Dutch airline operator KLM, part of Franco-Dutch Air France-KLM said on 18 March it wanted to make commercial flights which use biofuel from 2011. Last November, during a 1.5 hour KLM flight above the Netherlands, one engine of a Boeing 747 ran on a mixture of 50 percent sustainable biofuel and 50 percent on traditional kerosene. The other three engines ran on 100 percent normal kerosene. "We have proven it is possible," said a KLM spokeswoman.
http://www.reuters.com/article/idUSLDE62H28E20100318?type=marketsNews