VHF airband

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VHF-AM aircraft band, worldwide allocation 108-137 MHz, divided into two subbands:

108.0 MHz - 117.95 MHz - aeronautical navigation only - VOR, VORTAC, localizers (50 kHz channel spacing) 117.975 MHz - 136.975 MHz - aeronautical voice and data communication, AM (25 kHz / 8.33 kHz channel spacing)

Emergency frequency 121.5 MHz is often known as GUARD CHANNEL.

8.33 kHz channel spacing is used in Europe and in select other locations, most of the world uses 25 kHz spacing for a total of 760 channels. VDL (VHF data link) systems such as ACARS (aircraft communications addressing and reporting system) use select frequencies in the VHF airband, including 131.550 MHz and 136.975 MHz (in the United States).

Military aircraft retain the capability to transmit and receive on the VHF-AM aircraft band, with US military aircraft radios covering up to 150 MHz in AM mode. Military aircraft also make extensive use of the UHF-AM aircraft band 225-400 MHz, often with ECCM systems such as HAVE QUICK, HAVE QUICK II and SATURN frequency hopping modes. The 225-400 MHz band is also extensively used for SATCOM and other purposes outside the scope of air-to-air communications. 380-400 MHz is shared with land mobile radio systems used by the US military in the United States. Military aircraft in close air support, MEDEVAC and other roles will also be equipped with VHF-FM SINCGARS tactical military radios for air-to-ground and air-to-air communications in both frequency hopping (FH) and single-channel (SC) modes.

Icom IC-A210E VHF-AM airband transceiver, designed for installation in aircraft, this version of the IC-A210 supports the 8.33 kHz narrowband channel spacing required in Europe. Frequency coverage is 118.000 MHz to 136.975 MHz in 25 kHz or 8.33 kHz steps with 6 watts AM carrier power.

Selected VHF aircraft frequencies

Frequency Purpose/Use
121.500 MHz Emergency Frequency known as Guard, see also 243.0 MHz - UHF Guard
122.900 MHz Secondary SAR (Search and Rescue) air-to-air/air-to-ground
123.100 MHz Primary SAR (Search and Rescue) air-to-air/air-to-ground, also used by Civil Air Patrol
123.450 MHz Unofficial air-to-air pilot chit-chat frequency
123.475 MHz Unofficial air-to-air pilot chit-chat frequency
126.200 MHz Common US military airfield VHF frequency (often as backup to UHF-AM and FM tactical radios)
131.550 MHz ACARS air-to-ground datalink frequency (North America)
136.975 MHz ACARS air-to-ground datalink frequency (North America)

See also: