New air technologies in the early mid-twentieth century had played major roles in war. The United States air forces were rapidly evolving between World War I and World War II. Aircraft structures and weapons developed along with the manufacture of new systems and devices. The United States Air Force made technological advancements in aviation, including weaponry, aircraft structure, and navigation, during the World Wars (1914-1945). Most strategists during the First World War saw no military future for aviation.
The French Marshal Ferdinand Foch once said, “Aviation is good sport, but for the Army it is useless” (Bailey 10); however, as air technology advanced in the 1920s, the idea of air power gained strength. World War II was the first war in which air power was considered vital to winning. At the beginning, in 1939, air supremacy belonged to Germany and the Luftwaffe, the German air force, which consisted of five hundred thousand men. England had one hundred thousand men in its Royal Air Force. The United States had only twenty-six thousand in the American Air Corps.
Two years before the United States even entered the war, Franklin D. Roosevelt sought to strengthen U. S. air power (Nelson). As advancements were made in aeronautics and new innovations were being fashioned, a prodigious belief in air power was rapidly emerging. For six years beginning in 1939, Congress had been increasing the demand for the purchase of military aircrafts. New manufacturing plants were being built for their construction just as the United States entered World War II. By the end of 1943, more than two million workers were busy assembling military aircrafts.
At this time, the United States was capable of producing one hundred ten thousand aircraft a year (Nelson). Mass production techniques were used for American military production. The United States and the Allied Powers were able to produce armaments in much greater number than the Axis Powers (Brinkley 819). The United States was more than ready to manufacture countless numbers of new aircrafts and armaments even before entering World War II. Mass production was greatly utilized by the military. The National Advisory Committee for Aeronautics (NACA) carried out significant research in aeronautics.
It was established in 1915 by Woodrow Wilson. The committee researched new innovations that were incorporated into both American civil and military aircraft. They made great advancements in aircraft aerodynamics, were responsible for reducing much of the drag on early aircraft, and airfoil was also a major topic of research. Wind tunnels also helped the committee perform such tests (U. S. Centennial of Flight Commission). The National Advisory Committee for Aeronautics contributed greatly to the efficiency of aircraft.
President Roosevelt authorized the Office of Scientific Research and Development (OSRD) in 1941. It was designed by to be a civilian organization of scientists and engineers that would manage the research of various fields that the government was involved with (Nelson). The OSRD was responsible for many rapid aeronautic advances during the early 1940s. They improved many already present technologies and worked with new innovations. The various forms of research undertaken by this organization varied greatly. The group researched bombs, radar, hand weapons, medical treatment, and much more (Nelson).
The Office of Scientific Research and Development was responsible for much of the United States’ technological achievements in aviation. Toward the end of the 1920s, the United States Navy began constructing new non-rigid airships, which several years later, the Navy hired Goodyear to build. The airships burned a gas that resembled propane as fuel, rather than burning a liquid (Century of Flight). This allowed the airship to remain steady while burning fuel; there was no need to compensate for the weight of the fuel because it had a density close to that of air before being burned.
Following the attack on Pearl Harbor, Congress authorized the construction of two hundred airships. They were two hundred fifty-three feet long, sixty feet in diameter, and powered by two four-hundred-twenty-five-horsepower engines; the top speed was fifty miles per hour (Century of Flight). The United States was the only nation to use airships during World War II. They were used for minesweeping, reconnaissance, escorting convoys, and antisubmarine patrols. Airships were large slow structures, but they were utilized by the military to continually have position in the skies.
The helicopter was being fashioned into a practical military machine just before World War II broke out. In 1939, a Russian developed the VS-300 single-rotor helicopter for the United States Army (Greatest Engineering Achievements of the 20th Century). Helicopters were not at all significant to anyone in World War II. They were still limited in their size and power by the time of the war. Nonetheless, they showed themselves to have potential value. They were sometimes employed as supply craft or for rescue operations (Century of Flight). Helicopters were entirely new technology and offered a unique structure for aircrafts.
