AOPA Pilot Magazine - July 2013 - 90

P&E

AVIONICS

Who are you talking to?
There’s no doubt with new Garmin radios
B Y D AV E H I R S C H M A N

THE GNC 255A at

aren’t slide-in replacements. The
GNC and GTR are about one-quarter inch taller than the SL series and
have some added pins in the back
for new features.
That extra height allows the
high-contrast digital displays to
show frequencies using impressively big numbers, a very nice
feature for those of us whose near
vision could use all the help it can get.
Garmin makes it easy for the new radios to communicate with other Garmin avionics. Travis’s Cherokee
180, for example, has a G500 PFD/MFD in which the
GNC serves as the number-two nav and com. But the
GNC and GTR also connect to Aspen and Avidyne PFDs
and MFDs (and many others), and just about any CDI
can connect to the nav side of the GNC.
“The GNC is compatible with just about any HSI or
nav head on the market,” Travis said. “You won’t have
to replace the nav head when you update your radio.”
Travis said the GNC feature that allows it to show
bearing, distance, and groundspeed to a station is especially popular among old-school IFR pilots accustomed
to distance measuring equipment (DME).
The radio clarity and signal strength of the GNC and
GTR units are very good. (Both have up to 10 watts of
transmit power, up from 8 watts in the SL series.)
The new units range in price from $3,958 to $4,785
depending on options—a roughly $1,000 jump from the
SL series. Preowned SLs can still top $3,000 on the used
avionics market.
“The SLs are highly capable radios and they’ve been
around for a long time, so people aren’t rushing out to
replace them,” Travis said. “But when they do get their
hands on the GNCs and GTRs, I think they’ll be pleasantly surprised.”
AOPA

the center of this
Garmin avionics
stack includes
a database
that identifies
frequencies for
nearby airports,
ATC, and navaids.

THERE’S A momentary doubt each time we check in on
a new frequency: Did I hear it right? Did I dial it in correctly? Was I given the proper frequency? Garmin’s new
radios, the GNC 255A nav/com and the GTR 225 com, take
away any uncertainty.
“You always know you have the right frequency because
the radio shows you,” said Ben Travis, principal at Smart
Avionics near Harrisburg, Pennsylvania, who has installed
several of the Garmin units—including the GNC 255A in
his own Piper Cherokee 180. “It lets you know exactly who
you’re talking to.”
In this case, I was dialing in the tower frequency at
Frederick Municipal Airport in Maryland (132.4 MHz). But
when I let go of the tuning knob, a window in the standby
frequency let me know it was tuned to a ground controller
in Newark, New Jersey, on 132.45. The radio has an extensive national database of radio frequencies, and when
linked to a GPS, it also lets you know the nearest ATC frequencies (both com and nav). Dial in an airport identifier
and it will list all the relevant frequencies for that location. Then choose the frequency you want (ATIS, tower,
et cetera) and it’s automatically loaded in the standby window. Ask for the nearest airport or nearest VOR and the
radio provides a list of 25.
The GNC and GTR are Garmin’s long-awaited replacements for its popular SL30 and SL40 radios. Like their
predecessors, the new radios have a monitor feature that
allows the operator to listen in on the standby frequency
while keeping another one active. But the new units

90 | AOPA PILOT July 2013

EMAIL dave.hirschman@aopa.org

AOPA Pilot Magazine - July 2013

Table of Contents for the Digital Edition of AOPA Pilot Magazine - July 2013