What is a legacy system? The key is relevance, not age. By: Thomas G. Mahnken and Christopher Bassler February 22 Rows of F-4 Phantoms and T-38 Talons line the grounds of the 309th Aerospace Maintenance and Regeneration Group, also known as the "Boneyard," at Davis-Monthan Air Force Base, Ariz. (Tech. Sgt. Bennie J. Davis III/U.S. Air Force) Two decades into the 21st century, far too much of the U.S. military consists of systems that were designed and initially produced at the end of the last century, and in many cases back to the late Cold War. While the United States and it...