maker because of the millions of consumer
GPS devices it has designed and built. The
company had already announced touch-screen control systems for its turbine-level
avionics systems that will be in the
HondaJet and an Embraer business jet, so
it was easy to see where the company was
headed with avionics control and input
technology. Despite its success making
touch-screen GPS navigators for everyone
from drivers to joggers, airplanes are different, and the design and implementation of
touch screen for cockpit use needed to be
perfected. Garmin has spent the past several
years experimenting and testing touch-screen controls for the GTN series, and that
investment has paid off.
I found it to be not only
easy but also natural to
use the touch screens.
Though Garmin had given me confidential briefings on the GTN development over
the past few years and I got to operate prototypes, I still wondered how well the touch
screen mounted in a vertical instrument
panel would work in actual flight. Back in the
1970s and early ’80s both King Radio and
Collins went down in flames with keyboard
avionics control systems that were mounted
in vertical panels. It was just too hard to find
and press the desired buttons in turbulence.
The FMS keyboards in turbine airplanes
work fine because they are mounted horizontally in the pedestal between the seats, or on
tilt panels that allow you to rest your palm on
the bezel while pressing the keys with your
fingers. But would the vertical mounting in
GA airplane instrument panels work?
After flying the GTN 750 and 650 in
Garmin’s Mooney Ovation I can emphatically tell you that my fears were totally
unfounded. I found it to be not only easy
but also natural to use the touch screens for
all data entry and mode selections. Garmin
has built in finger grips on the display bezel
PHOTOGRAPHY COURTESY GARMIN AVIONICS
so you can use a thumb and finger to steady
your hand, but I never felt the need to use
them. Tapping the screen with my finger,
even in some turbulence, was no problem.
It took a few tries to figure out just how
much pressure the screen responds to best,
but by the time we landed after an hour or
so of IFR flight, I felt perfectly at home
using the new systems.
Like smartphones and many other
touch-screen electronics, the GTN
responds to moving your finger across the
screen in addition to pressing on a “button.”
If you want to pan the moving map, for
example, simply slide your finger in the
direction you want to go and the screen
moves. You do the same for moving up or
down in a menu. The operation is perfectly
intuitive, and enough finger movement is
required so that the display doesn’t jump
quickly but changes smoothly.
The touch-screen technology Garmin
used in the GTN is the pressure-sensitive
type rather than the capacitance type found
in many smartphones and tablets. It takes a
little firmer touch to operate the GTN than
some touch screens you may be using, but I
found that to be a good thing because there
is less chance of getting a “double hit” or
making some unintended entry.
A big reason the GTNs are so easy to use is
the effective menu design. The menus are
short, and on the 750 with its greater size,
the item you want is usually no more than a
second press away. For example, to enter a
new frequency, simply tap the standby frequency at the top of the display and a big
keypad appears. Touch the numbers of the
new frequency—and the numbers are really
big on the 750 so even fat fingers don’t
miss—and one more tap sends the new frequency into the standby window. To
transfer the frequency to active, all it takes
is a touch of the frequency.
Even though the touch screen is easy to
operate the GTN series retained a twist
knob to enter data. If the bumps are too bad
to use the touch screen you always have the
knob to hang onto.
At their heart, the GTN series are WAAS-capable GPS navigators combined with
The GTN 750 is double the size of the GNS 530. The extra
display size allows it to be a full multi-function display
showing IFR charts, airport diagrams, XM Weather,
traffic, terrain, and moving maps.