A disagreement on costs and scheduling is holding up a plan to upgrade Japan’s Boeing F-15J fighters to a new ‘Japanese Super Interceptor’ standard.

The US Air Force (USAF) and the Japanese Ministry of Defence confirm that active discussions are underway to resolve the issue.

F-15J Super Interceptor

Source: Boeing

An artist impression of the upgraded F-15J

“The F-15 upgrade programme is an important programme from the perspective of comprehensively enhancing air defence capability in order to secure and maintain air superiority,” says Japan’s defence ministry.

“On the other hand, while we have been working on the project since JFY2019, it has become clear through technical bilateral discussions regarding details of the modification schedule that cost increase as well as extension of schedule for the modification for the first aircraft will occur.”

Japan’s 2019 fiscal year ran from 1 April 2019 to 31 March 2020.

Japanese defence officials are speaking with the US government, US companies, and local industry “on every possible measure to reduce cost and shorten the schedule”.

According to the USAF, bi-weekly discussions between the US and Japanese sides have been taking place since January, and conversations are taking place “at multiple levels”. It expects a decision on how to proceed by the middle of the year.

The remarks follow reports in Japanese media that the deal is being held up by cost concerns. The Nikkei Asian Review and Asahi Shimbum both reported that Japanese defence minister Nobuo Kishi raised the issue with US defence secretary Lloyd Austin in March, during Austin’s visit to Japan.

In December 2020, Kyodo News, quoting sources, said that Tokyo would not provide funding of Y21.3 billion ($196 million) for F-15 upgrades in the FY2021 defence budget. Apparently rising costs associated with the upgrade were at issue.

According to the Nikkei report on 22 April, the US side initially pegged the cost of designing upgrades and buying the necessary production equipment at $745 million, but this later ballooned to $2.2 billion. Another issue the report cited is that certain components necessary for the upgrade are out of stock, requiring a costly production restart.

In October 2019, the US Department of State approved a Foreign Military Sales package valued at up to $4.5 billion to upgrade 98 F-15Js.

Boeing and Mitsubishi Heavy Industries (MHI), which built the F-15Js under licence, will be heavily involved in the programme.

In July 2020 the two companies entered a direct commercial sale deal related to the upgrade, covering retrofit drawings, ground support equipment, and technical publications related to the first two aircraft. The contract laid the foundation for MHI to develop a detailed modification plan and develop facilities and the workforce to start upgrading 98 jets in 2022. The companies have not disclosed the deal’s value.

As part of the modernisation package, Tokyo asked for 103 Raytheon APG-82(v)1 active electronically scanned array radars; 116 Boeing Advanced Display Core Processor II mission system computers; and 101 BAE Systems ALQ-239 digital electronic warfare systems to be installed in the F-15J fleet.

In addition to improved electronic warfare capabilities, the jet would get a new cockpit, new mission computer, and the ability to carry surface attack weapons, namely the Lockheed Martin AGM-158 Joint Air-to-Surface Standoff Missile.

Japan is a key ally in North Asia as the USA works to counter the rising militarism of China.

Cirium fleets data suggests that Japan has 155 in-service F-15Js with an average age of 33.1 years, and 45 in-service two-seat F-15DJs, with an average age of 30.2 years.