The airplane was invented only ten years before World War I. They were at first used only for reconnaissance, and the fastest speed reached was merely one hundred miles-per-hour. Scouts eventually began shooting at the enemy with rifles and then machine guns. Soon they were dropping hand grenades. Sometimes pilots even shot at the enemy in the air with pistols (Cox). It was not long before the first fighter planes were constructed. They were often small and provided room only for a pilot and a gunner. Gunners fired machine gun mounted at the back of the aircraft.
Since the birth of airplanes, they have rapidly evolved to serve certain military purposes. World War I was the first conflict in which airplanes were so greatly utilized and played significant roles. The military’s flying machines were first used mostly for reconnaissance, but soon made into offensive weapons (Greatest). Aircrafts were relatively simple and not very maneuverable; but at the same time, anti-aircraft technology was not highly developed. During the years 1914 to 1918, dramatic improvements were made to the structures of airplanes, as well as in control and propulsion systems.
Great advancements were being made in the field of aerodynamics (Greatest). World War I required planes to be built for higher speeds, higher altitudes, and greater maneuverability. Aircraft were now being constructed to complete various tasks. The most common types being produced were bombers, fighters, and reconnaissance (Brinkley 689). The major powers were competing for control over the skies, and by countering one another, technology progressed one step at a time. Monoplanes were already being used by the time WWI came around. They proved to be more useful than the original biplane designs.
The earlier multi-winged airplanes had wings that were not capable of carrying as much weight; therefore, the airplanes were built to reduce wing loading (U. S. Centennial), which is the ratio of weight to wing area. The weight carried by the airplane was dispersed over the larger wing surface. But as the study of aeronautics progressed, this became no longer an issue. Most of the monoplanes in WWI were being used as “fighter scouts. ” They could reach higher speeds than biplanes. They did not cause as much drag and could fly much faster with the same engine. Monoplanes were also more maneuverable (U. S. Centennial).
Monoplane structures were utilized to increase airplane speed and allowed for the development of more efficient aircraft designs. The new monoplane structures required new methods for wing support. Wings experience high degrees of stress while in fight. Forces come from every direction as gusts of wind push back on the wings. This can even cause wings to twist (U. S. Centennial). They must be able to maintain structural strength. Prior to the World War I era, the wings on airplanes were externally braced. They had several struts and wires that ran between the different layers of wings. With the development of monoplanes came cantilever wings. A cantilever is a projection supported at one end. ) These configurations internally brace the wings directly to the fuselage, without need of any external, stress-bearing structures. The cantilever wing structures were stronger than external bracing (U. S. Centennial). Airplanes were being built with stronger, more durable wing designs. Wing structures greatly advanced and became more compact during the time of World War I. Variable-pitch propellers were being developed for airplanes during World War I. The original versions of these propellers existing at the time, such as those on airships, were not safe enough to use on airplanes (U.
S. Centennial). These propellers would not have had much of an affect on performance, anyhow. Before the war, airplanes were still slow and flew at relatively low altitudes. This would have made the propellers unnecessary; but as air technologies continued to advance, they became increasingly practical. By 1920, airplanes were being built with variable-pitch propellers and were able to produce significant thrust (U. S. Centennial). The development of variable-pitch propellers played a major role in improving aircraft performance.
Within the last few years of the First World War, airplanes were beginning to be built entirely out of metal. The development of airframes was one of the most significant of improvements of air technologies. The standard construction of earlier planes consisted of fabric stretched over a wood frame. These materials were lightweight and readily available (Greatest). In 1917, the German professor of mechanics Hugo Junkers introduced the first all-metal airplane. He called it the Junkers J4, and it was built almost entirely out of a relatively lightweight aluminum alloy, duralumin.
It contained steel armor which could be found around the fuel tanks, engine, and crew (Greatest). This German airplane would have been indestructible, but it was used to late into the war to serve much of an effect. By 1920, the American pilot John M. Larson demonstrated the value of an imported passenger plane, the Junkers JL-6 (U. S. Centennial). It brought great excitement to the American aviation community. The National Advisory Committee for Aeronautics expressed their approval declaring that metal was superior to wood. By 1924, the United States Navy had its own all-metal aircraft (U. S. Centennial).
