The F-15E’s Eagle Passive/Active Warning Survivability System, or EPAWSS, may only just have been issued to frontline units, but BAE Systems is already working on a new iteration of the radar warning and electronic warfare suite. The new EPAWSSv2 has not yet been flown, but the manufacturer is confident that its improved processing power and ability to handle a greater number of threats — coupled with other undisclosed improvements — will be of interest to Eagle operators, including the U.S. Air Force.
Speaking to TWZ at the Air & Space Forces Association’s 2025 Warfare Symposium, Lindsay Gallagher, product line director of TacAir EW at BAE Systems, confirmed that the EPAWSSv2 is headed into its critical design review (CDR) before the end of this month but has not yet been flown. CDR is a technical review that ensures the design is mature enough to move forward into manufacturing and flight testing.
Gallagher explained that the v2 version of the system emerged as the company — together with Boeing — worked through the normal life cycle of the baseline EPAWSS. “You have obsolescence issues,” she said, “and through that process, we’ve been able to make some improvements to the system, which we are now calling EPAWSSv2.”
BAE Systems has revealed very few details about EPAWSSv2, but Gallagher confirmed that it encompasses both software and hardware changes.
“I can say that the biggest thing to note is the processing power,” Gallagher continued. “This gives us the ability to handle future threats. We’re very in tune with them, and so we’re trying to stay ahead of them.”
Compared to the baseline version, EPAWSSv2 will do “everything a bit quicker,” Gallagher said, and will also be able to handle more threats simultaneously.
In the past, BAE Systems has also suggested that future upgrades to EPAWSS could include a fiber-optic towed decoy, although it’s unclear if this is part of EPAWSSv2. Other potential enhancements that the company has alluded to in the past include “expansion of frequency coverage and cognitive electronic warfare processing.” The latter capability, which we have discussed in depth in the past, would allow the system to identify previously unknown threat signals not in the system’s threat library and potentially create a countermeasure response to them on the fly.
Gallagher noted that at least some of the software improvements that come with EPAWSSv2 could potentially be applicable to the baseline system. However, EPAWSSv2 primarily exists as a retrofit option for existing F-15 operators as well as a new-fit option for any new Eagle customers.
Presently, BAE Systems is under contract to produce the baseline EPAWSS for the U.S. Air Force, for retrofit in the F-15E and for installation in the new-build F-15EX Eagle II. The company is also building the baseline system for Japan for the F-15J Japan Super Interceptor (JSI) upgrade program.
Gallagher said that the BAE Systems is not currently talking to the U.S. Air Force about EPAWSSv2, but this is very much an aspiration. She also confirmed that the company is talking to other F-15 operators around the world who might be looking to swap out their comparatively archaic Tactical Electronic Warfare System (TEWS) and upgrade to the new EPAWSSv2.
News of EPAWSSv2 broke last month, but it had remained very low-profile until now.
In February, Rob Novotny, Boeing’s executive director for F-15 business development, took to the social media site X after a visit to BAE Systems.
“Great day in Nashua, NH, with our BAE Systems Inc. teammates talking EPAWSS and … EPAWSSv2!,” Novotny wrote.
A reference to EPAWSSv2 also surfaced last month when BAE Systems mentioned it in a job advertisement that was looking for a “senior TacAir product line test lead.”
As for the original baseline EPAWSS, also known as the AN/ALQ-250, it began to be developed around a decade ago to replace the previous AN/ALQ-135 TEWS. The earlier suite had comprised three separate subcomponents: a radar warning receiver, a countermeasures controller, and a countermeasure dispenser.
EPAWSS brings all of these functions together in the same system, which offers enhanced performance and is also integrated with the Raytheon AN/APG-82 active electronically scanned array (AESA) radar. Altogether, this provides a major boost to the F-15E’s survivability.
However, actually getting the baseline EPAWSS into operational service has taken a long time.
As we reported at the time, the first operational F-15Es equipped with EPAWSS were delivered to the 48th Fighter Wing at RAF Lakenheath in England on Jan. 15. The jets in question received the upgrade from BAE Systems in San Antonio, Texas.
“F-15 EPAWSS substantially improves pilot situational awareness with the capability to autonomously detect, identify, and locate threat systems, and then deny, degrade, and disrupt those same threats,” the Air Force said in a media release at the time, which also noted that the F-15E’s original TEWS was developed to counter Cold War-era threat systems
“It has taken us a long time to get to this point,” Brig. Gen. Jason Voorheis, program executive officer for the Air Force Life Cycle Management Center’s Fighters and Advanced Aircraft Directorate, admitted, “but this system is vital to our 21st-century fighter force structure. Not only does this system keep our most lethal fighter in the modern fight, [but] it’s an incredible deterrent in our Great Power Competition initiative.”
Designed to sample the electromagnetic spectrum, identify threats, prioritize, and allocate jamming resources against them, the baseline EPAWSS is described by its manufacturer as follows:
“Providing both offensive and defensive electronic warfare options for the pilot and aircraft, EPAWSS offers fully integrated radar warning, geolocation, situational awareness, and self-protection solutions to detect and defeat surface and airborne threats in signal-dense contested and highly contested environments. Equipped with advanced electronic countermeasures, it enables deeper penetration against modern integrated air defense systems, providing rapid response capabilities to protect the aircrew.”
