This paper presents an economic flight operation for medium range scheduled passenger flight services. The Flight Operation Quality Assurance (FOQA) system of flight performance data from a Taiwan’s airline is used for analysis and calculation. The engineering parameters are extracted and decoded from the FOQA system. Considering different flight performance, the proposed method estimates the operational fuel consumption by eight continuous flight stages. A parameter correlation is analyzed to evaluate the different affecting factors in significance in each flight phase. The highly correlated non-operational factors, such as weight and wind direction, are used to classify the flight database to support the highly correlated operational factors to identify the fuel saving operation control ranges. From total 2416 real flight data, the flight operation can accomplish a feasible 6.77% fuel saving from the flight route of RCTP to VMMC.