Douglas Aircraft developed the C-124 from 1947 to 1949, from a prototype they created from a World War II–design Douglas C-74 Globemaster, and based on lessons learned during the Berlin Airlift. The aircraft was powered by four large R-4360 piston engines producing 3,800 hp (2,800 kW) each. The C-124's design featured two large clamshell doors and a hydraulically actuated ramp in the nose as well as a cargo elevator under the aft fuselage. The C-124 was capable of carrying 68,500 lb (31,100 kg) of cargo, and the 77 ft (23 m) cargo bay featured two overhead hoists, each capable of lifting 8,000 lb (3,600 kg). As a cargo hauler, it could carry tanks, guns, trucks and other heavy equipment, while in its passenger-carrying role it could carry 200 fully equipped troops on its double decks or 127 litter patients and their attendants. It was the only aircraft of its time capable of transporting fully assembled heavy equipment such as tanks and bulldozers.
The C-124 first flew on 27 November 1949, with the C-124A being delivered from May 1950. The C-124C was next, featuring more powerful engines, and an APS-42 weather radar fitted in a "thimble"-like structure on the nose. Wingtip-mounted combustion heaters were added to heat the cabin, and enable wing and tail surface deicing. The C-124As were later equipped with these improvements.
First deliveries of the 448 production aircraft began in May 1950 and continued until 1955. The C-124 was operational during the Korean War, and was also used to assist supply operations for Operation Deep Freeze in Antarctica. They performed heavy lift cargo operations for the US military worldwide, including flights to Southeast Asia, Africa and elsewhere. From 1959 to 1961 they transported Thor missiles across the Atlantic to England. The C-124 was also used extensively during the Vietnam War transporting materiel from the U.S. to Vietnam. Until the C-5A became operational, the C-124, and its sister C-133 Cargomaster were the only aircraft available that could transport very large loads.
The United States Air Force's Strategic Air Command (SAC) was the initial operator of the C-124 Globemaster, with 50 in service from 1950 through 1962. Four squadrons operated the type, consisting of the 1st, 2nd, 3rd and 4th Strategic Support Squadrons. Their primary duty was to transport nuclear weapons between air bases and to provide airlift of SAC personnel and equipment during exercises and overseas deployments.
Prototype rebuilt from a C-74 with a new fuselage and powered by four 3,500 hp R-4360-39 engines, it was later re-engined and redesignated YC-124A.
Prototype YC-124 re-engined with four 3,800 hp R-4360-35A engines.
Douglas Model 1129A, production version with four 3,500 hp R-4360-20WA engines; 204 built, most retrofitted later with nose-radar and combustion heaters in wingtip fairings.
Douglas Model 1182E was a turboprop variant of the C-124A with four Pratt & Whitney YT34-P-6 turboprops; originally proposed as a tanker, it was used for trials on the operation of turboprop aircraft. Originally designated C-127.
Douglas Model 1317, same as C-124A but with four 3,800 hp R-4360-63A engines, nose radar, wingtip combustion heaters and increased fuel capacity; 243 built.
23 March 1951: A C-124A 49-0244 flying from Loring to Mildenhall RAFB reported a fire in the cargo crates, signaling Mayday. They began jettisoning the crates and announced they were ditching. The C-124 ditched at approximately, 50°45′0″N24°03′0″W / 50.75000°N 24.05000°W / 50.75000; -24.05000 (Airy Transit) 700 miles SW of Ireland. The aircraft was intact when it touched down on the ocean. All hands exited the aircraft wearing life preservers and climbed into the inflated 5-man life rafts. The rafts were equipped with cold-weather gear, food, water, flares, and Gibson Girl hand crank emergency radios. Shortly after the men were in the life rafts, a B-29 pilot out of Ireland spotted the rafts and the flares that the men had ignited. Their location was reported and the pilot left the scene when his fuel was getting low. No other United States or Allied planes or ships made it to the ditch site for over 19 hours, until Sunday, 25 March 1951. When the ships arrived all they found were some charred crates and a partially deflated life raft. Ships and planes continued searching for the next several days but not a single body was found. The men of C-124 #49-0244 had disappeared. There is circumstantial evidence that the airmen may have been "snatched" by the Soviet Union for their intelligence value, but their fate remains a mystery. See 1951 Atlantic C-124 disappearance.
20 December 1952: C-124 50-0100 flying out of Moses Lake, Washington (Larson AFB) and taking airmen home to Texas for the holidays as part of "Operation Sleigh Ride" crashed not long after takeoff. A total of 87 airmen were killed.
18 June 1953: C-124 51-137 took off from Tachikawa Air Base in Japan. Shortly after takeoff, one of the engines failed, forcing the pilot to make an emergency landing. Due to a loss of airspeed, the pilot lost control and crashed into a melon patch, killing all seven crew and 122 passengers. At the time, it was the worst accident in aviation history.
6 April 1956: C-124 52-1078, crashed on takeoff from Travis AFB. Three of the seven crew members died in the crash. The cause of the crash was attributed to the crossing of the elevator control cables by maintenance personnel.
2 April 1957: C-124A 51-5176, crashed on final approach in Cambridge Bay, Nunavut while ferrying supplies for the construction of the DEW Line station. There were no fatalities and the aircraft was damaged beyond repair.
27 March 1958: C-124C 52-0981 collided in midair with a USAF Fairchild C-119C Flying Boxcar, 49-0195, over farmland near Bridgeport, Texas, United States, killing all 15 on the Globemaster and all three on the Flying Boxcar. The two transports crossed paths over a VHF omnidirectional range (VOR) navigational radio beacon during cruise flight under instrument flight rules in low visibility. The C-124 was on a north-north-easterly heading flying at its properly assigned altitude of 7,000 ft (2,100 m); the C-119 was on a southeasterly heading, and the crew had been instructed to fly at 6,000 ft (1,800 m), but their aircraft was not flying at this altitude when the collision occurred.
16 October 1958: C-124C 52-1017 crashed into a 3200 feet mountain near Cape Hallett Bay, killing seven of the 13 on board. Navigational errors were made during this air-drop mission over Antarctica.
24 May 1961: C-124 51-0174 crashed following takeoff from McChord Air Force Base. Eighteen of the 22 passengers and crew were killed. M/Sgt Llewellyn Morris Chilson, the second highest decorated soldier of WW2, was one of the four survivors.
28 July 1968: C-124A 51-5178 flying from Paramaribo-Zanderij to Recife, while on approach to land at Recife, flew into a 1,890 ft high hill, 50 miles (80 km) away from Recife. The ten occupants died.
26 August 1970: C-124 52-1049 crashed on approach to Cold Bay Airport, all seven on board were killed.
3 May 1972: C-124 52-1055 crashed on approach to Johan Adolf Pengel International Airport, all 11 on board were killed.