The U.S. Navy Reserve was the first customer for the newest member of the Boeing 737-700C Next-Generation family. The Clipper was ordered by the U.S. Navy to replace its fleet of aging C-9B Skytrain IIs. The C-40A is the first new logistics aircraft in 17 years to join the U.S. Navy Reserve. The Navy Reserve provides all of the Navy's medium and heavy airlift capabilities. The Clipper meets or exceeds international noise and environmental requirements, which the fleet of Naval Reserve C-9s did not. It is also more fuel-efficient and offers increased range and payload capabilities. The Clipper is certified to operate in an all-passenger (121 passengers), all-cargo or combination ("combi") configuration that can accommodate up to three cargo pallets and 70 passengers on the main deck.