Editing Lockheed C-121 Constellation

{{short description|Military transport version of Constellation}}
{|{{Infobox aircraft begin
  |name = C-121/R7O/R7V <br>Constellation
  |image = File:Lockheed C-121G-LO 54-4052 1501st Air Transport Group over Golden Gate Bridge.jpg
  |alt = A MATS C-121G Super Constellation flying near the Golden Gate Bridge.
  |caption = A [[Military Air Transport Service]] C-121G Super Constellation flying near the Golden Gate Bridge.
  |long caption =
 }}{{Infobox aircraft type
  |type = Military transport
  |national origin = United States
  |manufacturer = [[Lockheed Corporation]]
  |designer = 
  |first flight = March 14, 1947
  |introduction = November 12, 1948
  |retired =
  |status = Retired from military service, two operated by civilian preservation organisations
  |primary user = [[United States Air Force]] <br>[[United States Navy]]
  |more users =
  |produced = 1947 to 1958
  |number built = 332
  |developed from = [[L-749 Constellation]] <br>[[L-1049 Super Constellation]]
  |variants with their own articles = [[Lockheed L-1249 Super Constellation|R7V-2/YC-121F Constellation]] <br>[[EC-121 Warning Star]]
 }}
 |}
The '''Lockheed C-121 Constellation''' is a military transport version of the [[Lockheed Constellation]]. A total of 332 aircraft were constructed for both the [[United States Air Force]] and [[United States Navy]] for various purposes. Numerous [[Lockheed EC-121 Warning Star|airborne early warning versions]] were also constructed. The C-121 later saw service with smaller civilian operators until 1993.

==Design and development==
[[File:VC121A480614atPima.JPG|thumb|left|VC-121A 48-0614 ''Columbine'', the personal transport of General Dwight D. Eisenhower, on display at the [[Pima Air & Space Museum]]]]
[[File:Superconstellation2594.jpg|thumb|left|A C-121C aircraft, formerly USAF 54-0153, operated by the Super Constellation Flyers Association in [[Switzerland]]]]

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]] engines that powered the aircraft. After the war, the few military Constellations built (designated [[Lockheed C-69 Constellation|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, designated the [[L-749]]. It had increased fuel capacity and a more economical version of the R-3350. However, Lockheed had lost 1200 workers that year, and by 1948, production of the L-749 was at a near halt. It was then that the [[United States Air Force]] (USAF) signed a contract with Lockheed for ten L-749A aircraft designated the C-121A. The [[United States Navy]] (USN) had also placed an order for two AWACS versions of the L-749A designated the [[Lockheed EC-121 Warning Star|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]]. [[Dwight Eisenhower]] and [[General Douglas MacArthur]] 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]] until it was replaced by a [[Lockheed C-130 Hercules]] in 1971.

[[File:Lockheed Super Constellation "Southern Preservation" (VH-EAG) at Illawarra Regional Airport.jpg|thumb|The former USAF 54-0154, a C-121C operated by the Historical Aircraft Restoration Society fitted with non-standard wingtip fuel tanks, starts one of its engines]]

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]], [[Turbo-compound]] 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 [[Surveillance aircraft|observation aircraft]].

[[File:Superconstellation movie.ogv|thumb|left|A video of the Super Constellation Flyers Association's C-121C in flight.]]

After their retirement from military service, some C-121s and R7V-1s were used by civilian operators as cargo aircraft. The last operators were small [[Dominican Republic]] 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]] (FAA) banned these operators from flying into the United States due to safety concerns. One former C-121C flies today with the Historical Aircraft Restoration Society of [[Australia]], and the other flew until 2016 with the Super Constellation Flyers Association of [[Switzerland]].<ref>[http://conniesurvivors.com/L1049.htm L1049 Super Constellation - Lockheed Constellation Survivors]; Petersen, Ralph M.; ''Retrieved 8/4/11''</ref><ref>Breffort, 2006, pp.146-159.</ref> The Swiss example was put up for sale in April 2023.<ref>{{cite web | url=https://aeroin.net/um-dos-dois-ultimos-lockheed-constellation-c-121c-do-mundo-pode-nunca-mais-voar/ | title=Um dos dois últimos Lockheed Constellation C-121C do mundo pode nunca mais voar | date=7 April 2023 }}</ref>
{{Clear}}