The creation of all-metal aircraft structures paved the way for a stronger, more powerful air force. Around the years 1925 and 1926, lightweight radial engines were invented and effectively placed within airplanes, allowing for further technological advancements. They were a powerful type of air-cooled engine which replaced water-cooled engines (Greatest). Their shape provided for more efficient cooling. Air was able to pass around each cylinder, like through spokes in a wheel. They were also powerful and reliable. The earlier water-cooled engines would occasionally leak, burst a hose, corrode, or fail to pump water (U.
S. Centennial). These engines could be completely housed inside the fuselage to reduce drag, but too many problems arose to mark them as sufficient. Also, water-cooled engines did not offer as much power. The radial engine revolutionized aeronautics by supplying the strength required for larger, faster aircraft in a lightweight structure. During the mid-1920s, engine cowlings were placed over the front of airplanes. They were practical for those with radial engines. Before, engines were exposed so that air was able to flow over the cylinder heads and thus cool the engine.
However, this presented a problem concerning the drag that resulted (U. S. Centennial). Cowlings were designed to reduce drag while still allowing air to cool the engine. Forming the most efficient covering that would not disrupt airflow was seemingly complex. Every aircraft had to have its own specialized cowling design (U. S. Centennial). The successful construction of low-drag engine cowlings was a technological achievement that effectively reduced drag. Retractable landing gear became essential to airplane design. Aeronautical engineers found that protruding landing gear contributed to drag.
They were not only a hindrance to speed, but also to fuel efficiency, maneuverability, and controllability (U. S. Centennial). Airplanes would fly faster and smoother if they could retract their landing gear. Fixed landing gear was easy to design, strong, and fairly light. However, it contributed up to forty percent of fuselage drag (U. S. Centennial). Any new landing gear had to remain strong and light to be effective. Retractable landing gear greatly improved the overall efficiency of airplane structures. The United States introduced various bombing planes during World War II.
These were much larger than fighter planes and included more guns situated at different locations. Medium sized bombers supported ground troops by targeting fortified positions, warehouses, and railroad stations; however, the most significant bombers were the B-17, B-24, and B-29 (“Army Air Forces Aircraft”). The B-17 “Flying Fortress” was first of the giant bombers having four radial engines. It was extremely popular throughout the war. But the B-24 “Liberator” was produced in greater number than any other aircraft. This bomber could have been found operating in every combat theater of the war.
It had exceptional range, reaching distances of three thousand two hundred miles (“Army Air Forces). Built in 1942, the B-29 “Superfortress” was primarily used in bombing raids against Japan. It became the largest and was able to fly three thousand seven hundred miles—farther than the B24—at more than three hundred miles per hour. It was over one hundred forty feet wide, almost one hundred feet long, and weighed more than one hundred thirty-three pounds (“Army Air Forces”). These enormous bombers were the ones used to drop the atomic bombs on Hiroshima and Nagasaki in August 1945.
As World War II progressed, the United States built larger bombers capable of traveling farther and carrying more weight. Near the end of World War II, jet engines were being put into airplanes. By 1939, the first jet engine designs were being experimented with. Although the Germans designed some of the first jet engines, the British also had designs of their own, which they shared with the United States. General Electric built America’s first jet fighter, the Bell XP-59 (U. S. Centennial). Both the Allies and the Axis Powers were testing new jet airplane models before the end of the war.
Adolf Galland, a commander in Germany’s Luftwaffe, commented on the Messerschmitt ME 262: “For the first time, I was flying by jet propulsion and there was no torque, no thrashing sound of the propeller, and my jet shot through the air. It was as though angels were pushing” (Greatest). The jet engine gave more power and thrust in a fairly compact size, enabling airplanes to travel at much faster speeds. Even so, jets came around too late to have any effect on the outcome on the war. Aircraft carriers played an important role in transporting United States aircraft. In 1919, a ship had been designed pecifically to launch and recover airplanes while at sea—the USS Langley (“The US Navy Aircraft Carriers”). Catapults were fitted onto the flying deck. They would compensate for the lack of runway so that airplanes could reach take-off speeds. Arresting gear was also installed onto carriers. Airplanes landing on the ship had tail-hooks attached underneath. They would have to catch onto a steel cable which would stop the aircraft before reaching the length of the ship. In 1934, the Naval Aircraft Factory constructed a flush-deck hydraulic catapult called Type H Mark I (“The US Navy”).
