The Official 439th Airlift Wing. The 439TH Airlift Wing is a unit of the Air Force Reserve Command. The wing is assigned to Westover Air Reserve Base, Mass. And operates 16 C-5B airlifters. The 439TH reports to 4TH Air Force headquartered at March ARB, California. The 439TH's mission is to provide worldwide air movement of troops, supplies, equipment and medical patients.