What is the primary disadvantage of VOR navigation?

The primary disadvantage of VOR navigation is its line-of-sight reception characteristic. VOR, which stands for Very High Frequency Omnidirectional Range, relies on radio signals transmitted from a ground station. Because the VOR signals are subject to the curvature of the Earth and can be obstructed by terrain, buildings, or significant weather phenomena, the effective range of the VOR can be limited. This means that a VOR station can only be received when the aircraft is within a certain distance, usually maintaining a line of sight to the station, leading to potential navigation issues if flying at very low altitudes or in mountainous areas.

Understanding this limitation is crucial for pilots, especially when planning routes that may take them outside the reliable range of VOR stations, or when flying in areas with numerous obstructions. Other navigation systems, such as GPS, do not have this line-of-sight limitation, making VOR's reliance on such a characteristic a significant disadvantage.