Airbus and Shell Oil announced a test flight was completed recently with one of the four engines operating on an alternate fuel.

The alternative fuel used on the test flight was gas to liquid (GTL), which looks like kerosene, but is clear coloured. It is a natural gas, which has been cleaned and has undergone the Fischer-Tropsch process – the conversion of synthesis gas to liquid fuel.

The goal of these experiments is to find both cheaper and “greener” fuels. While they announced the test was a success, no mention was made of how much cheaper or how much greener the fuel is than conventional jet fuel. Airlines and by extension airplane manufacturers are getting increasing pressure from the public to reduce their carbon emissions and lower ticket prices driven up in part by the rise in fuel costs.