Our last unit focused primarily on commercial and civilian aviation in the interwar years, although some developments and research from the military were discussed with Jimmy Doolittle and instrumentation. This first lesson for unit 3 will carry forward our story of military aircraft developments between World War I and World War II through a broad overview of developments.
By the end of this lesson, you will be able to:
Explain assumptions about the role of air power that influenced military planning in the interwar years
Identify the differences in approaches to the development of air forces in Britain, the United States, and Germany during the 1930s
At the end of World War I, the load capacity and range of aircraft was still limited. Although military planners saw the potential for aircraft in combat, the Treaty of Versailles limited the production of military weapons like aircraft and there were few civilian uses for planes that justified substantial government support for the nascent aircraft industries in Europe and the United States. As a result, during the 1920s some companies shuttered their factories, but others found ways to continue designing and producing aircraft. They shifted their focus towards record-setting, air meets, and the numerous cash prizes that could support research and development in other ways.
By the 1930s, despite the Great Depression in the United States, trends like the convergence of new materials and production techniques with growing civilian aircraft demands based on these heartier aircraft (discussed in the last unit) helped buoy the American aircraft industry. In Europe, there was a growing need for government subsidization of the aircraft industries as the 1930s seemed to be indicating a march toward another European war. Thus, the 1930s were a 'rebound' period for aviation developments in both Europe and the U.S.
The Italian military theorist Giulio Douhet wrote about the use of air power during this interwar period. He anticipated what an aerial war should look like in the next conflict. Although there is limited evidence of how widespread Douhet was read outside of Italy--his writings were at least translated and shared with the United States--his thinking is representative of how both American and British theorists envisioned air power impacting the next war.
Military planners often prepare for the next war as part of training exercises conducted by senior officers during peacetime. Fort Leavenworth, for example, has a long housed a leadership command school that asks officers to conduct theoretical operations against possible future enemies. It is within that context in the 1930s that military leaders on both sides of the Atlantic envisioned strategic bombing to be the key contribution of aircraft during a future war. They tended to view aircraft units as independent of ground operations, and that the airplane's contribution would be in strategic bombing of the enemy homeland that could lead to swift, decisive victory in the next war. Their limited understanding of the rapid development of airplane technologies helped to blind them to the real possibilities represented by aircraft.
The only aspect of their analysis that proved accurate was the role played by strategic bombing in defeating an enemy, although even here they underestimated how long it would take to achieve victory given the massive mobilization of resources during World War II. The potential for how aircraft could be used in military operations was apparent in World War I, but many leaders failed to grasp these insights and learn from the lessons of WWI. What they did not foresee was the critical roles aircraft would play in aerial defenses of bombers and homeland; transporting men and materiel; reconnaissance and scouting; close air support for ground and naval operations; and in anti-submarine patrols, among other duties. In many ways, the airplane was critical to success in World War II. Imagine the D-Day landings with thousands of gliders, fighter escorts, bombers, and transport planes for the paratroopers--it would be little more than a naval flotilla that the German defenses of the Atlantic Wall likely could have handled, preventing the invasion of Europe. It is through the integration of aircraft into virtually every aspect of military operations and missions that enabled initially the Germans (i.e. the Blitzkrieg) and later the Allies to achieve military success.
That military success depended heavily upon having aircraft with greater range, cargo capacity, durability, and maneuverability. In the last unit we talked about the research and development in wing design, fuselage materials and aerodynamics, instrumentation, stronger engines, etc. Let's take a look at some of the important airplanes that incorporated those changes, as well as some of the events of the 1930s that moved nations closer to World War II. The advent of air power as a critical component of military operations is one of the most important developments of the twentieth century.
