Commercial passenger air travel is essentially facilitated by the technology of flight via airplane. The technology of flight itself, particularly the flight of a commercial airplane, is reliant on the interaction of four forces: lift, drag, weight and thrust. The delicate balancing of these four forces has transitioned throughout history with developments in technology, including the jet engine. NASA describes how these forces interact during flight. Weight, a force which is always directed toward the centre of the earth, is determined by the mass of the airplane, as well as any passengers and cargo on board, and mass that transitions throughout flight: fuel. To overcome the weight of the aircraft, lift is generated mostly via the wings, although it is dependent on the size and shape of the aircraft. Drag is generated through the air’s resistance to the motion of the aircraft, and to counteract this, airplanes use a propulsion system in the form of an engine to generate thrust. When these four forces are in balance, an aircraft will ‘cruise’ at a consistent velocity.
The main advantage of commercial air passenger travel is to move people from one place to another, over great distances, with speed. With this, however, comes many other advantages as a result. Tourism is a major economic boost to global economies, and particularly impacts economies of developing countries (both perhaps positively and negatively). Another advantage is that it offers a method of travel with reduced infrastructure spend. In comparison to road and railway transport, the infrastructure footprint is much smaller. No tracks need to be laid, no roads need to be built – only airports need to be constructed. Air travel overcomes physical land barriers (bodies of water, mountain ranges) and offers a high speed method of travel.
Commercial passenger air travel historically targeted the wealthy. Many could not afford to travel by air and it was seen as a luxury for those with higher disposable incomes. In an article referencing observations by Guillaume de Syon, a Professor at Pennsylvania’s Albright College, it is observed that it may have cost those with average occupations a month’s salary to purchase a domestic flight ticket in the United States. With developments in technology meaning aircraft are cheaper to construct, together with budget carriers demanding better economies of scale with suppliers and streamlining process operations, air travel now targets a much wider market. Domestic air travel in Europe, for example, became affordable for lower-middle income markets with the introduction of budget airlines. This expanded to global markets and air travel has subsequently grown exponentially since 2010.
Prior to commercial air travel, in developed nations large scale rail and road networks were the major forms of overland transport. For overseas travel, passenger ships were the only method of commercially travelling from one continent to another. This method of travel took considerably longer, with a passenger vessel travelling from Southampton in the United Kingdom to Sydney in Australia completing the journey in 45 days in 1909, in comparison to a 24 hour flight journey today. Even with evolutions in sea vessel transport and developments in technology, the journey time was reduced to just under a month by 1960, when commercial travel by sea was comparatively cheaper to commercial travel by air. Sea travel also increased overland journey times depending on passenger destinations within a particular continent. For example, the coverage and density of airports and the capacity to quickly deliver passengers to an airport as close as possible to their final destination decreases the need for reliance on other overland transport methods.
The invention of flight itself did not immediately spark interest in commercial passenger air travel. It took two brothers, Wilbur and Orville Wright, six years spanning 1899 to 1905 to successfully invent an aircraft and complete flights lasting minutes. Following this period, an iconic event in the history of air travel was the first commercial passenger flight, a 34 kilometre flight between St Petersburg and Tampa, Florida in the United States which occurred in 1914. ). Similarly, in 1926. Ben F. Redman and J.A. Tomlinson accompanied C.N. James on his regular mail flight from Salt Lake City to Los Angeles and sat on US mail sacks, with a tin cup to be used as a toilet. Interest in expanding commercial flight and sustainably creating a commercial model for higher speed journey times was piqued. For the St Petersburg to Tampa flight, this demonstrated how air transport had the potential to reduce journey times dramatically. In 1914, the journey between the two cities by car took 20 hours, by rail could take up to 12 hours, and by flight – 20 minutes. Transatlantic flight was a subsequent key milestone with Charles Lindburgh completing the first successful transatlantic flight in 1927. Subsequently, the first non-stop transatlantic commercial flight carrying 26 passengers and “specially employed stewardesses” flew from Berlin to New York in 1938. Again, the appeal of high speed point-to-point travel was sparking the interest of the public, with thousands gathering to watch these flights take off and land, however, the relative cost of air travel in its early years of development was still an inhibitor in expanding to markets outside the wealthy.
