World War II saw the advent of many different types of new warfare - however, the most dramatic improvements came in the development of strategic bombing and multipurpose aircraft, with high flight ceilings, heavy armor, and incredibly large payloads and armaments. In World War II, the multi-engined heavy bomber became an important tool of aerial warfare. From carpet bombing to Fat Man and Little Boy, these large, slowly moving but intimidating aircraft ruled the skies of the Pacific Ocean and Europe. Two important pieces of aerospace technology that saw use in the war are the B-17 Flying Fortress and the B-25 Mitchell. In this essay, the bombers themselves and the campaigns they flew in will be detailed and examined in terms of their importance to the Allied campaign.
The B-17 is an iconic aircraft in the story of World War II; with its incredible flight ceiling and impressive payload capacity, they became symbols of the strategic bombing efforts of World War II, becoming a long-range, high-flying and durable bomber that could get the job done and return home. The B-17 Flying Fortress was a heavy bomber known for its many variants, all of which were utilized for a special type of warfare. After many different variants and experiments with the design, the B-17G was the final version to come out; it featured thirteen guns and used for many different purposes, from reconnaissance to troop transport to straightforward bombing. It could carry nearly 8,000 pounds of ordinance, allowing for a greater bombing capacity. External fuel tanks, called 'Tokyo tanks,' were installed on each wing in order to increase the bomber's operational range by 900 miles. Its chief importance in World War II relates to the daylight precision strategic bombing of German military and industrial targets during Operation Pointblank. Over the course of the war, more than 640,000 tons of bombs were delivered by US B-17 Flying Fortresses onto German targets (Davis, 1984).
The B-25 Mitchell was made by North American Aviation, and was a twin-engine medium bomber used for many bombing and strafing runs over Japanese and Axis forces and cities. The B-25 typically featured dorsal and ventral turrets, or a rear turret, with .50 caliber machine guns attached to defend the craft from enemy planes. It could fly up to 275 miles per hour, with an operational range of 2700 miles; as for armaments, it typically featured twelve to eighteen .50 caliber machine guns, depending on the variant, as well as hardpoints for nearly 6,000 pounds of bombs and 3,000 pounds of rockets (Cunningham, 1944).
The usefulness of the B-25 as a strafing aircraft led to the development of the B-25G variant, which had two .50 cal machine guns in the nose, as well as a 75mm M4 cannon, which was one of the biggest guns ever attached to an aircraft. The way the B-25 flew was also innovative; even with one of the engines gone, it was possible to fly the aircraft and maintain tight turns in either direction. With the proper deceleration in speed to around 145 mph, a Mitchell could bank 60 degrees with a dead engine. Taxiing on the runway was also made easier due to the B-25's tricycle landing gear. The B-25's real advantage was in its ability to take incredible punishment from enemy fire - there were many B-25s that took hundreds of hits and still kept flying throughout the various campaigns.
The B-17 began its career in World War II in 1941, where it served under the Royal Air Force. The first B-17s to see service in America during the war was a contingent of planes that had been deployed to Clark Field in the Philippines, shortly before Pearl Harbor (Davis, 1984). Many of these airplanes were eliminated on December 8, 1941 during yet another surprise attack, but those that remained continued to attack the Japanese invasion force as best they could. The United States Army Air Force began using the B-17 and other types of bombers once it officially entered the war by transferring them to Europe, performing raids in France for their initial missions (Davis, 1984).
The first large B-17 campaign would come in 1943, when the Casablanca Conference would decide to create the Combined Bomber Offensive. This was meant to deal a significant blow to German morale and destroy a significant portion of Germany's fighter base. Operation Pointblank was the name given to the mission, wherein B-17s would destroy German fighters on the ground, paving the way for ground forces to take German military establishments. The 8th Air Force of the USAAF was growing in strength and learning the advantages and strategies that would best make use of the B-17; the use of tightly packed formations made their .50 cal machine guns offer the most firepower and protection from enemy fighters (Davis, 1984).
While this strategy was far from effective, it was a slight improvement. In the two Schweinfurt raids, B-17s bombed war equipment manufacturing facilities to slow the German war machine; these raids were somewhat successful, though the second Schweinfurt raid was known as Black Thursday, due to the high casualties that resulted from the lack of proper escort for the B-17s. While 230 bombers were sent out on that mission, 60 of those bombers were absolutely destroyed, and nearly 90 more were left damaged beyond repair upon returning (Davis, 1984). Despite their being dubbed 'Flying Fortresses,' it was found that German fighters found them exceptionally easy to shoot down, making it necessary to ground them for awhile until a suitable escort fighter could be found (Davis, 1984).
