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 Pratt & WhitneyR-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 heavy equipment such as tanks and bulldozers without disassembly.
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 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.
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 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: A C-124 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: A C-124 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.
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 3 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 7 out of the 13 on board. Navigational errors were made during this air-drop mission over Antarctica.
24 June 1965: A United States Air Force Douglas C-124 Globemaster II out of 442nd Wing out of the Richards-Gebaur AFB, crashed just outside of Whiteman AFB, Missouri. The aircraft burned completely except for the wingtips and tail section. All six crewmen escaped before the aircraft was destroyed by the fire. As reported by the Kansas City Star, this was only the second crash of this type; the other occurred on 19 December 1961, killing all seven crewmen.
C-124C 53-0044 one of the last two Air National Guard C-124s retired in 1974, was located for many years on the corner of Koval Lane and Reno Avenue near McCarran International Airport in Paradise, Nevada. Numerous plans were made to use the aircraft for advertising, display, and even as a restaurant, but nothing came of this and over the years the aircraft's condition deteriorated. This aircraft was scrapped in 2001.