The past decade has witnessed remarkable signs of a struggling aviation industry. In the aftermath of 9/11 carriers faced a massive crisis, only further handicapped by the economic downturn during the global recession. At the same time, client demand for greener and cleaner but also fast and comfortable travel methods has increased.

Beyond this, perhaps the biggest challenge the industry has to face have been soaring fuel prices. In January 2011, the International Energy Agency raised the alarm as after several weeks of steady prices, the Brent Crude benchmark opened trading with a push to $95 per barrel, its highest price in more than two years.

By early February, with the rising unrest in the Middle East, the reference had reached $100 per barrel. While the International Air Transport Association (IATA) has forecasted a 40% industry profit slump from $15.1bn to $9.1bn for 2011, assuming an average Brent Crude at $84 per barrel, the benchmark hit $123 on April 2011.

Unless the industry, desperate for economy and a cleaner image, can find significant ways to save costs, airlines seem predestined to return to losses once again.

"In preparation of an ‘oil peak’ and what will happen after, reducing fuel consumption is not only a must from the economical point of view but also a societal and political one," says the executive director of the European Clean Sky initiative, Eric Dautriat.

But as Dautriat points out, rays of hope can be found in the research and development of new fuel-saving and ‘green’ airplanes.

"Reducing fuel consumption is not only a must from the economical point of view but also a societal and political one."

Green airplanes

In the last few decades, aircraft fuel consumption has already been decreased by 70%. An impressive improvement, believes Dautriat. However, efforts must be increased to keep track with increasingly difficult circumstances and more competitive goals of the aviation industry.

Efforts to develop a green airplane are being led by big manufacturers such as Airbus, Rolls-Royce, Safran and Boeing who have invested billions of dollars in the research and development of eco-friendly aviation.

In February 2011 for instance, Boeing unveiled its new 747-8 Intercontinental bringing green aircrafts once more at the centre stage of the industry. Vice president and general manager of Airplane Programs at Boeing, Pat Shanahan, said during the launching ceremony: "The new 747-8 Intercontinental will set a new standard in economic and environmental performance."

The plane provides 16% better fuel economy, 16% lower carbon emissions per passenger and a 30% smaller noise footprint than its predecessor, addressing three major goals of reducing the environmental impact of air travel.

The goals of green aviation

Beyond the ambition to unearth an efficient business model to save costs due to growing financial concerns of the struggling industry, probably the most important goal of green aviation is reducing the impact on global warming and cutting down on CO2 emissions. Even though aviation only represents 2%-3% of man made emissions, this impact has yet to reach its peak as air travel is expected to double in the next 20 years. 

"Researchers and regulators have joined the efforts of industry giants in greening aviation."

"This is why we have to take action on these emissions in order to reach a carbon-neutral growth," says Eric Dautriat from Clean Sky, the biggest European aeronautical research programme in green aviation.

The reduction of noise and the enhancement of local air quality in the vicinity of airports is the second goal of green aviation. Noise has already decreased by 70% in the last 40 years and new aircraft, such as the Boeing 747-8 Intercontinental, are far quieter than the previous generation. "Nevertheless, there is still a need for improvement just because of the same reasons, the continuous growth of air traffic because the citizen’s demand for comfort is increasing in all areas," says Dautriat.

A green product lifecycle, starting at the design and manufacturing stage, going onwards to the plane’s maintenance and disposal, is the third major area of concern. Green aviation is aimed at decreasing the use of natural resources and chemicals. Emissions from pollutants in manufacturing should be reduced and the aircraft should be fully recyclable.

The Clean Sky initiative

Researchers and regulators have joined the efforts of industry giants in greening aviation. In the US, the Federal Aviation Administration (FAA) and the Nasa have funded and managed several different greening programmes over recent years. However Europe, with the Clean Sky programme, a cooperative project between the EU and the European aviation industry, is currently the research leader.

The programme is aimed at speeding up technological breakthroughs and to shorten the time to market for new solutions, a process that usually takes more than a decade. This is a necessary step to reach the environmental aviation targets set by the Advisory Council for Aeronautics Research in Europe (ACARE).

"But as preparing greener aircraft technologies will for sure provide a competitive edge in the future, we can expect without a doubt that the US will be following the same track," says executive director, Eric Dautriat.

By 2020, the industry wants to reach the goals set by ACARE: a 50% reduction of CO2 commission through the drastic drop in fuel consumption, an 80% reduction of NOx (nitrogen oxide) emissions and a 50% reduction of external noise. Beyond this horizon, the European aviation sector has just defined a further reduction target of -75% by 2050.

"Clean Sky is addressing six research areas: large aircraft, regional aircraft, helicopters, engines, onboard energy management and the lifecycle of products," explains Eric Dautriat. The work in these areas will be closely monitored and to reach the goals, which were set with the start of the programme in 2008. First results are expected in 2013.

Nasa’s green aviation programme

In the US on the other hand, Nasa has been focussing on the long-term development of economical airplanes, funding different research projects and programmes. An MIT-based team for instance, has developed a concept for a quieter subsonic commercial plane, as part of a Nasa research programme, known as N+3.

Since October 2008, the team at the Department of Aeronautics and Astronautics, MIT Boston has worked on the conceptual design, mainly using forecast technologies that do not yet exist in the commercial sense. Aimed at identifying key technologies, such as highly developed airframe configurations and propulsion systems to enable green airplanes to take off in 2035, the team has eventually developed a plane that burns 70% less fuel and produces 75% less NOx.

"We forecasted better materials, better engines, better aerodynamics and a novel configuration," says the lead designer of the project, Marc Drela. "It is essentially four components that go into the design and add up to this big total number of saving 70% fuel."

In May 2010, the team presented the design to Nasa and was selected for the second phase of the programme, which involves the building of small wind tunnel models and the testing of those in the next 2.5 years. "The first phase was merely paper study and now we are running some experiments on scale models," says Drela. "Obviously we can’t build a prototype because that’s a $10trn exercise."

"Air travel in general will grow; it will more than double by 2035."

"Air travel in general will grow; it will more than double by 2035. So it’s imperative to minimise the resource requirements for airplanes," says the MIT lead designer. "And it’s not just things like fuel but also air and airport space is very tight and we had to look at things like reduced take-off and landing performance of the airplanes."

For more short-term gains, however, increased research into biofuels could help the aviation industry. In particular drop-in biofuels, which can be mixed with conventional kerosene and put inside the same tank, pose a reasonable opportunity for the industry, as they do not involve the development of new engines for alternative fuels.

Manufacturers, however, have been cautious with investment into biofuels as enormous outlays are required to bring them from the research stage to market and therefore only play a very limited role in developing these fuels.

Despite the industry’s efforts, Dautriat believes the question whether a fully green airplane can exist in the near future has to be answered with a straight no.

"Maybe in the remote future for instance with a solar powered aircraft. A very first attempt was successfully made recently but there is still a very, very long way to go for such an airplane with a commercial use," he says. "It is still a dream."