The C-40 combines the Boeing 737-700 fuselage with the strengthened wings and landing gear of the larger and heavier 737-800. It also has auxiliary fuel tanks allowing an unrefuelled range of up to compared with for the standard 737-700.
C-40A
The C-40A Clipper provides critical logistics support to the United States Navy. Its flight deck features a flight management computer system with an integrated GPS, and is compatible with future GATM/FANS operating environment. It is outfitted with the Traffic Alert and Collision Avoidance System II, and is RVSM-capable. It also has an enhanced ground proximity warning system, predictive wind shear, head-up display and TACAN/UHF/IFF functions. First flight took place in April 2000 and the first of the C-40A aircraft entered service in April 2001. 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, all-cargo or combination configuration that can accommodate up to three cargo pallets and 70 passengers on the main deck. The Navy purchased the airplanes using standard commercial practices, ordering six of the 737-700C models. The first two of four aircraft were delivered on 21 April 2001 to Fleet Logistics Support Squadron Five Nine at the Naval Air Station/Joint Reserve Base Fort Worth, Texas, with two more aircraft following before the end of the year. The fifth and sixth aircraft were delivered in August 2002 to VR-58 at the Naval Air Station Jacksonville, Florida. Further aircraft have been delivered to VR-57 at the Naval Air Station North Island, California. The C-40A provides superior fuel efficiency, range and payload compared to the C-9B aircraft it placed. In the 2018 Marine Aviation Plan, the U.S. Marine Corps indicated that it intended to acquire two C-40A aircraft for airlift missions, replacing its Skytrain fleet. On 4 December 2018 an online notice was posted by the Marines seeking a supplier of C-40s to be delivered in 2020. The USMC Skytrains were retired in 2017 and to prepare for the transition to new aircraft, personnel from Marine Transport Squadron One were assigned to operate Navy Clippers until the arrival of their own aircraft.
C-40B
The United States Air Force selected the C-40B, a military version of the 737-700 Boeing Business Jet, to replace the aging fleet of C-137 aircraft for U.S. combatant commanders. The Air Force awarded the medium lift contract in August 2000. The 89th Airlift Wing acquired its first C-40B aircraft in December 2002. Both units are based at Andrews Air Force Base, Maryland. The 15th Airlift Wing, Hickam AFB, Hawaii, acquired its C-40B for U.S. Pacific Command in February 2003. The 86th Airlift Wing, Ramstein AB, Germany, acquired its C-40B for U.S. Air Forces in Europe in December 2004. The cabin area is equipped with a crew rest area, distinguished visitor compartment with sleep accommodations, two galleys and business class seating with worktables. The C-40B is designed to be an "office in the sky" for senior military and government leaders. The aircraft features two-way broadband data communications, including secure voice and data communication; elements include internet and network access, telephones, satellites, facsimile and copy machines. The C-40B also has a computer-based passenger data system.