Avionics News January 2016 - 28
AUDIO CONTROL PANELS
Continued from page 27
attractions driving the retrofit of new audio panels - features
and conveniences common to today's personal electronics
devices: Bluetooth connections for phones and music players; USB ports for connecting external hardware - such as a
music device or external recorder.
At least one audio panel model even offers an integral
control input for a remotely mounted VHF communication
radio, further increasing the little audio panel's usefulness for
some of aviation's simplest panels.
Feature options vary widely
Aircraft owners and operators today enjoy more variety in
audio panel choices than ever before - from simple, basic audio panels for basic entry-level, light sport and experimental
panels to systems capable of handling six audio output channels, and the full boat of features, including phone, music and
wireless device connectability.
The Bluetooth connection, for example, can allow passengers or crew to make cellphone calls through their headset
- a benefit in a light plane with the engine running.
The same wireless audio technology can enable a featuredeep audio panel to play music on an iPod, iPad, iPhone,
Android smartphone or tablet, or other Bluetooth-enabled
Feature-rich audio panels allow the crew to isolate passenger audio from pilot, co-pilot or both - not a new feature, but
one more attractive in an age when passengers can do more
than chat among themselves ... such as play music.
For the crew, many up-feature audio panels also allow the
crew to have one comm radio as the active radio while allowing another crew member to use a second comm radio.
Some audio panels also sport hard connections to input
audio; one pilot of my acquaintance brings a portable DVD
player for his grandkids, and uses its headset connection to
pipe the movie's audio through the six-place intercom of his
plane. The arrangement, he said, gave him his first major
appreciation of the pilot-isolate controls. The passengers get
to enjoy the video's audio while he hears only comm-radio
For helicopter installations, rotor-wing-oriented audio
panels are built to tougher physical and vibration standards
- and typically offer more channels for voice communications. This is acknowledgment of the high percentage of the
helicopter fleet used in law enforcement, emergency medical and firefighting work - any work environment involving
regular coordinating with multiple agencies using different
radio types and frequency bands.
Same job, varied in dimensions
Helping an owner or pilot pick an audio panel for a stack
upgrade should take into account any other work planned for
the same job, of course, and a look at plans for the future.
The answer to those questions can have a bearing on choosing the best option for the flying and equipment.
But regardless of the panel and its needs or space, an audio
panel likely exists that can fit and fulfill its mission.
Some are small enough to fit into a standard 3.5-inch instrument hole; others take up as much space as a 1960s nav/
As previously noted, some take up no panel space at all.
Instead of mounting in the panel, the remote mounts ride in
a bay or on an avionics shelf somewhere remote from the
panel - but still controlled by a pilot-accessible device, like a
multifunction display or primary flight display with the ability to control remote devices.
But by and large, the form factor most common for an
audio panel is the standard-width radio width and 1 inch tall.
Installation considerations ...
the task can vary widely
Installation considerations can cover the map, given the
almost infinite variety of equipment - age, technology, functionality - installed in older aircraft.
If the job is solely to upgrade the audio panel, a check for
compatibility with existing equipment is a common-sense
step owners will well understand.
Some lucky owners of older-model BendixKing audio
panels can pick from a few models from competing companies with the benefit of being plug-and-play replacements.
Loosen the locking mechanism, remove the old unit, slide
in the new unit, lock it down - and turn on the power. That's
it. But there's no assurance this approach will support use of
all the features of the new audio panel.
In fact, most avionics shops counsel that the first installation question to answer concerns the wiring.
Is the old wiring in good shape? Can it support what the
new audio panel - or other new equipment - offers, without
some work updating the wiring, as well?
For example, for a stereo intercom function, available in
many audio panels, to be viable, the monaural wiring to the
monaural headset jacks can't support stereo sound, even with
stereo-capable headsets. So even if the new panel can be
plugged into the old tray, some wiring update and new headphone jacks will be in order just to deliver the stereo audio
the audio panel offers.
Perhaps the biggest consideration, however, is the wiring
behind the panel, itself - the spaghetti connecting the audio
panel to the radios it will serve.