In the Pacific Theater, the B-17 also saw significant use; the craft were used in the Battles of Coral Sea and Midway, but with limited success. The Fifth Air Force used B-17s to attempt runs on Japanese supply lanes by sea, but their kill ratio to ordinance used was far too small at first to be effective (Salecker, 2001). The advantage they were finding, however, was that Japanese Zeroes could not reach the B-17s as they were operating at far too great a height, making them virtually ineffective. What's more, the machine guns and turrets made easy work of the lightly-armored Zeroes. Therefore, while these bombers were not hitting much, they were not getting hit back in retaliation. March 2, 1943 saw the Battle of the Bismarck Sea, wherein six B-17s attacked a large troop convoy belonging to the Japanese, sinking three merchant ships and dispersing the rest. B-25 Mitchells were also involved in the fight, skip bombing at low altitudes to destroy the rest of the supply convoy being attacked (Salecker, 2001).
Despite these victories, the B-17 was eventually decided to be unfit for use in the Pacific Theater; by the end of 1943, all B-17s were removed from the theater and transferred to other campaigns. Soon, operations picked back up again on the Western front with the help of P-51 Mustangs and P-47 Thunderbolts, who turned out to have exceptional long range fighter escort capabilities. In 1944, the B-17s were making deep strikes into Germany once more (Salecker, 2001).
Operation Argument took place on February 20th, 1944, starting the "Big Week" of large missions against Germany, One of the most significant contributions the B-17 made to the war effort was its participation in Big Week, which lasted until February 25th, 1944 (Davis, 1944). In this week, the overall goal was to bomb targets of the German aircraft making industry, forcing the Luftwaffe to fight, where they would be soundly defeated. With the heavy escort provided by the P-51s and P-27s, the survival rate for B-17s became much higher - only 7% of Allied aircraft were lost during Big Week (Davis, 1984). Throughout the week, B-17 bombers were the primary aircraft used to decimate German installations and factories. Airfields at Cambrai and Epinoy are hit, and one flight of B-17s dropped leaflets in France.
This action ended up leading to the Allies achieving air superiority over Europe, making way for Western Europe's invasion. The victories during Big Week showed the effectiveness of the B-17 bomber, as its heavy armor and combination of effective fighter escort allowed these heavily armored bomb-dispersal units to deliver their payloads across the whole of the Western front. These events led to the completion and success of the Combined Bomber Offensive, as B-17s and their accompanying escorts defeated the Luftwaffe and dealt a serious blow to German planemaking and supply capabilities (Davis, 1984). Given the dramatic effect the strategic bombing efforts of the Allies turned out to be, their resupply capacity was severely diminished, leading to a gradual slowdown of refueling and resource allocation, giving Allies the tactical advantage.
The B-25 first came to prominence within the war, making a name for itself, on April 18, 1942 - the Doolittle Raid. Four months after the Pearl Harbor attack, Lieutenant Colonel Jimmy Doolittle attacked the Japanese mainland with 15 B-25B bombers successfully; taking off from the USS Hornet, the force attacked four Japanese cities without losing a single plane. However, this attack did lead to the loss of all the planes save one on the way back, due to lack of fuel and exhaustion (Mizrahi, 1965). This attack did not leave a significant amount of damage, but the boost it gave to American morale and spirit was great. As it was the first retaliatory attack on the Japanese since Pearl Harbor, it was a refreshing reminder that America could still win, and that enemy forces would not be able to attack American soil and get away with it. The combat effectiveness of the B-25 made this possible.
While the B-17s true calling was on the Western front, the B-25 Mitchell saw most of its service on the Pacific front. The B-25s were originally meant to be a medium altitude bomber; however, other uses were found for the plane, making it a versatile and dangerous craft in the Allied arsenal. During the island hopping campaign that took place in the central Pacific, the B-25s saw action as a ground attack bomber, where it was shown to be highly effective. Normal bombing was not working in the jungle environments of the Pacific Islands, leaving the need for a low level attack bomber to pick up the slack (Mizrahi, 1965). The B-25, with its low flying altitude and forward firing guns, made it a perfect low level attack and strafing aircraft. With these discoveries, the B-25 was quickly repurposed for these tasks.
The attack on Burma saw the B-25s used to attack the communications lines of the Japanese, blowing up bridges and the like to prevent supply lines from continuing. In 1944, the troops at Imphal were supplied with the help of the B-25s. In addition to these tasks, the B-25s true calling proved to be the destruction of Japanese naval ships; they carried the capability to destroy these ships without significant risk to themselves, and were able to resupply quickly given their proximity to the islands and Allied ships. As the Pacific War raged on, islands became more and more distant from each other, making the B-25's operational range less effective, but it still found significant use against Japanese forces in Tinian and Guam.
