Major Advancements in Aviation by Eleanor Brunsman
Aviation has come a long way. With humble beginnings in a bicycle shop in Dayton, Ohio, the leaps and bounds are nothing less than remarkable. Aircraft such as the Model XI inspired a record-setting culture and led to major advancements in reconnaissance and bombers. Glenn Curtiss, a famous engineer and pilot, changed the aviation world forever with the Jenny, which brought airmail and barnstorming; he made advancements including dual pilot control, ailerons, and retractable landing gear. At the same time, Sikorsky was changing the industry within another sphere of the industry with flying boats, helicopters, multi-engine aircraft, and luxury in the airplane. The focus of advancements would quickly change from luxury in aircraft to how they can be used as a weapon; combat forced the world into advancement. The planes that entered WWI were nothing like the planes that left; there were major improvements on drag reduction, airfoils, stability, control, handling, and structural design. The Sausewind introduced the propeller, encouraged aircraft racing, and quickly led to the Boeing Monomail with an engine cowling and retractable landing gear. Sir Frank Whittle ignited the Jet Age with a patent for a jet engine. The Lockheed XC-35 introduced the pressurized cabin. Amelia Earhart set a multitude of solo flying records and inspired people to take up aviation. Tex Johnston demonstrated the speed, strength, and maneuverability of commercial aviation and paved the way for today’s commercial aircraft. The War on Terror inspired fear in the hearts of many people and aviation will never be the same. This is only the beginning.
The Wright brothers had a major impact on aviation; they launched not only mechanical flight, but also, strategies for aircraft guidance. In 1900, they built their first experimental design. They proceeded to improve on their designs in 1903 and 1904, but these designs only connected pitch and yaw, which are explained in Figure 1. In 1903, they were met with success when their flyer took off out of Kitty Hawk, North Carolina. This flyer established independent 3 axis control, which involves yaw, pitch, and roll, and set a standard for all aircraft to come. After this success and because they knew the military funded such projects, the Wright brothers immediately thought of how useful the airplane would be to the military. However, the US Army Board of Ordnance and Fortification saw their proposal as just another request for money with a potential flying machine. The brothers then wrote a letter to Secretary Taft, who sent it to the US Army Board of Ordnance and Fortification, who again rejected their proposal. Luckily, President Roosevelt caught wind of the flyer and directed Taft to work on it. After a good amount of progress with the Army, a crack in the propeller sent Lt. Thomas E. Selfridge barrelling into the ground, seriously injuring Orville, who was instructing him. Progress was put on hold for a year, but the 1909 flyer came back with major improvements and passed all of the Army testing. The Wright flyer, in reality, wasn’t in great shape. It needed repairs after almost every flight. At this time, flight instruments consisted of a single piece of tape, signaling whether the pilot was climbing, gliding, skidding, stalling, or turning. The Wright brothers turned their focus to maintaining a business; Orville liked selling airplanes, especially the new Wright Model B, which can be seen in Figure 2, and they began instructing. Wilbur would die soon thereafter due to Typhoid, but Orville pursued his passion for as long as he could keep up with the business on his own. Three years after Wilbur’s death, Orville sold the Wright Company, but together, the brothers made an irrevocable impact on aviators then and now.
Figure 1: Roll, Pitch, and Yaw F igure 2: The Wright B Flyer at the Wisconsin State Fair
Louis Blériot focused on improving aviation within the realms of distance and altitude. After many failed attempts, which can be seen in Figure 3, he finally developed the Model XI. His Model XI was meant to change the world. With it, he flew across the English Channel in 1909, but not without difficulty. The nose had a tendency to suddenly pitch down during high-speed dives, but he made it the 23.5 miles across the English Channel. With this first, he inspired many other aviators to set firsts of their own, whether that be in altitude, speed, endurance, or distance. The special thing about the Model XI was that it had an engine in front, unlike the aircraft to precede it. People started getting as many pictures as they could of the Model XI and began trying to build their own plane off the image. One of the most notable people that took inspiration are Jules “JJ” VanDersal, age 12, and his little brother, Frank; they successfully recreated the Model XI almost exactly, except on a budget. Frank later went on to establish an airport and a barnstorming operation. They went on to fly Jennys, which will be talked about later in this report, and standards. Thankfully, they kept the plane in relatively good condition and provided an authentic representation of the materials of the time, enabling museums to restore their aircraft. The Model XI eventually lead to major advancements in reconnaissance, bombers, and the first successful air exports. Just a few years later, Igor Sikorsky and Glenn Curtiss would radically change the aviation world.
Figure 3: A Blériot aircraft crashing into a crowd before the successful Model XI
Glenn Curtiss transformed the economic feasibility and early industrialization of aviation. He had the first successful publicly viewed steered flight in his June Bug because the Wright Brothers didn’t allow press, which prevented others from building off of their designs. His Jenny, the JN-4, popularized barnstorming and ignited the airmail service. This aircraft could be bought inexpensively, allowing the everyday person to buy an airplane. He worked with Alexander Graham Bell on powered flight. Curtiss developed ailerons and retractable landing gear, sold the first private plane, constructed the first pontoon aircraft, invented dual pilot control, received the first pilot’s license, and introduced planes to the Navy. He invented hydroplanes to satisfy the Navy’s need of planes that could land on water; as a result, he is known as the “Father of Naval Aviation.” He introduced the idea of firing guns from a plane. With G.H. Curtiss Manufacturing Company, Inc., Curtiss became the first US aircraft manufacturer. In 1910, the first radio communication occurred in a Curtiss biplane. He created the first military flying school and the first flying school. He had countless contributions to the aviation world, one of which can be seen in Figure 4, and was later inducted into the National Aviation Hall of Fame. At the same time, Sikorsky was making advancements.
The aviation world wouldn’t be the same without Igor Sikorsky, who focused on split modifications, specialization of aircraft, and helicopters. He introduced “Flying Boats,” known today as seaplanes. He created the first multi-engine aircraft, enabling major developments in bombers and reconnaissance. He ushered in intercontinental aviation and improved bombers. Perhaps his greatest accomplishment, however, was his career as a helicopter manufacturer; nicknamed the “Father of American Helicopters,” he invented the first successful helicopter, which can be found in Figure 5. He popularized the idea of cargo planes flying non-stop across the US. He developed the first aircraft that could be used for both military and civilians, a four engine biplane, which was made possible by his advancements in mountable nose and tail gun turrets. With this aircraft, he established dual controls and is widely admired for creating a sense of luxury in the plane; with cabin heating and cooling and the focus on a “grand” cabin via decorations, seats, a couch, and a bathroom, which was revolutionary at the time. Sikorsky’s developments within aviation occurred concurrently with many of the advancements of Glenn Curtiss. War was on the horizon, which proved to be beneficial for the development of aviation.
Figure 4: The Curtiss Monoplane
Figure 5: Orville Wright and Igor Sikorsky in front of a Sikorsky Helicopter
World War I brought many changes to the world of aviation, especially with the help of Hugo Junkers, as seen in Figure 6; the war was a catalyst of innovations aimed at military use, including bombing, guns, and reconnaissance. Junkers reinvented the airplane with his F-13, launched global air transport, and initiated the era of mass produced, all metal, aluminum alloy planes. He invented the first practical cantilever, which are also known as internally braced wings, producing greater lift and reducing drag. The war initiated major developments in drag reduction, airfoils, stability, control, handling, and structural design. People began experimenting with monoplanes, which quickly earned a reputation to be unsafe and unreliable. “The reputation of the monoplane was redeemed in 1915, by German engineer Hugo Junkers, who developed an all-steel low-wing monoplane, the Junkers J-1. This plane was covered with sheets of steel welded to the tubular fuselage. The center section of its fuselage and the center section of its wings were constructed as one unit. This made the wing structure stronger, and less susceptible to structural failure, than the semicantilevered wings of the Bleriot XI” (Ehrenman 27). Covered airplanes became popular to inspire airplanes to go faster and airfoils became thicker. The P-51 brought a multitude of new innovations, including the laminar flow wing. Control surfaces proved to be a major struggle; finding a balance between how far the controls had to be turned and how easily it should be to turn them proved to be complicated. As a result, many pilots died, but these experiments eventually inspired the control surfaces airplanes have today and inspired further advancements.
