short-field landings. The increasing importance of strategic vs. tactical missions eventually led to the end of the AMST program in December 1979. Then, in November 1979, the C-X Task Force formed to develop the required strategic aircraft with tactical capability. The C-X program selected a proposal for an enlarged and upgraded YC-15 and one prototype (72-1875) was reclaimed from the Pima Air & Space Museum refurbished and returned to Edwards AFB, CA for flight testing that was later incorporated into development of the C-17 Globemaster III. References Kennedy, Betty R. Globemaster III: Acquiring the C-17, Air Mobility Command Office of History, 2004. Norton, Bill. Boeing C-17 Globemaster III, Specialty Press, 2001. . External links Edwards AFB: A Pair of Most Unusual Transports (Internet Archive) History of the AMST project on GlobalSecurity.org AMST Prototypes: Boeing YC-14 and McDonnell Douglas YC-15 on theaviationzone.com AMST vs. C-130 comparison Boeing C-XX all-cargo carrier (concept) Military transport aircraft Military aircraft procurement programs of the United States Cancelled military aircraft projects of the United States