As new adversary fifth-generation stealth fighters such as the Russian Sukhoi Su-57 PAK-FA and the Chengdu J-20 emerge from development, the United States Navy is working on developing and fielding new capabilities that will allow naval aviators to defeat the threat.

The key is Boeing’s new F/A-18E/F Block III Super Hornet—and the advanced new technologies incorporated into the jet—combined with the upgraded capabilities of the Boeing/Lockheed Martin Infrared Search and Track (IRST) Block II pod. By upgrading older platforms with new datalinks, massively increased processing power and new sensors, Boeing and the Navy have found a way to negate the threat to carrier aviation from emerging low observable threat platforms. “IRST—infrared search and track long range counter-stealth targeting technology,” Dan Gillian, Boeing’s vice president of F/A-18 & EA-18 Programs for Strike, Surveillance and Mobility, told reporters on May 23. “This is filling a gap for the carrier air wing, bringing that sensor back to the carrier air wing in a networked kind of way.”

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Boeing is well into the development of the new Block III Super Hornet, Gillian said. The production of the first six new build Block III jets is expected to start in fiscal year 2018 with production transitioning fully onto the new variant in 2019. The fleet should start receiving their first operational Block III aircraft in 2020 and the jet should deploy onboard a carrier by 2022, Gillian said.

Meanwhile, starting in 2022, Boeing will start to upgrade older Block II aircraft into the Block III configuration as part of the Navy’s Service Life Modification program. Eventually, the entire Navy Super Hornet fleet will be brought up to the Block III standard. Altogether, the Navy intends to modify more than 500 Block II Super Hornets into the Block III configuration and build 116 new Block III aircraft by 2024, however, the fleet could be operating a mix of Block II and III aircraft for quite some time into the 2020s given the program’s ambitious schedule. Together with the Lockheed Martin F-35C, the Block III Super Hornet will remain the backbone of the Navy’s frontline strike fighter fleet for decades to come.

The Block III Super Hornet aircraft incorporates a host of new capabilities ranging from an upgraded 9000-hour airframe, new range-extending conformal fuel tanks (~120 nautical mile boost in mission radius), radar cross-section improvements, enhanced satellite communications, to a new advanced cockpit display system. But the two most significant developments are the addition of the Distributed Targeting Processor-Networked (DTP-N) computer—which exponentially increases the Super Hornet’s processing power—and the high-speed, high-bandwidth, high-throughput anti-jam Internet Protocol-based Tactical Targeting Network Technology (TTNT) datalink.

When the power of the DTP-N and TTNT are combined with the IRST Block II sensor, the resulting capability allows for a pair of Block III Super Hornets to engage enemy stealth aircraft from well beyond visual range—far beyond the range of the jets’ Raytheon AN/APG-79 active electronically scanned array (AESA) radar.

As Gillian explained, while the IRST Block II is not part of the Block III program, the advanced processing, datalinks and sensor-fused display onboard the new Super Hornet variant enable the new capabilities envisioned for the new sensor.  As Bob Kornegay, Boeing’s capture team leader for domestic F/A-18E/F and EA-18G programs, explains, the critical Common Tactical Picture sensor-fused display will be enabled by the Block III aircraft’s powerful high speed anti-jam TTNT datalink and the sheer computing power of the DTP-N processor, which is needed to run the complex algorithms that make multi-aircraft data-fusion possible.

What makes the new IRST particularly capable is that it operates in the long wave infrared band, which allows the sensor to passively detect and track targets well beyond the range of the APG-79 radar. “It can see a hot airplane,” Kornegay said. “It has much longer range—it is a long wave long range IRST—so it can see much further than radar can.”

Boeing has taken into account the traditional limitations of infrared sensors, where performance can be severely degraded by inclement weather—particular clouds and atmospheric moisture—when testing the new sensor, Kornegay said. The new IRST is so advanced that it still consistently generates tracks at extended ranges even taking into account inclement weather and other factors. “We’re not assuming a clear day,” Kornegay said.

A single Block III Super Hornet equipped with a Block II IRST would be able to detect and track a low observable enemy aircraft such a J-20 or Su-57 at extended ranges. However, that lone Block III jet would not be able to generate a weapons quality track on that enemy stealth aircraft because an infrared sensor cannot independently generate range data.

“If you have a single IRST ship, with your IRST, you can get a line of bearing—it’s going to see a hot spot out there, what direction it’s in, but it doesn’t have the distance. You don’t have a weapons quality track,” Kornegay said. “Now if you combine two aircraft, the fusion algorithm, now you have lines of bearing from two different sources. Where those two sources cross, the algorithm is going to compute a weapons quality track on that aircraft. So that’s a huge advantage for the warfighter to see that long before you’re in the enemy’s radar range.”

Indeed, as Gillian noted, the IRST is explicitly a counter-stealth development designed to defeat enemy low observable aircraft. “If the enemy aircraft coming at you is low radar cross section—low radar signature—it is still emitting a heat signature,” Kornegay said. “So it helps us as the enemies are starting to develop their stealth aircraft. It helps us to defeat that by moving outside of that X-band range.”

The U.S. Navy demonstrated the capability of the networked IRST, DTP-N and TTNT during the service’s Fleet Exercise 2017 onboard a pair of specially modified Super Hornets. The feedback from the naval aviators who flew during the exercise was that the capability was “eye-watering”—they were developing weapons quality tracks on targets that they had never seen before, Kornegay said.

Capt. David ‘DW’ Kindley, the Naval Air Systems Command’s (NAVAIR) F/A-18 and EA-18G Program Office (PMA-265) program manager, said that he could not talk about the specific types of platforms that the Navy practiced against during Fleet Exercise 2017. “Can’t talk about specific experiments and specific threats, but IRST is designed to be a long-range counter-stealth technology,” Kindley said.

Indeed, the Block I IRST was so effective during Fleet Exercise 2017 and other tests that the U.S. Air Force—which has traditionally been the Pentagon’s leading proponent of stealth technology—is planning on buying 130 of the pods for its Boeing F-15 Eagle fleet as a counter to emerging enemy stealth aircraft. Thus, ironically, the best counter to fifth-generation threats is a fourth-generation fighter equipped with new sensors and networking capability.

Dave Majumdar is the defense editor for The National Interest. You can follow him on Twitter: @davemajumdar.