This paper presents an economic flight operation. Based on Flight Operation Quality Assurance (FOQA) system, flight performance database from local airline is used for analysis and assessment. Considering the environment difference, there are various methods to estimate the operational fuel consumption by eight continuous flight stages. A correlation statistics is established to look into different affecting factors in significance to fuel saving. The highly correlated non-operational factors, correlated operational factors are identified in different phases of flight operation. A medium range scheduled flight service operating by local airline between Taipei and Macau is raised as an example of study. From total real 2416 flight data, with appropriate flight operation, a feasible 6.77% fuel saving from RCTP to VMMC.