B-25 Gunship - A Tank Gun in the Sky

Days after the Japanese conducted a surprise attack against US forces in Pearl Harbor, President Franklin Roosevelt held an urgent meeting with Joint Chiefs of Staff to discuss American military response to their enemy in the Pacific. The President, visibly preoccupied about American morale after the treacherous Japanese carrier airstrike, told his senior officers that mainland Japan had to be bombed as soon as possible. This, he thought, would boost the country's morale, increase voluntary and fortify war bonds. The result of his order was the Doolittle Raid, under the command of renowned aviator and engineer James H. Doolittle, who later wrote in his autobiography, QUOTE "...an attack on the Japanese homeland would cause confusion and demise of the Japanese people and so doubt about the reliability of their leaders. Americans badly needed a morale boost." The operation took place on April 18, 1942, and it was a resounding success. Thanks to the newly converted medium bomber, the B-25 Mitchell, the squadron of B-25s bombed Tokyo and Honshu, claiming over 60 lives and injuring 500 people. Although damage was relatively minimal, it achieved the desired effects. US morale drastically increased because it proved American aircraft could take the fight to the heart of the enemy, no matter where they stood. In contrast, the Japanese fighting spirit took a heavy blow, for they realized that their archipelago was not as impenetrable as they thought it was. The mission and the B-25's Doolittle performance became so famous that it easily overshadowed the B-25's next combat role. Equipped with a powerful 75mm M4 tank gun, a dozen high-caliber machine guns, rockets, and a 3,000-pound bomb load capacity, the B-25 Model G was a heavy-hitting gunship to be reckoned with. Leading up to World War II, the Luftwaffe and the United States Air Corps both tried installing 75mm tank guns in aircraft, with an eye on pulverizing ground objects in close support of combat troops. The German HS-129B3 and the Ju-88P1 were equipped with long-barreled anti-tank guns whose most important goal was to stop the heavily armored and deathly Soviet T-34 tanks. For their part, the U.S. Air Corps had the B-25G Mitchell Gunship. Created to sink Japanese ships and interrupt the Empire's supply line, the gunship would go through several armament modifications that made it the most powerful Pacific war bomber. From a medium and high-altitude bomber to a low-altitude aircraft capable of skip-bombing and strafing, the B-25 steadily dominated the skies that once belonged to Japanese Zeros and Mitsubishis. By the time the war against the Axis reached an end, the B-25 Gunship was the most heavily armed airplane of the U.S., with defensive armament of up to 14 .50-caliber machine guns. After observing the four-year-long Spanish Civil War, U.S. officers from the Air Corps concluded that low-altitude bombing was no longer sufficient. Anti-aircraft batteries' fire got deadlier with every passing day, making low-altitude bombing extremely dangerous for crews. Thus, the military considered high-altitude bombing the next logical step for strategic raids. Aircraft needed to climb higher to stay safe from anti-aircraft guns and carry more bomb loads to deal with the maximum damage during a single raid. Additional research from the Air Corps suggested that, when it came to maritime warfare, the best option available to effectively sink enemy vessels was by hitting them with the heavy payload of a bomber. The reports concluded that, when compared to the damage done by the 16-inch shell of a ship cannon, a 2,000-pound bomb had, "...greater potential destructive effect against battleships than any other known weapon." These reports, and the way combat developed in the Pacific Theater, shaped the future American B-25 Mitchell Gunship. In March 1939, the Air Corps issued a specification for a medium bomber that could carry a payload of 2,400 pounds over 1,200 miles at approximately 300 miles per hour. North American Aviation used one of its previous failed designs, a twin-engine airplane dubbed XB-21, as the foundation for their new prototype design. They designated it NA-40. Unfortunately, one month later, the prototype crashed during testing and was destroyed. The new design had some modifications that made it larger to accommodate a 3,000-pound bomb load and seat the pilot and co-pilot side by side. With the increased bomb load capacity and overall weight, this new prototype, dubbed NA-62, transitioned from a light to a medium bomber. And, ironically, that was precisely what the Army was looking for in August 1939. Straight off the drawing board, the Army Air Corps ordered 184 NA-62s and put them into production under the name B-25 Mitchell. During production, North American Aviation incorporated various modifications to the The first one was flattening the outer wing panels to produce a slight angle outward the engine nacelles to prevent stability problems. The result was the peculiar gullwing configuration that would make the B-25 easily recognizable. Other tweaks included the size increase of the tail fins, including various 30-caliber machine guns, additional armor, and self-sealing fuel