Fuel flow analysis for the cruise phase of commercial aircraft on domestic routes

From the point of view of the environmental impact of aviation, rather than fundamental strategies mainly intended for lower fuel consumption, and thereby less carbon dioxide emissions, more comprehensive approaches have emerged as climate optimized flight concepts, which promise potentially better strategies due to consideration of the tradeoff elements in a broader sense. Since climate optimized flight concepts introduce dynamic flight parameters for the best tradeoffs between economic and environmental indicators, defining the effect of these parameters on fuel consumption becomes ever more crucial. In this context, this study develops empirical equations for the cruise phase fuel flow which could be used to better understand fuel consumption. Major domestic routes in Turkey and the most frequently used narrow body commercial aircraft are investigated. The empirical equations are generated using actual flight data of 3857 flights (4320 cruise observations) performed by A319/320/321 and B737/B738 in Turkish air space. All of the flight data are obtained from the national flag carrier airline of Turkey, Turkish Airlines. According to the results, the effects of three main performance parameters, cruise altitude, mass and speed on the fuel flow, are characterized. The results show the amount of inefficient fuel usage through the carriage of unnecessary mass, departing from the optimum cruise altitude or expediting cruise flight.