Which frequency band is used for standard civil aviation voice communications?

• A. HF band from 2 to 30 MHz
• B. UHF band from 300 to 3000 MHz
• C. VHF, typically 118.0 to 136.975 MHz
• D. VLF band from 3 to 30 kHz

Answer: (C)

Voice communications in civil aviation use the VHF band because it provides reliable, clear air-to-ground links within controlled airspace. The allocated range for civil aviation voice is about 118.0 to 136.975 MHz, which supports line-of-sight propagation between aircraft at cruising altitude and ground stations like air traffic control towers or en-route centers. This frequency range makes antenna sizes practical for both aircraft and ground installations and keeps interference manageable with the channel spacing used for aviation communications.

Other bands serve different needs. The HF band (2 to 30 MHz) is used for long-range, over-water and remote-area communications that rely on ionospheric reflection, where VHF cannot reach. The UHF band (300 to 3000 MHz) is mainly used by military and certain specialized civil systems, not the standard civil air-ground voice. The VLF band (3 to 30 kHz) is used for submarine communications and other specialized services, not regular aviation voice.