The U.S. State Department has approved a possible $4.5 billion upgrade program for 98 of the Japan Air Self Defense Force (JASDF)’s fleet of Boeing/Mitsubishi F-15J Eagles to the Japanese Super Interceptor (JSI) standards. According to a Defense Security Cooperation Agency release, the program will see the delivery and integration of the APG-82(v)1 Active Electronically Scanned Array radar, Advanced Display Core Processor II Mission System Computer, ALQ-239 Digital Electronic Warfare System, ARC-210 digital radio, and other support systems such as the Joint Mission Planning System.
Most Japanese F-15Js were built by Mitsubishi Heavy Industries (MHI) between 1981 and 1997, and MHI will continue to be the prime direct commercial sales (DCS) contractor for the upgrade and integration, while Boeing leads the FMS elements and will act as subcontractor to MHI for DCS elements. Japan’s F-15Js have been heavily utilized in recent times on air defense missions, with an average of two scrambles daily, but it is unclear if the upgrade will also include extending the airframe hours.
The announcement comes months after the defense ministry requested 5.3 trillion yen ($50 billion) for the next fiscal year, primarily for the purchase of more F-35A/Bs. The unclear future of its domestic F-3 stealth fighter program and a relatively drawn-out introduction of the F-35A to replace more than 200 JASDF combat aircraft could have also prompted the decision to proceed with the JSI.
Around the turn of the century, the F-15Js were locally upgraded with Raytheon AN/APG-63(V)1 radar, F100-IHI-200E engines, and new ejection seats, as well as certified to carry the domestic AAM-4 (Type 99) medium-range air-to-air missile. Later, in 2009, some received upgrades for Link 16 datalink and helmet-mounted sights for the AAM-5 (Type-04) short-range missile.
The F-15s to be upgraded to JSI configuration are those that were originally delivered with the Multi-Stage Improvement Program (MSIP) modifications. Non-MSIP aircraft are due to be phased out and replaced by F-35s.