Drone That Mimics Enemy Stealth Fighters Ordered By DoD

The U.S. military needs a 5th Generation Aerial Target, or 5GAT, to replicate stealthy jets and missiles in tests and training.

byJoseph Trevithick|
The Pentagon has rebooted work on an advanced target drone for test and training use with a recent contract award.
The Pentagon has rebooted work on an advanced target drone for test and training use with a recent contract award. Sierra Technical Services


The U.S. military has restarted a program to acquire a new fighter-sized stealthy target drone that can serve as a stand-in for advanced adversary combat jets like the Chinese J-20 and the Russian Su-57, and their electronic warfare capabilities in particular. There is a growing demand to replicate these types of high-end aerial threats in training exercises and test and evaluation events, and, in some cases, doing so cheaply enough that the mock opponents can be destroyed if desired.

Advanced Technology International, Inc. received the contract for the 5th Generation Aerial Target (5GAT) prototype project on August 4. Aviation Week's Defense Editor and friend of The War Zone, Steve Trimble, was first to notice the announcement about the deal, which had been posted earlier this month on the U.S. government's System for Award Management (SAM) contracting website.

The U.S. Army Contracting Command's office in Orlando, Florida awarded the contract, which would have a total value of nearly $77.2 million "if all milestones and options are exercised," on behalf of the Pentagon's Test Resources Management Center (TRMC), according to the contracting notice. It also says Advanced Technology International, Inc. is acting as the "managing prime" for this award and names Sierra Technical Services, Inc. as a major subcontractor. This arrangement is a product of the specific contracting mechanism being employed for this deal, which is leveraging the Training and Readiness Accelerator II (TReX II) consortium. Advanced Technology International manages TReX II.

A previous 5GAT design developed by Sierra Technical Services. Sierra Technical Services

Broadly speaking, the U.S. military uses aerial target drones to test and evaluate weapons and other systems, including air-to-air and surface-to-air missiles, as well as countermeasures, radars, and other sensors. They can simulate different kinds of threats for training purposes, too.

The design of the drone that Advanced Technology International and Sierra Technical Services are now set to supply will be a refined version of one that the latter company developed under a previous iteration of the 5GAT program. That effort was shelved in 2020 after the initial prototype was totally destroyed in a crash during its maiden flight.

A head-on view of Sierra Technical Services' previous 5GAT design. Sierra Technical Services

"The air vehicle was lost during its maiden flight test as the result of an undiscovered software error," according to the announcement about the award of the new 5GAT contract. However, "the combined system successfully met all ground test objectives" and "the aircraft configuration and overall design is [sic] still considered to be sound."

Sierra Technical Services' original design, the development of which dates all the way back to 2006, is understood to have been dimensionally similar and to have had roughly the same gross weight as a T-38 Talon jet trainer. It was powered by a pair of General Electric J85 turbojet engines, the same type used on the T-38. Additional components reportedly came from F-5 and F/A-18 fighters. It was expected to be able to fly at least at high subsonic speeds and possibly even go supersonic, as well as a very high degree of maneuverability.

A pair of US Air Force T-38 Talon jet trainers. Sierra Technical Services' previous 5GAT design is said to be similar in size and weight. USAF

The initial 5GAT prototype had a long nose section, rear-positioned diamond-shaped wings and intakes, and tricycle landing gear, and was designed to take off and land like a traditional aircraft. It also had a number of stealthy features, including a chined forward fuselage, honeycomb composite structures used in its construction, snaking intakes to hide the radar-reflecting fan faces of its J85 engines, and saw-toothed engine exhausts.

A top-down view of Sierra Technical Services' first 5GAT prototype, giving a good look at its general planform and its saw-toothed engine exhausts. Sierra Technical Services

As originally designed, the 5GAT drone would be able to carry various payloads, including sensors, electronic warfare suites, and expendable countermeasures, internally, as well as various stories externally. Stores loaded under its wings would, of course, negatively impact its stealthy characteristics.

A rendering of a 5GAT drone dueling with an F-35 Joint Strike Fighter. The drone appears to have released countermeasure flares to help evade an AIM-9X Sidewinder missile fired by the F-35. Sierra Technical Services

Sierra Technical Services has said in the past that it was aiming for a unit price under $10 million. 

All of this is in line with what the TRMC and the Army say has been needed in an advanced target drone for the better part of two decades now, at least.

"Over the past 15 years, the Government has investigated various aircraft configurations and legacy engine options that could be combined to produce an affordable 5GAT," the notice about the new 5GAT contract award explains. "The U.S. military has used aerial targets for over fifty years to test and improve the lethality of their weapons systems. The purpose of aerial targets is to replicate critical characteristics of threat aircraft, such as performance, signature, and countermeasures."

"These [target] aircraft must represent the threat throughout an engagement, i.e., from initial acquisition until missile impact and hence the target is often destroyed after completing only a few tests," it continues. "To contain costs for these limited lifetime assets, unmanned versions of retired fighter aircraft have previously been employed for this mission; however, due to the increased cost and lifespan of the latest, 5th Generation of fighter aircraft, there are no retired airframes available that adequately represent the characteristics of 5th Generation threats. Key amongst these characteristics is size, signature, and electronic attack (EA) payloads."

It is worth noting here that the U.S. Air Force does employ a pocket fleet of F-117 Nighthawk stealth jets, which are officially retired, to represent higher-end low-observable (stealthy) threats during training exercises and for test and evaluation purposes. At the same time, those are first-generation stealth aircraft. It is also very unlikely that they would ever be subjected to destructive aerial testing for operational security and environmental reasons.

