The US Air Force (USAF) and defence manufacturer BAE Systems have finished initial testing of a new electronic warfare countermeasures system designed for Boeing’s F-15EX fighter.

The Eagle Passive Warning Survivability System, or EPAWSS, is an electronic warfare system viewed as critical for making the fourth-generation F-15EX more survivable against modern air defences.

BAE on 2 April said the USAF had completed initial operational and test evaluations of EPAWSS, “validating the game-changing capabilities” of the system.

“EPAWSS is a leap in technology, improving the lethality and combat capabilities of the F-15E and F-15EX in contested, degraded environments against advanced threats,” says Major Bryant Baum, EPAWSS test director for the Air Force Operational Test & Evaluation Center.

Baum describes EPAWSS as having “set the baseline” for electronic warfare within the fighter community. It has been in development for more than a decade.

F-15EX in Alaska c USAF

Source: US Air Force

BAE Systems and the US Air Force experimented with AI-powered electronic warfare during recent air combat exercises in Alaska that involved one the service’s new Boeing F-15EX fighters

According to BAE, the system offers a range of instantaneous capabilities across the electromagnetic spectrum, including radar warning, geo-location, situational awareness and protection against air defences.

“The system enables freedom of manoeuvre and deeper penetration into battle spaces protected by modern integrated air defence systems,” the company says.

Onboard protection against high-end air defences in particular is a key capability for the multi-role F-15, which the USAF expects to operate alongside stealthy Lockheed Martin F-35s.

While the fifth-generation F-35 boasts improved survivability compared to older peers, the latest F-15EX offers a substantially greater weapons payload. The latest avionics incorporated in the jet, including EPAWSS, have led Boeing to refer to the F-15EX as a “4.5-generation” fighter.

Rob Novotny, Boeing’s executive director for F-15 business development and a former USAF F-15 pilot, described EPAWSS in a 2 April LinkedIn post as a “critical enabler” to the jet.

Boeing has delivered six test-variant EXs to the USAF, with the first two combat-configured aircraft nearly complete. The air force expects to turn over the first combat F-15EX to the Oregon Air National Guard’s 123rd Fighter Squadron this summer.

F-15EX arrival at Eglin AFB c USAF

Source: US Air Force

Boeing has delivered six test-configured F-15EXs to the US Air Force at Eglin AFB in Florida

BAE says it is working with F-15 manufacturer Boeing and the USAF to continue enhancing the EPAWSS technology, including through the use of cognitive electronic warfare.

“By incrementally testing and fielding cognitive EW solutions to proven systems such as EPAWSS, we are enabling tactical spectrum over-match against advanced threats that are unpredictable, evolving and adaptable,” says Chip Mosle, programme director at BAE.

Cognitive processing refers to the application of artificial intelligence or machine learning to help solve problems. In the case of electronic warfare, BAE says cognitive systems can help researchers identify patterns and develop hypotheses “that can result in broad improvements across multiple systems”.

The process can also help anticipate specific technical demands for particular missions.

“EPAWSS was designed for upgradeability and rapid capability insertion,” says Amy Nesbitt, EPAWSS programme manager at BAE. “We’re using agile software development to provide iterative upgrades to fielded EW systems – allowing our customers to defeat future electromagnetic threats.”

BAE say it is delivering EPAWSS hardware in support of new-aircraft production for the F-15EX and fleet modifications for existing F-15Es.

In recent fiscal year 2025 budget documents, the air force indicated it has reduced its F-15EX acquisition target to 98 aircraft from a previous level of 104. That number has fluctuated repeatedly in recent years.