Aircraft fuel consumption calculated from the payload-range diagram

Abstract

Purpose – To calculate the fuel consumption as function of flight distance from only a few aircraft parameters. The parameters are: Maximum Take-off Mass (MTOM), Maximum Zero Fuel Mass (MZFM), Mach number in cruise, number of cabin seats, mass of one passenger, distance to alternate, reserves on distance (in %). Notably from the Payload-Range Diagram: maximum payload, payload at maximum range, range at maximum payload, maximum range, ferry range. Rules for fuel reserves are considered. It is distinguished between so-called international reserves and domestic reserves. --- Methodology – Fuel consumption during take-off, climb, descent and landing is estimated from assumed Mission Segment Mass Fractions (MSMF). Reserve fuel is estimated from reserve distance and fuel consumption. This requires an iteration. Possible payload is calculated from required fuel at take-off (considering reserves). As flight distance is increased, payload must be reduced. According to the default strategy, cargo is sacrificed first. As flight distance is increased further, the number of passengers needs to be reduced. This influences fuel mass per distance and number of passengers versus distance. Calculated is also: Fuel mass per distance versus distance, fuel mass versus distance. It is assumed that fuel reserves are not used, are available for the next flight and as such do not count as fuel consumption. --- Findings – The aircraft's fuel consumption per passenger and 100 flown kilometers decreases rapidly with distance flown until a near constant level is reached around the aircraft’s average flight distance. At longer flight distances, where a reduction of the number of passengers becomes necessary, fuel mass per distance and number of passengers increases significantly. This typical consumption pattern is called the bathtub curve. --- Research Limitations – The environmental impact of burning fuel is not considered here. --- Practical Implications – The presented method allows calculating aircraft type specific fuel consumption based on publicly available information. --- Social Implications – Fuel consumption of every aircraft can be investigated and can be discussed openly. --- Originality – The method follows from first principles. No other text (including the required software) to present the method was known before 2017. The poster originates from the Bachelor project of Marcus Burzlaff (2017), which was further developed in many ways by other students under the supervision of Prof. Scholz.