COMM Radio

A COMM radio transmits and receives voice communications on VHF frequencies between 118.000 and 136.975 MHz. Most modern radios support 8.33 kHz channel spacing (common in Europe) as well as the traditional 25 kHz spacing used in the US. You dial in a frequency, press the push-to-talk, and talk to ATC, ground, or other aircraft in the area.

Most aircraft carry at least two COMM radios. COMM1 is the active transmit radio and COMM2 is typically used to monitor a second frequency such as ATIS while working approach or tower. Switching, monitoring volume, and intercom routing all run through the audio panel. Many installations combine the COMM radio with a VOR/ILS receiver in a single unit, referred to as a NAV/COMM.