Lockheed C-121 Constellation

C-121/R7O/R7V Constellation

A Military Air Transport Service C-121G Super Constellation flying near the Golden Gate Bridge.
Role	Military transport
National origin	United States
Manufacturer	Lockheed
Designer	Clarence "Kelly" Johnson
First flight	March 14, 1947
Introduction	November 12, 1948
Status	Retired, two flying in airshows
Primary user	United States Air Force United States Navy
Produced	1947 to 1958
Number built	332
Developed from	L-749 Constellation L-1049 Super Constellation
Variants	R7V-2/YC-121F Constellation EC-121 Warning Star

The Lockheed C-121 Constellation was 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 AWACS versions were also constructed. The C-121 later saw service with smaller civilian operators until 1993.

Design and development

VC-121A 48-0614 Columbine, the personal transport of General Dwight D. Eisenhower, on display at the Pima Air & Space Museum

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 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 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 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 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.

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 observation aircraft.

After 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. Two former C-121Cs fly today with the Historical Aircraft Restoration Society of Australia and the Super Constellation Flyers Association of Switzerland.^[1]^[2]

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.

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.
YC-121F: Two former United States Navy R7V-2s with Pratt & Whitney T34 turboprop engines transferred to the United States Air Force. Designated L-1249A by Lockheed.^[3]
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.

^[3]^[4]

Specifications

C-121A (L-749A)

Data from Lockheed Constellation:From Excalibur to Starliner.^[5]

General characteristics

Crew: 5
Capacity: 44 Passengers (Passenger configuration)
Length: 95 ft 2 in (29.007 m)
Wingspan: 123 ft (37.49 m)
Height: 22 ft 5 in (6.8326 m)
Wing area: 1,650 sq ft (153.29 sq m)
Empty weight: 61,325 lbs (27,816.6 kg)
Max. takeoff weight: 107,000 lbs (48,534.4 kg)
Powerplant: 4 × Wright R-3350-75 radial engines, 2,500 bhp (1,866 kW) each
Propellers: 4 propeller, 1 per engine

Performance

Maximum speed: 334 mph (537.52 km/h)
Cruise speed: 324 mph (521.43 km/h)
Service ceiling: 24,442 ft (7,450 m)

R7V-1/C-121J (L-1049B)

Data from Lockheed Constellation:From Excalibur to Starliner.^[6]

General characteristics

Crew: 4
Capacity: 97-107 Passengers (Passenger configuration)
Length: 116 ft 2 in (35.408 m)
Wingspan: 123 ft (37.49 m)
Height: 24 ft 9 in (7.5438 m)
Wing area: 1,650 sq ft (153.29 sq m)
Empty weight: 72,815 lbs (33,028.3 kg)
Max. takeoff weight: 145,000 lb (65,770.9 kg)
Powerplant: 4 × Wright R-3350-34 radial engines, 3250 bhp (2,240 kW) each
Propellers: 4 propeller, 1 per engine

Performance

Maximum speed: 368 mph at 20,000 ft (592.24 km/h at 6.096 km)
Cruise speed: 259 mph at 10,000 ft (416.82 km/h at 3.048 km)
Service ceiling: 24,442 ft (7,449 m)

References

Notes

↑ L1049 Super Constellation - Lockheed Constellation Survivors; Petersen, Ralph M.; Retrieved 8/4/11
↑ Breffort, 2006, pp.146-159.
1 2 C-69/C-121 - US Warplanes.net; Retrieved 11/6/11
↑ Breffort, 2006, pp.166-169.
↑ Breffort, 2006, p.175.
↑ Breffort, 2006

Bibliography

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.

External links

Wikimedia Commons has media related to Lockheed Constellation.

Lockheed Constellation Survivors - A website that explains information and whereabouts of surviving Constellations of all variants, including the Super Constellation.

Lockheed and Lockheed Martin aircraft
Airliners and civil transports	Vega Model 8 Sirius Altair Model 9 Orion Model 10 Electra Model 12 Electra Junior Model 14 Super Electra Model 18 Lodestar Constellation L-049 L-649 L-749 L-1049 Super Constellation L-1249 Super Constellation L-1649 Starliner Saturn L-188 Electra L-402 JetStar L-100 Hercules L-1011 TriStar
Military transports	C-69 Constellation C-121 Constellation C-130 Hercules C-130J Super Hercules DC-130 HC-130 KC-130 LC-130 MC-130 C-141 Starlifter C-5 Galaxy R6V Constitution Tristar (RAF)
Attack and bombers	YP-24 Hudson XB-30 Ventura AC-130 A-4AR F-117 Have Blue FB-22
Drones/UAVs	AQM-60 Kingfisher D-21 Desert Hawk Desert Hawk III Fury MQM-105 Aquila Polecat RQ-3 Darkstar RQ-170 Sentinel
EW and reconnaissance	YO-3 EC-121 Warning Star EC-130 EC-130H WC-130 EP-3 U-2 TR-X A-12 SR-71 Blackbird SR-72
Fighters	XFM-2 YP-24 P-38 Lightning XP-49 XP-58 Chain Lightning P-80 Shooting Star XF-90 F-94 Starfire F-104 Starfighter variants YF-12 F-16 Fighting Falcon F-22 Raptor YF-22 F-35 Lightning II
Helicopters	CL-475 XH-51 AH-56 Cheyenne VH-71 Kestrel
Maritime patrol	P-2 Neptune P-3 Orion P-7 S-3 Viking CP-140 Aurora
Trainers	T-33 T2V SeaStar
Experimental	L-133 L-301 NF-104A QueSST Senior Peg Senior Prom XC-35 XF-104 XV-4 Hummingbird X-7 X-17 X-24C X-26B Frigate CL-1200 Lancer X-33 X-35 X-44 X-55 X-56 XFV
Other	Air Express Big Dipper Model 44 Excalibur Explorer Little Dipper

