weapon system requirements into a single vehicle. Much like Boeing’s ATS concept, each platform would contain a modular nose section that provides a plug-and-play capability to swap different payloads between missions. With the ability to procure multiple vehicles for the cost of a single manned fighter, the Aggressor UAS would capitalize on increased vehicle quantities and utilize teaming over MADL to fuse sensor data and maximize replication capabilities. This effort would not only reduce cost and increase adversary numbers, it would also increase flexibility to better meet training requirements.

Integration of the Aggressor UAS into the execution of the Aggressor mission would begin with mission planning. Mission specific training objectives and presentations would be developed internally or coordinated with the lead Aggressor unit assigned to each mission. Aggressor UAS payloads would be allocated to each vehicle based on mission requirements and initial flight profiles and parameters would be paired to the mission.

Control of each UAS vehicle would occur from the ground station where a controller, or group of controllers, would direct each vehicle via established profiles, as groups via an intuitive control interface, or individually via cockpit-like controls at individual stations. Connectivity with the scenario manager, the range training officer, adversary control (Baron) and other Aggressor assets would occur via UHF, VHF, Have-Quick, or SATCOM. The Aggressor UAS could operate either independent from manned Aggressor platforms or augment them to maximize the spectrum of Aggressor capabilities. Figure 3 depicts a UAS teaming concept as demonstrated between a four-ship of Aggressor UAS vehicles and a legacy F-16C Aggressor. Adversary training scenarios that incorporate modernized F-16Cs, LRIP F-35As, and the Aggressor UAS would most effectively represent the operational air threat of near-peer adversaries and significantly increase CAF readiness for MCO.

OTH, Emerging Security Environment, Multi-Domain OperationsFigure 3. Aggressor UAS Teaming Concept

A short vignette of how the Aggressor UAS could be implemented into missions flown on the Nevada Test and Training Range (NTTR) begins with Aggressor UAS basing at Creech AFB or the Tonopah Test Range Airfield. Either of these locations would maximize available on-station time while reducing the impact to ramp space at Nellis AFB and both air traffic congestion and environmental impacts to the Las Vegas valley. Mission planning would be accomplished remotely and coordinated with either the 64th or 65th AGRS to maximize replication effects for each training scenario. While Nellis based aircraft depart for the NTTR, the Aggressor UAS vehicles would launch from their base and establish themselves on-station in their pre-coordinated airspace and altitude block. Much like other UAS participants in NTTR missions, the Aggressor UAS vehicles would follow all pre-established range procedures and mission specific rules of engagement. If the Aggressor UAS is based at Tonopah Test Range Airfield, scenario realism could be increased by simulating adversary alert launches via actual UAS vehicle takeoffs during a mission. The Aggressor UAS would be optimal to support NTTR LFEs where a robust and dense adversary presentation is required to effectively replicate advanced adversary air defense capabilities. A scenario containing an initial picture of eight modernized Aggressor F-16Cs, four Aggressor F-35As and 24 Aggressor UAS vehicles would present a significant challenge to CAF operators unlike anything the USAF is able to currently achieve in a live-fly scenario.


The increasing capabilities of operational adversary fighters fielded by the PLAAF and VKF have set a replication benchmark that exceeds the capabilities of the current USAF Aggressor fleet. While the addition of contracted ADAIR has addressed capacity shortfalls and highly capable F-35As will soon augment the current fleet of F-16C Aggressors, these efforts are likely not enough to resolve replication deficits. Current Aggressor F-16Cs require modernization to maximize the potential of their airframe and capitalize on their advanced EA capabilities, but that also will not holistically solve the problem. An innovative approach to evolve the Aggressor enterprise must be taken to provide a robust replication capability that is threat representative of operational near-peer adversary capabilities. An investment to procure an affordable, indigenous, 5th generation replication capability to integrate with modernized F-16C and F-35A Aggressors is one possible approach to be taken. The resulting future capability, the Aggressor UAS, will satisfy both capability and capacity shortfalls, evolve Aggressor replication capabilities, and ultimately raise the bar for CAF readiness in live-fly air-to-air training.

Major Branden Felker is a recent graduate of the Multi-Domain Operational Strategist concentration at the Air Command and Staff College. He is an F-16C pilot with over 2,200 hours and has flown in operational F-16C units and as an Aggressor Pilot in the 64th Aggressor Squadron. While an Aggressor, Major Felker was certified as a subject matter expert in Advanced Russian Fighters.

The views expressed are those of the author and do not necessarily reflect the official policy or position of the Department of the Air Force, Department of Defense, or the United States Government.

Feature Image: Air Force Times

OTH, Emerging Security Environment, Multi-Domain Operations

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2 thoughts on “The Evolution of the Air Aggressor

  • June 2, 2020 at 6:15 am

    I would also recommend that the development of an aggressor UAS fleet incorporate an air refueling capability that also utilizes airborne C2 of those same UAS vehicles, preferably from an air refueling tanker aircraft that is able to perform both support missions simultaneously.

  • June 2, 2020 at 7:44 am

    This article highlights a deficiency that all USAF fighter pilots have been voicing for years. The costs for ADAIR are expensive, but necessary. The current commander of ACC wrote “The Counterair Companion: A Short Guide to Air Superiority for Joint Force Commanders,” in 1995 and highlighted a very telling argument for investment in ADAIR:
    “Training provides the final cog in the counterair system. Counterair training is expensive and time consuming. The cost of acquiring and operating the weapons systems is tremendous, and the cost of recruiting, training, and retaining quality people to operate them is also high. The cost of training a mission-ready fighter pilot may be $5 million dollars over three years, and continuation-training costs run to thousands of dollars per hour. This money is wasted unless training is conducted efficiently and realistically. Effective counterair training also involves risk and results in accidents and deaths. An effective counterair force must be willing to pay the penalties in costs and lives required to train a capable force. After quality people are trained, they must also be retained long enough to provide a reasonable return on the training investment and provide future leadership. Retaining quality people requires more money and interest. If reduced budgets limit training opportunities and reduce skill levels, capable people may look elsewhere for new challenges. If a reduced force structure and increasing worldwide military commitments drive deployments and family separations beyond a breaking point, “burned out” counterair specialists may leave in search of more comfortable lifestyles.”

    The USAF needs to modernize its aggressor fleet and adapt an unmanned capability coordinated with the modernization described in this article.


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