The USSR’s Experimental Flying Aircraft Carriers WWII’s Forgotten Fleet

The idea of an airborne aircraft carrier first appeared during World War I. Military planners wanted to send bombers deep into enemy territory, but fighters at the time had very limited range. The solution some nations explored was to have large airships carry smaller fighter planes, which could detach, engage in combat, and ideally return to the mother aircraft.

In 1918, Germany launched an Albatros fighter from a Zeppelin. The aircraft successfully detached and landed safely at an airfield, but there was no system for it to reattach in midair. The British attempted a similar experiment that same year with comparable results. While these tests proved the concept was possible, they also showed the enormous difficulty of retrieving the fighters. After the war, the United States took an interest in the concept, building two airships designed as aircraft carriers, but both were lost in accidents and never used in combat.

The USSR’s Pursuit of Airborne Aircraft Carriers

During the 1920s and 1930s, military theorists promoted the idea of large formations of aircraft, including bombers that could serve as flying aircraft carriers. The Soviet Union was the only country with a bomber force large enough to experiment with this idea at scale. Soviet military planners envisioned an air fleet that would include bombers, reconnaissance planes, airborne command posts, refueling aircraft, and even airborne carriers capable of launching and recovering fighter planes in flight.

Vladimir Vakhmistrov, a Soviet engineer, led the development of these airborne aircraft carriers. The first design, called Zveno-1, used a Tupolev TB-1 bomber with two I-4 fighters mounted on its wings. Tests showed that while the fighters could detach midair, the separation process was extremely complicated and risky. No major accidents occurred during testing, but the TB-1 was too small for large-scale use. With the introduction of the larger TB-3 bomber, the project expanded.

Several versions of the Zveno system were tested, with different combinations of fighter planes. Some configurations included as many as eight fighters attached to a single bomber. Most of these were designed to protect heavy bombers from enemy aircraft, but later versions experimented with using the fighters for bombing missions.

Combat Deployment of the Zveno System

By 1939, the Soviet military planned to have 40 modified TB-3 bombers and 80 I-16 fighters assigned to the airborne carrier program. However, production delays and political purges within the Soviet aviation industry slowed progress. Only a single squadron of aircraft was operational by the time World War II began.

In July 1941, Soviet forces needed to destroy a strategic bridge over the Danube River. Long-range bombers had failed to inflict serious damage, and the Soviet Air Force lacked a dedicated dive bomber like Germany’s Ju 87 Stuka. The Zveno system, which could carry fighters modified for precision bombing, was reconsidered.

The first combat test took place on July 26, 1941, when two TB-3 carriers flew to the Romanian port of Constanța. Four I-16 fighters, each carrying 250 kg bombs, were launched toward oil storage tanks. German fighters patrolling the area failed to recognize the threat in time. The Soviet planes hit their targets and successfully returned to their home base.

On August 10, the Zveno squadron attempted to destroy the bridge but was only partially successful. One of the three TB-3s had to turn back, and the remaining aircraft did not cause significant damage. However, all planes returned safely. Three days later, another raid finally destroyed a section of the bridge. Six I-16 fighters launched from three TB-3 bombers successfully hit their target and attacked Romanian ground forces on the way back.

The End of the Program

In the following weeks, the Zveno aircraft continued their bombing missions. On August 17, six I-16s attacked a dock in Constanța. A week later, they bombed German positions near the Dniester River. On September 9, four I-16s targeted river crossings and even engaged in aerial combat, downing two German fighters. The total number of combat missions flown by the airborne carriers is unknown, but estimates suggest at least 30 sorties took place.

By early 1942, the Zveno system was phased out. While the idea of airborne aircraft carriers was innovative, the difficulties of midair docking, combined with the increasing effectiveness of conventional bombers and fighters, made the system impractical for large-scale use. However, for a brief period, the Soviet Union’s experimental flying carriers played a unique role in air combat.