In the Southwest Pacific theater, the B-25 found significant use as a treetop-level strafing aircraft, also deploying parafrag weapons in the Philippines and New Guinea. This proved to be devastating for the Japanese shipping efforts, as land-based armies had trouble with resupplying after B-25 strafing runs. The combined efforts of the SWPA and B-25s belonging to the Fifth and Thirteenth Air Forces led to a retreat of the Japanese from the Southwest Pacific Islands back to home islands in Japan (Mizrahi, 1965).
The Pacific Theater was not the only place where the B-25 was found to be helpful. In the Middle East, B-25s played a significant role in the battle of El Alamein, preventing the Axis forces from occupying Egypt and accessing the Suez Canal. For more than fifty missions, precision bombing and skip bombing efforts were made against the Axis troops, the overall goal of which was to get them to retreat into Middle Europe (Cunningham, 1944). From here, the North Africa campaign continued to utilize the B-25 bomber; it proved highly effective in strafing and bombing runs. Eventually, the North African campaign ended in May and the fight was taken to Italy, where B-25s took up a role of a ground attack fighter, disrupting rail and road links in the Balkans, Austria and Italy (Mizrahi, 1965).
The primary advantage of the B-25 bomber in these instances was its increased operational range, compared to the A-20 and A-26 fighters - this left it uniquely capable of reaching targets deeper into occupied territory (Cunningham, 1944). American forces were not the only ones to use the B-25, though they only used them in the North African campaign and in Italy. The Royal Air Force also had a complement of 900 B-25s, which it used to supplement existing strategic bombing efforts in occupied territory. After D-Day, the English B-25s provided support for the European armies, operating out of Belgium and France as they performed continued strikes on Axis forces (Cunningham, 1944).
The Air Force was not the only department to find use for the B-25; the Marine Corps received a number of the planes from the Air Force, which they then navalized into the PBJ-1. Some of these improvements included search radars that were added to the plane to provide added radar and sensing capabilities. In 1943, the PBJ-1s began to be used as land-based bombers for the Marines, but were not put into action in the war until 1944. At that point, the Marines used their PBJs to intercept enemy shipping efforts along the Pacific theater; while Japan was under a blockade, the Marines were used to disrupt attempts to run the blockade (Mizrahi, 1965).
The enduring legacy of both of these incredible planes lies in their unprecedented use of technology, as well as their unique uses throughout World War II. The B-17 lived up to its moniker as the Flying Fortress; it maintained an iconic status as the high-altitude, heavily-armored bomber that would wreak havoc from a safe distance from German planes and flak guns. The sheer amount of payload it could deliver at a time made the carpet-bombing and strategic bombing on the Western front incredibly successful, especially during Operation Pointblank. While there were some troubles getting the bombers into enemy territory safely, the addition of the P-38 and P-51 as fighter escorts vastly improved the survival odds of B-17 bombers.
Meanwhile, on the Pacific front, the B-25 proved to be an effective medium-range bomber that could easily be used in strafing runs. During the island hopping campaigns, it was able to fly quickly from island to island, take down enemy forces and supply lines with its bomb payload or forward-facing guns, and then return home with fuel to spare. Its signature debut in the Doolittle Raid also cemented its place in the American imagination, as it represented America's first real strike back after Pearl Harbor. Its significance in the North African campaign also proves its worth as a long-range, deep-strike bomber. All of these myriad uses for the plane made it a mainstay throughout the Second World War.
Whether it is the single-purpose nature of the B-17 or the swift versatility of the B-25, both of these bombers made significant strides in the tide of the war. Without the help of these innovative planes and their brave crews, the Allied forces would have had a much more difficult road ahead in both European and Pacific theaters, if not lost altogether. They have proven to be indelible, iconic pieces of aerospace technology, which demonstrated the importance of air superiority even from a ground combat standpoint. The concept of strategic bombing was also cemented by the aerial raids that these planes were committed to; the effectiveness of these raids could be directly attributed to the sheer firepower and combat range of these new bombers.
References
Cunningham, R.L. (1944). I Fly 'Mitchells.' Popular Science 144(2), pp. 70-74.
Davis, L. (1984). B-17 in Action. Carrollton, Texas: Squadron/Signal Publications.
Green, W. (1975). Famous Bombers of the Second World War. New York: Doubleday &
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Salecker, G.E. (2001). Fortress Against The Sun: The B-17 Flying Fortress in the Pacific.
Conshohocken, Pennsylvania: Combined Publishing.
Mizrahi, J.V. (1965). North American B-25: The Full Story of World War II's Classic Medium.
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