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New research challenges industry claim to continuous aircraft emissions improvement

Improvements in the efficiency of new aircraft entering service have stagnated in the last two decades, according to research published today, exploding the myth that the aviation industry is on the way to becoming clean and green.

For many years, the aviation industry has claimed that aircraft efficiency has followed a path of continuous improvement and that the financial benefit to airlines of reduced fuel burn makes environmental measures unnecessary. But research published today by the International Council on Clean Transportation concludes that fuel price alone has failed to stimulate the uptake of the most efficient designs.

While the average fuel efficiency of new passenger aircraft has approximately doubled on both a seat-km (passengers only) and tonne-km (passengers + freight) basis since 1960, new aircraft efficiency has improved substantially in only two of the last five decades, and has stagnated in recent years. On average, fuel efficiency has remained flat on a seat-km basis and improved only 0.29% annually on a tonne-km basis since 2000.

Low fuel prices between 1997 and 2004 appear to have shifted the focus in aircraft manufacture away from fuel efficiency and towards increases in speed and distance range. At the same time, the average age of aircraft and engine manufacturer production lines has tripled since 1989, making new aircraft designs slower to enter the market.

The findings suggest that measures such as a CO2 efficiency standard for all new aircraft, similar to the standards now being introduced for road vehicles, may be necessary if we want to see future efficiency improvements from the aviation sector. The correlation between low fuel prices and stagnation in aircraft fuel efficiency (allowing for the time lag between aircraft design and entry into the market) also suggests that market-based measures such as taxes and charges could help to stimulate environmental improvements.

AEF’s Director, Tim Johnson, said “The aviation industry often talks up the historical average fuel efficiency improvement of 1-2% per year. But this masks the fact that in the last decade improvements in new aircraft have stagnated. Clearly, new measures are needed if we want to guarantee emissions improvements from the aviation sector in future.”