Running head: ENVIRONMENTAL IMPACT OF THE AVIATION INDUSTRY 1
ENVIRONMENTAL IMPACT OF THE AVIATION INDUSTRY 38
Towards an Environmentally Sustainable Aviation:
Managing the Environmental Impact of the Aviation Industry
Environmental degradation caused by mankind are beginning to take a huge toll on the planet. The constant need for expansion in the aviation industry is depleting Earth’s natural resources and will be insufficient to satisfy mankind’s never-ending needs as time passes. Man’s needs have resulted in many detrimental impacts to the environment. Despite the aviation industry’s efforts in creating an environmentally friendly industry, it is still a major contributor to Earth’s carbon emissions. In 2017 alone, the aviation industry as a whole, has generated an estimated 859 million tons of carbon dioxide (CO2) (IATA, 2018). Increased Greenhouse Gases (GHG) and climate change have prompted a need for action from relevant authorities and organizations to come up with sustainable solutions to solve this ecological problem. This paper aims to examine areas of pollution within the aviation industry as well as come up with solutions to reduce the environmental impacts using sustainable methods. Sustainable methods include adopting newer clean-and-green technologies, better management, enhanced safety and improved legislation. Technological advancements play a very important role in creating a sustainable aviation. Hence this paper aims to explore new clean-and-green technologies such as alternative and sustainable fuels, biomimetic engineering and generative design technology can help to mitigate or possibly even eliminate, the industry’s negative impact on the environment. Furthermore, this paper will discuss about the legislative powers of regulatory bodies on order to determine commercial airlines liabilities when conforming to regulation being imposed by organizations such as ICAO and FAA. Also, this study will investigate on the potentials of alternative technologies such as machine learning and the obsolescence of manned flight.
Keywords: Sustainable, aviation, environmental impact, pollution
Towards an Environmentally Sustainable Aviation:
Managing the Environmental Impact of the Aviation Industry
The aviation industry has come a long way since the Wright brother’s first manned flight in 1903. Today, at peak traffic, there is more than 16,000 flights in the air at any given moment (Morris, 2017). According to the World Bank (2018), in 2010, the aviation industry has transported an estimation of 2.6 billion passengers. In 2017, the number of passengers has risen to over 3.9 billion. This number is projected to rise to 16 billion passengers by 2050 (World Wild Life, 2016). Hence, without action, emissions from increased air travel will triple by 2050 (Word Wild Life, 2016). Thus, to protect Earth for future generations to come, world leaders, organizations and the public need to understand the aviation effects on the environment as well as come up with sustainable methods to reduce the overall negative environmental impacts of this industry.
The exponential growth of the aviation sector comes with a given price: the increased extraction of Earth’s natural resources. According to a data analysis conducted by the International Aviation Transportation Association (IATA), the aviation industry accounts for 2 percent of man-made carbon emissions, producing 859 million tons of CO2 in 2017 globally (IATA, 2018). 2 percent may seem like a small number to casual observers, however, the aviation industry is predominantly reliant on Earth’s finite resources and because of foreseen continuous growth in the future, there is a need for all stakeholders, organizations and airlines to focus on creating sustainable energy sources and solutions in the medium term. Natural resources such as minerals, oils and gases are being extracted at an alarming rate just to incessantly provide adequate infrastructure or fuel for the growing industry such as the construction of newer airports, aerodromes and technologically advanced aircraft.
The aviation industry being made aware of the gravity of the situation, recognizes the need to address the global challenge of climate change and therefore has come up with a four-pillar strategy in 2009 to address the climate impacts and to meet the carbon targets (IATA, 2018). The four-pillar strategy includes coming up with newer technology, improvements to aircraft operations, improvements to infrastructure and lastly, to create a single Global Market Based Measure (GWBM) (IATA, 2018).
To address the negative environmental impacts brought about by the aviation industry, in first pillar of aviation climate action: “New technology” was suggested as a means to target aircraft engineering and manufacturing sectors. Even though technology has been constantly improving and developing rapidly throughout the years, development of aircraft designs has been restricted by economic and time related issues (Fielding, 2017).
Figure 1. Aircraft Designs throughout the years. Retrieved from https://whyfiles.org/2014/on-the-wing-birds-skeeters-jet-planes-same-design-rule-applies/index.html
Figure 1 above displays many aircraft designs from the early 1900s to present day. Ostensibly, the core airframe design of the commercial aircrafts has remained relatively the same. Since there were no major design flaws with the aircraft, engineers do not see the value in making major changes to the design of commercial aircrafts (National Aeronautics and Space Administration, 1999).
