BBC: A passenger plane has successfully completed a two-hour test flight partly powered by vegetable oil. Air New Zealand hailed the flight as a “milestone” in the development of sustainable fuels that could lower aeroplane emissions and cut costs. One engine of the Boeing 747-400 was fueled by a 50-50 mixture of jatropha plant oil and standard A1 jet fuel. A Virgin Atlantic test flight in February used fuel derived from a blend of Brazilian babassu nuts and …