All the Connies coming off the production lines until the end of hostilities in 1945 were bought by the military as the Army model C-69. The various civilian airlines were contracted to fly them for the military.

The very troublesome Wright R-3350 Cyclone engine was used - the same engine used in other aircraft such as the Boeing B-29 . As a result, the Connie was infected with the same maladies; engine fires, overheating, etc. At one point, Lockheed accused Wright Aeronautical of failure to properly engineer, build and inspect the engine. And rather than consider a Lockheed proposal to switch to Pratt-Whitney R-2800 engines, the Army merely stopped production of the C-69 and waited for the bugs to be worked out of the Wright Cyclone. The evolution of the Connie was slowed several times due to these problems. Another major factor was the low priority assigned to the C-69 by the Army. All this had a negative effect on development of the craft and as a result the Connie finished the war with many of its problems still to be worked out.

During its twelve year production run after the war, a total of sixteen civilian model designations were assigned, starting with the original model 49 and progressing in increments of 100 through model 1649 ("1349" was omitted for reasons of superstition). Less than one third ever got off the drawing boards. Some that did had a sub variant designation "-A", "-B" and so on. Quite a few of these sub variants also failed to go into production. Thus, the major civilian Constellation models read: 49, 649, 749A, 1049, 1049C, 1049G, 1049H and 1649A. The models 1049 were officially known as the "Super Constellation", and the 1649A as the "Starliner".

The original model 49s had their civilian interiors stripped and a combination of seats and benches installed, among other modifications, in order to be accepted by the Army as C-69s. At the end of WWII, Lockheed bought back from the Army as many as were available, and took those C-69s still on the production line and converted them back to model 49s and began delivering Connies to the airlines of the world. All model 49s were basically "dressed up" C-69s. A rash of incidents in 1945 and 1946 caused this first civilian model of the Connie to be grounded for six weeks in July/August 1946 while the government aviation experts tried to sort out the causes. It was found the aircraft had no basic flaws and it was again pronounced airworthy, though engine problems continued to plague the craft, giving rise to the "Best Tri-Motor" label.

Mechanics standby for engine startup

In fact, one Connie actually did fly as a tri-motor. On June 18, 1946, PanAm’s NC88858 had an engine fire while climbing out over the Atlantic ocean on its way to London. The fire in #4 engine became uncontrollable and eventually burned through the engine mount, causing the entire engine assembly to drop into the Atlantic. NC88858 managed to return to a small emergency field where it was landed without injuries or further mishap.

PanAm mechanics determined the aircraft would require factory repair which meant moving the Connie all the way across the continent to Burbank, California. They removed the ragged pieces of the engine nacelle, faired over the gaping hole in the wing with sheets of aluminium and flew the Connie 2,450 miles back to the Lockheed factory with three engines, and looking as if it had been manufactured that way! Many telephone calls were received by radio stations, newspapers, sheriffs offices and military bases about the strange aircraft flying over their cities.

In late 1946, the model 49 was succeeded by the model 649 Constellation. The model 649 was essentially a "beefed-up" 49, with strengthening in the internal wing structure, landing gear and brakes and a host of other improvements in passenger comfort items such as cabin heating, cooling and ventilation. The 649 was actually the first Connie to be designed without military specifications (or "interference", depending on how one looks at it). At 94,000 lbs (42,638 kg), the 649 represented a 7,500 lb (3,515 kg) increase in maximum takeoff weight and an 1,850 lb (839 kg) increase in payload over the `model 49. The 649s cruise speed was boosted to 327 mph (526 kph), or 14 mph (23 kph) faster than the model 49. Dimensions remained the same.

The model 749A was designed in response to airline needs for a longer range aircraft. It featured a fuel tank configuration allowing an extra 1,555 gallons (5,886 litres) to be carried. This increased the Connies range with full payload to 2,600 miles (4,184 km) or 310 miles (499 km) further than the 649. The 749A offered a nose-mounted weather radar option which increased overall length from 95’ 3" (29.03 m) to 97’ 4" (29.67 m). Otherwise, dimensions remained the same as the previous two models.

The 1049 Super Constellation was the first of the "Stretched Connies". It was 18’ 4" (5.6 m) longer than previous basic models. The "stretch" was accomplished by splicing an extra 9’ 2" (2.8 m) section into the body just in front, and another just aft of the wing. The 1049 also had more powerful turbo compound R-3350 engines and carried 6,550 gallons (23,974 liters) of fuel with an optional wing centre tank capable of carrying an additional 730 gallons (2,763 litres). The 1049 inaugurated non-stop Los Angeles to New York flights on October 19, 1953, though the return trip required a stop in Chicago because the trip took more than the 8 hour limit set by the pilots union. An early problem with the 1049 was again the Wright engines. The exhaust gasses flamed excessively, sometimes sending flames past the trailing edge of the wing. This tended to be more upsetting to the passengers than hazardous, but could also, in rare cases cause a loss of structural integrity in the wing. Once the problems were solved, the 1049 Super Connie went on to become an immensely `successful airliner.

When work began on the 1649 in May 1955 it was still called the Super Constellation. Shortly after, it was renamed the "Super Star Constellation" and finally the "Starliner" by Lockheed. Individual airlines had their own names for the plane with TWA referring to their 1649s as "Jetstreams". Whatever the name, the 1649 became the definitive Constellation. It featured a new, longer, narrower wing which provided for nearly double the fuel capacity of the first Connie, to 9,278 gallons (35,121 litres) and well over twice the range with maximum payload, to over 5,400 miles (8,690 km). The Starliner could reach any European capitol non-stop from any major airport in the US. It was the fastest piston engined airliner at ranges over 4,000 miles (6,437 km) ever built.

Creature comforts abounded. The engines were set farther out on the longer wings, which meant less cabin noise. Noise was further reduced with new state of the art sound deadening materials. Cabin temperature control and ventilation were perfected. Seats were fully reclining for comfort on long flights. Everything about the Starliner was impressive; it made a handsome profit for the airlines, passengers flew in total comfort, and it was practically trouble free.

But even as the new Connie was taking to the air at Burbank, the death knell was sounding 950 miles to the north.

Lockheed built a total of 856 Constellations (331 of these were for the military). An inordinate number were used to smuggle arms, aliens and drugs. More than one Connie has been anchored to the ground and used as a restaurant or cocktail lounge. General Dwight Eisenhower used a C-121A military variant as his personal craft, named "Columbine" and another after he became President, named "Columbine II". General Douglas MacArthur named his Connie the "Bataan". Connies were used extensively for spraying. They were used for secret snooping, with at least one being shot down by hostile gunfire. Constellations were used to carry thousands of tons of food to starving nations.

In the end, the Connie was brought down by the fast developing technology of the jet engine, and in particular the Boeing Model 707 . jet airliner.

Larger, faster, and more profitable aircraft have come and gone in the intervening forty-odd years, but the "Connie" remains to this day one of the most beautiful aircraft ever built.