Propelling metal tubes weighing more than 500 tonnes*1 that carry hundreds of passengers in thin air is an engineering marvel. Over the course of the past century, commercial aviation has witnessed leaps of progress driven by both individuals, such as the Wright Brothers in the early days, to private giants such as Boeing or Airbus. Yet, the door to further innovation remains ajar, with a plethora of possible initiatives promoting sustainable development. To predict future flight, it is necessary to include some key milestones of the past and current aspirations within the aerospace industry.
One of the most profound ways of appreciating the evolution to today’s impressive aircrafts is to time-travel to its infancy: pre-World War I.
Prior to the Great War, airplanes have mainly remained in the pioneering or recreational stage. Solely a handful of ingenious (almost rebellious) individuals possessed the sheer perseverance to fly, largely on their own. The renowned Wright Brothers were part of this elite band of inventors.
The Wright Flyer, often famed as the first manned aircraft*2, was devised (from design, manufacture, and operation) by Wilbur and Orville Wright. Technically speaking, attempts to use a fixed-wing flight (that was denser than the air surrounding it) or even hot air ballooning existed before 1903- the year of first successful Wright Flyer test run. Yet, the Wright Brothers demonstrated significant improvements in their stability/control mechanisms and engine systems. Such extraordinary pioneering work effectively earned them the triumph of achieving the first manned flight. It is also astonishing to note that these two pilots had not even finished high school, let alone obtain any form of ‘certification’ to fly. Regardless, they were professional bicycle makers, thus applying their bicycle expertise to aviation and even building their own engine from scratch in their own factory. This is markedly different from the complex supply chains in today’s aeronautics industry, often with large corporations specialising in a few parts of the aircraft- such as Rolls-Royce only producing jet engines, while Boeing acts as an assembler, integrating multiple systems and structures to construct many of the aircraft that fly the Earth’s skies. It is also difficult to imagine how individuals would be able to build practical, fully-functioning aeroplanes that satisfy rigorous quality control.
Almost a decade after the invention of the Wright Flyer, contemporary entrepreneurs initiated the world’s first scheduled flight across two cities, separated by Tampa Bay, Florida, USA. Even though the plane significantly reduced travel time, it is crucial to note the limited nature of this route to mainly seasonal tourism (rather than being a worthy competitor to the contemporary railroad in terms of practicality, safety, comfort, etc). However, the public’s astonishment was momentous. Marching parades organised, thousands of townsfolk gazed; the first-flight honour was sold to the highest bidder at a whopping $400. It is tempting to draw an analogy to space flight. For example, a vast community of space enthusiasts were glued to Space X’s recent Crew Dragon Launch. This seems no different from the thrill around the world’s first public air travel route. Other similarities between 21st-century space flight and pre-WW1 flight include restricted access, room for improvement in safety and experimenting with prototypes. These are commonly associated with exploring the technological limits of a fledgeling industry.
‘[I] dreamed of the skies filled with air lanes carrying the world’s passenger and freight traffic.’Thomas Benoist, an airplance manufacturer c. 1914
Fast-forward to the present day, Benoist’s dream is an everyday reality. Can we draw yet another analogy between aviation back in the early 20th-century and current space ventures?
The link between military and civil aviation
The transition from small airline ventures or clusters of airplane innovators to wide-scale military usage was initially catalysed by WW1. In fact, the 20th century has been marked with numerous examples of aircraft tech development being accelerated by such military conflict. Oftentimes, the military later found use for their enhanced aircraft technology in the realm of civil aviation.
Let us specifically consider the impact of WW1 on aeronautics. First of all, the advent of mounting machine guns on aircrafts, specifically the synchronisation gear on Fokker E.I., amplified the AirForce’s lethality. No longer being used only for reconnaissance, the military was quick to expand on its aircraft production, incorporating mass manufacturing techniques as well. This was a case of a dire situation when engineers are integrating relatively modern technology and improving multiple complementary technologies together. The war period also witnessed several improvements in engines; newer fighter and bomber airplanes could fly more than twice as fast as their peacetime predecessors. Such developments in propulsion systems led to the possibility of even bigger planes. However, many thought that the vast military fleets would soon become obsolete shortly after combat. Yet, these speculations were not realised. For instance, the American machines that were once used in aerial dog fights and bombings found themselves in service of the US Air Mail. With all said, it is rather saddening that the same technology that has added so much socioeconomic value to whole nations was primarily devised with the intent to kill.
