The Boeing-built C-40A Clipper flies the Navy Unique Fleet Essential Airlift mission, providing high-priority cargo and passenger airlift for the U.S. Navy fleet worldwide. The Marines Corps uses a variant on the A for a similar mission, and the United States Air Force uses the C-40B and C-40C. Members of the C-40 family provide their operators with performance, low-cost operations and reliability for their support missions.

Boeing delivers its 737-700C aircraft from Renton, Wash., to San Antonio, where an FAA-certified modification creates the C-40.