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Turboprop YC-124B Globemaster Didn’t Quite Make The Grade

Was it a brilliant idea or brilliant mistake? Was it an aircraft that should have been pressed into service or only an idea that might have been?

On Dec. 7, 1950, while the nation became aware that China had entered the Korean War, the U.S. Air Force and Douglas Aircraft Co. announced development of a turboprop version of the C-124A Globemaster II, the largest and longest-legged transport aircraft then in service. “With horsepower almost doubled, the improved model will fly faster, carry more payload and have greater range than current models,” the announcement said.

“With horsepower almost doubled, the improved model will fly faster, carry more payload and have greater range than current models,” the announcement said.

The piston-powered Globemaster II was the big transport of its era. In today’s parlance, it would be a strategic airlifter. Douglas manufactured 448 Globemasters in Long Beach, Calif., between 1949 and 1954.

Pilots and flight crews liked the C-124 and were being affectionate when they nicknamed it “Old Shaky.” The nickname derived in part from the vibration caused by the Globemaster’s four 3,500-horsepower Pratt & Whitney R-4360 Wasp Major reciprocating engines.

C-124A Globemaster II

The C-124A Globemaster II was a the U.S. Air Force’s strategic airlifter for the Korean War-era, but suffered from engine vibration and reliability issues. The turboprop YC-124B was the hoped-for solution. U.S. Air Force photo

The C-124 was less popular among troops during the Korea era after a trio of fatal crashes, including the June 18, 1953 loss of a Globemaster II at Tachikawa Air Base, Japan, that killed 129 airmen and was, at that time, the worst air crash in history.

Whether the C-124 should have been improved upon, or simply left behind in the dust, remains an open question.

 

Turbine Transport

The hoped-for solution to vibration and reliability issues was a powerplant of four 5,550-shaft horsepower (shp) Pratt & Whitney YT34-P-1 turboprop engines, driving three-bladed Curtiss-Wright propellers designed specifically for gas turbine operation. But this next-generation Globemaster II, dubbed the YC-124B, was more than three years in development, and the passage of that amount of time may have been critical.

The YC-124B (51-072, c/n 43406) belatedly made its first flight on Feb. 2, 1954, with pilot Frank Boyer, co-pilot Frank Aitkin, and flight engineer Duncan Hall aboard for the 60-minute journey from the Long Beach, Calif., factory to Edwards Air Force Base.

YC-124B

The four Pratt & Whitney YT34-P-1 turboprop engines on the YC-124B developed 5500 shp each. Robert F. Dorr Collection

During its gestation, the new aircraft was contemplated as filling a dual-role, tanker-transport mission and identified in some documents as the YKC-124B.

The Korea armistice of July 27, 1953 and, more importantly, the prospect of new transports designed from the ground up, dampened prospects for an operational version of the YC-124B.

Soon after the maiden flight, Douglas aerodynamics engineer Donald L. Elder wrote in a company paper that the YC-124B “is a true forerunner of the military turboprop transports of the future.” Elder also wrote: “The design of the YC-124B was carried out with the firm conviction that the turboprop was the best choice of power for a large cargo aircraft. This pioneering of the use of a new type of aircraft engine was with some reservation, for at the inception of the design no firm set of requirements had been reached for a more advanced type of cargo carrier than the C-124A.”

Douglas officials knew that a Lockheed engineering team under Willis Hawkins was developing a turboprop transport in the tactical weight category. The YC-130 Hercules made its first flight on Aug. 23, 1954. If any turboprop transport was the wave of the future, it was the “Herk.”

YC-124B

Despite never winning a production contract, the YC-124B proved that the turboprop was an ideal engine for large cargo aircraft. Robert F. Dorr Collection

The Korea armistice of July 27, 1953 and, more importantly, the prospect of new transports designed from the ground up, dampened prospects for an operational version of the YC-124B.

Once initial tests had been carried out, the Air Force took the YC-124B on a tour of transport bases. Retired Tech Sgt. Carmen R. Bradt, of Newport, N.Y., saw the YC-124B on the ramp at Travis Air Force Base, Calif. in 1956. “It was pretty impressive,” said Bradt.

“It was pretty impressive.”

In later years, Douglas engineer Elder said that the YC-124B was always intended to be a one-off prototype for engine and propeller development. But documents from Douglas files, including at least one written by Elder, indicate that Douglas was hoping to for a contract to produce rebuilt or new-build turboprop Globemaster IIs for the Air Force.

Douglas also had high hopes for a different transport design, the C-132A, which would have been a very large swept-wing cargo hauler. The C-132A never went past the mock-up stage.

YC-124B

Despite claims that the YC-124B was intended only as an engine and propeller development prototype, Douglas apparently hoped the YC-124B would lead to a production contract with the U.S. Air Force. Robert F. Dorr Collection

 

One of a Kind

While the YC-124B apparently exhibited no important flaws, it wasn’t impressive enough to win a production contract for itself. However, it helped pave the way for Douglas’s turboprop-powered C-133 Cargomaster for strategic airlift duties.

The turboprop YC-124B never made it to an Air Force squadron.

Douglas turned out 50 Cargomasters. As it turned out, they, too, were disliked by troops: again, the fleet suffered three fatal crashes. The service also invested heavily in the turboprop C-130. A decade later, the service shifted to the all-jet C-141 Starlifter and C-5 Galaxy for the strategic airlift mission.

The turboprop YC-124B never made it to an Air Force squadron.

Douglas C-133A Cargomaster

The C-124 paved the way for the 50 C-133 Cargomasters Douglas built for the Air Force. The Cargomasters were the only turboprop strategic airlifters ever bought by the Air Force. They were replaced by the C-5 Galaxy. U.S. Air Force photo

 

Douglas YC-124B Globemaster II

Type: Four-engine, long-range cargo and troop transport

Powerplant: Four Pratt & Whitney 5,500 shp YT34-P-1 turboprop engines driving three-bladed, 18-foot Curtiss Wright C-735S-B2 electric propellers

Performance: Cruising speed 323 mph (520 km/h); service ceiling, 25,900 feet (11898 m); range, 1900 miles (3058 km) for basic mission or 2550 miles (4103 km) empty with maximum fuel

Weights: Empty 101,160 pounds (45890 kg); loaded 194,500 pounds (88210 kg)

Dimensions: Wingspan 174 feet 4 inches (53.10 m); length 129 feet 8 inches (39.16 m); height 51 feet 2 inches (1.98 m), wing area 2,510 square feet

By

Robert F. Dorr is an author, U.S. Air Force veteran, and retired American diplomat who...