Following a brief period of peace- the European Arms Race of the 1930s (build-up to the Second World War) had also witnessed dramatic breakthroughs in various aspects of aeronautics. These included air-cooled jet engines (replacing older water-cooled ones, giving rise to a new generation of lighter flight), in-cockpit radio communications and more efficient manufacturing techniques. Thus, the ‘30s are sometimes nicknamed the ‘Golden Age of Aviation’. Regardless of its truth from a technical standpoint, the sheer brutality of aerial warfare seriously questions the reason behind advancing new technology, especially ones that can actively be used by the military. The irony remains that certain useful instrumentation, such as the in-cockpit radio, emerging from a wartime backdrop, is still used today.
Furthermore, aircraft technology continued to develop during the Cold War era as well. With the need for reconnaissance without radar detection, the USA developed supersonic (traveling faster than the speed of sound) aircraft such as the Lockheed U2 (a.k.a. Dragon Lady) and SR-71 Blackbird. In the aerospace world, the latter contests to be the best aircraft to be constructed and utilised. The unique technology harnessed in said aircraft is considered to exceed the design requirements of standard commercial flight. This often comes at a price, however, namely unsustainable fuel use and high manufacturing costs among others. Hence, there has still not been a significant application of the Blackbird’s design*2 into our everyday airplanes.
Make no mistake: this is not a generalisation. For instance, one of Boeing’s refuelling planes*3 was eventually revamped to Boeing 707 in 1958. Boeing 707 resembles the airplanes we fly on far more closely than its preceding commercial/military planes. It was one of the premieres with a passenger capacity of an unprecedented 180 passengers and a long fuselage length of almost 40m. The increased capacity helped air travel’s popularity even more, as an indirect and time-lagged result of the US AirForce willing to invest in research and development (refueling fuel in mid-flight in this case).
All in all, there has been a clear historic trend of increased demand and functionality in the air force, sparking a chain of innovation within the military domain, followed by the application of such enhanced technology to commercial aviation. As outlined, both World Wars substantiate this claim. Having said that, not all military technology has found use in civilian aircraft, nor have breakthroughs in commercial aviation always been co-dependent on the army.
Nevertheless, we have left a major question unanswered: How can more futuristic aircraft be accessible to the masses without any military conflict or investment as the driving force behind innovation?
Sustainable aviation could be an answer.
The aviation industry contributes about 3% of the global carbon dioxide emissions. With this number expected to increase due to the predicted long-run increase in demand, despite setbacks due to the current COVID-19 situation, there is tremendous pressure to develop sustainable (and even carbon neutral) solutions. Whilst the impact of green initiatives is debated, this article is drawn more towards exploring the potential technological solutions spearheading greener change.
Introducing some background on aeronautics, the fundamentals of optimising aircraft designs for sustainability remain unchanged. Namely: aircraft weight is minimised; fuel efficiency is maximised; aerodynamic profile is enhanced. Sometimes, the navigation systems can be improved as well. These concepts can easily be illustrated by looking at an example: the Flying V. The sleek concept is developed by KLM (national carrier of the Netherlands) and Delft University of Technology. It aims to reduce emissions by 20%*4 by integrating a range of ideas such as combining the cabin/ fuel tanks with the wing itself and using lightweight composite components (an in-depth technical discussion has been omitted as it is beyond the scope of this article). A sizable amount of interdisciplinary work has been invested in this project so far, coupled with optimism that the majestic aircraft takes it to the skies commercially. Yet, this is not planned to take place in the near future; multiple test flights, attractive investment, securing manufacturing contracts, and authorising safety certification may take decades. To put the timescale into perspective, wartime aircraft took mere months*. In fact, the overly mid/long-term nature of the technological solutions to tackling climate change in commercial aviation is a major challenge.
Sustainable aviation does have immense applications for public use, from both environmental and economic perspectives. The continued work towards achieving carbon neutrality may result in more innovative aircraft technology for commercial use in the future (or atleast incredibly inspiring prototypes). Yet, sustainable aviation is simply one of the recent players to propel aircraft innovation. Historically, a handful of ambitiously relentless pioneers and the armed forces resorting to the skies has driven aeronautical innovation, thus evolving civil aviation to become a quintessential aspect of today’s society.
*1 specifically, Airbus A380
*2 for a more technical discussion on Blackbird’s design, click on our previous article here
*3 (namely, Doughlas DC-3)
*4 compared to Airbus A350
This article is inspired by Delft University of Technology’s Intro to Aerospace Engineering 1 Course. The basis of some discussion points are taken from Prof. J Hoekstra and Prof. G. Saunder’s descriptions of aviation history.