In the past, TWZ has also outlined how the original EPAWSS enhances the survivability of the F-15E in an operational scenario:
“EPAWSS ensures the Strike Eagle aircrew receives timely and accurate warnings of ground-based and airborne radio-frequency (RF) threats, including their specific type and location. With this enhanced situational awareness, the crew is much better able to avoid, engage, or negate the threat. As well as alerting the crew to the threats as a defensive system, EPAWSS is able to target these threats offensively, employing countermeasures and providing targeting for effectors. The system can also be used to detect and counter incoming infrared threats, but the F-15Es do not appear to have the missile approach warning systems (MAWS) detectors installed at this time, which would help significantly in this regard.”
In particular, the nature of the air defense threat has changed hugely since TEWS, which was developed based on analog technology from the 1970s.
The kinds of high-end surface-to-air missiles (SAMs) that are proliferating now provide challenges to allied airpower that are far beyond what was in service with the primary Warsaw Pact adversary when the F-15E first entered service in the second half of the 1980s.
But even since work on the baseline EPAWSS began, there have been further advances in the air defense threat, and the electromagnetic spectrum has become increasingly contested. This is especially the case for China and Russia, widely seen as the most likely high-end adversaries in any future conflict.
Typical air defense systems now fielded by these countries include very long-range missiles, active electronically scanned array (AESA) technology, counter-jamming capabilities, and a significant degree of mobility, making them hard to target. Perhaps most significantly, these systems can be woven together, with many different sensor types now being networked across a battlespace as part of an integrated air defense system (IADS). At the same time, weapons in this class are also becoming increasingly available to lower-tier adversaries.
Clearly, the rapidly changing nature of the threat has driven BAE Systems to develop a new iteration of EPAWSS, although it’s worth noting that even the baseline system, with its open-architecture design, is intended to be rapidly updated to keep pace with the developing air defense threat.
“EPAWSS is a line update item, it’s one of those things that we just need to get the appropriate data and maintenance to load updated information,” Maj. Aaron “Kamikazze” Eshkenazi of the 85th Test and Evaluation Squadron at Eglin Air Force Base, Florida, explained to TWZ in a previous interview.
There is even the possibility that the baseline EPAWSS can be configured to meet new threats in near real-time in the future, something you can read more about here. Regardless, despite the undoubted capabilities of the baseline system, its manufacturer has determined that more can be done to protect the F-15 against new and emerging air defense threats.
In the past, we have also examined how EPAWSS might become a very valuable tool for the integration of Collaborative Combat Aircraft (CCA) drones and launched effects. The same capabilities it brings in terms of self-defense and situational awareness could be harnessed to provide the pilot with intelligence on where companion drones and launched effects should be best deployed. It’s certainly conceivable that the EPAWSSv2 will be even more applicable for this mission, thanks to its improved command over the electromagnetic battlespace.
While BAE Systems appears to have earmarked the U.S. Air Force as the target customer for EPAWSSv2, it’s worth noting that there is still some uncertainty about the future size of the F-15E fleet.
Currently, the Air Force has 218 F-15Es in its inventory. Of those aircraft, 119 are powered by Pratt & Whitney F100-PW-220 turbofan engines that produce some 23,500 pounds of thrust each. The other 99 have the significantly more powerful F100-PW-229s, each rated at 29,000 pounds of thrust. The Air Force had planned to retire all of the F-15Es with the -220 engines, which are also older overall, by the end of Fiscal Year 2028.
The National Defense Authorization Act for Fiscal Year 2024 blocked the Air Force from retiring more than 68 F-15Es before the end of Fiscal Year 2029. Previously, it was reported that 99 F-15Es (those with F100-PW-229 engines) would get EPAWSS, but the new legislation could potentially see the number increase.
However, with F-15Es upgraded with the baseline EPAWSS only starting to trickle back into the operational inventory, the F-15EX might be a more obvious target for the EPAWSSv2, especially considering this platform’s growing relevance for a future high-end conflict in the Indo-Pacific theater, where electronic warfare self-protection would be at an absolute premium. Furthermore, the capabilities offered by EPAWSSv2 would be further enhanced by the large-area display in the Eagle II.
Overall, at this early stage, the F-15EX appears to be excelling, with a glowing recent test report highlighting its performance in simulated combat, even against fifth-generation threats. On the other hand, the same report notes that new enemy long-range missiles could prove a challenge. EPAWSSv2 could also help mitigate that threat.
Currently, the F-15EX is receiving the baseline EPAWSS as it comes off the Boeing production line.
However, F-15EX fleet numbers have been reduced from the original plan for at least 144 aircraft to what is now expected to be only 98 aircraft.
With that in mind, it makes sense that BAE Systems is also targeting export F-15 operators. While Japan has signed up for the baseline EPAWSS already, other international Eagle operators could be interested in EPAWSSv2. In addition to Qatar, Saudi Arabia, Singapore, and South Korea, Israel would appear to be a prime candidate for EPAWSSv2.
As well as its existing fleet of F-15I Ra’am aircraft, which are at the forefront of its long-range strike operations, Israel has also signed up for 25 F-15IA versions, a derivative of the Advanced Eagle. Traditionally, Israel has incorporated certain locally produced electronic warfare systems in its F-15s, but the EPAWSSv2 could well be of interest. With the current security situation in the Middle East, further Israeli acquisitions of combat aircraft — potentially also F-15s — are likely.
Furthermore, Indonesia plans to buy up to 24 Advanced Eagles, and the aircraft has also recently been pitched fairly aggressively toward Poland.
Suffice it to say, the future of the F-15 looks secure, with new orders still coming in and with existing fleets set to serve for many decades to come. At the same time, the rapidly evolving nature of the air defense threat means that new electronic warfare self-protection capabilities are likely to not just be attractive but outright necessary for current and future F-15 fleets.
Contact the author: thomas@thewarzone.com