The $451 million contract will support the upgrade of 68 JASDF F-15Js as part of the Japan Super Interceptor program, introducing some capabilities currently being fielded on the U.S. Air Force F-15EX Eagle II.
The U.S. DoD (Department of Defense) announced on Dec. 10, 2024, that the Air Force Life Cycle Management Center awarded Boeing a contract worth $450.5 million to support the F-15 Japan Super Interceptor program, following another similar contract on Nov. 22, 2024, worth $129.2 million. This contract, which also involves FMS (Foreign Military Sales), covers the acquisition of new radars, self-protection systems and mission computer units destined to equip the Super Interceptor.
The Japan Super Interceptor (JSI) program will see Boeing modernizing 68 of Japan’s aging single seater F-15J fighter jets for Japan. The JASDF (Japan Air Self-Defence Force) currently has 155 single seater F-15J and 44 two-seater F-15DJ in service, according to World Air Forces 2024, part of which were upgraded through the Japan-Multi-Stage Improvement Program (J-MSIP).
The JSI program, which will be worked on in Boeing’s St. Louis plant, Missouri, and Eglin Air Force Base, Florida, is projected to be completed by Feb. 2030. Japan’s MHI (Mitsubishi Heavy Industries), which built under license 163 F-15Js and 36 two-seat F-15DJs for the JASDF, will carry out upgrade work locally once the upgrade package is done, continuing the country’s tradition of producing American military technologies under license to strengthen its defense capabilities.
The F-15 Japan Super Interceptor Program
Japan’s modernization program for their aging F-15 Eagle interceptors will see 68 of the existing fleet of F-15J/DJ fighters upgraded to a Japan-specific variant of the Advanced Eagle. The number of aircraft aligns with Tokyo’s plans to upgrade only around half of its F-15J fleet, with the rest being replaced with 105 F-35As as outlined in the Medium Term Defence Program.
Originally initiated in 2019 with a requirement for kits to upgrade up to 98 of the JASDF’s Eagles, the Japan Super Interceptor program briefly came to a halt in 2020 amid rising costs. This was in part due to the need for a new production line and a switch to a newer electronic warfare system.
The U.S. State Department already approved new components’ sales in 2019 through an FMS case. The Japanese government ultimately included the modernization of 68 F-15Js in the fiscal year 2022 budget, resuming the works on the program.
According to Japan’s ATLA (Acquisition, Technology, and Logistics Agency), these upgrades are crucial for national security, particularly in light of rising regional tensions, especially with China’s and North Korea’s advancements in military technology.
Although it is likely to have many similarities with the heavier, Strike Eagle-based Advanced Eagle series of F-15s, the JSI is set apart from them in the fact that it is a lighter interceptor, due to it being based off the F-15C/D air superiority variant. The JSI will largely stick to the air superiority mission that JASDF F-15s are currently tasked with, although it is expected to integrate some land-attack capabilities.
In fact, a contract to integrate Lockheed Martin’s AGM-158 JASSM was signed on Jul. 2024, as reported in a recent article here at The Aviationist. Tokyo will procure 50 AGM-158B JASSM-ER (Joint Air-to-Surface Standoff Missile-Extended Range) to strengthen its stand-off defense capability and equip the F-15 with a long-range land-strike weapon.
The upgrades
The key aspects of the JSI upgrade include the Raytheon APG-82(v)1 AESA (Active Electronically Scanned Array) radar, Honeywell’s ADCP II (Advanced Display Core Processor II), and the BAE Systems AN/ALQ-250 EPAWSS (Eagle Passive Active Warning Survivability System). These technologies are also used in the Boeing F-15EX Eagle II, the USAF’s newest fighter, and upgrade packages for F-15s operated by other countries like South Korea.
After the upgrades, which will involve only F-15J-MSIP aircraft, the Japanese Eagle will have enhanced air-to-air capabilities, with improved detection, targeting and self-defense capabilities, as well as a first taste of multirole capabilities. As already mentioned, the upgraded Eagles will be able to complement the F-35s while also acting as cruise missile carriers.
It is not yet clear if the Japan Super Interceptor’s F-15 will receive a new cockpit, since its configuration will be similar to the Eagle II. In fact, the F-15EX has a full glass cockpit equipped with a 10×19-inch touch-screen multifunction color display and JHMCS II both in the front and rear cockpit, Low Profile HUD in the front, stand-by display and dedicated engine, fuel and hydraulics display, in addition to the standard caution/warning lights, switches and Hands On Throttle-And-Stick (HOTAS) control.
Either way, the systems will be powered by the Advanced Display Core Processor II, reportedly the fastest mission computer ever installed on a fighter jet, and the Operational Flight Program Suite 9.1X, a customized variant of the Suite 9 used on the F-15C and F-15E, designed to ensure full interoperability of the new aircraft with the “legacy Eagles”.
The F-15JSI will be equipped with the new AN/APG-82(V)1 Active Electronically Scanned Array (AESA) radar. The radar, which has been developed from the APG-63(V)3 AESA radar of the F-15C and the APG-79 AESA radar of the F/A-18E/F, allows to simultaneously detect, identify and track multiple air and surface targets at longer ranges compared to mechanical radars, facilitating persistent target observation and information sharing for a better decision-making process.
The AN/ALQ-250 EPAWSS will provide full-spectrum EW capabilities, including radar warning, geolocation, situational awareness, and self-protection to the F-15. Chaff and flares capacity will be increased by 50%, with four more dispensers added in the EPAWSS fairings behind the tail fins (two for each fairing), for a total of 12 dispenser housing 360 cartridges.
EPAWSS is fully integrated with radar warning, geo-location and increased chaff and flare capability to detect and defeat surface and airborne threats in signal-dense and highly contested environments. Because of this, the system enables freedom of maneuver and deeper penetration into battlespaces protected by modern integrated air defense systems.