Recent test flights using alternative fuels have been carried out by consortia made up of Airbus with Shell and Rolls Royce and Virgin Atlantic, General Electric and Boeing. Another group comprising Air New Zealand, Rolls-Royce and Boeing are aiming for a test flight in the near future. Recent test flights by Airbus and Virgin Atlantic have begun the testing process for alternative aviation fuels. There is, of course, a long way to go, but the search for alternative fuels is another avenue that the aviation industry is exploring as it seeks to combat the challenges of climate change. Aviation fuel systems must be able to operate over a much wider range of conditions (from hot day take-off to the cold temperatures and pressures at altitude) and power settings while satisfying multiple requirements. To date, the only fuel that has been shown to fulfill all of these criteria, at a reasonable cost is kerosene. Therefore, kerosene has been utilized almost exclusively by the aviation industry throughout the world for many years. Proposed alternative fuels include: synthetic kerosene made from coal, gas or biomass; biodiesel from crops such as rape, sunflowers, or plants such as palm or algae, and hydrogenated plant or vegetable oils.