Military Aircraft Monitoring
Radio Bands and Equipment
Frequency Ranges: 225-400 MHz
UHF or "Uniform" (mostly AM in 25kHz steps)
118-150 MHz VHF or "Victor" (mostly AM in 25 kHz steps)
30-88 MHz FM or "Fox Mike" (mostly FM in 25 kHz steps)
How Radio Bands are Used:
- Uniform (225-400 MHz) - This is the primary band for combat aircraft.
Some aircraft appear to have two radios for this band, but possibly none for Victor or FM.
Notably F-14s, F-15s, and some carrier-based aircraft. This situation is probably changing
as systems become more integrated, and electronics become more miniaturized. Aircraft with
UHF only, generally have two radios. One for air traffic control, and one for tactical
comms. Every FAA air traffic control frequency, from the control towers to the Class B
& C airspace, to the ARTCC's have a parallel UHF frequency for each of the VHF
frequencies that they use with civilian aircraft. They also have some discrete UHF
frequencies for military aircraft.
- Victor (118-150+ MHz) - VHF radios are becoming
increasingly common in military aircraft. They sometimes enjoy primary use in helicopters
and transport aircraft. Most F-16s and many A-10s use this band for their air-to-air
chit-chat. This is found mostly in the 137-144 MHz range, but some of these radios go from
118 up to around 160 MHz. Some tankers have also been heard talking air/air on Victor. It
should also be noted that this is not exclusively an aircraft band above 137 MHz. The
military has extensive land mobile communications in the 138-144 and 148-150.8 ranges,
144-148 is a ham band, and above 150.8 are civilian land mobile operations. Military
activities generally avoid these ranges, but there are exceptions. F-18s have been
reported using FM signals in the 160-174 MHz range.
- FM (30-88 MHz) - These frequencies have traditionally been used by
ground or surface forces, and you'll most likely find them used by aircraft which interact
closely with such forces. Helicopters and close air support aircraft like the A-10 are the
most likely to make use of this band. This band is also shared with a multitude of other
services. The 30-50 is the VHF-Low land mobile band, filled with sheriffs and cement
trucks. 50-54 is occupied by amateur radio (on a shared basis), 54-72, and 76-88 are TV
channels, and 72-76 is more land mobile. Most military ops are found in set-aside federal
segments of this band, including 32-33, 34-35, 36-37, 38-39, and 40-42 MHz. Even so, some
units regular operate in the low 50s to the upper 60's. Most units will keep their
frequencies within a few MHz of each other because of the differences in antenna
length/impedance over this range.
Types of Frequency Use:
- Air Traffic Control - Military aircraft are controlled by the same
agencies that control civilian aircraft. They may use either civilian frequencies or
parallel military frequencies. You can find both sets of frequencies on NOAA charts.
- Tactical - These frequencies are used for planes to communicate
air-to-air, or to interact with surface forces. Most combat fighters will be using UHF for
Air Traffic control, so air/air comms will either be on a second UHF radio, or on a VHF or
FM radio. Most Navy aircraft seem to favor UHF for air/air, as do Air Force F-15s. F-16s
favor VHF and A-10s favor FM. Marine Corps aircraft favor UHF and FM, but apparently not
VHF. FM is favored mostly by aircraft which work directly with surface forces--mostly
helicopters and attack jets in the Close Air Support mission. Such aircraft are
generally summoned and directed by ground forces to help them on the battlefield.
- Operational Control - In combat this would take the place of air
traffic control. Most of the time, this is communication between an aircraft and its
squadron or base headquarters. Every squadron has such a frequency, but the aircraft do
not constantly monitor it. Instead, they switch to it temporarily to give progress reports
or seek instruction on something. Such frequencies are also used by bombing ranges, Air
Combat Maneuvering (ACM) ranges, refuelling tracks, etc. Aircraft participating in these
activities will switch from air traffic control frequencies to operational frequencies
once they have entered the airspace controlled by their training agencies.
- GUARD - All military aircraft monitor 243.0, which is known as
"Guard." This enables any military aircraft to communicate with another military
aircraft even though they may be operating on different frequencies. Very handy during
emergencies or confusion. Enemy aircraft may also use this frequency to prevent an
unnecessary engagement if someone strays into the wrong territory. A downed pilot can use
it to hail a passing aircraft. The guard receiver is a separate piece of equipment, and
anyone transmitting on this frequency uses the words "on guard" when
identifying themselves. Transmissions must be kept shorter than 30 seconds to avoid having
the Search and Rescue Satellites (SARSAT) mistake the transmission for that of an
Emergency Locator Transmitter. (ELT)
Radio Equipment:
- Audio Console - The aircraft's pilot simultaneously monitors a
large number of devices including several radios, navigation devices, threat detection
devices, and aircraft system warnings. A rotary switch on this device selects which radio
that the pilot's microphone will feed. So a flight leader, for example, has to switch his
microphone back and forth for communications with air traffic controllers, and
communications with his wingmen.
- UHF Radio - May have one or two. Usually one for ATC/operations and one
for tactical.
- VHF/FM Radio - Browsing Janes Avionics, and some other
research has convinced me that VHF and FM communications are accomplished using the same
radio.
- Guard Receiver - Dedicated receiver for 243.0 MHz.
- HF Radio - Generally used for long distance comms by larger aircraft.
Found in transports and bombers, using SSB. Interceptors have also been found with HF
radios, particularly 9023 kHz.
- TACAN - This device is co-located with civilian VORs, and helps the
pilot navigate. The station is identified by a three-letter morse code transmission. I
presume that miliary pilots listen for this just like the civilians.
- ILS & Marker - Probably more common in transports than in fighters.
Instrument landing systems also have morse IDs (in the 108-118 range) and approach markers
are set to 75.0 MHz. Marker receivers generally have lights that are activated by each
marker, but I believe that they're available as audio, too.
- Ground Crew Radio - Some larger aircraft have UHF FM radio designed for
communications with ground crews. They use preset channels in the 406-420 MHz range.
To say the least, this is a lot of stuff to be going simultaneously in the pilot's
headphones.
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