The United States Air Force (USAF) has the largest and most powerful fleet of modern fighter jets in the world. At the same time, the fleet is gradually shrinking and aging. The fleet is expected to grow in the 2030s as older aircraft are retired, and more F-35As and F-15EXs arrive. Around that time, Collaborative Combat Aircraft (CCAs) are expected to enter service, and they could permanently change the structure of the Air Force’s fighter jet fleet.