Nevertheless, technology is becoming so advanced today such that technology can effectually supplement the proficiencies of skilled personnel and provide innovative ways to combat prevailing issues (McCarthy, 2017). According to McKnight (2017), “by effectively adopting the ability of the aforementioned technologies and infusing them into the process of aircraft engineering design, engineers and scientists are able to study details in mechanical and biological designs, troubleshoot design problems which were difficult to identify at earlier stages and run many simulations and come up with permutations to determine and achieve the most feasible design; thus circumventing conventional factors limiting the development of new, efficient, and eco-friendly airframes” (p. 176).
This paper aims to investigate and examine the adoption of various sustainable methods such as alternative aircraft fuels, the study of nature through biomimicry and generative design based on Artificial Intelligence (AI). The author will also analyze various ecological impacts produced through the aviation sector and determine how the adoption of aforementioned technologies can perhaps mitigate or even eliminate the negative impacts on the environment.
According to “The point of no return for climate action: effects of climate uncertainty and risk tolerance” (2018), Year 2035 is the deadline set for climate action to have a profound impact globally by environmental scientists (Aengenheyster, Feng, van der Ploeg, & Dijkstra, 2018). Aengenheyster et al (2018), estimates with a 67% probability, if no corrective action is taken by 2035, global warming will hit a point of no return and mean global temperatures around the world will increase by 2°C by year 2100 (Aengenheyster et al., 2018). This growing issue has prompted organizations and world government to take immediate action so as to mitigate the effects of global warming. Similarly, over 15,000 scientists have come together to be a signatory of the report “World Scientists’ Warning to Humanity: A Second Notice” (2017). The purpose of this report is to give humanity a second notice about these alarming trends. It aims to corral immediate collaborative action so as to mitigate the ecological detrimental activities by stressing upon the increasing production of carbon emissions. According to both reports, the present industrial production is beginning to surpass the threshold of the environment and is triggering irreversible and substantial harm to the environment.
According to an assessment report on transportation sector emissions done by the Intergovernmental Panel on Climate Change’s (IPCC), GHG emissions have increased by more than twice since the 1970s (Sims et al., 2014). This study has shown that the transportation sector’s emission rates have increased at a faster rate than any other energy end-use sector, amounting to 28% of total end used energy in 2010 (Sims et al., 2014). If global aviation were to be counted as a country, it would rank as the 7th largest emitter of carbon dioxide in 2011 (ICCT, 2014).
Exhaustible Natural Resources
One of the biggest drivers for the excessive extraction of Earth’s raw materials is that of burgeoning affluence. According to a report by the International Resource Panel (IRP), raw materials extraction has increased by over three times in 40 years, from 22 billion tons in 1970 to 70 billion tons in 2010 (Schandl et al., 2016). The constant harvesting of non-renewable resources does not bode well for the environment and could cause a shortage of critical resources in the near future as these resources would gradually deplete and cease to exist (Schandl et al., 2016).
Understanding this, Government agencies and other organizations have enacted countermeasures to the environmental issue. For example, by considering the associated environment detriments, the Australian government has come up with an initiative intended for a total shift of the whole country to renewable energy by 2030 and for 40% of its country’s transportation to be emission free by 2035 (Australia Conservation Foundation, 2016). This initiative will not only improve energy efficiency and reduce the detrimental impacts on the environment but also help to generate cost-savings of 20 billion a year on fuel costs (Australia Conservation Foundation, 2016).
Carbon Emissions and Climate Change
According to the American Meteorological Society, GHG emissions have already risen close to four times since the 1960s. The exponential increase of CO2 due to industrial demands has already hit an all-time high and is beginning to take a toll on the environment. Figure 2 below shows a sharp increase in CO2 emissions in 2016 hitting an average of 402.9 parts per million (ppm).
Figure 2. Carbon Emission Trends. Retrieved from https://www.climate.gov/sites/default/files/paleo_CO2_2016_620.gif.
One of the major drivers of carbon emissions is the combustion of fossil fuels. When being burnt for energy, fossil fuels releases stored carbon molecules from fossil fuels back into the atmosphere as CO2. CO2, being a greenhouse gas, absorbs heat and releases it gradually over time (Lindsey, 2017). It helps to keep the Earth’s annual average temperature close to 15°C, without it, Earth’s temperature would be below freezing point (Lindsey, 2017). However, the exponential increase in CO2 emissions has tipped Earth’s thermal balance, trapping more heat and raising Earth’s temperature higher before any recovery could take place.
In relation to aerodynamics, the increase in temperatures would adversely affect the aviation industry. Higher temperatures cause air to become less dense thus decreasing the performance of aircraft to climb. Lesser air density would result in lesser molecules of air around the wings to generate lift and reduced mass of air entering the engine cylinders for combustion. This ultimately increases fuel consumption, which further causes increased CO2 to be released into the atmosphere. Hence, there is a greater need for the aviation industry to focus and address the environmental issues at hand to break this vicious cycle.
