New Radars Are Giving Old Air Force F-16s Capabilities Like Never Before

The Scalable Agile Beam Radar is now flying inside 72 Air National Guard F-16s and is already set to go into hundreds more Vipers.

byJoseph Trevithick, Tyler Rogoway|
A Northrop Grumman AN/APG-83 radar installed on an F-16 Viper fighter jet.
USAF / Bobbi Zapka. USAF / Bobbi Zapka


Last month, the U.S. Air Force and Northrop Grumman announced the completion of an important modernization effort that saw 72 Air National Guard Block 30 F-16C Viper fighter jets get powerful new AN/APG-83 active electronically scanned array radars. Hundreds more Air Force F-16s and other Vipers around the world are now in line to get the same radars, which are also known as Scalable Agile Beam Radars or SABRs. The War Zone subsequently had the chance to talk with Northrop Grumman's Mark Rossi, the company's director of SABR programs, about this milestone, what these radars can do, and what the future might hold for this scalable and readily upgradable sensor.

Northrop Grumman first began the development of the AN/APG-83 more than a decade ago specifically with the F-16 in mind. The company had previously integrated another AESA radar, the AN/APG-80, onto F-16E/F variants for the United Arab Emirates (UAE). When developing SABR, it leveraged its previous work on the advanced AN/APG-77 and AN/APG-81 radars for the F-22 Raptor and F-35 Joint Strike Fighter stealth fighters, respectively, when designing the SABR. The AN/APG-83's software code is around 95% "block common" with the code that runs the AN/APG-77, Northrop Grumman's Rossi told The War Zone in his interview with us on June 29.

"It’s the closest thing an F-16 can get to F-35 performance within the limitations of the jet,” Rossi added.

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Compared to the mechanically-scanned radars that are still fitted to hundreds of U.S. Air Force F-16C/Ds, as well as other Vipers around the world, any AESA would represent a major boost in capability. AESA radars, in general, offer major benefits in terms of speed of target acquisition, the range at which those threats and potential threats can be spotted, and the precision and fidelity of the subsequent tracks, even when it comes to smaller objects. They are also far more reliable, with no need for a complex apparatus to mechanically steer the dish, resulting in far more 'up time.' Better resilience to jamming is also a major plus.

More advanced AESAs, like SABR, offer other improved functionalities, as well. The AN/APG-83 increased power and precision improves its capabilities when used in a synthetic aperture mapping mode, also referred to as SAR mapping. This enables it to produce high-resolution images for target acquisition and identification purposes, as well as reconnaissance, for instance. Rossi could go not go into detail, but he did confirm that it has baked-in electronic protection and attack capabilities, as well. The War Zone has long pointed out that AESA radars have an inherent secondary potential to carry out non-kinetic attacks using highly focused beams of electromagnetic energy to disrupt or even damage the electronics within aircraft, missiles, and other systems.

"What I can tell you is that there is advanced targeting and ID capability that comes with an AESA radar and those capabilities are being integrated on the F-16 platform," Northrop Grumman's SABR Programs Director also told us when asked about the radar's ability to be used for non-cooperative target recognition (NCTR). This involves identifying and categorizing aircraft and other aerial targets, at least to some degree, based on their signatures alone.

When it comes to radars like the AN/APG-83, NCTR could mean something like matching a certain radar return signature to a specific type of aircraft, even down to the number of fan blades 'seen' on the face of the target's engine, using a comparative database. AESAs are thought to be able to do this with much higher fidelity, which could also include taking a radar image of the target to identify it.

With all this in mind, it's hardly surprising that the U.S. Air Force chose the AN/APG-83 as the new radar to upgrade the 72 Air National Guard jets back in 2017. That contract was the product of a so-called Joint Emergent Operational Need (JEON) statement from U.S. Northern Command (NORTHCOM) outlining a requirement to improve the ability of Vipers tasked with the homeland defense mission to be able to spot, track, and engage hostile cruise missiles. The F-16s in question include jets assigned to the District of Colombia Air National Guard that stand on alert to protect the particularly sensitive airspace over America's capital.

Air Force Lt. Gen. Michael Loh, the Director of the Air National Guard, at right, listens to details about the AN/APG-83 radar, as seen here install in an F-16. This picture was taken at a ceremony on June 9 to mark the completion of an upgrade program to add these radars to 72 Air National Guard jets. Northrop Grumman

Cruise missiles typically fly at low levels, which, combined with their small size, radar cross-section, and infrared signature, makes them inherently difficult for traditional mechanically scanned fighter radars to spot. Similar issues apply to small drones, another threat that is only becoming more significant, as The War Zone highlights regularly, as well as other kinds of low-flying targets.

With the older mechanically-scanned AN/APG-68 radar, “I had the ability to target up to two tracks, that’s it,” Air Force Lt. Col. Michael Trujillo, commander of the District of Columbia Air National Guard's 113th Aerospace Control Alert Detachment, one of the units now flying these updated jets, said at a ceremony on June 9 marking the completion of the radar upgrade effort. “At that point, my radar is completely saturated and has no more bandwidth. With the AESA radar, [without getting into] specific numbers, I can target more things than I can shoot."