While many were experimenting with the principles of flight globally at the beginning of the 20th century, Orville and Wilbur Wright were the first to successfully design, build and fly the airplane as we know it today. In looking at the early years of the invention of a flying craft, it is evident that flight was a merger of two broader technological fields: aerodynamics, and, based on the findings of the study of aerodynamics, the invention of sustainable engine technology to successfully balance the four forces of flight and propel the flying craft.
In studying the principles of flight, the Wright brothers experimented with kites, wing warping and several designs of gliders of different sizes. In 1903, after several glider flights at Kitty Hawk, North Carolina, the brothers made four successful flights with their first powered aircraft using propulsion technology. The initial propulsion system engine was designed by the Wright brothers, as none of the gasoline engines available at the time could satisfy the airplane’s weight and power requirements. Their engine utilised lightweight aluminium, which is still a primary material in the construction of aircraft today. Subsequently, an aerodynamic propeller and “chain and sprocket” transmission system was installed. The initial craft’s first flights lasted three and 12 seconds before it was damaged. However, the technology for flight was established. “A human had flown”.
Following perhaps the most remarkable technological invention in the history of flight, which could be considered as the flight of an aircraft itself, there are several key technological developments throughout the following decades. Development largely related to aircraft size and engine technology. The DeHavilland Comet, the first commercial jet aircraft, completed its inaugural flight in 1949. The jet engine signalled a new era for flight and commercial aviation. In 1947, United Airlines introduced the first aircraft with full cabin pressurisation. The development of radio and navigation technology was also a key evolution during the growth of commercial flight and complimented the hardware aspects of the technology to increase the length of point to point journeys. 
Early experiences of flights were not without incident. It wasn’t until 1940 that United Airlines confirmed they had completed a full year of commercial passenger flight without serious injury or death to a passenger or crew member. Initial design of aircraft had to be altered to accommodate passenger safety. The fit out of aircraft in the “golden age” of flying, considered to be the 1940’s through to the late 1960’s was not without flaw and there were often injuries simply due to flaws in cabin design. This is vastly different compared to the design of today’s aircraft interior which has a much heavier focus on safety, versus appearance.
Early phases of aviation development primarily occurred in the United States, although development activity was underway globally, with airlines like KLM and Lufthansa beginning operations in 1919 and 1926 in The Netherlands and Germany respectively. Initially, the market for commercial aviation was relatively small compared to today’s current market diversity, and largely targeted travellers with higher overall net worth. Air travel was a high-speed method of moving between one domestic destination to another, but was not affordable for the majority of the population. With the introduction of transatlantic flights, a completely new market was born. Passengers could now journey from one continent to another in drastically reduced amounts of time compared with other methods available like sea travel. In the US, the introduction of transatlantic flights prompted Congress to regulate the industry, and adopt the Air Commerce Act of 1926, signalling the implementation of designed air routes, air navigation systems and license requirements for pilots and aircraft. The rise of passenger uptake was relatively slow in early years. Aircraft accidents were far more frequent and aside from lack of affordability, the majority of the wider population were generally afraid to travel.
The commercial airline industry carried significant safety risks during the birthing phase, and throughout the growth of the technology. In America in 1926, the Air Commerce Act was put into place, which placed regulation on both pilots and aircraft. This required pilots and aircraft to be licenced. It also safety rules, and ensured accidents were properly investigated. Commercial aviation has continued to be regulated by safety authorities to this day, which by removing the conflict of interest it could be argued that this regulation provided much safer air travel, thus promoting the growth of the industry.