Aircraft noise is a significant problem which needs to be addressed indefinitely. Noise pollution primarily occurs during the landing or take off phase where the aircraft is closest to the ground. In a study conducted by the National Institutes of Health (2017), it has been noted that noise pollution causes annoyance in a community by disrupting sleep and rest. Basner et al (2017), reports this has been linked to an increase risk of cardiovascular disease when individuals are exposed to relevance noise levels over a long period of time. Noise pollution caused by the aviation sector is currently regulated by authorities with compliance to IATA, ICAO or local authorities. One such example would be the Federal Aviation Administration (FAA), a governing body which regulates civil aviation in the Unites States (U.S.) to promote safety.
FAA has long recognized the effects of aircraft noise pollution and has been developing a variety of programs in a bid to understand how noise pollution would affect the environment and public health. FAA has come up with a multitude of programs and solutions to reduce those impacts and lastly, to educate its public on the problems and their ongoing efforts to reduce noise pollution (FAA, 2018). For one, FAA has begun an initiative to phase out older, noisier civil aircrafts. The agency has come up with a standard that requires the aircraft to meet or fall within the designated noise levels. There are four stages in this standard with stage one being the loudest and stage four being the quietest. Different states have different regulations in terms of aircraft noise levels. Some states require the noise level to be at Stage one, while some allow some laxity for Stage Two. Aircraft that do not meet these requirements are not allowed to fly within the U.S. Additionally, the FAA also has active programs such as The Continuous Lower Energy Emission, and Noise (CLEEN) program in a bid to tackle noise pollutions.
Even though federal and international agencies can step in to reduce noise impacts, it is usually the local authorities who control the land use decisions near airports (Waitz, Townsend, Gershenfeld, Greitzer & Kerrebrock, 2004). There are still many instances where federal land use guidance designed to mitigate these impacts are not followed by local authorities and have instead worsened the problem (Waitz et al., 2004). Even though some communities have taken a proactive approach in addressing the noise pollution near airports, there still exists a lack of regulation and communication between federal agencies and local authorities.
Despite this, there are still potential for technological and operational improvements when it comes to reducing nose pollution. This was evident in the plans made by the European Union (EU). In a report drafted by the Advisory Council for Aviation Research and Innovation in Europe (ACARE), plans were made to reduce perceived noise from aircraft to one half of the current average levels by year 2020 (ACARE, 2001). Additionally, National Aeronautics and Space Administration (NASA) has also planned to develop a technology which could reduce up to 50% in effective noise level (Waitz et al., 2004).
The International Civil Aviation Organization (ICAO) has also established a committee in 1983 to assist the council and formulate new policies and adopt a new standards and recommended practices to aircraft noise and emissions (ICAO, n.d.). It is known as the Committee on Aviation Environmental Protection (CAEP). ICAO’s CAEP has established a new global noise reduction standard, which already has rallied a number of supporters from various countries. The standard consists of noise reduction technology, community engagement for aviation environmental management, and continuing development standard for supersonic aircraft (ICAO, 2018).
Besides coming up with new policies, standards and technological innovations, the government can also reduce noise pollution by attacking the root cause of the problem. One such method to combat noise pollution is the relocation of airports and aerodromes to isolated areas with lesser people.
Even though noise is the main ecological constraint on both aerodrome operations and expansion, many airports still put air quality on equivalent foothold with noise pollution (Waitz et al., 2004). Aviation air pollution is typically caused by the combustion of fossil fuels in aircraft engines and aerodrome service equipment. When fossil fuels are combusted, harmful emissions such as nitrogen oxide (NO), carbon monoxide (CO), unburned hydrocarbons (UHC) and particulate matter (PM) are released into the environment (Waitz et al., 2004). These harmful emissions can result in local air quality degradation, which may deteriorate human health and accelerate Earth’s greenhouse effect. Cokorilo (2016) reports that even though air pollutants from transport are typically declining over the past decade, more than 80% of cities are still exposed to air pollutants produced by the transport sector.
One effective method to reduce air pollution is by accurately obtaining the emission output from aircraft. This can be obtained by calculating the amount of fuel it consumed during flight. However, calculating emissions may not be as simple as it is, factors such as weather conditions, engine model, engine size, distance, takeoff weight and flight altitude all need to be considered before one can produce accurate figures for emission output (Jardine, 2005). After obtaining emission figures, certain programs such as the Aircraft Particular Emission eXperiment (APEX) will be used to measure the emissions of the aircraft through intrinsic calculating technology in the system (NASA, 2006). World leaders and decision makers can therefore introduce safety measures according to the emission outputs to mitigate air pollution.
