Lockheed L-1249 Super Constellation
Encyclopedia
The Lockheed L-1249 Super Constellation was a turbine powered version of the Lockheed Constellation
aircraft family. Built in 1954 and 1955 respectively, the aircraft were used as prototypes for possible future turbo-powered Military transport aircraft for both the United States Air Force
and United States Navy
. Both aircraft saw very short lives and the airframes were later used to build L-1049 Super Constellations
.
signed a contract for 11 military transport versions of the Lockheed L-1049. The aircraft was to be a convertable troop/cargo transport based on the model L-1049B (which was already being constructed as the PO-2W Warning Star). The R7O-1 would also feature round portholes in place of the rectangular ones on Air Force C-121C Constellations. The aircraft would enter service in the Navy's oldest transport squadron, based in Patuxent River, Maryland.
In November 1951, an idea came about to build a turbine powered version of the R7O-1. This new aircraft was designated L-1249A by Lockheed. In 1954, two R7O-1s (then designated R7V-1) were pulled off the assembly lines for conversion in to prototypes for the new L-1249A. The landing gear was strengthened along with the fuselage and wings of the aircraft. Extra fuel tanks were also added on the wingtips of the two aircraft, increasing the fuel capacity to 7,360 gallons. The wings were also shortened from 123 ft 9 in (37.719 m) to 117 ft 7 in (35.84 m). Last but not least, two Pratt & Whitney YT-34-P-12A turboprop engines, rated at 5,500 bhp (4,100 kW) each, were installed in place of the usual Wright R-3350 Duplex-Cyclone radial engine
s. The new aircraft was designated R7V-2, and first flew on 1 September 1954. The R7V-2 reached 412 mph (663.05 km/h) making it the fastest tranpsort aircraft in the world at the time. The two R7V-2 aircraft were delivered to the Navy on 10 September the same year.
In 1953, the United States Air Force
became interested in the L-1249A project. Two R7V-1 aircraft were again taken off the production lines in 1955 and converted to L-1249A standards. These aircraft, designated YC-121F, were identical to the R7V-2s in service with the Navy. The YC-121F was able to carry a crew of four and 87-106 passengers, depending on the conditions of the flight (transoceanic and overland). Lockheed also had a planned medical evacuation version, able to carry 73 Stretcher cases and a crew of 15. The R7V-2 and YC-121F both had a cabin similar to the R7V-1 and C-121C. The first YC-121F flew on 5 April 1955 and was delivered to the Air Force in July 1955. The aircraft were put in to service with the Test Squadron of the 1700th Air Transport Group
of the Military Air Transport Service
, based at Kelly Air Force Base
, Texas
. Other aircraft in the Squadron included the YC-97J Stratofreighter and YC-124B Globemaster II, both also powered by T34 engines. After undergoing brief testing, the YC-121F was used on regular basis transportation flights. One on occasion, Lockheed test pilot Roy Wimmer managed to reach a top speed of 479 mph (770.88 km/h) in the YC-121F during a 20 degree dive.
Lockheed proposed an airliner version of the L-1249A, designated L-1249B. This would have the fuselage of the L-1049E and be equipped with extra fuel tanks on the wingtips as well as two 5,500 hp (4,100 kW) Pratt & Whitney PT-2F1 turboprops (the planned civilian version of the YT-34). This would allow the L-1249B to fly from London
to Moscow
in seven hours, from Honolulu
to the U.S. west coast in six hours, or London to New York City via Gander, Newfoundland in nine hours. The L-1249B was to have a top speed of 415 mph (668 km/h) and a range of at least 4,125 miles (6,639 km). In the end, airlines were still in favor of the piston engined airliners, so no L-1249B was ever constructed.
In the end, no more than four airframes were constructed. Also, the complex T34 turboprop was only used in large operations with the 50 examples of the Douglas C-133 Cargomaster. When the L-1249A finished service with both the Navy and Air Force, the four existing airframes were scrapped and recycled to build civilian L-1049 Super Constellations. For example, the two YC-121F fuselages were attached to the wings engines and tails of two used L-1049G aircraft to make two L-1049H freighters for the Flying Tiger Line
. One R7V-2, before being torn apart, was used for testing the Allison 501D turboprops for the development of the Lockheed L-188 Electra
(earning the nickname "Elation" during testing).
