The analisys of airports being operated, routings, as well as the meteorological conditions and aircraft performances is one of the most important factors in the process of flight operations in order to achieve the maximum safety, reliability, and efficiency of commercial flights. In the process of flight planning we often meet a series of limiting factors dictating the level of aircraft's ability in the form of a maximum load capacity or maximum range in a given meteorological conditions. Due to all of this the flignt planning and the performance analisys are a crucial part of every flight and that is the subject of this work. Also, the point of this research is to analize and compare the possibilities of aircraft exploatation in different seasons of the year, meaning different meteorological conditions while operating adequate airports within a given route. In this paper will be shown the whole process of airport and route evaluation, as well as aircraft's performance and potential limiting factors analisys in different conditions for commercial flight operations. Aircraft's performance analisys and abilities in form of fuel consumption, maximum load and range capability will be calculated using specialized computer programs.