Inside America's F-15 Eagle: One of the Deadliest Fighter Jets Ever The USAF bought its last F-15 in 2001, but foreign sales have kept Boeing’s production line humming since. Here's What You Need to Know: This jet might be old, but it can still kill. For nearly three decades, the F-15 Eagle fighter was considered the undisputed king of the skies. Until the debut of its replacement, the F-22 Raptor, the F-15 was the U.S. Air Force’s frontline air superiority fighter. Even today, a modernized Eagle is still considered a formidable opponent, and manufacturer Boeing has proposed updated versions that could keep the airframe flying for the better part of a century.