The aircraft may have flown from one chilly European city to another, but the fuel it used was decidedly tropical.

 

Virgin Atlantic made headlines Sunday after one of its Boeing 747 jumbo jets journeyed from London to Amsterdam powered partially using a concoction of coconut and babassu oils. The flight, which did not carry any passengers, marked the first-ever attempt by an airline to fly using biofuel; one of the four fuel tanks was filled with about 20 percent biodiesel.

Virgin Atlantic, Boeing, GE Aviation and Imperium Renewables all contributed to the research and development leading up to the flight.

The news is a sign that the next green frontier might be the sky.

Indeed, Virgin Atlantic is not the only outfit exploring fuel alternatives for flight.

A group of international experts is meeting in Switzerland for the Solar Impulse Project, which aims to develop asolar-powered aircraft that would generate energy from solar panels by day to fuel batteries that would power the plane at night. And U.K.-based Reaction Engines is working on the creation of its A2 jet, which it says will be hydrogen-powered and therefore would not emit carbon dioxide.

The European Union recently pledged 1.6 billion euros to research and development of engines that use less energy and run on alternative fuels, as well as to technology that cuts noise in airports.

“Ethanol is not limited to cars; that is what the demonstration by Virgin is all about," said Thilo Koslowski, Gartner vice president and lead automotive analyst. "It at least shows a commitment by companies that they want to explore alternative technologies and how they can be developed for long-term use.”

Sir Richard Branson, president of Virgin Atlantic, hailed the flight as a "breakthrough" for the airline industry. "This pioneering flight will enable those of us who are serious about reducing our carbon emissions to go on developing the fuels of the future," he said in a written statement.

But some environmental scientists dismissed the flight as a publicity stunt. Greenpeace chief scientist Doug Parr went as far as telling the Globe and Mail that the announcement was "high-altitude greenwash."

The quest to reduce carbon emissions in the transportation sector has prompted discussions of fuel alternatives ranging from batteries to biofuels. But ethanol and other biofuels have been hit by a backlash as grain prices have skyrocketed in response to demand for the crops, leading experts to argue that the consequences of ethanol production aren’t worth the environmental benefits.

While Koslowski admitted that ethanol production has not reached a point where it is a good alternative to oil-based fuels, he said any step forward in the search for alternatives is a good one.

"Nobody would expect this to be figured out within a couple of weeks," he said. "Any support we can see from industries to develop alternative fuels is a positive."