As an example, before the Environmental Protection Agency (EPA) was established, the United States was plagued with very severe air pollution. Twenty people were killed, and thousands were sick after a cloud of air pollution was formed over a local factory in 1948 (Ross, Chmiel & Ferkol, 2012). This tragedy was one of the few incidents which prompted authorities to establish the EPA so as to minimize environmental impact in the country. The first piece of effective air quality regulation was passed in the 1970 under the Clean Air Act (CAA). Under the CAA, the EPA has the right to control emission of pollutants which compromises health of the public and welfare. Moreover, EPA (2011), reports that in 2010 there was a significant drop in fine particle pollution and ozone pollution accomplished by the CAA. This act has helped to avoid an additional 160,000 premature deaths, millions of potential cases of respiratory problems, 130,000 potential cases of heart attacks, and 86,000 potential hospital admissions (EPA, 2011).
Decreased Mean Surface Albedo
Surface albedo is the measure of reflectivity of the Earth’s surface which determines its light reflection characteristics. The darker the surface albedo of the object, more light is absorbed, thus leading to the object trapping more thermal energy (Grenfell & Maykut, 1977). This is the reason why people tend to feel hotter when wearing darker colored clothes. Hence, white ice and permafrost play a very important role in Earth’s thermal regulation (Grenfell & Maykut, 1977).
As white ice and permafrost start to melt due to global warming, it decreases the surface area of white surfaces leading to less energy being reflected back into space. This phenomenon causes heat radiated from the sun to be absorbed, thus warming up the Earth even more (Grenfell & Maykut, 1977).
Consequently, permafrost acts as Earth’s natural repository for large amount of carbon and nutrients from organic matter (Gasser et al., 2018). Gasser et al., (2018) reports that as more and more permafrost is melted through Earth’s higher mean temperatures, it will release an inordinate amount of CO2 and GHG into the atmosphere thus warming up the Earth even further.
The Aviation Industry’s Role
The aviation sector, being one of the fastest growing sources of emissions is the most climate intensive form of transport. Greenhouse gas emissions in the aviation industry has risen by over 75% in a mere 22 years from 1990 to 2012 (UNFCC, 2014). The aviation industry is also accountable for roughly 5% of all man-made global warming (Lee et al., 2009). In spite of this, the aviation industry has the least governmental jurisdiction in the transportation sector perhaps due to the need for international standardization through organizations such as ICAO (Transport & Environment, 2016).
The International Civil Aviation Organization (ICAO) was initially created to promote the safe and efficient development of the aviation industry. However, since it was customary that international aviation was not included in the United Nations Framework Convention on Climate Change (UNFCCC) climate negotiations, the United Nations (UN) gave ICAO the right to emissions consistent with the goals of the Paris Agreement (ATAG, n.d.).
ICAO has no power over its signatories despite serving as the regulatory body for civil aviation (Abeyratne, 2007). ICAO has numerous experiences in environmental protection in the form of international Standards and Recommended Practices (SARPS) which serves as recommendations and guidelines for their signatories to follow. Failure to conform to ICAO’s standards would typically result in a suspension of an airlines right to operate in a signatory state or the removal of a voting power of a state (Abeyratne, 2007).
Annex 16 Volume II of the Chicago Convention deals with aircraft engine emissions. According to Liu (2011), “it contains SARPS for the control of smoke and gas emissions from aircraft engaged in international civil aviation” (p. 111). “The annex also contains SARPS which require certification of aircraft engines to prevent intentional fuel venting” (Liu, 2011, p.111). This practice involves the intentional discharge of fuel into the atmosphere during flight or ground operations (Liu, 2011). These standards are there to provide a standardized and uniform aviation practice around the world.
ICAO’s expertise and experience makes it an obvious choice to be aviation’s regulator in terms of climate change. However, it is only effective now due to a mutualistic agreement amongst their signatories. Furthermore, political complexities may undermine ICAO’s purpose in ensuring safety through international uniformity. One such example can be linked to Taiwan’s application to ICAO being rejected since China sees Taiwan as its own territory and not an independent state which is eligible to join UN agencies (Jennings, 2016).
Technology, Research & Development
Technological advancements in research and development has advanced dramatically over the last few years. With concerns over aircraft greenhouse gas emissions on the rise, it comes as no surprise for technology to also play a part in improving aircraft fuel efficiency and reducing aircraft emission outputs. The FAA and its NextGen Program attempts to understand, manage and reduce the overall environmental impacts caused by aviation so as to promote a sustainable aviation growth. One such area where NextGen has created, is a new interconnected system which allows National Airspace System (NAS) users to switch to a new satellite navigation system. The new satellite system helps FAA to create a more efficient and optimum routes for use anywhere in the NAS. The system provides precious and efficient navigation aids which can reduce flight time, fuel use and aircraft emissions (FAA, 2018).
Alternative Energy Sources
In order to create an eco-friendly industry, solutions need to be implemented to cut down on aircraft carbon emissions. Globally, the aviation industry produced 781 million tons of CO2 in 2015, with domestic aviation accounting for 35% and international aviation accounting for 65% of the 781 million tons (ATAG, 2015). Furthermore, the aviation industry in EU is expected to grow by over 80% by 2030, this will further drive global emission levels to an all-time high if nothing is done. Even though, aircraft fuel efficiency has improved by over two times since 1990, the increase in aviation activity still poses a substantial threat to the environment (ATAG, 2015). In order to cut down on carbon emissions in the environment, two methods are proposed: the usage of alternative fuel sources and improvements in engine fuel efficiency.
The production of energy using other sustainable and renewable sources no longer poses an issue. Hypothetically speaking, there will be no energy scarcity even if all coal burning power plants all over the world are replaced by renewable energy resources (Taylor, 2018). However, there need to be a means of storing energy cost-efficiently (Taylor, 2018).
Energy density is the measure of energy produced from 1kg of an energy source. It is represented by the unit “megajoule/kilogram”. Even the most up-to-date Lithium Ion (Li-ion) batteries being created at the moment have an energy density of around 1 MJ/kg (Green Transportation, 2018). On the other hand, aviation fuel such as kerosene has an energy density of 42.6 to 42.8 MJ/kg (Bisio & Boots, 1995). Hence, an aircraft with the intention to make use of electrical energy produced from alternative sustainable sources would therefore need to carry over an estimated 40 times the weight of fuel to produce the same amount of energy (Ng, 2018). With an increase in weight of the aircrat, more power is needed for the aircraft to take flight. Thus, in terms of both engineering and economic perspectives, this is an unfeasible design. There needs to be an option for the exploration of alternative engineering methods such as sustainable alternative and low emission fuels, biomimetic engineering and generative design based on Artificial Intelligence.
Alternative, Sustainable and Low Emission Fuels
The projected exponential growth of the aviation industry has led to the development of alternative jet fuels. In 2013, globally, jet fuel was used at approximately 5.7 million barrels per day, with 1.4 million barrels used per day by the U.S (EIA, 2013). The aviation industry is expected to increase by approximately 4.3% per year (ATAG, 2016). This projected increase in aviation demand could give rise to both fossil fuels consumption and GHG emissions if sustainable low emission fuels are not developed.
The benefits of switching to biofuels include creating more jobs and employment opportunities as well as creating a more sustainable and environmentally friendly alternative to fossil fuels. The aviation industry is already facing tremendous pressure and challenges from authorities to improving environmental sustainability and reducing its carbon footprint on the environment. Thus, using a sustainable and greener alternative such as biofuels could relieve some of the pressure on them.
However, unlike other unsustainable fuels such as diesel and gasoline, sustainable aviation biofuels are still a considerably new market and is in its early stages of development. In the short term, the most promising possibility is to be able to develop these sustainable biofuels for the aviation industry. Furthermore, bioderived ambition fuel has already piqued much interest from various manufacturers in the aviation industry. Airlines, engine manufacturers to fuel manufacturers as well as governments and international organizations such as ICAO are beginning to initiate the development and production of aviation jet biofuels. According to the Department of Energy (2017), “experts believe that biofuels are the key to mitigating the growth constraints of the aviation industry” (p. iii).
Biofuels are good contenders to reduce environmental impacts that may arise from the use of fossil fuels. Beginner’s Guide to Aviation Biofuels (2011), reports that aircraft biofuels made from oilseed camelina still has an 84% decrease in GHG emissions when compared to conventional fossil fuels over the entire lifecycle.
Figure 3. Lifecycle emissions of fossil fuels vs Biofuels. Retrieved from Beginner’s Guide to Aviation Biofuels, 2011
Figure 3 shows the lifecycle of aircraft running on fossil fuels versus one that runs on biofuels. As feedstock is used in the production of biofuels, CO2 from the atmosphere is being absorbed by these plants for energy. Through the burning of crop derived fuel, CO2 is released again. This cycle creates a positive feedback loop where a shorter carbon cycle is created. However, besides emissions from the burning of biofuels, additional emissions such as seeding, growing, harvesting, transporting are still created during the lifecycle (Beginner’s Guide to Aviation Biofuels, 2011).
Biomimetic engineering is the study of science which focuses on the imitation elements of nature to solve complex human problems (Miller, 2010). Biomimicry helps to seek sustainable solutions to human problems by emulating nature’s forms, processes and strategies (Miller, 2010). Nature has given scientists many options of materials that are multi-functional with adaptive functions which scientists desire to imitate. It is based upon the fact that scientists understand nature has been constantly evolving and perfecting solutions to universal problems for four billion years. Hence, biomimetics aims to use nature as a guide to derive sustainable alternatives to technical challenges in aviation (Miller, 2010).
Biomimetics, albeit seen as a new and emerging technology, has always been prevalent in human history. Leonardo Da Vinci, the founding father of Ichnology, applied biomimicry to the study of birds in a bid to achieve human flight (Vierra, 2016). Even though Leonardo Da Vinci was unsuccessful with his flying machines, his designs were used as a source of inspiration for the Wright Brothers who eventually created and flew the first airplane in 1903 (Vierra, 2016).