It was designed to launch land planes from aircraft carriers. Aircraft carriers contained many new innovations that helped strengthen United States air power. Simple devices were installed into aircraft to help pilots maintain altitude. Pilots used a bubble in liquid to help in keeping an airplane’s wings level (U. S. Centennial). It was a basic design that revealed any imbalance or tilt. They also used an altimeter to measure air pressure at different heights (Bailey, 12). Pilots could find their altitude above ground level through this device, although it was somewhat dangerous.
It was typical for the standard altimeter in the 1920s to register ten seconds late (Bailey, 12). These simple devices were used in aircraft for navigational purposes and made flying relatively safer. Radar became a necessity to aircraft during World War I. The first practical radar system was created in 1937 by the British scientist Sir Robert Watson-Watt (Greatest). American and British physicists continued to make advances to improving radar and sonar technology. The British soon made radar airborne (Brinkley, 820). It was miniaturized and could efficiently be put into aircraft. It was used by pilots in the air to detect enemy aircraft.
The Allied Powers would remain far beyond the Axis Powers in radar technology. The advancements made with radar contributed to the Allies’ win in the Second World War. Bombers used electronic devices to guide their bombs to their targets. The Gee Navigation System was created by the British, but was further developed into LORAN system by the United States (Bailey 55). Electronic pulses were synchronized with ground transmitters to help pilots plot their exact location. Before, only highly-skilled navigators could do so. Studies showed previous night-bombing raids had only been thirty percent accurate.
Bombers with the Gee system had now doubled their accuracy (Brinkley 821). The United States had developed radar and radio guidance systems to improve its bombing capabilities. Before the 1930s, flagmen were used to direct aircraft as they were landing. Different methods were used with different colored flags (U. S. Centennial). By the 1930s, radio towers were being installed. Radio controllers could directly provide aircraft with information while landing. Also, lights were now being used to mark runways (U. S. Centennial). Control towers and other runway technologies have offered pilots safety and order while landing.
New aircraft landing technologies were being introduced in the late 1920s and early 1930s. These technologies made landing much safer and less challenging. Ground Control Approach consisted of two radar displays involving cathode ray tubes. One displayed the approaching aircraft to a radio operator, another to the pilot determining how they should steer and what angles to use (U. S. Centennial). This process and equipment made landing less demanding. The Instrument Landing System used high frequency transmitters to draw an electronic picture of a glidescope onto cockpit instruments.
It was tested and proven to be helpful for blind landings. In 1945, the United States Army introduced a higher frequency transmitter created to reduce static and to form straighter courses. It was called the Army Air Forces Instrument Approach System Signal Set 51 (U. S. Centennial). These and other navigational technologies greatly advanced aircraft landings. During the 1920’s, wind tunnels were becoming much more advanced than they had previously been. There were over twenty wind tunnels existing throughout the world, yet they all were operating at normal atmospheric pressures (U.
S. Centennial). It was demonstrated that airflow conditions can act much differently on a model than on a full-scale aircraft. Since it was deemed too expensive and impractical to build large tunnels for full-size aircraft, it wad figured that a tunnel operating at high pressures could compensate for size. By 1923, the United States had built the Langley Laboratory’s Variable Density Tunnel, which was a wind tunnel placed inside of a strong pressurized tank. This was the most advanced for its day. The United States became a leader in aeronautical research.
Later, in 1927, another wind tunnel, the Propeller Research Tunnel, was built at Langley Laboratory (U. S. Centennial). It enabled engineers to experiment with full-size aircraft fuselages. Researchers found design flaws in airplane structures which caused a great deal of drag. The National Advisory Committee for Aeronautics also began constructing its first high-speed wind tunnel. Wind tunnels were used by scientists to discover ways to improve aircraft designs. In the years before 1930, electromechanical flight simulators had been invented and were put into use (Greatest). Flight simulators were a safe practical way to train pilots.
