In the VHF Range Formula, what do h1 and h2 represent?

In the VHF Range Formula, h1 and h2 represent the altitude of the aircraft in feet. The formula is used to calculate the radio line of sight range between two points, which can be significantly affected by the altitudes of both the transmitting and receiving antennas. Higher altitudes typically increase the radio range because they allow the signal to travel farther over the curvature of the Earth.

Using this formula is crucial in aviation for ensuring effective communication over long distances, as both h1 and h2 directly impact the maximum possible range of VHF communications depending on how high the aircraft is positioned relative to the terrain and other obstacles.