Figure 5. Biomimicry applications per different areas and their developmental stage. Retrieved from https://www-sciencedirect-com.ezproxy.libproxy.db.erau.edu/science/article/pii/S0734975014001517
The largest area of biomimicry research can be seen from figure 5 where close to 50 percent of all reviewed references is found in material development. Lurie-Luke (2014), noted that, “biomimetics material design can be categorized into four classes: (i) smart materials inspired by nature’s ability to react and change in response to external stimuli; (ii) surface modifications which include novel surface topographies with improved functions; (iii) material architectures which feature novel shapes and structural arrangements and (iv) technologies which are based on enhancing existing systems using specific parameters of an adaptation” (p. 1496-1497). Using biomimicry in material design has given new opportunities for material development across a range of industries, including optics, coating materials, medicine, agriculture and textiles (Lurie-Luke, 2014).
Biomimicry emulates nature at three different levels: form, process and system (Miller, 2010). Should engineers and designers be able to mimic all three levels, humans can begin to do what all well-adapted organisms learned to do which is to create conducive conditions to life (Benyus, n.d.).
Natural form. The first level of biomimicry is to mimic nature’s natural form. Natural form is the most common and simplest approach to using nature as its model (Miller, 2010). It emphasizes on the physical physiognomies of natural designs, for instance, mimicking the hooks of burdock burrs to make Velcro (Miller, 2010).
Natural process. The second level of biomimicry is the imitating of natural process or studying how something is made. This level is analogous with sciences such as chemistry to determine the processes essential to create materials from nature (Miller, 2010). One such example is the processing of spider silk. The spider uses common raw materials, without any form of pollutants, as per nature’s chemistry (Miller, 2010).
Natural ecosystems. The last level of biomimicry, to mimic natural ecosystems is to investigate how each product fits in to complete a system. This level attempts to create products and processes to fit in seamlessly within the larger system so as to work and restore rather than deplete Earth’s resources. One example is the Owl’s feathers. The owl feathers are part of an owl which is part of the forest that is part of a biome and is part of a sustaining biosphere (Benyus, n,d,). Hence, in the same way, this owl inspired fabric must be part of a larger economy which is able to restore rather than deplete Earth’s natural resources (Benyus, n,d,).
Biomimetics in Airbus Aircraft
For the past 2 years Airbus have been employing the use of nature as its source of inspiration for their newer aircrafts. Airbus has created a concept plane of what an Airbus aircraft would look like in the year 2050. It uses biomimicry as a guiding principle in their designs which aims to use fewer resources, lightweight structure, waste-free manufacturing, and wireless electrical systems, all of which can help in reducing GHG emissions and fossil fuel use (Rich, 2012).
Sharkskin surface. Certain Airbus models were fitted with small ‘riblet’ patches onto their fuselage and wings to mimic those of a sharkskin. Oeffner & Lauder (2012), reports that this ribbed nature of the shark helps to produce an anti-fouling effect which reduces drag on the aircraft. Airbus engineers have also tested and demonstrated that the ribbed edges on the aircraft is highly suitable for long-range aircraft, since its drag-reducing surface is particularly effective during high-speed cruise flight (Airbus, 2018). This would help to effectively reduce fuel consumptions and in turn reduce GHG emissions.
Albatross wings. The albatross is a seafaring bird which can fly very long distances without a single flap of their wings. In order to fly such long distances, the birds need to extend their wings away from their body so as to glide in the wind. Similar to aircraft, these birds rely on both speed and wind to maintain their flight. Speed is produced by gravity when the birds fall towards Earth and lift is produced by the differences in air pressure flowing under and over the wing. Both factors help to keep soaring birds in flight without expending much of their energy. Furthermore, airbus engineers have also found out that the aspect ratio of an albatross wings is significantly greater than those of the Airbus (Airbus, 2018). These have shown that having a higher aspect ratio which helps the birds to fly higher can reduce drag, thus reducing fuel consumption and GHG emissions.
Noise Abatement: Biomimicry of Owls
The U.S. General Accounting Office (GAO, 2000) has reported that in 29 out of 50 airports, noise was accounted as the pollution with the greatest environmental concern. Aircraft noise remains one of most significant barriers to the expansion of the aviation industry (Girvin, 2009). Despite having technological developments made to aircraft engines, noise reduction policies and strategic placement of aerodromes, noise pollution still remains a major problem for the aviation industry (Hsu & Lin, 2005). Besides the aviation sector, Agarwal (2012) reports, the amount of people who will be affected by aircraft noise may increase from 24 million in 2000 to 30.5 million by 2025. Hence, there exists an urgency to address noise pollution issues and problems of GHG emissions using technological means of design and operational improvements in commercial aviation.