Lockheed Constellation family
Constellation	L-049 (C-69) L-149 L-549 (C-69C) L-649 L-749 (C-121A/B PO-1W/WV-1)
Super Constellation	L-1049 (C-121C/G/J EC-121 R7O-1/R7V-1 WV-2/WV-3) L-1249 (YC-121F * R7V-2)
Starliner	L-1649
See also List of models of the Lockheed Constellation List of Lockheed Constellation operators List of accidents and incidents involving the Lockheed Constellation

United States military transport aircraft designations, Army/Air Force and Tri-Service systems
Army/Air Force sequence (1925-1962)	C-1 C-2 C-3 C-4 C-5 C-6 C-7 C-8 C-9 C-10 C-11 C-12 C-13¹ C-14 C-15 C-16 C-17 C-18 C-19 C-20 C-21 C-22 C-23 C-24 C-25 C-26 C-27 C-28 C-29 C-30 C-31 C-32 C-33 C-34 C-35 C-36 C-37 C-38 C-39 C-40 C-41/A C-42 C-43 C-44 C-45 C-46 C-47/T C-48 C-49 C-50 C-51 C-52 C-53 C-54 C-55 C-56 C-57 C-58 C-59 C-60 C-61 C-62 C-63 C-64 C-65 C-66 C-67 C-68 C-69 C-70/A/B/C/D C-71 C-72 C-73 C-74 C-75 C-76 C-77/B-D C-78 C-79 C-80 C-81 C-82 C-83 C-84 C-85 C-86 C-87 C-88 C-89 C-90 C-91 C-92 C-93 C-94 C-95 C-96 C-97/KC-97 C-98 C-99 C-100 C-101 C-102 C-103 C-104 C-105 C-106 C-107 C-108 C-109 C-110 C-111 C-112 C-113 C-114 C-115 C-116 C-117 C-118 C-119 C-120 C-121/F C-122 C-123/A C-124 C-125 C-126 C-127 (I) C-127 (II) C-128 C-129 C-130/J C-131 C-132 C-133 C-134 C-135/KC-135 C-136 C-137 C-138¹ C-139¹ C-140 C-141 C-142
Tri-service sequence (1962-present)	C-1 C-2 C-3 C-4 C-5 C-6 C-7/B C-8 C-9 C-10 C-11 C-12 C-13¹ C-14 C-15 C-16¹ C-17 C-18 C-19 C-20A-D/F-H C-21 C-22 C-23 C-24 C-25 C-26 C-27/J C-28 C-29 C-30¹ C-31 C-32 C-33 C-34¹ C-35 C-36 C-37A/B C-38 C-39¹ C-40 C-41 C-42¹ C-43¹ C-44¹ C-45 C-46
Revived original sequence (2005-present)	C-143 C-144 C-145 C-146
Non-sequential designations	C-767 C-880
¹ Not assigned See also: AC-47 • AC-119 • AC-130 • DC-130 • EC-130 • HC-130 • KC-130 • LC-130 • MC-130 • WC-130 • CT-39 • CT-43

USN/USMC transport designations 1931–1962
Atlantic Aircraft	RA
Budd	RB
Curtiss	RC R2C⁴ R3C⁴ R4C R5C
Douglas	RD R2D R3D R4D R5D R6D
Bellanca	RE
Kinner	RK
Kreider-Reisner	RK² R2K
Martin	RM
Lockheed	RO R2O R3O R4O R5O R6O R7O-1/-2 to "V" (see below, at "Lockheed")
Stinson	RQ R2Q² R3Q
Fairchild	RQ R2Q R3Q² R4Q
Ford	RR
Sikorsky	RS
Northrop	RT
Lockheed	from "O" (see above, at "Lockheed") R6V R7V-1/-2 R8V
Convair	RY R2Y R3Y R4Y
¹ Not assigned ² Assigned to a different manufacturer's type ³ Sequence restarted ⁴ Assigned to a different class of aircraft

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