==Variants==
{{Main|Lockheed Constellation 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.
[[File:Lockheed VC-121E Super Constellation.jpg|thumb|right|President [[Dwight D. Eisenhower]]'s personal VC-121E, called ''Columbine III''.]]
;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.
;[[Lockheed L-1249 Super Constellation|YC-121F]]
:Two former United States Navy R7V-2s with [[Pratt & Whitney T34]] [[turboprop engine]]s transferred to the United States Air Force. Designated L-1249A by Lockheed.<ref name="US Warplanes.net"/>
;C-121G
:Redesignation of 32 R7V-1 transports transferred from the USN to the Air Force.
;TC-121G
:Three C-121Gs converted to [[Airborne early warning and control|AWACS]] crew trainers.
;VC-121G
:One C-121G converted to a VIP transport.

===Navy===
[[File:Lockheed C-121J in flight 1965.jpg|thumb|C-121J in flight 1965. This aircraft called Pegasus crashed in Antarctica in 1970, thus giving its name to [[Pegasus Airfield]]]]
;R7V-1
:Initial Navy version based on the L-1049. 50 built. Originally designated '''R7O'''.
;R7V-1P
:One R7V-1 modified for Antarctic service.
;[[Lockheed L-1249 Super Constellation|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]].

<ref name="US Warplanes.net">[http://www.uswarplanes.net/c69c121.html C-69/C-121 - US Warplanes.net] {{Webarchive|url=https://web.archive.org/web/20151026103610/http://www.uswarplanes.net/c69c121.html |date=2015-10-26 }}; ''Retrieved 11/6/11''</ref><ref>Breffort, 2006, pp.166-169.</ref>

== Surviving aircraft ==
* N422NA - C-121A - Airworthy<ref>{{cite web |title=C-121A Constellation |url=https://lewisairlegends.com/lockheed-c121a-constellation-bataan |access-date=2023-05-08 |publisher=Lewis Air Legends}}</ref>
* 54-0177 - C-121C of the [[West Virginia Air National Guard|West Virginia Air Guard]] on static display at the [[Smithsonian Institution]]'s [[Steven F. Udvar-Hazy Center]] in [[Chantilly, Virginia]]<ref name="National Air and Space Museum 1943 i364">{{cite web | title=Lockheed 1049F-55-96, "Constellation" | website=National Air and Space Museum | date=1943-01-09 | url=https://airandspace.si.edu/collection-objects/lockheed-1049f-55-96-constellation/nasm_A19880371000 | access-date=2024-04-21}}</ref>

==Specifications (C-121A / L-749A)==
{{multiple image
 |total_width = 500
 | image1 = Lockheed Model 649 Constellation 3-view line drawing.png
 | alt1 = 3-view line drawing of the Lockheed Model 649 Constellation
 | caption1 = 3-view line drawing of the Lockheed Model 649 Constellation
 | image2 = Lockheed C-121C Constellation 3-view line drawing.png
 | alt2 = 3-view line drawing of the Lockheed C-121C Constellation
 | caption2 = 3-view line drawing of the Lockheed C-121C Constellation
}}