The growth of commercial flight truly took off with the introduction of the DC-3 aircraft in 1935. These aircraft could carry more passengers, travel faster, and had a longer range than anything of the time. This step made commercial flying viable for both aircraft carriers, and passengers alike. Significant growth has continued ever since with a steady improvement on technology, decreased carrier costs, quite typical of a magic bullet scenario. With the introduction of the De Havilland Comet in 1952, came much stronger growth in the space. This was the Worlds first commercial jet airliner. Early variants seated 32 to 44 passengers (depending on the carrier, and keeping in mind that the cabins were much more spacious at this point in time, due to the market of the time), had a range of over 2,400km (with later variants having a much larger range), and was fast, with a cruise speed of over 700km/h at altitudes of 42,000 feet. 1958 also saw the introduction of the Boeing 707, with significantly larger capacities for passengers, and increased range. The Boeing 707 could carry between 140 to 219 passengers, and had a range of over 10,000km. The 707 was used by Pan American for the first New York to London route.
More recently, improvements in technology have continued to promote growth. In 1995, The Boeing 777 was introduced to the market, and was the first aircraft to be designed by computer-aided design. The Airbus A380 was only introduced to the market in 2007, with a significant payload of up to 850 passengers. Most recently, the Boeing 787 Dreamliner was placed into service in 2011, made of composite materials which eliminate many issues with metal fatigue, and have significant increases in fuel efficiency.
Governments played a role in the growth of commercial aviation by regulation of the industry. In the US, regulation commenced in 1938, placing restrictions on routes, fares, and flight schedules. This in turn placed significant pressure on airlines – the regulation placed constraints on approvals for new routes and pricing, slowing the ability for airlines to grow. Following mounting pressure from the public, and concern that regulation was not healthy for the industry, commercial aviation in the US was deregulated in 1978. In Australia, the government placed regulations on the airline industry in 1952 by having a “two airlines policy”, whereby only two airlines were able to operate between capital cities and major regional cities. This was deregulated in the 1990’s. In both instances, deregulation allowed for increased numbers of carries, new routes, and competing fares, thereby stimulating further growth in the industry.
Regulation was not limited to airline routes and fares. The commercial airline industry carried significant safety risks during the birthing phase, and throughout the growth of the technology. In America in 1926, the Air Commerce Act was put into place, which placed regulation on both pilots and aircraft. This required pilots and aircraft to be licenced. It also safety rules, and ensured accidents were properly investigated. Commercial aviation has continued to be regulated by safety authorities to this day, which by removing the conflict of interest it could be argued that this regulation provided much safer air travel, thus promoting the growth of the industry.
Whilst the industry is still undergoing strong growth, the decrease in theoretical year-on-year growth is decreasing, showing that commercial flying is within the early mature phase of the lifecycle. The most significant development throughout the mature phase of the lifecycle has been for commercial aircraft manufacturers (and for carriers) to improve on efficiencies. This is not simply limited to the fuel efficiencies of aircraft – to remain competitive, carriers must provide cost-effective routes
Providing even larger aircraft than the Airbus A380 becomes quite challenging, due to “locked-in” constraints of runway lengths (required for take-off), aircraft apron sizes, and pavement design for heavy loading. Whilst improvements in all of these areas are possible, they are expensive solutions, and require even more efficiency benefits to become a cost-effective solution.
It could be argued that with the introduction of the Boeing 787 Dreamliner, there is no longer a constraint in technology on the range of aircraft since non-stop travel can now be achieved half-way around the world. There is the opportunity for flight technology to be re-invented, by providing cost-effective travel at supersonic speeds. This has not yet been achieved at a cost-effective level, and if so, would provide significant room for growth.
Whilst commercial aviation has undergone significant growth over the last half century, year-on-year percentage increases are slowing, suggesting that the technology of commercial flight is within the early stages of the maturity phase. Data has been obtained and is shown.. S-curve modelling is also undertaken, in an attempt to further understand the phase of commercial aviation, and provide insight into the future growth.
- , The American Institute of Aeronautics and Astronautics – History of flight time.
- , International Civil Aviation Organization, Civil Aviation Statistics of the World and ICAO staff estimates (Data from 1970 to current).
- Aviation Beyond Borders-2014 report, pp58-59 (Data prior to 1970 derived from graph)