McDonnell Douglas C-9

The McDonnell Douglas C-9 was a military version of the McDonnell Douglas DC-9 airliner. It was produced as the C-9A Nightingale for the United States Air Force, and the C-9B Skytrain II for the U.S. Navy and Marine Corps. The final flight of the C-9A Nightingale was in September 2005, and the C-9C was retired in September 2011. The U.S. Navy retired its last C-9B in July 2014. The two remaining C-9s in Marine service were retired in April 2017.
Design and development.
In 1966, the U.S. Air Force identified a need for an aeromedical transport aircraft and ordered C-9A Nightingale aircraft the following year. Deliveries began in 1968. The U.S. Air Force received 21 C-9A aircraft from 1968 to 1969. The C-9As were used for medical evacuation, passenger transportation, and special missions from 1968 to 2005. The C-9A were named for English social reformer Florence Nightingale (1820–1910), the founder of modern nursing.
After selecting a modified DC-9 for passenger and cargo transport, the U.S. Navy ordered its first five C-9Bs, bureau numbers 159030 thru 159034 in April 1972. However, since the Air Force was responsible for moving military personnel from place to place in the early 1970s under the Military Airlift Command, this order was canceled.
The Navy documented to Congress that their people were being given last seating on Air Force flights. Congress authorized the Navy to fly its own passenger/cargo jets shortly thereafter. The Navy ordered eight aircraft, bureau numbers 159113 thru 159120. The first four went to VR-30 at NAS Alameda in California for west coast logistical support while the second four went to VR-1 at Norfolk in Virginia for east coast support. An additional six aircraft, bureau numbers 160046 through 160051 were delivered to the Navy and the Marine Corps in 1976 with the first two aircraft being delivered to the Marine Corps at MCAS Cherry Point, the second two delivered to VR-1 at NAS Norfolk and the last two delivered to VR-30 at NAS Alameda. An additional ten more new and ten used DC-9s were purchased and converted to C-9B for the Navy. The last C-9B to fly for the Navy was retired on 28 June 2014.
Many of the Navy's C-9Bs had a higher maximum gross take-off weight of . Auxiliary fuel tanks were installed in the lower cargo hold to augment the aircraft's range to nearly for overseas missions, along with the addition of tail mounted infrared scramblers to counter heat seeking missile threats in hostile environments.
Operatonial history.
The C-9B aircraft have provided cargo and passenger transportation as well as forward deployed air logistics support for the Navy and Marine Corps. (The original "Skytrain" was the World War II era C-47 developed from the civilian DC-3.) A C-9B was also chosen by NASA for reduced gravity research, replacing the aging KC-135 Vomit Comet.
The C-9B squadron (VR) were located throughout the continental U.S., with detachments operated in Europe, and Asia.