United Press International: Alternative fuels for cars and trucks are becoming increasingly viable, but there’s another area of the transportation sector where they haven’t quite taken off: aviation. Convincing the aircraft industry to start full-scale use of petroleum alternatives won’t be easy because of the risks involved with testing new fuels in airplanes. If the switch can be made, though, there are several advantages to using biodiesel over traditional jet fuel, said Robert Dunn, a food and oil researcher …