The proponents of non-conventional lightning protection devices claim that these devices are superior to the conventional Franklin Rod. Lack of systematic study and insufficient field data make it difficult to compare the non-conventional lightning protection devices with the conventional ones. Previously, the performance of various air terminals was studied by comparing the emission current through various dissipation devices in the MSU High Voltage Laboratory. The study of emission current from the air terminals gives an idea about the space charge developing over them. However, it does not show the behavior of air terminals to attract or repel lightning strikes. The present study presents the measurements of critical flashover (CFO) voltage of the air terminals. The CFO voltage shows the ability of an air terminal to attract or reduce the chance of lightning strike to the protected object.