The first and second Eagle IIs—wearing ET and OT tail codes for the respective developmental and operational test units—formate on a tanker during the deployment to Alaska for Exercise Northern Edge

The first two Boeing F-15EXs to be handed over to the U.S. Air Force have recently returned to their home base at Eglin AFB, Florida, following two weeks of participation in their first large force test exercise. The aircraft—which were handed over by Boeing in March and April—were part of a sizable contingent from the 53rd Wing that deployed to Joint Base Elmendorf-Richardson (JBER) for Exercise Northern Edge 21. Located in the outskirts of Anchorage, Alaska, JBER combines the former Elmendorf AFB with the U.S. Army’s adjacent Fort Richardson.

During the exercise, the F-15EX—now officially named Eagle II—was tested in a joint force, “operationally represented” environment that included threat elements such as “red air” aggressors. Among the aims of the F-15EX’s participation was to test the performance and behaviour of the Raytheon APG-82 AESA radar, other new features such as the wide-area cockpit display, and the latest operational flight program (OFP, mission software). The F-15EX is currently loaded with the 9.1X edition.

Also undergoing an operational evaluation was the BAE Systems ALQ-250 Eagle Passive Active Warning Survivability System, better known as EPAWSS. This is an advanced digital multi-spectral warning and jamming suite with numerous antennas distributed around the airframe. The system entered low-rate initial production in March 2021 and is intended for both the F-15EX and the F-15E Strike Eagle.

During Northern Edge, large-force electronic warfare tactics were evaluated using four EPAWSS-equipped F-15Es. At the end of the exercise, a trial was conducted using an EPAWSS-equipped F-15Es escorting a Lockheed Martin F-35A, with the Eagle using its system to electronically jam threats so that the low-observable F-35 did not need to make any emissions. According to the 53rd Wing, EPAWSS performed well in both F-15E and EX, and BAE Systems demonstrated the ability to reprogram the mission data files in one to two days.

F-15C Eagles—the aircraft that the Eagle IIs will replace—were also tested with the latest OFP, edition 9.1 RR, which is similar to the 9.1X loaded in the F-15EX. The primary difference between the newest and earlier OFPs is the former's ability to use the Data Transfer Module II, which transfers data from the ground-based mission planning suite to the aircraft’s own mission computer. The DTM II offers 256GB of memory compared with 2MB for the original DTM, in turn significantly increasing the amount of mission data that can be loaded. OFP 9.1 RR is due to be issued to the operational fleet in the fall.

"Legacy" F-15Cs also completed the operational test and evaluation of the Legion Pod during Northern Edge. Carried on the centreline pylon, the Legion Pod contains an infrared search and track (IRST) sensor that allows the aircraft to detect and track targets passively. The 53rd Wing also conducted equipment trials with the General Atomics MQ-9A Reaper and OFP tests with the F-35A during the exercise.

For the Eagle II, the exercise represented an important opportunity to assess the aircraft’s new systems in an operationally relevant scenario at an early stage of the evaluation. For the first time in any new aircraft, the developmental and operational test and evaluation programs are being conducted concurrently, with an aim of rapidly fielding the aircraft. The Eglin test fleet is due to receive six more Eagle IIs in 2022/23.

Air Force planning envisages an acquisition of up to 144 Eagle IIs to replace the aging F-15C/Ds that serve with the Air National Guard from 2024-25. While the service acknowledges that the F-15EX will not be survivable against sophisticated air defences beyond the late 2020s, the aircraft can offer great value for operations in more benign air defence environments and in the homeland defence duties that the current fleet performs. Moreover, the type is viewed as a platform from which hypersonic weapons can be launched at stand-off ranges well outside high-threat areas.