Owls, being nocturnal hunters possesses the ability to hunt in effective silence by suppressing the sound of their wings at a specific sound frequency (Lehigh, 2017). Owls possess three distinct features in their wings which are assumed to be responsible for their noiseless flight capability. First, their feathers on the upper wing surface are extraordinarily complex with a wide array of hairs and interlocking barbs which form a thick canopy just above the nominal wing surface (Jaworski & Peake, 2013). This unique feature creates a buffer layer which helps to reduce noise. Secondly, the trailing edge of their wing contains a small flexible and porous fringe. The trailing edge of the wing is usually where the most noise is generated not only for the owl but also aircraft (Jaworski & Peake, 2013). With this flexible and porous fringe, it helps to give a significant decrease in noise generated. Lastly, a downy material spread across the top of the wing (Jaworski & Peake, 2013). This velvety material on the top of the wing creates a compliant but rough surface and even though it is the least studied of the three features, Jaworski (2013), believes that it also helps to eliminate sound at the source through a novel mechanism which is unlike those of ordinary sound absorbers.
Pertaining to the aviation industry, scientist and engineers are particularly interested in the comb-like flexible serrations on the trailing edge of the owl’s wing. Scientists and engineers believe that this unique feature can help to not only reduce noise but also improve the aerodynamic performance of the aircraft (Bachmann & Wagner, 2011). Besides applications in aircraft design, the biomimicry of owl feather aeroacoustics properties is also being researched for use in the texturing of wind turbine blades (Peters, 2016).
Swarm Technology: Biomimicry of Insects
Technology has improved by leaps and bounds since the past 20 years. One such area that has improved exponentially is the Unmanned Aircraft Systems (UAS) sector in the aviation industry. In the past, UAS are mostly used by the military to perform intelligence, surveillance, and reconnaissance missions. Today, UAS are not limited to the use of the military but also in the commercial and public sector. According to studies done by Teal team, in the next 10 years the development of civil UAS will increase four-fold and by 2025, non-military UAS production will reach $10.9 billion (Geiver, 2016). Geiver (2016), reports that in year 2016 one million drones are produced, and by year 2018 the number of drones produced will increase by two-fold.
Scientists and engineers are beginning to look into the biomimicry of insects due to the collective and decentralized intelligence which insects possess. This concept can be used to apply to groups of UAS under autonomous control. Using swarm intelligence, these UAS would be able to work in concert, accomplishing tasks which a single UAS is not able to. By studying a certain insect called the Aphaenogaster desert ant, scientists realise that these ants do not have a central coordinator, they sense their neighbors and objects to have an implicit coordination across the whole group (Kumar, 2012).
Similar to Aphaenogaster desert ants, the UAS swarming formation is when UASs monitor the separation between each other as they fly in formation. The distance between each UAS is constantly monitored to ensure that they are within acceptable levels so as not to crash into each other (Kumar, 2012). The UASs constantly monitor and calculate the control commands at 100 times per second which translates into motor commands at 600 times per second (Kumar, 2012). When swarm intelligence is applied to UAS robotics systems, these UAS can climb synchronously and transmit information with each other inflight. Thus, allowing fixed formation group flights and complex acrobatic group flights to be possible in the very near future (Kumar, 2012). Basically, how autonomous flight works is that an individual UAS would sense the distance between its neighboring partner and adjust its position accordingly. If any UAS senses that it is close to an object, it would correct itself and then maintain the appropriate distance according to the information shared (Kumar, 2012).
The potential use for swarm technology in commercial aviation are many. This technology can be introduced into the air traffic system as a traffic collision avoidance system or be used to improve airport congestion and traffic sequencing issues (Valavanis & Vachtsevanos, 2015). This can help to minimize fuel wastage and reduce GHG emissions.
Technologically-Enabled Design and Operations
The aviation industry is automating its processes rapidly due to the ongoing technological innovations such as automated landings of commercial aircrafts. Automation is gaining its prominence in aviation whereby the safety of operations is of utmost importance. Statistics have shown that with the advancement and dependability of material technologies and machines, accidents caused by human error has increased dramatically from a mere 20% in the olden days of aviation to a staggering 80% (Rankin, 2007).
The study of human factors is vital to ensure the safety of aviation operations. In many circumstances, people usually have a general error rate ranging from 0.5% to 1.0% (Lee, 2009).
It is virtually impossible to eliminate human error from the field of operations in spite of the comprehensive training programs and strict certification requirements. Thus, the gradual elimination of human influence from the equation altogether is seen as a viable countermeasure. In light of the recent issues to pilot shortage, one of the biggest aircraft manufacturers in the world – Boeing has been intently working on a technology which enables the aviation industry to progress to single-crew passenger operations. This new technology circumvents orthodox European Aviation regulations suggesting that a commercial aircraft with above 19 seats needs to have at least 2 flight crew members in the cockpit (Batchelor, 2018).
Swift improvements in technology have paved ways for the realization of exceptionally efficient autonomous operations along with enabling technologically augmented engineering design process (McKnight, 2017).