They taught pilots many basic operating procedures without the cost and danger of using a real aircraft. Emergency situations could be practiced without having to accept any undesirable consequences. Pilots could learn how to fly without leaving the ground until readily trained. Military pilots were able to receive their training without taking many costly trips in real aircrafts. In 1929, Edwin A. Link patented his Link Aviation Trainer. It was a training device that could simulate the feel of an aircraft’s controls. He later designed the Link Model 45, with which he sold thousands to the United States military (U.
S. Centennial). Almost every American World War II pilot was trained in a flight simulator (Greatest). Air Force pilots were now better trained and developed an experience for difficult situations. American doctors and scientists looked into using animals for military purposes. A World War II experiment classified Project X-Ray was undertaken by the United States Navy. Incendiary devices were attached to living bats to determine if they could be released from aircraft and into enemy cities (Pedersen, Scott). A bomb-like canister with a parachute could be dropped from high altitudes carrying over a thousand bats.
Timers would have been set on the napalm devices and the bats released just before dawn. The idea was that when daylight approached, the bats would look for dark recesses in homes and buildings. Once the bats were secure and asleep, the devices would ignite. This plan, however, suffered many difficulties. At one time, the bats woke early from their hibernation state and burnt down the brand new Carlsbad Auxiliary Army Air Base in New Mexico (“Bat Bombs Away! ”). Another experiment was developed during World War II by behavioral psychologist B. F. Skinner.
He attempted to harness the pecking movement of pigeons to steer missiles (“Nose Cone, Pigeon-Guided Missile”). The nose cone was divided into three compartments, each with a pigeon inside. While the missile was plummeting to earth, each pigeon would peck at the target on its screen activating a guidance system. The United States military eventually dismissed the idea calling it impractical. After being confronted by the failure of World War II “ani-missile” experimentation, the United States military finally resigned from using animals to fly its bombs.
The Untied States government established the Manhattan Project in 1939. It was a secret project for the development of the nuclear bomb, the most powerful and destructive weapon ever devised. The government secretly spent approximately two billion dollars towards the effort (Brinkley 839). The research for the project was conducted in hidden laboratories scattered around the nation; scientists in Los Alamos, New Mexico were charged with the assembling of the bomb. By the summer of 1945, the government was ready to test their nuclear weapons. The war in Europe was now over, but Japan continued to resist surrender.
In August 1945, Truman ordered the bombing of Hiroshima and Nagasaki. Over one hundred eighty thousand people died between the two explosions (Brinkley 838-839). The United States military made an immense technological achievement with the creation of the atomic bomb. The United States air forces used many new and further developed technologies between World War I and World War II. During this era, airplanes had rapidly evolved into their fundamental form. Today, aircrafts are taking on new shapes and are being modified in several ways. But they have not lost the basics constructed from 1914-1945.
The weaponry, aircraft structure, and navigation of World War I and II remain today, having been updated and further developed. Aviation continues to be a major component to the United States military. Works Cited “Army Air Forces Aircraft. ” Air Force Historical Studies Office. 3 January 2006. 9 June 2008 . Bailey, Ronald H. The Air War in Europe. Chicago: Time-Life Books, 1979. “Bat Bombs Away! ” Defense Tech. org. 5 June 2008 . Brinkley, Alan. The Unfinished Nation: A Concise History of the American People. New York: McGraw-Hill, 2000. Cox, Kim. “aWarbirds—Fighter Planes of WWI. WWI Aircraft. 5 June 2008 . Greatest Engineering Achievements of the 20th Century. National Academy of Engineering. 2008. 26 May 2008 . Nelson, Melissa A. “U. S. Technology: History—Aviation and Military Technology. ” Suite101. com. 29 May 2008 . “Nose Cone, Pigeon-Guided Missile. ” History Wired. 5 June 2008 . Pedersen, Scott. “Bats in Military Service. ” BatHead. 5 June 2008 . Century of Flight. 9 June 2008 . “The US Navy Aircraft Carriers. ” Navy. mil. 4 June 2008 . U. S. Centennial of Flight Commission. U. S. Centennial of Flight Commission. 29 May 2008 .