Avionics News June 2016 - 29

Today, there's no technological reason for a small
aircraft to go without an intercom system that
accommodates every seat. The options are as
voluminous as the needs are varied.

The date was May 14, 1908 - the dawn of the passenger-aircraft era and, simultaneously, the emergence of a new need ... a
way to communicate with another person in the aircraft.
Shouting over the din of the straight exhaust pipes and the rush
of air gave birth, first, to sound tubes - adapted from maritime
technology proven at sea. These sound tubes often lacked clarity
- and volume. But they were a step forward.
Years later, with the advent of new electronics technologies for
aircraft, the first wired intercoms finally arrived.
General aviation technology has come a long way since 1908,
when Orville and Wilbur created the first need to talk to the person in the adjoining seat. Today, there's no technological reason
for a small aircraft to go without an intercom system that accommodates every seat. The options are as voluminous as the needs
are varied.
Flyer's choice: Portable or panel-mounted?
Aircraft intercoms evolved much like everything else in aviation, to the point that many of today's intercom choices come
integrated into audio-control panels. Designed to manage audio
from VHF comm and nav radios and ADF receivers, the audiocontrol panel also became the home for marker-beacon receivers
and cockpit intercom functions.
Today's advanced audio-control panels also may manage
multiple other sound inputs, including music players of varying
types and cellphones. But broad options remain for stand-alone
intercoms, in packages ranging from two-place to multi-place capabilities - and some with auxiliary audio inputs similar to their
audio-panel brethren.
In examining the world of intercoms this month, we focus on
stand-alone systems, rather than full audio-control panel packages previously profiled.
For many aircraft, the intercom works in parallel with the
comm radios to facilitate communications with controllers, other
pilots and the passengers in the aircraft.
The choices are many and generally fall into one of two categories: portable systems that can move from aircraft to aircraft;
and panel-mounted intercoms for permanent installation.
Which best serves for any given aircraft varies with the needs
of both the aircraft and buyer, since both forms typically cover
the basics.

And increasingly both variations provide options for expansion and a variety of input sources that leave the pilot free to
handle the tasks at hand without audio interference from others
in the aircraft.
Variations on a function
One thing aviators enjoy in avionics is a broad variety of
choices for almost every need. As noted, that particularly applies
to intercom systems.
Helping an aircraft owner select an intercom starts with what
fulfills the needs of the pilot in their specific aircraft - which circles back to what's installed in the panel.
Some examples include:
* The owner of an aircraft with one comm, one nav or one
nav/comm may feel no need for an audio panel that allows the pilot to switch input from a multitude of radios.
* The owner of an antique or other aircraft without an electrical system may need a portable operable on battery power.
* For some, a two-place system is all they will ever need,
one that moves with the pilot to other aircraft. If the aircraft
has an electrical system and a power plug, either a shippowered or a battery-powered system fulfills the need.
* A simple four-place aircraft may be best served by a
panel-mounted system - or, depending on what's in the
panel, a portable of either power option.
* Some owners of simple aircraft may fly with four seats
but seldom - if ever - put a third or fourth person in the
aircraft, often because the plane's payload can't handle
three or four with any more than partial fuel in the tanks.
* And some may want an intercom that's independent of an
audio panel for their own sense of redundancy.
Beyond a power source for portables, the issue of space looms
for owners and operators interested in a panel-mounted intercom.
Intercom manufacturers help on that issue by offering systems of
differing sizes and configurations.
In fact, avionics manufacturers offer variations on all these
options - portable power, panel-space and orientation - giving
owners a wide array from which to choose.
The options are numerous.
Continued on following page

avionics news

june

2016

Table of Contents for the Digital Edition of Avionics News June 2016