A highly-successful four-engine Lockheed propliner built from 1941 through 1958 in several variants, known for its distinctive streamlined fuselage and triple vertical tail.
The Lockheed Constellation, nicknamed the Connie, was a series of four-engine propliners built from 1941 through 1958; although not the first airliner to make use of cabin-pressurization (that honour goes to the boeing-307-stratoliner), it was the first pressurized airliner to see widespread use (a total of 856 were built), and also one of the fastest airliners in the world at the time, with a top speed of up to 607 kph (327 kts; 377 mph). It was instantly recognisable by its sleek, streamlined fuselage and by its three vertical-stabilizers and rudders, with one vertical tail mounted on top of the aft fuselage and one on each end of the horizontal-stabilizer (this arrangement was chosen over a single, large vertical tail in order to allow the Constellation to fit under the roofs of hangars built for smaller aircraft).
The Constellation was developed from a prior project, the Lockheed L-044 Excalibur; Lockheed's launch customer, Howard Hughes (via his airline, TWA), initially ordered 40 Excaliburs, but then demanded a range beyond what would have been possible with the Excalibur, along with a revamped cabin arrangement (having looked at a mockup of the Excalibur's cabin and not liked it). The resulting changes were so extensive as to merit a new name, and "Excalibur" was dropped in favour of "Constellation", initially as an unofficial name, but later becoming official under Army direction.
There were five civilian versions of the Constellation, plus a number of military versions. All used the Wright R-3350 radial piston-engine, unless otherwise stated.
- The first was the L-049, which first flew on 9 January 1943 as the C-69 Constellation (the United States having entered World War II in the intervening time, resulting in the production lines being taken over by the military). Its development was plagued with problems, mostly due to the still-new and still-buggy R-3350s; this, combined with Lockheed's emphasis on producing combat aircraft and with the ready availability of douglas C-47 and C-54 transports (military versions of the dc-3 and dc-4, respectively), slowed C-69 production, with only fourteen built (plus one prototype). When the war ended, the fourteen production C-69s, along with seven more still under construction, were converted to civilian L-049s; by this time, the bugs had mostly been worked out of the design, and 67 more L-049s were built in 1945-46 before the production lines switched over to the newer variants of the Constellation. A longer-range version, the L-149, was planned, but cancelled in favour of...
- ...the L-649 and L-749, which entered production in 1946, first flew in October 1946 and March 1947, and entered airline service in May and April 1947, respectively (the L-649, despite its lower version number and five-months-earlier maiden flight, did not fly paying passengers until a month after the L-749). The L-649 featured improved engines, a redesigned cabin interior, and an optional belly-mounted external cargo pod; the L-749 featured all of these plus additional fuel-tanks (for increased range) and strengthened landing-gear (to take the weight of all that extra fuel). Most airlines preferred the longer-ranged L-749 over the L-649, and only 22 L-649s were built, as compared to 119 L-749s. Twelve more L-749s went to the military, as nine C-121A and one C-121B military transport aircraft, and two WV-1 radar-equipped airborne early warning aircraft. Production of both ended in 1951, to make room for...
- ...the L-1049 Super Constellation, a stretched version which first flew in July 1951 and entered service in December of that year, its development prompted by Douglas's introduction of a new and improved version of the dc-6. In addition to being longer, the L-1049 also had an increased fuel capacity, even-stronger landing gear, larger windows, better air-conditioning, more powerful engines, a nose-mounted weather-radar system (first offered with the L-749, but only becoming common on the L-1049), and a host of various other improvements. Ironically, the prototype L-1049 was the first Constellation ever built, the single XC-69; having no pressurization system fitted, it was the only C-69 not converted to L-049 standard, and was, consequently, available for Lockheed to use as a testbed for the various improvements destined for the L-1049. The L-1049 was the first Constellation to fly nonstop revenue flights between the U.S. east and west coasts, and the first variant able to reliably fly transatlantic routes. It was also the most successful Constellation variant, with 259 being built for the civilian market before production ended in 1957, plus 320 military C-121 transports and WV-2/3/EC-121 airborne early warning aircraft.
- The last Constellation, and the only one not to bear the Constellation name, was the L-1649 Starliner, which first flew in October 1956, and entered service in June 1957. Work on what became the Starliner began in 1954-55, when Lockheed (again reacting to a new version of a Douglas airliner, in this case of the dc-7) sketched out a design for the L-1449, a further-stretched Constellation powered by four Pratt & Whitney PT2 turboprop engines. (Around this time, the PT2 was being tried out on four military L-1049s, which were temporarily redesignated the L-1249.) Unfortunately, the PT2 proved unreliable, and airlines weren't yet ready to trust turboprops, so the L-1449 was dropped, as was the even-larger L-1549, without a single example of either ever being built, in favour of the piston-engined L-1649 (although all L-1049s from 1954 onwards, as well as all L-1649s, had strengthened wings to enable conversion to higher-thrust turboprops should that have become viable). Unlike the L-1449 and L-1549, the L-1649 used the same fuselage as the L-1049, but had an all-new wing and a further-improved version of the R-3350 engine. Unlike the L-1049, the Starliner was a commercial failure, with only 44 being built from 1956 through 1958, before the Constellation production lines shut down for good.
The Constellation competed primarily with the DC-6 and DC-7, as well as (to a much lesser extent) the boeing-377-stratocruiser and bristol-britannia.
Lockheed did not produce a first-generation jet airliner to replace the Constellation (they did have a jetliner on the drawing board - the L-193 Constellation II - but it was cancelled before production ever started), instead opting for the lockheed-l188-electra turboprop airliner; Lockheed's first (and only) jetliner, the lockheed-tristar, only entered service in 1972. Lockheed was spectacularly unlucky with the Electra and TriStar, and lost millions of dollars on both projects, which caused it to bow out of the airliner market completely and focus on producing military aircraft.
The Constellation was primarily succeeded by first-generation jetliners, like the boeing-707 and Douglas dc-8.
For more information, see Wikipedia's articles on: