Pub. 7 2017 Issue 2

14 AT THE CENTER OF UTAH INDUSTRY T he first airplanes were built of wood and cloth. For example, the Wright brothers built the Wright Flyer from spruce and ash and covered its surfaces with muslin. The Red Baron, a German pilot named Manfred von Richthofen (1892 – 1918) who was famous for his dogfights during World War I, flew many wooden planes. When he died, the British Royal Air Force gave him a funeral with full military honors because of their admiration for his courage and skill. Using wood and fabric soon led to problems: wood and fabric don’t last long, and planes made from these materials needed far too much maintenance. It didn’t take long before those building planes were seeking alter native materials. The Ford Tri-Motor became the first passenger plane in 1928; it was made out of aluminum. Later on, so was the Boeing 747. The Boeing 247D (1933) and the Douglas DC-3 (1935) are two examples of why metal became the material of choice for airplanes during the 1930s. In many ways, they are not substantially different than the planes being built today. The DC-3 is still in use 80 years after its first flight, is likely to continue being around until it hits the century mark, and is a favorite of enthusiasts who take an interest in the history of airplane flight. Even at the beginning of the age of aviation, at least one person thought building planes with metal was a better idea than the perishable alternatives. Count Ferdinand Zeppelin (1838 – 1917) used aluminum instead of wood or cloth when he was building his Zeppelin airships. His efforts were initially very successful, as evidenced by the fact that an airship crossed the Atlantic Ocean before an airplane duplicated the feat years later. The first airship crossing took place in August 1919, about eight years before Charles Lindbergh’s famous flight between New York and Paris in May 1927. Airships, in fact, looked like the direction of the future for air travel. It wasn’t until the Hindenburg aircraft caught fire and crashed in 1937 at Lakehurst, New Jersey, killing the 36 people who were on board at the time, that the idea of airships built to carry passengers came to an end. What are the main requirements for materials to build airplanes? Planes are held up by air pressure, and they also have to resist the power of gravity. That means any materials used to build them need to have the following qualities: • High specific strength • Light weight • Resistance to corrosion, cracking, fatigue load, and heat What materials currently provide these characteristics? • Aluminum: Most airplanes built today use aluminum alloys in 75 to 80 percent of the plane. Aluminum is effective as a building material because it is strong and light, and it conducts heat and electricity well. Aluminum also resists corrosion. The only problem is that at high temperatures it becomes weaker. As a result, it is not well-suiting to being on the skin surface of an aircraft, especially those that fly faster than two times the speed of sound. • Steel: As an alloy of carbon and iron, steel is stronger than aluminum, but it is also three times heavier. At the same time, it has high resistance to heat. Engineers use it in the landing gear because of its hardness and strength. They also use it on the airplane’s skin surface. Making Planes