tanks. When interviewed by author Stephen Wilkinson, veteran pilot Jim Harley said that the B-25 was... "...rock-stable, painfully easy on takeoff, and one of the most stable platforms in the landing configuration of any airplane I've ever flown, other than maybe the Mustang." Single-engine control speed was probably the biggest thing to be concerned about. It was around 145 miles per hour, and you lifted off at 90 to 100. Get it off the ground, get the gear coming up, level the airplane over the runway, and let it accelerate to 145. Then you can go right into the climb. Takes 20-30 seconds. It accelerates really fast. The B-25B variant, used for the Doolittle Raid over Tokyo in 1942, was equipped with a nose-mounted 30-caliber machine gun, two turrets powered by twin 50-caliber machine guns, and the full 3,000-pound bomb load capacity. Although the raid was a success, it proved that the B-25B still needed some modifications for long-range missions and low-level combat. Some of the aircraft crashed or got stranded in China and Russia because they ran out of fuel. As a result, the B-25C incorporated more fuel tanks and more 50-caliber machine guns, reaching a total of six guns. One of them, placed in the nose, was fully controllable by the pilot. This became the first hint of the strafing role the B-25 would develop for the rest of the Pacific Theater. Additionally, engineers added external bomb racks under each wing to increase firepower. The bomb bay could now carry a 2,000-pound torpedo for taking down enemy vessels. The B-25C version was shipped to Great Britain, Russia, China, and Canada. The British RAF and the Canadian Air Force used B-25Cs to attack supply lines and oil depots controlled by the Wehrmacht in East Flanders and other secondary objectives scattered in French-German borders. The Dutch also received the same B-25C variant and participated in the East Indies Campaigns, raining fire upon the Japanese advance through Asia's jungles. The USSR used different variants employed by the Soviet Air Force from the early days of the Siege of Stalingrad up to the end of the war. In the European Theater, all countries used it as just another strategic bomber, but in the Pacific, it shone as a fast and brutal strafing bomber. Although the B-25 was initially intended to be a medium bomber, delivering bomb loads more rapidly from moderate altitudes than the high-altitude heavyweight B-17s, it performed best in the Pacific as a low-level attack bomber and strafer. In October 1942, under a US requirement for a ground attack and strafing platform, North American came up with the B-25G, the first American gunship. Author Brian J. Smith, in his work The Dynamics of B-25 Innovation, wrote that North American Company made history when they, "...mounted the largest forward-firing cannon ever used in a U.S. bomber. This was a 75mm M4 cannon, basically a tank gun with an 18-pound projectile." But that was not all. Months later, in 1943, the ultimate pack-a-punch aircraft entered production. The B-25H and B-25J were equipped with up to 14 .50 caliber machine guns. This moving castle was impregnable. It could not be flanked from any side. North, South, East, and West were entirely covered by machine guns that rained hell everywhere they went. Pilots began to call the B-25 gunship the Commerce Destroyers. The manufacturer was undoubtedly interested in improving the airplane. However, General George Kenney of the Army Air Forces and Captain Paul Ervin Gunn had a significant influence on the modifications done to the bomber throughout the war. General Douglas MacArthur once said of Kenney, "...of all the commanders of our major air forces engaged in World War II, none surpassed General Kenney in those three great essentials of successful combat leadership— aggressive vision, mastery over air strategy and tactics, and the ability to exact the maximum in fighting qualities from both men and equipment." Both Kenney and Captain Pappy Gunn insisted on customizing the B-25s with up to 18 MGs. They also pushed forward the role of skip-bombing for the aircraft, which became crucial for the Pacific. Stephen Wilkinson thus described the role, QUOTE "...often skip-bombing meant literally throwing a bomb against a hull, and the B-25's speed made it particularly effective at this. Skip-bombing had first been tried with B-17s, but they weren't fast enough to get the job done." Strafing Japanese airfields was the main objective of the B-25s in the Pacific. With more than a dozen MGs and a powerful tank cannon, the aircraft could deal heavy damage in one run when above an enemy airfield. Destroying Japanese airplanes on the ground proved so tremendously effective that, for a brief time, Allied forces tried doing the same thing in Europe with experimental jet ammunition. This motivated German airplanes to wreak havoc on the ground. When the war ended, the B-25s served in the air forces of over 15 countries. The U.S. Navy, Marines, and the future USAF experimented with other configurations, but those never saw combat in great numbers as in World War II. The B-25 Mitchell gunship became the foundational rock of the legendary Lockheed AC-130 of the USAF that would first see action during the Vietnam War.