YC-121F
L-1249B
Bibliography
Lockheed Constellation
The Lockheed Constellation was a propeller-driven airliner powered by four 18-cylinder radial Wright R-3350 engines. It was built by Lockheed between 1943 and 1958 at its Burbank, California, USA, facility. A total of 856 aircraft were produced in numerous models, all distinguished by a...
aircraft family. Built in 1954 and 1955 respectively, the aircraft were used as prototypes for possible future turbo-powered Military transport aircraft for both the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
and United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
. Both aircraft saw very short lives and the airframes were later used to build L-1049 Super Constellations
Lockheed L-1049 Super Constellation
The Lockheed L-1049 Super Constellation is an aircraft in the Lockheed Constellation aircraft line. The aircraft was Lockheed's response to the successful Douglas DC-6 airliner and first flew in 1950...
.
Design and development
On 18 August 1950, the United States NavyUnited States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
signed a contract for 11 military transport versions of the Lockheed L-1049. The aircraft was to be a convertable troop/cargo transport based on the model L-1049B (which was already being constructed as the PO-2W Warning Star). The R7O-1 would also feature round portholes in place of the rectangular ones on Air Force C-121C Constellations. The aircraft would enter service in the Navy's oldest transport squadron, based in Patuxent River, Maryland.
In November 1951, an idea came about to build a turbine powered version of the R7O-1. This new aircraft was designated L-1249A by Lockheed. In 1954, two R7O-1s (then designated R7V-1) were pulled off the assembly lines for conversion in to prototypes for the new L-1249A. The landing gear was strengthened along with the fuselage and wings of the aircraft. Extra fuel tanks were also added on the wingtips of the two aircraft, increasing the fuel capacity to 7,360 gallons. The wings were also shortened from 123 ft 9 in (37.719 m) to 117 ft 7 in (35.84 m). Last but not least, two Pratt & Whitney YT-34-P-12A turboprop engines, rated at 5,500 bhp (4,100 kW) each, were installed in place of the usual Wright R-3350 Duplex-Cyclone radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s. The new aircraft was designated R7V-2, and first flew on 1 September 1954. The R7V-2 reached 412 mph (663.05 km/h) making it the fastest tranpsort aircraft in the world at the time. The two R7V-2 aircraft were delivered to the Navy on 10 September the same year.
In 1953, the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
became interested in the L-1249A project. Two R7V-1 aircraft were again taken off the production lines in 1955 and converted to L-1249A standards. These aircraft, designated YC-121F, were identical to the R7V-2s in service with the Navy. The YC-121F was able to carry a crew of four and 87-106 passengers, depending on the conditions of the flight (transoceanic and overland). Lockheed also had a planned medical evacuation version, able to carry 73 Stretcher cases and a crew of 15. The R7V-2 and YC-121F both had a cabin similar to the R7V-1 and C-121C. The first YC-121F flew on 5 April 1955 and was delivered to the Air Force in July 1955. The aircraft were put in to service with the Test Squadron of the 1700th Air Transport Group
1700th Air Transport Group
The 1700th Air Transport Group is an inactive United States Air Force unit. Its last was assigned to the Continental Division, Military Air Transport Service, stationed at Kelly Air Force Base, Texas...
of the Military Air Transport Service
Military Air Transport Service
The Military Air Transport Service is an inactive Department of Defense Unified Command. Activated on 1 June 1948, MATS was a consolidation of the United States Navy Naval Air Transport Service and the United States Air Force Air Transport Command into a single, joint, unified command...
, based at Kelly Air Force Base
Kelly Air Force Base
Kelly Field Annex and is a former United States Air Force facility located in San Antonio, Texas. In 2001, the runway and land west of the runway became "Kelly Field Annex" and control of it was transferred to the adjacent Lackland Air Force Base, part of Joint Base San Antonio...
, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. Other aircraft in the Squadron included the YC-97J Stratofreighter and YC-124B Globemaster II, both also powered by T34 engines. After undergoing brief testing, the YC-121F was used on regular basis transportation flights. One on occasion, Lockheed test pilot Roy Wimmer managed to reach a top speed of 479 mph (770.88 km/h) in the YC-121F during a 20 degree dive.
Lockheed proposed an airliner version of the L-1249A, designated L-1249B. This would have the fuselage of the L-1049E and be equipped with extra fuel tanks on the wingtips as well as two 5,500 hp (4,100 kW) Pratt & Whitney PT-2F1 turboprops (the planned civilian version of the YT-34). This would allow the L-1249B to fly from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...
in seven hours, from Honolulu
Honolulu, Hawaii
Honolulu is the capital and the most populous city of the U.S. state of Hawaii. Honolulu is the southernmost major U.S. city. Although the name "Honolulu" refers to the urban area on the southeastern shore of the island of Oahu, the city and county government are consolidated as the City and...
to the U.S. west coast in six hours, or London to New York City via Gander, Newfoundland in nine hours. The L-1249B was to have a top speed of 415 mph (668 km/h) and a range of at least 4,125 miles (6,639 km). In the end, airlines were still in favor of the piston engined airliners, so no L-1249B was ever constructed.
In the end, no more than four airframes were constructed. Also, the complex T34 turboprop was only used in large operations with the 50 examples of the Douglas C-133 Cargomaster. When the L-1249A finished service with both the Navy and Air Force, the four existing airframes were scrapped and recycled to build civilian L-1049 Super Constellations. For example, the two YC-121F fuselages were attached to the wings engines and tails of two used L-1049G aircraft to make two L-1049H freighters for the Flying Tiger Line
Flying Tiger Line
Flying Tiger Line, also known as Flying Tigers, was the first scheduled cargo airline in the United States and a major military charter operator during the Cold War era for both cargo and personnel .- History :...
. One R7V-2, before being torn apart, was used for testing the Allison 501D turboprops for the development of the Lockheed L-188 Electra
Lockheed L-188 Electra
The Lockheed Model 188 Electra is an American turboprop airliner built by Lockheed. First flying in 1957, it was the first large turboprop airliner produced in the United States. Initial sales were good, but after two fatal crashes which prompted an expensive modification program to fix a design...
(earning the nickname "Elation" during testing).
Variants
Military Designations
R7V-2- Originally designated R7O-2. Four converted R7V-1 aircraft (BuNos 131630-131631, 131660-131661) with a shorter wingspan and powered by four Pratt & Whitney YT-34-P12A turboprop engines. Used by the United States NavyUnited States NavyThe United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
.
YC-121F
- Two R7V-2 aircraft transferred to and used by the United States Air ForceUnited States Air ForceThe United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
and powered by four T34-P-6 turboprops.
Civillian/Company Designations
L-1249A- Company designation for the R7V-2 and YC-121F.
L-1249B
- Planned airliner based on the L-1249A, with an L-1049E based fuselage and Pratt & Whitney PT2F-1 turboprops (civilian version of the YT-34). None built.
Specifications (YC-121F)
See also
Sources
CitationsBibliography
- Breffort, Dominique. Lockheed Constellation: from Excalibur to Starliner Civilian and Military Variants. Paris: Histoire and Collecions, 2006. Print. ISBN 2915239622
External Links
- The Characteristics Summary and the Standard Aircraft Characteristics of the R7V-2 from Alternate Wars.com
- Characteristics Summary for the YC-121F, available on alternatewars.com
- Lockheed Constellation Survivors - A website that explains information and whereabouts of surviving Constellations of all variants. The fates of the four L-1249 aircraft are mentioned in the Q&A section of the website.
- 1000 Aircraft Photos - Lockheed 1249A-94-75 YC-121F Constellation - A photograph of the second YC-121F delivered to the U.S. Air Force. Below the image is a small detailed summary on the L-1249A.
- Zoggavia - Lockheed 1951-1960 - A link which includes photographs and brief summaries of Lockheed aircraft from 1951 to 1960, including the YC-121F and R7V-2.