Purpose: The purpose of this study is to provide an alternative graph-based airspace model for more effective free-route flight planning. Design/methodology/approach: Based on graph theory and available data sets describing airspace, as well as weather phenomena, a new FRA model is proposed. The model is applied for near to optimal flight route finding. The software tool developed during the study and complexity analysis proved the applicability and timed effectivity of the flight planning approach. Findings: The sparse bidirectional graph with edges connecting only (geographically) closest neighbours can naturally model local airspace and weather phenomena. It can be naturally applied to effective near to optimal flight route planning. Research limitations/implications: Practical results were acquired for one country airspace model. Practical implications: More efficient and applicable flight planning methodology was introduced. Social implications: Aircraft following the new routes will fly shorter trajectories, which positively influence on the natural environment, flight time and fuel consumption. Originality/value: The airspace model proposed is based on standard mathematical backgrounds. However, it includes the original airspace and weather mapping idea, as well as it enables to shorten flight planning computations.