With the “Model 649” introduced in October 1946, the primary change was fit of Wright R-3350-BD1 Duplex Cyclones with 2,500 hp each, permitting a further increase in MTO to 42,640 kg (94,000 lbs). The engines drove new reversible-pitch props, which shortened the landing roll. Passenger accommodations and fittings were re-thought, with climate control brought up to proper spec, and noise levels reduced considerably.
The Model 649 was such an improvement over the Model 049 that it became known as the “Gold Plate Connie”. Late production Model 649s – and all subsequent standard Connies – could be fitted with an optional “Speedpak” cargo module under the belly to boost the cargo load for short- and medium-range flights. The Speedpak was developed at the request of Eastern airlines, and was tested on a C-69; it could be loaded with up to 3,765 kg (8,300 lbs) of cargo. It looked something like an oversized bathtub, being snugged up against the belly using an electric winch system, and had sets of semi-recessed twin wheels fore and aft for rolling around on the tarmac. It caused no problems with flight handling, and cut top speed by only 19 kmh (12 mph).
Eastern was the only buyer of new-build Model 649s, obtaining a total of 14 machines. Six others were converted to L-649A standard and delivered to Chicago and Southern Air Lines. TWA had been forced to cancel orders due to a strike, and there were no other buyers. Lockheed, faced with stiff competition from the Douglas DC-6, quickly came out with the “Model 749” — which was much like the Model 649, but had additional fuel tanks in the outer wings, providing an increase in fuel capacity of 5,895 l (1,555 US gallons) — for a total fuel capacity of 23,670 l (6,245 US gallons). That permitted a range increase of 1,600 km (1,000 mi). MTO weight was raised to 46,260 kg (102,000 lbs). Engines remained the same as with the Model 649, though late-production aircraft had engines with “jet exhausts” that provided an increment of speed, if at the cost of increased noise.
Many of the airlines that had ordered the Model 649 upgraded their orders to the Model 749. 60 were built, with Lockheed retaining one for company use, the buyers of the others being KLM (13), TWA (12), Air France (9), Eastern (7), Aerlinte Eireann Teoranta of Ireland (5), Pan Am (4), QANTAS (4), Air India (3), and LAV (2).
The baseline Model 749 was followed by the “Model 749A”, which featured Curtiss paddle-blade propellers, and structural reinforcement for operation at higher MTO, raised to 48,525 kilograms (107,000 pounds). Although Constellation sales went dangerously soft for a time, the program was saved by the purchase of ten Model 749As to the US Air Force — the USAF having become an independent service in 1947 — under the designation of “C-121”, and two to the Navy with the designation of “PO-1W”. It is a minor puzzle as to why the Air Force chose to give the designation of “C-121”, instead of assigning them a designation in the “C-69” sequence; possibly USAF brass wanted to reassure Congress that the service was obtaining a “new” aircraft, and not buying an update of the C-69, which hadn’t worked out well in service.
Nine of the USAF machines were “C-121As”, which were combination passenger-cargo machines, a configuration later given the name “combi”, with a reinforced floor and an upward-hinging cargo door on the left rear fuselage. Along with cargo, they could haul 44 seated passengers, or 20 litters with medical attendants. Initially, they flew in natural metal colors, but were later painted white on top to keep them from heating up, with selective high-visibility orange markings added later. They saw extensive service during the Berlin Airlift of 1948:1949 — not flying into and out of Berlin, instead on the trans-Atlantic support route. Incidentally, Lockheed offered a combi version of the 749A to civil buyers, but got no takers.
The other C-121 – actually, the first to be delivered – was produced as a VIP transport. It was expedited on the presumption that Tom Dewey was going to win the 1948 presidential election, and that it would become his presidential VIP transport. Harry Truman scored a legendary upset victory over Dewey, with Truman preferring to stay with his DC-6, named INDEPENDENCE. The C-121B still remained a VIP transport, being used by high government officials.
The nine C-121As were quickly converted to VIP transports as well, becoming “VC-121As” — the C-121B was similarly redesignated “VC-121B”, with six of the VC-121As being upgraded to become VC-121Bs as well. One VC-121A was used by General Dwight Eisenhower from late 1950 into mid-1952 as a personal transport, supporting his role as supreme military commander in Europe; the machine was named COLUMBINE, after the state flower of Colorado, where his wife Name was from. When Eisenhower became president in 1953, he also used a VC-121A for a time, which was of course named COLUMBINE II. General Douglas MacArthur also used a VC-121A, named BATAAN, during his short stint as supreme commander during the Korean War.
After more modern VIP transports were introduced, the VC-121s mostly reverted to C-121s for cargo hauling, to be generally sold off to civil users in the late 1960s. MacArthur’s VC-121A ended up in utility use for the US National Aeronautics & Space Administration (NASA).
The two Navy PO-1W machines were strictly trial military radar platforms — the mission would be later called “airborne early warning (AEW)” — though they did retain the cargo door; first flight was in June 1949. The designation letters stood for “Patrol”, (somehow) “Lockheed”, and (radar) “Warning”. They were, of course, nicknamed “Po’ Ones”, with crews being known as “Po’ Boys”.
In 1952, the designation was changed to “WV-1”, with the letters standing for (again) “Warning” and (somehow) “Lockheed”; they would be nicknamed “Willie Victors”. In any case, they had a two-dimensional search radar in a belly radome and a height-finding radar in an elongated dome on the top of the aircraft, as well as a litter of other antennas. They also had weather radar in the nose, extending the Constellation’s length by about 90 centimeters (3 feet). The weather radar would become common in later Constellation production, and arguably enhanced the Constellation’s already good looks.
The WV-1s had a crew of 31, most of them being systems operators, with bunks and a galley to support the crew on long patrols. To compensate for the aerodynamic instabilities introduced by the radomes, the WV-1s had enlarged outer tailfins — the tailfins being raised in height by adding a “splice” above and below the tailplane. The WV-1s were eventually stripped of their radomes and warning radar gear, to be used by the US Federal Aviation Agency as support aircraft, and eventually end up in the hands of the Air Force, which may have used them for clandestine surveillance activities. They were retired in the late 1960s.
A total of 59 L-749As was sold to airlines, the big buyers being Airlines that bought the type from Lockheed included TWA, Pan Am, Eastern, TWA (26) and Air France (10), with smaller purchases by KLM (7), Chicago & Southern (6), QANTAS, Air India (4), South African (4), and Avianca of Colombia (2). A total of 131 749/749A Constellations, including the 12 military aircraft and one retained by Lockheed for company use, was built up to the end of production in 1951. Some sources give 132 L-749s, but it’s hard to figure out where that extra Connie went.
The type was highly regarded by airlines, in fact sometimes preferred by operators over later Constellation variants. Some L-749s were updated to L-749A configuration, while some L-649s were updated to a “near L-749A” configuration as “Model 649As”, with most or all of these updates later updated to full L-749A configuration.
After their first-line service, many of these machines were converted to air freighter configuration, some even being used as crop sprayers. One L-749 ended up in the hands of the French ENSA aeronautical university, being used for trials of turboprops and de-icing gear – a turboprop being mounted on a pylon above the fuselage. It made its first flight as a testbed in 1963, to be finally retired to the French Musee de l’Air in 1980.
Seven ex-Air France L-749As were acquired by SGAC, the French civil aviation directorate, in the for use as maritime search and rescue aircraft, with observation windows, along with the ability to drop life rafts and rescue kits. They were retired in 1970. Another ex-Air France L-749A was used by the president of Senegal, Leopold Senghor, as a VIP transport through the 1960s.