Figure 6: Hugo Junkers and his aircraft, the J4
Following World War I, air racing became popular and led to developments in propellers, wings, and retractable landing gear; this era became known as “The Golden Age.” Air racing demanded better construction, weatherproof housing for the engine so the racers could fly in any weather, and increased speed. Many of the popular aviators got their fame ignited or reignited in this era, including Amelia Earhart, Charles Lindbergh, and many more. Aviators from the war were still looking to be involved in aviation and there was a major surplus of Jenny biplanes so they began looking into aerial acrobatics. While the trophies caught the eye of the public, the race to set records had begun. Jimmy Doolittle performed the first blind takeoff and landing, during which he was unable to see outside the airplane due to a fabric hood, using only a directional gyro, artificial horizon, sensitive altimeter, and radio navigation to fly. Paul Bäumer’s Sausewind, which can be found in Figure 7, was the first airplane to have a mechanically controlled variable pitch propeller, which solved the problem of changing the engine thrust without having to change the engine power and speed of the propeller. It would become the basis for later high-speed transport and helped to popularize aircraft races. It was closely followed by the Boeing Monomail, as seen in Figure 8, which was one of the first planes to have an engine cowling, or a covering over the engine, and retractable landing gear, which had the major advantage of reduced drag. In the 1920s, the issues with retractable landing gear were that it was expensive, heavy, and unreliable. Pilots couldn’t trust that it would extend as it was supposed to and it sometimes collapsed on impact with the runway. Engineers couldn’t quite figure out the best way to balance retracting the gear and the amount of weight. This would also increase required landing distances and cancel out any of the benefits from reduced drag. In the 1930s, at the time of the Monomail, airplanes began to reach 200 mph; reducing drag became more important than reducing weight and retractable landing gear became popular. Two major issues at the time were the tendency of the aircraft to go into a spin or a stall. To resolve these, slotted wings and flaps were engineered. Slotted wings increased the maximum angle of attack, shortened the necessary take-off distance, and allowed for greater stability and maneuverability. Orville Wright developed the split flap. “[It] allowed pilots to perform steep dives at lower speeds, and to descend toward a runway at a steeper rate, making for easier landings. The split flap consisted of a hinged section on the trailing edge of the underside of the wing” (Ehrenman 29). The Golden Age paved the way for the jet.
Jet propulsion was ushered in with the designs and engineering of Sir Frank Whittle. In 1923, he entered the Royal Air Force, where he wrote a term thesis, predicting a rapid increase in speed in future aircraft. In order to achieve this, he predicted aircraft would fly at a higher altitude, which would necessitate an alternative way to create propulsive power; propellers and piston engines wouldn’t cut it. Within his squadron, he was known as a daredevil; he cheated death both in the air and on the ground a multitude of times. All of his engine proposals were quickly shut down by the RAF, but his colleagues encouraged him to apply for a patent. Today, Whittle is commonly referred to as the “Father of the Jet” because of his advancements with the jet engine and he helped start the “Jet Age.” His patent application for the jet engine became the building block for future engines. It was published along with all the specifications for the world to see. He began the race for creating the first practical aero turbojet engine. Whittle had just enough money to produce one prototype; on the second run of the prototype, he added one last piece and invented the first successful aero turbojet engine, which can be found in Figure 9. His designs would be used again 80 years later in airplanes such as the Concorde along with later developments in pressurization.
Figure 7: The Sausewind Figure 8: The Boeing Monomail
Figure 9: Whittle and his jet engine
The Lockheed XC-35 turned the focus of aviation to fuel efficiency. As airplanes became larger, the need arose for fuel to be used efficiently, which meant flying at higher altitudes where the air is thinner and fuel burned more efficiently. It was the first aircraft specifically designed with a pressurized cabin. This allowed passengers to fly higher without bulky suits and pointed the way to pressurized bombers and transports, beginning with Boeing’s B-29 and Model 307, which was the first in-service pressurized airplane. It was trusted to fly to great altitudes while maintaining pressure. Aviation had a terrible track record of successful flights; many people witnessed terrible explosions and crashes from airplane malfunctions. As time progressed, airplanes became more reliable and the crash rate began to go down. Louis Johnson, the assistant secretary of war in the United States, was a major advocate for military aviation. When the XC-35, which can be found in Figure 10, flew with him in it, people began trusting airplanes; if someone of his importance could fly, trusted the airplane to get him where he needed to go, and arrive safely, maybe airplanes weren’t so bad. Setting records within the industry quickly became popular after people began to trust the machine.
