The Lockheed C-121 Constellation is a military transport version of the

Lockheed Constellation The Lockheed Constellation ("Connie") is a propeller-driven, four-engined airliner built by Lockheed Corporation starting in 1943. The Constellation series was the first pressurized-cabin civil airliner series to go into widespread use. Its press ...

. A total of 332 aircraft were constructed for both the

United States Air Force The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...

and

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

for various purposes. Numerous airborne early warning versions were also constructed. The C-121 later saw service with smaller civilian operators until 1993.

Design and development

Lockheed's first attempt at a military version of the Constellation airliner had been unsuccessful. This was largely due to the problems encountered by the

Wright R-3350 The Wright R-3350 Duplex-Cyclone is an American twin-row, supercharged, air-cooled, radial aircraft engine with 18 cylinders displacing nearly . Power ranged from 2,200 to over 3,700 hp (1,640 to 2,760 kW), depending on the model. ...

engines that powered the aircraft. After the war, the few military Constellations built (designated C-69) were retrofitted by Lockheed for use in the post-war airline industry as the L-049. In 1947, Lockheed unveiled a more economical Constellation. The

L-749 The Lockheed L-749 Constellation is the first Lockheed Constellation to regularly cross the Atlantic Ocean non-stop. Although similar in appearance to the L-649 before it, the L-749 had a larger fuel capacity, strengthened landing gear, and even ...

as it was known, had extra fuel capacity and a more economical version of the R-3350. However, Lockheed had lost 1200 workers that same year. By 1948, production of the L-749 was at a near halt. It was then that the

(USAF) signed a contract with Lockheed for ten L-749A aircraft designated the C-121A. The

(USN) had also placed an order for two AWACS versions of the L-749A designated the PO-1W (later WV-1). The first L-749A variants off the production line were for the US military. The C-121A versions differed from the L-749 only through having a reinforced floor to handle cargo, and a large aft loading door. Although originally intended for cargo transport duties, they were usually fitted out with 44-seat passenger transport interiors. The aircraft also consisted of a five-man crew with four relief crew members on standby. All C-121As were assigned to the Atlantic division of the Military Air Transport Service (MATS). The aircraft would later see service in the

Berlin Airlift The Berlin Blockade (24 June 1948 – 12 May 1949) was one of the first major international crises of the Cold War. During the multinational occupation of post–World War II Germany, the Soviet Union blocked the Western Allies' railway, roa ...

. Dwight Eisenhower and

General Douglas MacArthur Douglas MacArthur (26 January 18805 April 1964) was an American military leader who served as General of the Army for the United States, as well as a field marshal to the Philippine Army. He had served with distinction in World War I, was ...

both used the C-121A as their personal VIP transports. In 1950, six of the C-121A Constellations were modified as VIP transports and redesignated VC-121A. The last C-121As were retired in 1968. In August 1950, the USN ordered eleven passenger/cargo convertible versions of Lockheed's stretched L-1049B Super Constellation (which it had already ordered as the WV-2 AWACS platform). These aircraft, originally designated R7O, were delivered before the WV-2 aircraft due to the R7O being more simple to produce. The R7O (now R7V-1) first flew in 1952. The R7V-1 was able to be quickly converted between a passenger transport for 97-107 individuals or a cargo carrying transport in two hours. The Navy reduced the number of available seats to fit room for life rafts on overseas flights. 73 stretchers could also be used for medical evacuation flights. The R7V-1s saw service over the Atlantic and Pacific in squadrons VR-1 (the oldest transport squadron in the Navy), VR-7 and VR-8. Two modified R7V-1 aircraft were used on Antarctic supply missions while conducting tests and observations at the same time. One crashed on landing in 1970 and remains at the spot to the present day; the other was retired in 1971. In 1962, 32 of the 50 R7V-1 aircraft in Naval service were transferred to the Air Force, being re-designated the C-121G. The remaining 18 in Naval service were redesignated C-121J. One C-121J was later used by the

Blue Angels The Blue Angels is a flight demonstration squadron of the United States Navy.

until it was replaced by a

Lockheed C-130 Hercules The Lockheed C-130 Hercules is an American four-engine turboprop military transport aircraft designed and built by Lockheed (now Lockheed Martin). Capable of using unprepared runways for takeoffs and landings, the C-130 was originally desig ...

in 1971.

The USAF had also ordered 33 L-1049F Super Constellations in 1951, designated the C-121C. Unlike its Naval equivalent, the C-121C featured square cabin windows instead of round ones. Otherwise, the C-121C resembled the USN R7V-1 aircraft. The C-121C also featured a reinforced structure to handle turboprop engines if necessary. Other features of the C-121C included an

Auxiliary Power Unit An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115& ...

