Boeing and Airbus maintain they will continue developing biofuel-powered aircraft, whilst European aviation authorities are designing traffic-friendly approach paths to save fuel and reduce emissions.
While Boeing and Airbus say they are not planning on making the biofuels themselves, they are working with ethanol and other biofuel producers to develop aircraft for the new fuels.
The sharp drop in oil prices since the start of the global recession has raised concern that the development of fuel-efficient jets may stall, while the airline industry is also being squeezed by plummeting passenger numbers.
"The economic downturn doesn’t lead to any change in our product strategy," said Christian Dumas, vice president for sustainable development at Airbus.
He said the airline industry has to think long-term because an aircraft’s life span is typically 30 to 35 years
"We are not going to diminish our efforts in research and development," Dumas told Associated Press in Geneva, where he was taking part in a meeting on aviation and climate change.
Meanwhile, Boeing has already made several successful test flights using plant-based oils that the manufacturer claims are as good as or better than normal jet fuel.
Boeing expects biofuels to be certified for regular use in three to five years and predicts that most airlines would use it in some planes by 2015.
Airbus expects it will take until 2025 before biofuel accounts for even a quarter of the fuel airlines use, and the company also has doubts about the availability of the alternative fuel in sufficient quantities.
Traffic-friendly approach paths
Currently, large aircraft burn up tonnes of fuel and generate unnecessary emissions following complicated, multi-level approach paths into airports. Recognising this, around 100 European airports plan to allow planes to descend directly from cruising altitude to the runway in one smooth glide, saving up to 450 kilograms of CO2 per landing.
In all, airlines are hoping to save 500,000 tonnes of carbon dioxide this way each year. The plan is expected to be implemented by 2013.