VERY HIGH FREQUECY (VHF), Range and Propagation

VHF :

Very high frequency (VHF) has long been the primary means of communication between aircraft and ground. The system operates in the frequency range 118 MHz to 137 MHz and supports both voice and data communication. VHF is used for various purpose including air traffic control (ATC), approach and departure information, transmission of meteorological information and ground handling of aircraft.

VHF Range and Propagation : 

In VHF range (30 MHz to 300 MHz) radio waves usually propagate as direct line-of-sight (LOS) waves. Sky waves propagation still occurs at the bottom end of the VHF range (up to about 50 MHz depending upon solar activity) but the frequencies used for aircraft communication, reflection from ionosphere is exceptionally rare.