{{Aircraft specs
|ref=Lockheed Constellation:From Excalibur to Starliner,<ref>Breffort, 2006, p.175.</ref> Lockheed Constellation:From Excalibur to Starliner<ref>Breffort, 2006</ref>
|prime units?=imp
<!--
        General characteristics
-->
|crew=5
|capacity=44 Passengers (Passenger configuration)
|length ft=95
|length in=2
|length note=
|span ft=123
|span in=
|span note=
|height ft=22
|height in=5
|height note=
|wing area sqft=1650
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil='''root:''' [[NACA airfoil|NACA 23018]]; '''tip:''' [[NACA airfoil|NACA 4412]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>
|empty weight lb=61235
|empty weight note=
|gross weight lb=
|gross weight note=
|max takeoff weight lb=107000
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=4
|eng1 name=[[Wright R-3350-75 Duplex-Cyclone]]
|eng1 type=18-cylinder air-cooled radial piston engines
|eng1 hp=2500
|eng1 note=

|prop blade number=3
|prop name=constant-speed feathering propellers
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed mph=334
|max speed note=
|cruise speed mph=324
|cruise speed note=
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|minimum control speed mph=
|minimum control speed note=
|range miles=
|range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=24442
|ceiling note=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|lift to drag=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption lb/mi=
|power/mass=
|more performance=<!--<br />
*'''Take-off run:''' {{cvt||ft|0}}
*'''Take-off distance to {{cvt|50|ft|0}}:''' {{cvt||ft|0}}
*'''Landing run:''' {{cvt||ft|0}}
*'''Landing distance from {{cvt|50|ft|0}}:''' {{cvt||ft|0}}-->
|avionics=
}}

==See also==
{{aircontent
<!-- include as many lines as are appropriate. additional lines/entries with a carriage return. -->
|related=
* [[Lockheed C-69 Constellation]]
* [[Lockheed Constellation]]
* [[Lockheed EC-121 Warning Star]]
* [[Lockheed L-049 Constellation]]
* [[Lockheed L-649 Constellation]]
* [[Lockheed L-749 Constellation]]
* [[Lockheed L-1049 Super Constellation]]
* [[Lockheed L-1249 Super Constellation]] (R7V-2/YC-121F)
* [[Lockheed L-1649 Starliner]]
|similar aircraft=
* [[Boeing 377 Stratocruiser]]
* [[Boeing C-97 Stratofreighter]]
* [[Boeing KC-97 Stratofreighter]]
* [[Bristol Britannia]]
* [[Canadair CC-109 Cosmopolitan]]
* [[Convair C-131 Samaritan]]
* [[Douglas C-54 Skymaster]]
* [[Douglas DC-6|Douglas DC-6/C-118 Liftmaster]]
* [[Douglas DC-7]]
* [[Ilyushin Il-18]]
|lists=
* [[List of Lockheed aircraft]]
* [[List of Lockheed Constellation operators]]
* [[Lockheed Constellation variants]]
}}

==References==

===Notes===
{{reflist}}

===Bibliography===
{{refbegin}}
*Breffort, Dominique. ''Lockheed Constellation: from Excalibur to Starliner Civilian and Military Variants''. Paris: Histoire and Collecions, 2006. Print. {{ISBN|2-915239-62-2}}.
*Winchester, Jim. ''Lockheed Constellation'' (Classic Airliners). St Paul, MN:MBI Publishing  2001. {{ISBN|0-7603-1198-6}}.
{{refend}}

==External links==
{{Commons category}}
* [http://www.conniesurvivors.com/ Lockheed Constellation Survivors] - A website that explains information and whereabouts of surviving Constellations of all variants, including the Super Constellation.

{{Lockheed aircraft}}
{{Lockheed Constellation family}}
{{USAF transports}}
{{USN transports}}
{{USAF system codes}}

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[[Category:Lockheed aircraft|C-121]]
[[Category:1950s United States military transport aircraft]]
[[Category:Four-engined tractor aircraft]]
[[Category:Low-wing aircraft]]
[[Category:Lockheed Constellation|C-121]]
[[Category:Articles containing video clips]]
[[Category:Aircraft first flown in 1947]]
[[Category:Four-engined piston aircraft]]
[[Category:Triple-tail aircraft]]
[[Category:Aircraft with retractable tricycle landing gear]]