2012-01-05

YC-121F




Lockheed L-1249 Super Constellation

L-1249 Super Constellation
R7V-2/YC-121F Constellation
Lockheed R7V-2
Role Experimental military transport
National origin United States
Manufacturer Lockheed
Designer Clarence "Kelly" Johnson
First flight 1 September 1954
Introduction 10 September 1954 (Navy)
July, 1955 (Air Force)
Status Retired
Primary user United States Navy
United States Air Force
Produced 1954 and 1955 respectively
Number built 4
Developed from C-121 Constellation
L-1049 Super Constellation

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.

Design and development

On 18 August 1950, the United States Navy 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 engines. 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.

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 Navy.
YC-121F
Two R7V-2 aircraft transferred to and used by the United States Air Force 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

Citations

Bibliography

External Links

Military Accidents/incidents Records

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