A 'retired' F-117 Nighthawk in Alaska supporting Exercise Northern Edge 2023. USAF

The Air Force has been winding down conversions of older F-16 Vipers into QF-16 target drones due to dwindling stocks of suitable retired airframes and a surge in operational demand within the service for modernized Vipers. A more capable, high-end threat representative airframe will be needed in the future, and that will be unmanned. The U.S. military already uses drones and even converted missiles to replicate various tiers of aerial threats, not just higher-end ones.

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There is a clear need for aerial targets to specifically represent fifth-generation aerial threats. The announcement about the new 5GAT contract award specifically points to a need for this kind of mock adversary capability to support various next-generation capability developments.

"The goal for the program is to obtain 'game-changing,' revolutionary high-risk/high-reward advancements that propel the ability to perform DoD T&E [Department of Defense test and evaluation] activities, thus mitigating the timeframes of associated military capability obsolescence," the notice says.

The War Zone has already reported a number of past examples of unusual and specialized airframes that appear to be supporting U.S. Air Force research and development and test and evaluation efforts, particularly in relation to the service's Next-Generation Air Dominance (NGAD) initiative. NGAD is a multifaceted modernization program that includes efforts to develop and acquire a new sixth-generation crewed stealth combat jet and advanced drones with high degrees of autonomy, as well as new sensors, weapons, networking capabilities, engines, and more.

In addition, the Air Force's NGAD program has a particular focus on what is described as "spectral warfare," which centers on the development of things like advanced electronic warfare suites, radars, infrared sensors and seekers, and defenses against similar enemy capabilities, as you can read more about here.

A rendering of a notional sixth-generation stealth combat jet. Collins Aerospace

Last year, the Air Force issued its own contracting notice expressing interest in a supersonic-capable Next Generation Aerial Target (NGAT). In regards to how this new unmanned target could factor into the service's testing and evaluation needs, and how it could help take over the FSAT role from the QF-16, we talked to those who fly the 'Zombie Vipers' all about it back in June:

"In July 2022, Boeing delivered the last of 75 ‘Zombie Vipers’ that it converted at its Cecil Field, Florida, facility since 2013. The lack of availability of suitable retired fighter jet airframes to convert, coupled with the advance in drone technology, and a need to remain cost-effective means that the next-generation of FSAT will be a purpose-designed drone.

“There’s a couple of programs we are looking at right now,” explains Col. DeWitt. “The Next-Generation Aerial Target, known as NGAT, and the Fifth-Generation Aerial Target, known as 5GAT. Requirements call for a completely unmanned drone program that will fulfill the full-scale requirement but allow us to do more electronic attack and also offer some different options. We have a limited number of QF-16s and when they are exhausted we need something else that allows us to continue doing the things the same way we do now. We are in a mix of proposals and contests between different companies right now.”

The QF-16 fleet will slowly be exhausted over the next few years, and the replacement full-scale target will gradually take its place. This means that some of the most fascinating flying in the Air Force — manned QF-16 operations — will come to an end. But that’s still a few years away, and for the time being Tom Mudge and his 82nd ATRS colleagues will continue to fly some of the most fascinating and stressful missions in the Air Force."

Demands for a fifth-generation aerial target aren't limited to the Air Force, either. The Navy has its own NGAD program, which is deeply intertwined with the Air Force's effort, and that service is also looking at a future where it will need to defend ships and facilities ashore against increasingly more capable aerial threats, including stealthy cruise missiles. The Army and Marine Corps face similarly evolving threats and, in particular, will need to be able to test future air and missile defenses against representative targets.

The video below shows SM-2 surface-to-air missiles fired by Navy ships destroying shore-launched  GQM-163 Coyote supersonic sea-skimming targets.

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This all sounds like exactly the kind of work that TRMC wants 5GAT to help support.

Though the rebooted 5GAT program is focused primarily on supporting test and evaluation efforts, the U.S. military has a definite need for similar advanced aerial targets for use in training exercises. Beyond the kinds of threats advanced target drones can replicate, their lower unit purchase and operating costs compared to actual fifth-generation fighters offer significant benefits when it comes to fielding them in large numbers. In recent years, U.S. aerial combat exercises have increasingly involved scenarios involving larger-scale operations across broader areas, as well as higher-end threats. This reflects the U.S. military's shift in focus to preparing for a future major conflict against a near-peer opponent, especially China.

Chinese J-20 stealth fighters, one of the threats the 5GAT is intended to help replicate. PLAAF

All this being said, when exactly new 5GAT drones will be available in quantity remains to be seen.

"The principal objectives of this project are to refine the aircraft design to meet its performance goals, build one or more prototypes, and conduct the necessary ground and flight testing... to prove the efficacy and affordability of the base vehicle design," according to the contracting notice. "If these objectives are met successfully, an additional project phase to integrate auxiliary equipment such as range-unique control system communications devices, scoring systems, and flight termination systems may be executed, or the project may be transitioned directly to the individual service branches to complete range integration and transition the aircraft into production."

"Upon successful completion of this prototype effort, the Government anticipates that a follow-on production effort may be awarded via either" a traditional contract or some other kind of contracting mechanism, the notice adds. "Successful completion will occur when the prototypes have been validated and are accepted by the Government."

However the new 5GAT program progresses now, there is already a clear need for advanced fifth-generation representative target drones, which is only set to grow in the near future.

Contact the author: joe@thedrive.com