"The F-16's previous ... radar had near-zero capability against cruise missiles," Trujillo added, according to an Air Force press release.

Air National Guard Director Lt. Gen. Loh, at right, receives a briefing on the existing AN/APG-68 radar that is still fitted to many Air Force F-16C fighter jets at the event on June 9. ANG / Staff Sgt. Sarah M. McClanahan

Defending the United States against incoming cruise missiles, as well as drones, among other air defense threats, has only become more of a pressing concern for U.S. military planners since 2017. American officials routinely point to Russian and Chinese efforts to develop and field improved cruise missile designs and more capable launch platforms, particularly modern ultra-quiet guided missile submarines, and the potential for proliferation of these capabilities, as examples of how the U.S. homeland is increasingly at risk. You can read more about this here.

The increased capabilities that SABR offers F-16 pilots don't just apply to the homeland defense mission, either. "If money wasn't a factor, we’d outfit every one of the airplanes with it just based on the fact that it is that great of a capability and is that much more reliable," Lt. Col. Trujillo had said at the event last month.

For years now already, the Air Force has been testing and evaluating just what this new radar can really do and what other tactics, techniques, and procedures might be possible as a result of its integration onto the service's F-16s. In 2020, multiple Air Force personnel explained what was being done then in interviews with The War Zone:

“Now that we have a number of these radars available, especially in operational test, we are going to work our way through all mission sets [...] all the way through air-to-air, air-to-ground, Suppression of Enemy Air Defense, Close Air Support, and how we integrate it across all types of other aircraft too,” Air Force Major Joe "Hurt" Viegas told The War Zone. Viegas is the AESA program manager from the 59th Test and Evaluation Squadron (TES) at Nellis Air Force Base, Nevada. That unit is part of the 53rd Wing’s 53rd Test Management Group, which is headquartered at Eglin Air Force Base, Florida.

“What’s somewhat unique about the overall F-16 test enterprise is that the 53rd Wing and the Test and Evaluation Group have been really trying to streamline our efforts in terms of rapidly fielding capabilities,” Viegas added. “Though this is a fielded capability, talking to the APG-83 specifically, this is being [rolled-out] in incremental phases.”


“The Air National Guard has already received this new capability to a certain degree and is already flying it. So, the significance of the most recent flight is that fielding of this capability has been quite a unique experience for the 53rd Wing. The initial task was basic integration of a new capability in the F-16 [for the] Air National Guard units that are protecting our nation from a homeland defense perspective, as quickly as possible,” the major continued. “Now the 53rd Wing has accomplished that task, which is to get capability to the warfighter as quickly as possible, the task is how can we further develop this radar and truly stress the capabilities that we can integrate it into our tactics, techniques, and procedures [TTPs], our three-dash-one [tactics manual],” added Maj Viegas. “Once we have the Guard sufficiently stocked with this capability, the Air Force is going to pivot and start fielding this to active-duty units.”

“The ANG has got it fielded as we are doing testing. The 53rd Wing is passing information to them so they can work effectively with the new capabilities as well as creating our recommendations and TTPs for when the active-duty starts getting the radar,” added Air Force Captain Michael "Echo" Arnold, the AN/APG-83 Tactics Investigation Unit Project Officer for the 85th TES.

As it stands now, Northrop Grumman's Rossi said that the U.S. Air Force currently plans to upgrade at least 512 F-16C/Ds of various blocks with the AN/APG-83 radar. The final number will, of course, be dependent on future budgets, “but we hear numbers higher than that” and “we anticipate it will be higher,” he added. This is in line with the Air Force's announcement in March that a total of 608 F-16C/Ds are slated to receive a host of upgrades in the coming years.

Installing SABR is arguably the simplest but most impactful upgrade that at least some portion of the Air Force's F-16C/D fleet is now set to receive. The AN/APG-83 was specifically designed to slot into the Viper's existing architecture, including in terms of physical mounting points and electronic connections.

Technicians prepare an Air Force F-16 to receive a new AN/APG-83 radar. Northrop Grumman

It is particularly notable that SABR's liquid cooling system – which Rossi described as being akin to a “very sophisticated car radiator” – is entirely self-contained to the radar itself. In this system, developed for Northrop Grumman by a company called PDT, the coolant is then chilled using bleed air fed in from an existing system on the Viper that was originally designed to cool the AN/APG-68.

All told, Rossi said that it only takes a day and a half to swap in a new AN/APG-83 on an F-16.

There are still some more significant physical modifications to the aircraft that come along with the new radars. Importantly, to make better use of the SAR mapping functionality, an additional screen, about the size of an iPad according to Rossi, goes into the cockpit. Northrop Grumman is not the supplier of this display and The War Zone is now seeking more information from the Air Force about that part of the complete upgrade package. It is worth noting that Israel defense contractor Elbit Systems offers a display upgrade for the F-16 series that very much fits this definition.

