The Aviation Industry

History of Aviation

The origin of the airplane is preceded by the origins of the hot air balloon, which can be confidently called the first time humanity actually achieved powered flight. The discovery of the hot air balloon resulted from a relatively simple observation made by Joseph-Michel Montgolfier, who noticed that when he tried to dry laundry over a fire, the pockets inflated and began to billow upward. Extrapolating from this observation, Joseph-Michel Montgolfier, along with his brother Jacques-Etienne Montgolfier, commonly referred to as the Montgolfier brothers, constructed the first hot air balloon of its time. The giant globe that made up the balloon was made of sackcloth, held together with three layers of paper on the inside. A fishing net of cord stabilized the balloon by covering its outside. On June 4th, 1783, in Annonay, France, the balloon took off, flying for approximately 10 minutes and reaching altitudes of up to 1,600 to 2,000 metres in the air, making the endeavor a resounding success. Together with Jean-Baptiste Réveillon, Jacques-Étienne Montgolfier began work on designing an even larger balloon to be flown in front of a much larger audience. The 37,500 cubic foot balloon with additional measures such as a coating of alum to ensure the balloon was fireproof, was named The Aerostat Reveillon. It took flight in Versailles, France, before  King Louis XVI and Queen Marie Antoinette, carrying three animals on it. The Aerostat Reveillon landed safely 2 miles away with all three animals surviving unharmed. 

In light of these successes, the innovation of the first Hydrogen Balloon Emerged. Designed by Anne-Jean Robert and Nicholas-Louis Robert, this balloon consisted of an airtight gas bag that was stitched together with rubber and silk. This also marks the occasion of the first manned flight of a hot air balloon, which took place on December 1, 1783, in Paris, making the Montgolfier brothers the first humans to achieve flight. The flight, which was witnessed by an estimated 400,000 people, caused a massive ballooning surge in the 19th century as hot air balloons began to be produced at a rapid pace for purposes of entertainment, scientific research, and their applications to warfare. During the US Civil War, the Union Army revolutionised the role of hot air balloons in the military through their use in reconnaissance missions.

The invention of steam power revolutionised the aviation industry. Henri Giffard, a French engineer, developed the first steam-powered airship known as a dirigible. It was a hydrogen-powered airship that utilized a three-horsepower steam engine and a giant propeller. On 24 September 1852, the Giffard Dirigible made the first ever steam-powered flight from Paris to Elancourt. The ship was also steerable, allowing its pilot to maneuver the airship in any direction they wanted. Then, in 1884, Charles Renard and Arthur Krebs launched an even more powerful dirigible called La France. La France had an electric motor with 8.5 horsepower, surpassing that of the Giffard Dirigible, which had an electric motor of 3 horsepower. La France is also marked as the first ever successful round-trip flight.

However, these dirigibles were quite frail and had relatively short flight times. This led to the invention of blimps, which lacked an internal structure like dirigibles and instead maintained their shape through the use of pressure from the lifting gas. In addition, the creation of the blimp also coincided with the switch from lifting gas made of hydrogen to one made of helium, which was seen as a much safer option due to the flammability of hydrogen gas. 

At the turn of the century in 1899, German inventor Ferdinand von Zeppelin began construction of the first Zeppelin airship. As a military observer during the American Civil War, he recognized the potential of airships in modern warfare and, accordingly, designed an airship with a greater cargo-carrying capacity, enabling it to mount military-grade weapons on board.

Soon after came a set of brothers who, in history, are considered pioneers of modern aviation: the Wright Brothers. Orville Wright and Wilbur Wright designed the Wright Flyer, the first piloted, engine-powered airplane. Being made entirely of spruce wood, the wings of the Wright Flyer were designed to be symmetrical to give the plane greater stability. The Wright Flyer was more powerful than previous iterations of airships with a 12-horsepower gasoline engine. The Wright  Flyer completed its first successful flight on December 17th, 1903.

In 1904, the Wright Brothers designed the Wright Flyer II, which differed from its predecessor in that it was made of pine wood instead of spruce wood. By using a more powerful engine, the Wright Flyer II was much heavier than the Wright Flyer. As such, much of the initial launches ended in failure, except for one. In this case, the Wright Brothers successfully launched the Wright Flyer II by using a catapult to enable the plane to gain sufficient speed for takeoff.

Soon after, at the end of 1904, the Wright Brothers began to design the final model of the Wright Flyer, the Wright Flyer III. On an initial test on July 14, 1905, the plane crashed in a nose dive, sustaining serious damage. While rebuilding, the Wright Brothers made certain modifications to the Wright Flyer III to improve its stability and reduce the likelihood of a crash. Certain modifications included doubling the size of the elevator and rudder, expanding the skid undercarriage, and placing two radiators on the front and back struts. On October 5, 1905, the Wright Flyer III made a record-breaking 39-minute and 23-second flight over Huffman Prairie.

As is the case with most modes of transport, the aviation industry underwent several changes during World War I. The German Army utilised Zeppelin airships in their army, while the US Army Signal Corps purchased the 1909 Wright Military Flyer to use in their air force. In arming these airships with machine guns, the Allied Powers and Central Powers made great use of these airships when conducting grand aerial battles.

In 1915, German engineer Hugo Junkers invented airships made entirely of metal. During the period after the war, the US and the Soviet Union began designing their own airplanes made out of aluminum instead.

In 1929, US aviator Jimmy Doolittle developed instrumental flight whereby the plane is able to take off, fly, and land using only flight instruments.

