The McDonnell Douglas C-9 was a military variant of the McDonnell Douglas DC-9 commercial aircraft.
It was manufactured 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 C-9A Nightingale made its final flight in September 2005, while the C-9C was retired in September 2011.
The U.S. Navy decommissioned its last C-9B in July 2014, and the two remaining C-9s in Marine service were retired in April 2017.
Despite their official retirement, one C-9B, BuNo 161529, was observed as recently as November 2020 being utilized by the U.S. Air Force as an experimental sensor testbed.
In 1966, the United States Air Force identified a requirement for an aeromedical transport aircraft and subsequently placed an order for C-9A Nightingale aircraft in the following year.
The initial deliveries of these aircraft commenced in 1968.
Over the course of 1968 and 1969, the United States Air Force received a total of 21 C-9A aircraft.
These aircraft were utilized for medical evacuation, passenger transportation, and special missions from 1968 until 2005.
The C-9A was named in honour of Florence Nightingale, a renowned English social reformer who is widely regarded as the founder of modern nursing.
Following the selection of a modified DC-9 for passenger and cargo transport, the United States Navy placed an order for its first five C-9Bs, with bureau numbers 159030 through 159034.
However, due to the Military Airlift Command’s responsibility for moving military personnel from place to place in the early 1970s, this order was ultimately cancelled.
The Navy subsequently documented to Congress that their personnel were being given the last seating on Air Force flights, leading to the authorization for the Navy to fly its own passenger/cargo jets.
The Navy ultimately ordered eight C-9B aircraft, with bureau numbers 159113 through 159120.
The first four of these aircraft were delivered to VR-30 at NAS Alameda in California for west coast logistical support, while the second four were delivered to VR-1 at Norfolk in Virginia for east coast support.
An additional six C-9B aircraft, with bureau numbers 160046 through 160051, were delivered to the Navy and the Marine Corps in 1976.
The first two of these aircraft were delivered to the Marine Corps at MCAS Cherry Point, the second two were delivered to VR-1 at NAS Norfolk, and the last two were delivered to VR-30 at NAS Alameda.
In addition to these aircraft, the Navy purchased ten new and ten used DC-9s, which were subsequently converted to C-9B configuration.
Many of the Navy’s C-9Bs had a higher maximum gross take-off weight of 110,000 lb (50,000 kg), and auxiliary fuel tanks were installed in the lower cargo hold to augment the aircraft’s range to nearly 2,600 nautical miles (4,800 km) for overseas missions.
Tail-mounted infrared scramblers were also added to counter heat-seeking missile threats in hostile environments.
The last C-9B to fly for the Navy was retired on 28 June 2014. Variants C-9A Nightingale 21 aeromedical evacuation aircraft based on the DC-9-32CF for U.S. Air Force delivered during 1968–69. One was converted for executive transport and stationed at Chievres, Belgium; a second aircraft was converted for VIP transport by the 86th Airlift Wing at Ramstein Air Base. C-9B Skytrain II 24 convertible passenger/transport versions of the DC-9-32CF for the U.S. Navy and Marine Corps delivered from 1973 to 1976. Five more C-9s were converted from passenger-configured DC-9s. VC-9C 3 executive transport aircraft for the U.S. Air Force; these were delivered in 1976 and served until 2011. C-9K 2 aircraft for the Kuwait Air Force. Specifications Crew 5 to 8 Capacity Up to 76 pax Length 119 ft 3 in (36.35 m) Wingspan 93 ft 5 in (28.47 m) Height 27 ft 6 in (8.38 m) Wing area 1,001 sq ft (93.0 m2) Airfoil Root DSMA-433A/-434A Tip DSMA-435A/-436A Empty weight 59,700 lb (27,079 kg) Max take-off weight 110,000 lb (49,895 kg) Powerplant 2 × Pratt & Whitney JT8D-9 turbofan engines,
14,500 lbf (64 kN) thrust each Performance Maximum speed 500 kn (580 mph, 930 km/h) Maximum speed Mach 0.84 Cruise speed 485 kn (558 mph, 898 km/h) Range 2,520 nmi (2,900 mi, 4,670 km) Service ceiling 37,000 ft (11,000 m) Rate of climb 3,000 ft/min (15 m/s) + Avionics Weather radar. Sources Air Mobility Command Museum. McDonnell Douglas aircraft since 1920: Volume I-René J Francillon. Remembering an Unsung Giant, The Douglas C-133 Cargomaster and Its People-Cal Taylor. San Diego Air and Space Museum Archive. The National Museum of the U.S. Air Force.