Figure 10: The XC-35
Amelia Earhart was both an icon and a promoter of the romance and drama of flight; she helped increase the public’s trust of aviation by introducing it into popular culture, attracting the media. She set the speed record over a 3K course and participated in the Women’s Air Derby, inspiring interest in aviation and air racing across the world. She was the first woman to fly solo across the Atlantic coast-to-coast, following only Charles Lindbergh. She was also the first person to solo the Pacific, flying to Honolulu from Oakland, California, which was the first flight where a civilian aircraft carried a two-way radio. She was the first person to fly solo from Los Angeles to Mexico City and the first person to fly solo nonstop from Mexico City to Newark. She helped establish an organization that promotes the advancement of women pilots, the Ninety-Nines, which still exists today. On June 1, 1937, she began a flight around the world; it was her second attempt to circumnavigate the globe. She was last seen alive July 2; she lost radio contact with the US Coast Guard and famously disappeared. There is a lot of speculation around her disappearance; President Roosevelt authorized a two-week search for her and her flight partner, Noonan, but nothing was found and they were declared lost at sea on July 19. According to some, she ran out of gas in her search for Howland Island and crashed into the ocean somewhere near the island. Others speculate that the two got off course and landed near modern-day Nikumaroro, which was uninhabited at the time, but Navy planes flew over it and saw some signs of habitation; they believe the pair survived for a little while before dying on the island. In general, however, people accept that they likely crashed into the Pacific Ocean somewhere. A photo of her can be found in Figure 11. Her disappearance did not stop aviation from advancing.
Figure 11: Amelia Earhart Crosses the Atlantic
Figure 12: Tex Johnston and President Dwight Eisenhower
Tex Johnston had a major impact on the economics of commercial aviation, especially within the United States. He was a test pilot for the Boeing 367-80. In 1955, Boeing President William Allen was walking the ground of the Seafair Gold Cup Hydroplane Races, talking to potential buyers, and he watched as his company’s pride and joy corkscrewed through the air. Tex, who can be found in Figure 12, took a huge risk with this maneuver. He could have destroyed the airplane, killed himself, got his license taken away, or all three. However, he successfully pulled it off and Boeing rocketed ahead in aircraft sales. Everyone watching could see that Boeing’s aircraft clearly had speed, strength, and maneuverability. His performance increased people’s trust in commercial aviation because the aircraft held despite the amount of stress he put on it. This airplane set basic jetliner configuration and raised the bar for North Atlantic air transport. It paved the way for the Boeing 700 series, which are some of today’s commercial aircraft. The 700 series jump-started the “Jet Airliner Revolution.” Air transportation was turning to focus on the regular citizen and away from the elite; a prime example of this was the Boeing 747s. They were large so they could carry many people and were available to people from different backgrounds. Then, as part of the Jet Airliner Revolution, the YF-16 brought computer controlled flight, increased stability, the production of a seat to aid the pilot with G tolerance, and the F-16A Fighting Falcon, which would become NATO’s main fighter. These large aircraft would change the world forever just a few years later.
Airplanes were soaring through advancements, but everything came to a screeching halt on September 1, 2001 when thousands of people perished because of people who used aviation to strike fear in the hearts of people. To some, 9/11 marks the beginning of the War on Terror. These attacks sent the world into a security frenzy; people were scared. Many people watched as major airlines were hijacked and barreled into the ground, the World Trade Center, which is pictured in Figure 13, and the pentagon; they lost friends, family, and coworkers. The FAA ordered civilian aircraft to land anywhere they could as quickly as they could and Canadian officials did the same. Within just a few hours, the only aircraft flying were military. Civilian air traffic would remain grounded for three days. People wanted to take action and prevent it from happening again, but arguments rose over passenger rights and security and where the balance is. The United States government implemented airport screening as part of the Aviation and Transportation Security Act, which included metal detectors and X-ray machines. TSA began pre-screening passengers and the Federal Air Marshals program was expanded. The focus at this point was turned to the security and safety of aviation. Aviation’s advancements will not stop here, however.
Figure 13: The World Trade Center September 11, 2001