The Boeing B-29 Superfortress heavy bomber achieved fame—and infamy—for its role in the atomic bombings of the Japanese cities of Hiroshima and Nagasaki. Developing the huge bombers, which could lug heavy bomb loads over long distances at high altitudes and speeds, amounted to the most expensive weapons program undertaken by the United States during World War II—more expensive even the Manhattan Project.

However, the Superfortress actually had a little-known rival developed by the manufacturer Consolidated, better known for its mass-production of the B-24 Liberator heavy bomber. Had the Superfortress failed to perform as expected, the so-called B-32 Dominator was to be the fallback option. However, the B-29 actually did end up performing according to expectations when it began operations in the Pacific Theater in 1944, but Consolidated still produced more than a hundred B-32s which were deployed into action in mid-1945. In fact, Dominator crews fought the last U.S. air battle of World War II—tragically, after the war had ended.

Recommended: America Has Military Options for North Korea (but They're All Bad)

Recommended: 1,700 Planes Ready for War: Everything You Need To Know About China's Air Force

Recommended: Stealth vs. North Korea’s Air Defenses: Who Wins?

The program for a super heavy bomber actually predated Pearl Harbor. However, Consolidated’s project, which used the B-24 as its basis, fell considerably behind Boeing’s development of the B-29. The hulking bomber went through several permutations—it’s original design included twin-rudder tail and bizarre configuration mounting 20-millimeter cannons to fire rearward from each engine nacelle, but these elements were eventually ditched.

In the end, the B-32 is most visually distinguished by its enormous tail which stretched ten meters tall. The Dominator wound up resembling the B-29 in key performance parameters: both aircraft used four Wright R-3350-23 Cyclone engines for power, had a maximum speed of around 358 miles per hour—as fast as an early-war Bf-109E fighter—and could lug a huge bomb load of 20,000 pounds. The B-32’s defensive armament included ten conventionally manned machineguns, operated by a similar number of crew.

However, though Consolidated also tried to implement the pressurized fuselage and remote-control gun turrets that were features on the B-29, it eventually gave up due to technical difficulties. This resulted in the Dominator being considered a low or medium-altitude bomber, when compared to the B-29.

On the other hand, the B-32 had a nearly 20 percent greater range of 3,800 miles, and could maintain a much higher cruising speed of 290 miles per hour, compared to 230 for the B-29. The Dominator also benefited from reversible-pitch propellers and the thick Davis wing inherited from the B-24, which minimized drag at lower speeds—an especially useful quality while attempting to land.

Despite the B-32’s upsides, the Army Air Corps was largely satisfied by the B-29’s performance and only dispatched three B-32s for operational testing in the Phillippines at the request of the 5th Air Force. Eventually transferred to the 386th Bombardment Squadron, the Dominators conducted a series of raids against Japanese forces in the Philippines and the island of Formosa (modern-day Taiwan). The targets in Taiwan included a sugar mill and an alcohol plant, indicative of just how far-reaching and indiscriminate the U.S. strategic bombing campaign against Japan had become.

The 386th was fully outfitted with B-32s in July, and in August was redeployed to Yontan airfield at Okinawa where it was reassigned to flying photo reconnaissance missions over Japan. On the evening of August 15, Emperor Hirohito made a speech declaring his intention to surrender and ordering the armed forces to cease resistance. While anticipating the surrender of Japanese forces on the USS Missouri in September 2, the Army Air Corps continued reconnaissance overflights of Tokyo to verify compliance with the terms of surrender and scout out the road network for the occupation forces.

However, Japanese fighter pilots on the ground perceived the overflying bombers in a different light. One Japanese ace, Saburō Sakai, later claimed that they feared the American bombers were returning to bomb Tokyo in violation of the surrender, and decided they were justified in attacking them.

Another Japanese ace, Sadumo Komachi, simply stated that they were infuriated by seeing the American bombers flying unopposed over the Japanese capital after the immense devastation wrought by American bombs.

To put things in perspective, earlier that year on March 9, 1945 American B-29s had dropped thousands of cluster bombs loaded with napalm bomblets over working-class residential areas of Tokyo, igniting a firestorm which sucked the air out of lungs and melted concrete. The conflagration killed around 100,000 Japanese civilians—more than died in either atomic bombing.

Thus on August 17, Japanese fighters intercepted the reconnaissance B-32s and harried them for two hours while the bomber crews shot back with .50 caliber machine guns, neither side inflicting much damage on the other. The surprised bomber unit decided to dispatch of a follow up recon mission on August 18 to investigate whether the intercept was an isolated incident. It’s worth noting that that same day, Japanese forces in the Kuril islands also engaged in air battles against Russian aircraft supporting a surprise amphibious invasion, another post-surrender conflict which would take several days to sputter to a halt.

At 7 AM on the morning of the 18th, two B-32s set out for Tokyo again, each plane loaded with three additional photo-recon specialists drawn from the 20th Reconnaissance Squadron. The extra crew normally flew aboard F-7s, a reconnaissance version of the B-24.

By 2 PM the two B-32s completed their runs over Tokyo at altitudes of ten and twenty thousand feet when they noticed Japanese fighters rising from their aerodrome towards them.

In fact, records show fourteen A6M Zero fighters and three N1K-J Shiden (“Lightning”) fighters launched to intercept from Yokusuka air base. The Shiden was one of the best Japanese fighters of the war, capable of exceeding 400 miles per hour and well-armed with four fast-firing 20-millimeter cannons, though it had relatively poor performance at high-altitude.

Nonetheless, the aircraft swarmed over the larger B-32s, their machineguns and cannons chattering. The ten .50 caliber machineguns on each bomber were soon spitting back curtains of lead in response.

Both the bomber crew and fighter pilots on that last mission recalled what happened next. Screaming down from 12 o’clock high, Komachi raked the engine of the B-32 named Hobo Queen II with his 20-millimeter cannons and burst the plexiglass bubble of the top turret, wounding turret gunner Jimmy Smart. Another fighter strafed Hobo Queen’s fuselage, the rounds slicing through the plane and riddling the legs of aerial photographer Joseph Lacharaite. The wounded specialist began applying a tourniquet to his wounds, and fellow photographer Sergeant Anthony Marchione, a nineteen-year old Italian-American from the Bronx, helped move him to a cot.

Suddenly, a cannon shell penetrated Hobo Queen’s fuselage and struck Marchione in the chest. The young man crumpled, bleeding from a big hole in his chest. Three crew members came to his aid, applying compression bandages and administering blood plasma and oxygen.

Meanwhile, both B-32s entered a steep dive, their relatively high speed combined with the momentum gained from their greater weight allowing them to surge ahead of the Japanese fighters. Both managed to limp back to base by 6 PM that evening. Hobo Queen II was down one engine, had a damaged rudder and was pocked by thirty large holes in its fuselage. Lacharite would spend several years recovering from his wounds.

Marchione, however, bled to death thirty minutes after his injury, and would bear the unfortunate distinction of being the last U.S. airman to fall in combat during World War II. His Italian immigrant family was stunned to receive notice of his death after the end of hostilities had been declared. The following day the Japanese military was compelled to begin removing the propellers from their aircraft to avoid further such incidents.

Just three weeks later the Army Air Corps canceled production of additional B-32s and began swiftly decommissioning the 116 already produced—the B-29 had simply rendered the type redundant. The last Dominator was scrapped in 1949, leaving little evidence behind of the aircraft type that had embarked on that fateful last mission over Tokyo.

Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

Image: Wikimedia Commons.