AOPA Pilot Magazine - January 2018 - 92

P&E

TECHNIQUE

What's the frequency?
Finding a channel on crowded coms
B Y T O M L EC O M P T E

THERE WAS A TIME, when I was a kid
riding in the back of my father's Piper
Comanche, when you could fly all day and
never talk to a soul. Nontowered airports
had no assigned frequency and pilots were
expected to self-announce, if at all.
Sometime between the 1960s and when
I started learning to fly in the early 1990s,
things changed. Expanded radar coverage
resulted in the more widespread use of VFR
flight following. Most nontowered airports
were assigned a unicom frequency for surface weather and pilot communications.
And my father's old 360-channel Narco
radio was deemed obsolete, replaced by
the requirement for 720-channel radios,
which halved the spacing between channels in the range of 118.00 to 135.95 MHz
(later expanded to 760 channels with the
addition of frequencies between 136.000
and 136.975 MHz).
Even the simplest flights nowadays
seem to involve some form of radio work,
whether it's getting the weather from a
ground-based ATIS or AWOS, announcing your intentions at a nontowered field,
or just repositioning your aircraft on the
ground at a towered field. And anytime
aircraft are close together in flight, communication is important.
Communicating with other pilots by
radio while airborne is a subject of confusion. For some longtime pilots, 122.9 MHz
has been the go-to air-to-air frequency for
coordinating a loose formation flight or
deciding where to fly for lunch. However,
since my days riding in my dad's airplane,
that frequency has been designated as
the multicom frequency for communications at nontowered airports without an
assigned unicom.
Weekend warriors flying warbirds
have been communicating on 123.45 for so
long that it has a nickname-"Fingers"-
and although officially designated for use

92 | AOPA PILOT January 2018

From air traffic control to hot air balloons or
deicing operations, nearly every aeronautical
activity has a designated frequency allocation.
in aircraft flight-testing and transoceanic communications, it has become an
unofficial air-to-air frequency. Legally,
for air-to-air communications between
private, fixed-wing aircraft, there is just
one authorized frequency: 122.75 MHz.
For general aviation helicopters: 123.025
MHz. Gliders and hot air balloons share
123.3 and 123.5 MHz.
T h e Fe d e ra l C o m m u n i c a t i o n s
Commission, which oversees the airways, has listed the proper (and legal)
use of each of the 760 channels available
in the VHF aviation band. From air traffic
control to hot air balloons or deicing operations, nearly every aeronautical activity
has a designated frequency allocation.
The official listing can be found in FAA
Advisory Circular 90-50D. And although
there's little reason for pilots to know all

the frequency allocations, there are times
a little knowledge can go a long way.
In 2001, Larry Gaines began hosting formation clinics near his Northern
California home base for the Bonanzas to
Oshkosh mass arrival at EAA AirVenture.
With up to 33 airplanes participating,
Gaines needed a unique frequency plus a
backup for air-to-air communications in
each of the eight practice sectors. A single
"official" frequency was not enough.
"I pored over my little Flight Guide,
writing down every frequency used by
every airport within 300 miles. I did the
same with instrument approach procedures within 300 miles to get Approach
and some Center frequencies," he said.
Gaines understood that, while all the
frequencies in the aviation band have a
designated use, not all the frequencies
AOPA Pilot Magazine - January 2018

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