Simplified methods for assessing the impact of fuel energy content on payload-range

The impact of varying fuel heating value on the range performance of jet airplanes has been investigated using simplified mathematical expressions. A computer program, capable of accurately determining the trip fuel, has also been used to explore the impact on range due to varying fuel heating values. Two cases were considered: maximum takeoff weight and full fuel tanks (fixed payload), for three kerosene fuels: "typical", low density and high density, and two non-petroleum fuels: FT-kerosene and biodiesel. The results indicate that fuels with a high gravimetric heating value (e.g. low density kerosene) yield a greater range for a weightrestricted calculation (e.g. maximum takeoff weight), but fuels with a high volumetric heating value yield a greater range for a volumerestricted calculation (e.g. maximum fuel tank capacity).