The test was performed by CFM International, using 30% vegetable oil methyl ester, and 70% Jet-A1 fuel, the current standard fuel for airliners. "Our goal is to support the industry in identifying replacements for traditional hydrocarbon-based fuels, including synthetic fuels that use a mixture of bio-fuels and jet fuel," said Pierre Thouraud, vice president of engineering at CFM.There are more problems associated with using alternative fuels in aviation than in road vehicles. It has to be very stable and usable at both very high and very low temperatures. It's also important that the raw materials are available worldwide, because you can't cram enough fuel into a jet for a round-trip, and it's hard to pull over for fuel on the way. ::Green Car Congress
A blend of bio-fuel and traditional jet fuel has been tested in an aircraft engine which is a common model used by Boeing. This is an exciting move because the engine required no modification to use the fuel, and because of the popularity of the model. Over 500 airlines use the CFM56-7B engines, and together they have racked up a total flight time of 50 million hours. If this fuel was to be used across all those aircraft, with the expected reduction in CO2 emissions of 20%, it's easy to see how enormous the effect would be.