Turbo-compound A turbo-compound engine is a reciprocating engine that employs a turbine to recover energy from the exhaust gases. Instead of using that energy to drive a turbocharger as found in many high-power aircraft engines, the energy is instead sent to ...

R-3350s, and the ability to carry 75 passengers, 72 fully equipped troops, or 47 stretchers. The seats could be stored under the floor of the aircraft when needed for cargo use. The first flight of a C-121C was in 1955. Deliveries began in August 1955, with aircraft being assigned to the MATS Atlantic division. The aircraft were later in service with the Air National Guard (ANG) and were retired in 1973. Four were later refitted as VC-121C VIP aircraft, six as EC-121S TV and radio broadcast relay systems, two became EC-121C Microwave Airborne Radio Communications (MARCOM) systems and one was converted to a DC-121C

observation aircraft A surveillance aircraft is an aircraft used for surveillance. They are operated by military forces and other government agencies in roles such as intelligence gathering, battlefield surveillance, airspace surveillance, reconnaissance, observat ...

. After military service, some C-121s and R7V-1s were used by civilian operators as cargo aircraft. The last operators were small

Dominican Republic The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares with ...

cargo airlines that operated to Miami with surplus military Constellations bought from Davis-Monthan Air Force Base. The operations stopped in 1993 after the

Federal Aviation Administration The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic ...

(FAA) banned these operators from flying into the United States due to safety concerns. Two former C-121Cs fly today with the Historical Aircraft Restoration Society of Australia and the Super Constellation Flyers Association of Switzerland.

Variants

Air Force

;C-121A :Initial variant, based on the civil L-749 Constellation. Nine built. ;VC-121A :Six C-121A transports converted to VIP use. Originally designated PC-121A. ;VC-121B :Similar to the VC-121A, but with the cargo door replaced by a smaller passenger door. One built. ;C-121C :Initial variant based on the L-1049 Super Constellation. 33 built. ;VC-121C :VIP conversion of four C-121C aircraft. Lockheed VC-121E Super Constellation

;VC-121E :Ordered by the United States Navy as a R7V-1 but modified before delivery as a presidential transport for the United States Air Force. ; YC-121F :Two former United States Navy R7V-2s with

Pratt & Whitney T34 The Pratt & Whitney T34 (company designation PT2 Turbo-Wasp) was an American axial flow turboprop engine designed and built by Pratt & Whitney. Its only major application was on the Douglas C-133 Cargomaster. Design and development In 1945, t ...

turboprop engines transferred to the United States Air Force. Designated L-1249A by Lockheed. ;C-121G :Redesignation of 32 R7V-1 transports transferred from the USN to the Air Force. ;TC-121G :Three C-121Gs converted to AWACS crew trainers. ;VC-121G :One C-121G converted to a VIP transport.

Navy

;R7V-1 :Initial Navy version based on the L-1049. 50 built. Originally designated R7O. ;R7V-1P :One R7V-1 modified for Antarctic service. ; R7V-2 :Two transport aircraft similar to the YC-121F. Also designated L-1249A. Two built. ;C-121J :18 remaining R7V-1s redesignated. ;TC-121J :Electronic testbed. One converted. ;NC-121J :Four C-121J aircraft converted to television broadcasting aircraft for use in Vietnam. Project Jenny ( Blue Eagles ) VXN-8 ;VC-121J :Four C-121J aircraft converted for VIP use. One operated with the

Blue Angels The Blue Angels is a flight demonstration squadron of the United States Navy.

. C-69/C-121 - US Warplanes.net
; ''Retrieved 11/6/11''Breffort, 2006, pp.166-169.

Specifications (C-121A / L-749A)

Lockheed Model 749A Constellation silhouette

Lockheed 1049C Super Constellation silhouette

References

Notes

Bibliography

*Breffort, Dominique. ''Lockheed Constellation: from Excalibur to Starliner Civilian and Military Variants''. Paris: Histoire and Collecions, 2006. Print. . *Winchester, Jim. ''Lockheed Constellation'' (Classic Airliners). St Paul, MN:MBI Publishing 2001. .

External links

Lockheed Constellation Survivors
- A website that explains information and whereabouts of surviving Constellations of all variants, including the Super Constellation. {{USAF system codes C-121 1950s United States military transport aircraft Four-engined tractor aircraft Low-wing aircraft C-121 Articles containing video clips Aircraft first flown in 1947 Four-engined piston aircraft Triple-tail aircraft