F-15X Will Come In Two Variants, And No, It Won't Cost $100M Per Copy - The Drive
http://www.thedrive.com/the-war-zone/26305/f-15x-will-come-in-two-variants-and-no-it-wont-cost-100m-per-copy?iid=sr-link1

ボーイングはF-15X構想に単座のCX、複座のEXの2形式を提案？

https://cgi.2chan.net/f/src/1550244406618.jpg