Avionics News June 2015 - 20

LONG LIVE THE NAVCOMM
Continued from page 19

more-viable candidate to replace the VHF NavComm
as the years pass.
As one avionics-industry insider noted, NextGen
and budgets may already impose a dampening effect
on future NavComm development - at least in the U.S.
and parts of the world making over their air traffic
management operations into systems with minimal
ground systems to support its functions.
Retiring scores of VOR transmitters has long been
a goal - and an expected outcome - of precision GPS
and NextGen's move toward space-based navigation
and surveillance.
Across the globe where ADS-B already prevails
- and places where it's gaining traction - fewer and
fewer VOR transmitters are going in.
According to various statements, as the Federal
Aviation Administration prepared to finalize the
2020 mandate for ADS-B Out, speculation that the
VOR system is destined for history is not unfounded;
not likely all VORs, at least not early on, but in the
coming years expect to see fewer of those distinctive
orange-and-white cones scattered around the country.
Locations where the VOR supports particular needs
or precision approaches are forecast to be the only
survivors.
This means most surviving VOR stations will be
near major airports and considered still needed to
support approach and landing in inclement weather.
And that, according to a few willing to venture
a guess, could lead to more NavComm models that
substitute WAAS GPS for the VHF navigation receiver
of old - IFR capable, of course.
"Now this is not a hint about products of tomorrow,
but at some point, the utility of the VHF navigation
system will inevitably become second tier because of
the lack of enough VORs to navigate cross-country,
VOR-to-VOR," said one electronics engineer whose
past work involved developing new cockpit avionics.
"The B-K folks showed us the potential years ago,"
the engineer continued.
This engineer requested anonymity because of his
employment situation - one in which he's not allowed
to speak on-the-record about avionics and other
developments in aviation.
"The natural next step would be to move NavComms
into the 21st century with a WAAS, IFR-approved
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june

2015

GPS on the nav side and that hardy VHF comm on the
other."
Let it drive an MFD, if desired; make it play with
other equipment, he added. Then NavComms live on
with GPS instead of VHF.
Meanwhile, the VHF NavComm remains; fewer
in numbers from fewer providers than just a few
years ago. Consider a few of the NavComm options
available.

BENDIXKING
Arguably among the longest-running products in this
field, BendixKing's line of NavComm models includes
four all-VHF models and one GPS/Comm. All five
date back decades, and remain active products in the
company catalog.
KX 125
A self-contained VHF NavComm, the KX 125 offers
contemporary features - like 760 comm channels, 200
nav channels and flip-flop frequency selection - with
a centrally mounted graphic CDI that eliminates the
need for a separate indicator. Other features include
"auto-TO," radial/bearing display, stuck-microphone
alert, integral audio amplifier and audio leveling. It's
available in either 14 or 28 volt.
KLX 135A
The lowest-cost panel-mounted GPS/Comm
available, this unit substitutes a VFR GPS and central
moving-map graphic display for the VHF Nav function
of the KLX 125. The result includes extra features like
direct selection of a standby frequency from the KLX
135A's GPS database.
KX 155/155A and KX 165/165A
Long the dominant NavComm with the early claim
to a digital display system, the KX 155 and 155A
and their higher-power cousins look nearly identical
thanks to their common displays and form factors. The
KX 155A and the KX 165A incorporate a number of
valuable control features:
Pre-selected frequencies are stored in a nonvolatile
memory circuit, eliminating the need for backup
battery power.
When interfaced to the KLN 94 GPS, both the
standby comm and nav frequencies can be selected and
remotely tuned from the GPS database, reducing pilot
workload.
Avionics News June 2015

Table of Contents for the Digital Edition of Avionics News June 2015