The invention of the jet engine propelled the aviation industry to new heights. In the early 1930s, the Turbojet was separately invented by English inventor Frank Whittle and German inventor Hans von Ohain. The first Turbojet aircraft, however, made its maiden journey in August 1939 in Rostock, Germany. Following this, the world of hypersonic air travel became a prime focus for aviation inventors. In 1967, the X-15 hypersonic aircraft broke the global airspeed record by travelling at 4,534 miles per hour. 

The world of commercialized aircraft emerged due to the increased efficiency and carrying capacity of aircraft, as well as rising demand for air travel. As such, now a majority of international travel is conducted via planes, making the industry a highly valuable asset in the fight against climate change. Air travel alone accounts for 2% of global emissions, with various innovations being introduced to address the issue of sustainability in the aviation industry.

History of Sustainability in Aviation

Aviation has long been linked with the idea of sustainability. Early hot air balloons such as those created by the Montgolfier brothers were quite unsustainable as they relied solely on the power of the heated gas that provided the lifting gas needed for the hot air balloon to fly. The Montgolfier brothers utilized fuels made of straw and wool, which they burned to provide the energy to lift the balloon. However, the rapid burning of the fuel and the inefficient transfer of energy from the fuel to heat energy caused the fuel to run out very quickly. As a result, hot air balloons, which primarily use heated air as the lifting gas, had very short flight durations and low altitudes before the fuel was exhausted.

The utilisation of hydrogen as a lifting gas marked a change in the industry, as hydrogen allowed for much longer flight durations as well as generally higher altitudes. This was due to the fact that hydrogen is much lighter than air and is not reliant on fuel to lift the hot air balloon. As such, while previous hot air balloons could only stay afloat for a couple of hours, the use of hydrogen allowed gas balloons to stay afloat for days. Additionally, the uneven burning of fuel causes hot air balloons to have uneven altitudes, whereas gas balloons have more stable flights. However, in response to safety concerns regarding the use of hydrogen, specifically the flammability of hydrogen, which makes hydrogen gas balloons incredibly dangerous, gas balloons have adopted helium as the lifting gas instead. Its inert nature makes it a safer choice. However, both hydrogen and helium are incredibly rare gases, making this route of aviation unsustainable. This has sparked a race in the industry to find a more sustainable fuel, while also designing more efficient planes to further reduce their environmental impact.

As such, steam power was seen to be a more sustainable energy source than helium. While helium was a limited resource that was incredibly rare, water used to make steam was incredibly abundant. The conversion of water into steam occurs in various ways, including the burning of fossil fuels like coal. As helium was rare and would eventually run out, steam was seen to be a much more sustainable resource. However, in this case, the use of steam also had its drawbacks in terms of sustainability. While helium is light, allowing the balloons to fly long distances, steam engines are much heavier, causing the weight of the balloon to increase drastically and limiting its ability to fly shorter distances. As such, to fly the same distance as a helium-powered balloon, the steam engine would have to produce significantly more steam, utilizing a substantial amount of the fossil fuel, thereby lowering the overall efficiency of the engine. In addition, the burning of fossil fuels to produce steam releases harmful greenhouse gases, such as carbon dioxide, which exacerbates the effects of global warming when released into the atmosphere.

To combat this issue, gasoline engines began to be adopted. With the invention of the Wright Flyer planes, the Wright brothers began to use gasoline-powered engines. Gasoline engines were much more efficient than steam engines, resulting in a higher energy output per unit fuel used. As such, while carrying the same mass of fuel, diesel engines, such as those used on the Wright Flyer aircraft, were able to power the aircraft for a longer period than the steam engines on the Dirigibles. With less refueling needed, the Wright Flyer used up less fuel and was, hence, seen as more sustainable than the Dirigibles. Additionally, per unit of fuel used, gasoline engines had a lower greenhouse gas output than steam engines, making diesel engines less harmful to the environment.

However, the adoption of gasoline engines resulted in certain problems of its own, namely, the emission of the oxides of nitrogen. These nitrous oxides (NOx) are harmful to the environment because they are potent greenhouse gases. These types of NOx were much stronger greenhouse gases than the carbon dioxide released by steam engines. In addition, NOx is harmful to human health, as continued exposure to such gases leads to various respiratory illnesses, including asthma, as well as certain types of respiratory cancer. The introduction of the diesel engine, a more efficient alternative to the gasoline engine, only exacerbated the issue, as diesel engines had a higher rate of output of both NOx and carbon dioxide, making them significantly more harmful to the environment.

While diesel engines have a wide variety of advantages for low-flying aircraft, the switch to jet engines powered by kerosene occurred due to the desire for faster planes that could fly further in a shorter period of time. To achieve greater speeds, planes began flying at higher altitudes. At these altitudes, jet engines have a slightly higher efficiency than diesel engines. Additionally, as jet engines enabled planes to achieve hypersonic speeds, unlike most diesel engines, the use of diesel engines slowly became less desirable. However, jet engines use kerosene, a fossil fuel with a high carbon content. As such, jet engines have a much higher carbon emission rate than diesel engines.

As such, aviation has increased in global prominence, accounting for a greater proportion of global greenhouse gas emissions, at 2-3%. However, this number is only expected to grow as the aviation industry expands in terms of travellers and trade. And with the fact that other industries are decarbonizing faster than it is, it is vital that the aviation industry continues to innovate so as to improve its global footprint 

Future of Sustainability in Aviation