A subdivision of Artificial Intelligence, machine learning is the tenet of computer science, in a bid to get computers to learn and act like the human brain process. Machine learning allows computers to improve learning at a given pace autonomously by integrating data and information using real world interactions. As computational power gains its prominence along with progress through the accessibility of big data, the derivations of machine learning has affirmed its importance in fields like Cyber Security (Dua & Du, 2016) and Earth science (Lary, 2010). Neural networks and vector machines are some types of machine learning algorithms being used typically.
A pressing problem with the use of machine learning in the aviation sector, particularly in the aviation security department is that the machine tends to wrongly classify images and data after minimal modifications to the system. Szegedy et al. (2013) did a thorough investigation on this phenomenon after knowing that their ability to “fool” the network into misclassifying images by making changes that are undetectable by normal visuals. Szegedy et al. (2013) tested this hypothesis by using an advanced neural network.
In a study conducted by Szegedy et at. (2013), AlexNet – a machine learning technology was presented with adversarial examples. It was shown that even when it was presented with complex examples, it remained relatively robust. This means that it was tougher for another neural network to detect the disturbance when one set of adversarial images were given, despite training the system using a spectrum of different information. The study suggested that a flaw in the system exists among a spectrum of neural networks as they explore to make use of identical counter-intuitive characteristics to generate allowable information (Szegedy et al., 2013). This same study by Szegedy et al. (2013), also indicated that authentication problems exists in neural networks accepting non-text inputs, restricting the network’s capability in security due to rising trend of environmental based and facial recognition
Technological advancements from harnessing energy via wind, sun and hydro are becoming increasingly popular and economically viable. Hence, machine learning is increasingly used by industries as a form for clean, cheap and reliable energy. Negative impacts such as GHG emissions from the burning of natural gas and fossil fuels has further accelerated this shift. Machine learning is being used by industries as smart grid to help monitor and control consumer and node which ensures two-way flow of electricity and information. Companies like Google are already using machine learning and AI to reduce energy use on their data centers. Google using their very own AI technology, was able to reduce its energy consumption by close to 40% (Neuromation, 2018). Hence, this proves that the aviation industry can also use this technology so as to reduce energy consumption levels in their airports, aerodromes and aircraft manufacturing companies.
Pertaining to the aviation industry, machine learning can be used to create forecasts for electricity demand and generation by predicting and managing the fluctuations in production. The aviation industry has also already incorporated the use of machine learning in many of their operations. Many operations in the airport such as passenger identification, baggage screening and customer assistance has one in form or another used machine learning to better improve their services for their customers (Peters, 2018).
Hence, machine learning could be a merit to aviation design and operations due to its ability to achieve a greater level of automation and outdoing human brains in many circumstances. Some examples of application of machine learning in aviation would include predictive maintenance, and aerodynamic simulations – leading to higher levels of efficacy, safety, and tightened security operations.
Improved Technologies: Obsolescence of Pilots
Flying on an aircraft that is unmanned and fully autonomous is a very interesting concept considering that most of plane accidents are caused by pilot error. According to Boeing, pilot error accounts for 80% of all aviation accidents, while the other 20% is largely due to weather conditions and faulty equipment (Haq, 2013). With such a high number of accidents being caused by pilot error, it may thus be safer to have fully autonomous aircraft to ferry passengers to their destination.
Relating to the aviation industry, the development of an autonomous aircraft may be considered due to its cost saving benefits and added value of safety which Unmanned Aerial Vehicles (UAV) possesses. Furthermore, Airbus (2018), indicates that using modern computer technology and increasing levels of autonomy can help to better optimize flight trajectories. This can bring about numerous social and environmental benefits such as reduction in fuel use and noise. In addition, autonomy also allows for easier vehicle sharing and can substantially take a toll off Earth’s natural resources (Airbus, 2018).
Even though the implementation of autonomous aircraft may be a merit to the aviation industry in terms of safety and sustainability, public perception is still an influential factor, especially for commercial aviation. People still do not like the idea of flying in a fully autonomous aircraft with AI at the helm of the cockpit. Furthermore, there is a lack of policies, standards and procedures for UAV access into the National Airspace System (NAS) which the FAA and ICAO need to address before autonomous aircraft can be made into a reality (Tam, 2011).
Recently, the FAA together with NASA has also pushed Section 744 of the FAA Reauthorization Act of 2018. This act establishes a research program in support of single piloted cargo aircraft assisted remote piloting and computer piloting (Carey, 2018).
This act however, received massive backlash from pilots since their jobs were on the line. Despite pilots’ objections, technology has already improved to the point where most of the operation in the cockpit is already highly automated. Thus, it comes as no surprise where one day pilots will be replaced with a fully automated cockpit. Furthermore, self-driving technologies assisted by machine learning is already out in the market. This is apparent in Tesla’s growing fleet of automated cars.