C-109 Tanker

The Specialized Fuel Transport That Enabled Long-Range Airpower

The C-109 Tanker was a highly specialized variant of the B-24 Liberator, engineered to meet an urgent wartime need: transporting aviation fuel over extreme distances. As Allied bombing campaigns pushed farther into enemy territory, and as remote bases in Asia and the Pacific expanded, a new type of aircraft was required — one that could carry vast quantities of fuel across hazardous terrain and deliver it where no pipeline or tanker ship could reach.

Consolidated’s solution was the C-109, a dedicated fuel-transport aircraft derived from the Liberator platform, designed to sustain operations that depended entirely on long-range aerial logistics.

Why the C-109 Was Created

By 1943, strategic demands had outgrown the Army Air Forces’ supply chain. Fuel was needed at:

• advanced bomber bases in China

• isolated airstrips in the Pacific

• high-altitude staging points for long-range reconnaissance

• forward refueling hubs for B-29 Superfortress missions

The only way to deliver fuel to many of these locations — especially over the Himalayas — was by air.

The B-24, with its long range and high payload capacity, provided the foundation. Consolidated removed combat systems and reconfigured the interior with sealed fuel tanks, turning the aircraft into a flying reservoir.

Characteristics and Operational Features

The C-109’s modifications were entirely mission-focused:

• Internal fuel tanks replaced cargo and crew areas

• Minimal crew accommodations optimized for ferry operations

• Enhanced fuel plumbing allowed quick transfer at remote bases

• Streamlined equipment reduced weight for maximum capacity

While not glamorous, these changes transformed the Liberator into a strategic support aircraft capable of sustaining long-range operations.

“The Hump” — The C-109’s Most Infamous Mission

The C-109 became one of the principal aircraft flying “The Hump,” the treacherous aerial supply route over the Himalayas between India and China. These missions were among the most dangerous of the war due to:

• violent turbulence

• extreme icing

• unpredictable monsoon weather

• high mountain passes

• overloaded aircraft operating at the limits of performance

Yet without these fuel deliveries, Allied operations in China — including B-29 staging missions — would have been impossible.

The C-109’s service in this role demonstrated both the strengths and the limits of adapting bombers for extreme logistics.

Performance and Operational Challenges

The C-109 was effective, but not without issues:

• high takeoff weight made departures risky

• handling characteristics became difficult when fully loaded

• center-of-gravity changes required careful management

• long missions left little margin for error

Even so, the C-109 proved indispensable in theaters where no other aircraft could carry the same volume of fuel over comparable distances.

Legacy of the C-109

While not produced in the same numbers as other Liberator variants, the C-109 played a pivotal strategic role. Its impact included:

• sustaining far-flung bomber bases

• enabling long-range operations in China and the Pacific

• pioneering techniques for aerial fuel transport

• demonstrating the flexibility and adaptability of Consolidated designs

The C-109 stands as a reminder that victory in World War II relied not only on fighters and bombers but also on the unseen logistical aircraft that kept the entire global aviation network operating.