In Britain Sir Hugh Trenchard, Marshal of the Royal Air Force (RAF), played a critical role in maintaining the RAF as a separate organization despite budget cuts. In the 1920s, he also began building airfields and infrastructure that was critical to allowing the RAF to expand during the 1930s (and was critical to the defense of the nation during the Battle of Britain). Other important developments were spearheaded by Sir Hugh Dowding. As the leader for research and development in the RAF, Dowding shepherded the specifications and design planning that eventually became the Hawker Hurricane and the Supermarine Spitfire. Together, the Hurricane and Spitfire were mainstays of British fighter squadrons during WWII, and in 1940 they were a core part of the defenses in the Battle of Britain. At a time when the British government was reluctant to fund bombers or fighter aircraft, even with Hitler's advances in Europe in 1938 and 1939, Dowding's leadership helped ensure Britain was not left totally unprepared for war. Dowding also invested in research using radio waves to detect and locate aircraft, what we know today as radar. Setting up a series of listening and reporting stations all along the English Channel helped the British anticipate German attacks and get fighters into the air while German aircraft were still over the Channel. Although the British expected strategic bombing to play a role in the next war, they were largely caught unprepared for war. The success of the Battle of Britain was in large part thanks to men like Dowding and Trenchard working to maintain the RAF and aerial defenses during the late 1920s and early 1930s.
In the United States, one of the most outspoken advocates of air power (to the point of being court-martialed for insubordination) was Col. William "Billy" Mitchell. Mitchell was an Army officer and he fought against the prevailing assumptions that strategic bombing was the only use for aircraft. Mitchell advocated for the Air Force to become an independent branch of the military (which would later happen following World War II) and that fighter aircraft were critical for defending one's own bombers as well as attacking the enemy's aircraft. Mitchell, as well as the U.S. Army, supported research efforts to develop faster and stronger aircraft, which in turn was supported by civilian uses for those aircraft.
The size of the country created more of a need for air mail, passenger services, and other commercial flight options that did not exist in Europe, driving innovation in the private sector, but the U.S. was also more willing to invest in the development of military aircraft than European governments were during the 1920s and 1930s. The U.S. Navy drove the adoption of a radial engine instead of an inline engine for aircraft based on the need for easier maintenance of planes on aircraft carriers, a plan that the U.S. also followed. As a result, planes like the B-17 Flying Fortress and the DC-3 (known as a C-47 in its military variation) were developed using radial engine technology, and both were critical to Allied success in World War II.
In terms of the Axis powers, both Japan and Germany had opportunities in the 1930s to test and refine their aircraft and Air Forces. In defiance of the Treaty of Versailles, Germany developed military aircraft under the auspices of commercial aviation until 1933 when Hitler came to power. The Luftwaffe, or German Air Force, was formally created a few months later in 1933. German pilots and aircraft gained some experience during the Spanish Civil War starting in 1936, but the Luftwaffe quickly gained more experience coordinating aerial attacks with ground operations (part of their Blitzkrieg strategy) starting in Poland in 1939. Likewise, Japan was not satisfied with the Treaty of Versailles or the lack of respect paid to their interests following World War I. The emperor and his military leaders had aspirations to extend the Japanese empire across the Pacific. Japan continued to build aircraft and ships in the 1920s and 1930s, and by 1937they were involved in the Second Sino-Japanese War and fighting in China. At the outbreak of World War II, Germany and Japan possessed substantial Air Forces with combat-experienced pilots and a diversity of fighter and bomber aircraft in production or in service, a significant advantage over Britain and the United States.
Although the ability of the United States to ramp up production during World War II was unparalleled, and the pre-war civilian and military or government support for innovation in aircraft design, were important factors for the United States' successes in World War II, it is clear that at the outset of the war the Allies were largely unprepared for war. Both Germany and Japan had mobilized and experienced military forces that included strong air forces, and this played an important role in setting the stage for fighting in 1940 and 1941, seen most notably in the Battle of Britain and the attack on Pearl Harbor. We will explore developments during World War II in the next few lessons.
Tom D. Crouch, Wings: A History of Aviation from Kites to the Space Age (New York: W. W. Norton, 2003).
Williamson Murray, War in the Air 1914-1945 (New York: Collins, 2005).