An F-16 cockpit mockup showing the improved Elbit Systems center display installed. Lockheed Martin

“The other traditional radar functionality, the targeting and tracking, are piped to the existing four-inch monitors that they have in the jet,” Rossi explained.

A picture of a representative F-16 cockpit showing, generally, how things would have looked inside the 72 Air National Guard jets prior to the AN/APG-83 upgrade. The two four-inch screens that Northrop Grumman's Rossi mentioned in his interview are visible on either side of the center console. Uncredited

This all raises a question about whether the Air Force might ultimately pursue a more extensive cockpit upgrade to make even better use of the data that the new radars can supply to the pilot. Improved cockpit displays, along with AN/APG-83 radars, are included in Lockheed Martin's F-16V upgrade package and are standard features on new-production Vipers. The company also pitched an entirely new cockpit configuration with a single large digital multi-function display as one feature of a proposed advanced Viper for India, dubbed the F-21, back in 2019.

Northrop Grumman is also supplying the Air Force with new AN/ALQ-253 electronic warfare suites for the F-16C/D and some of the service's Vipers are now flying with the company's AN/ASQ-236 Dragon's Eye radar pod. Rossi explained that the AN/ALQ-253 and the AN/ASQ-236 both work in different parts of the electromagnetic spectrum from the AN/APG-83 radar, allowing them to be used in a complementary fashion. Combining the AN/APQ-83 and the AN/ASQ-236, the latter of which contains another power AESA radar with side-looking SAR mapping and ground moving target indicator modes, on a single Viper would give the aircraft an extremely capable multi-functional radar capability.

An Air Force F-16C with an AN/ASQ-236 Dragon's Eye radar pod on its centerline station. Northrop Grumman

Though SABR was developed with the F-16 foremost in mind, Northrop Grumman makes clear that its potential applications aren't limited to the Viper platform. As the name makes clear, it is designed to be scalable. In particular, the antenna is made up of a number of standardized modules, all for it to be readily sized up or down depending on the space available.

Northrop Grumman submitted a variant of the AN/APG-83 as a possible radar upgrade for the Air Force's B-52H bombers, though it ultimately lost out to an AESA offering from Raytheon that will be based on that company's AN/APG-79 and AN/APG-82 radars. Northrop Grumman had previously presented SABR as a new radar option for the service's B-1 bombers, but there is no formal plan to add SABR to those aircraft at present.

"If it were to be used on the B-1, obviously we would scale that up [the antenna] to around about double the size [compared to the F-16 version] ... because of the available space in that nose," Northrop Grumman's Rossi explained, using that as a notional example of the flexibility of the radar's design.

The video below shows a fit check of the AN/APG-83 radar on an F/A-18C Hornet fighter jet, another type of aircraft it could work on.

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In the other direction, Northrop Grumman could offer more compact SABR variants or derivatives for various applications. Rossi said that versions of the radar small enough to go into certain types of unmanned aircraft or a pod "are within the realm of possibility, especially given the scalability and the technology we bring to bear. It’s all dependent upon size, weight, power, and affordability as to what that eventual technology or that actual offering would be.”

This scalability could also make SABR attractive on the export market beyond the international F-16 community, which is already admittedly large and still expanding. For instance, Northrop Grumman has offered this radar as an upgrade option for the South Korea Air Force's FA-50 Fighting Eagle light combat jets.

Pitching SABR as a way to add powerful AESA capabilities to newer light tactical jets like the FA-50, as well as other older fighters beyond the F-16, opens up a number of new markets. In addition to foreign air forces looking to upgrade, contractors who provide 'red air' aggressors to the U.S. military and other armed forces for training purposes – itself a growing business sector – are increasingly being called upon to at least replicate this kind of advanced radar capability in some way on their aircraft in order to present more realistic mock threats.

A scalable and affordable AESA that could potentially be adapted to even pre-fourth-generation fighters now flying in the red air role. Many of the contractors in this sector are even now acquiring older F-16s, which would make the upgrade process even easier. AESA radars are already flying on Top Aces F-16s and A-4s, as well as on Air USA Hawks, for instance.

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SABR is already a “fully export approved radar on the F-16 platform,” Rossi noted. "We are looking to see where else we can utilize this technology to bring other fourth-gen or fourth-gen-like platforms up to a fifth-gen-like radar capability."

Rossi said that Northrop Grumman, to date, has already received orders for around 1,000 SABRs, with 450 delivered so far. This includes the 72 Air National Guard jets, as well as upgraded F-16Vs and new-build F-16s that have been and will be delivered to at least eight other countries.

All together, SABR's future already looks bright when it comes to the F-16 platform and its scalable design means it is a real possibility that versions of this radar will eventually find their way onto other aircraft.

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