AEA Pilot's Guide 2018-2019 - 45

all-glass, all-electrical panel.
Consider these approaches to assuring power for
all-electrical aircraft.
The Gold Standard: stand-alone standby
electrical power
Original equipment manufacturers offered dual
alternators and, in some cases, dual batteries going
back decades, years before anyone in general
aviation uttered the words "primary flight display."
With digital cockpits the dominant standard
in today's factory-new aircraft, electrical power
redundancy has become more common. The
catalyst? The need for redundancy to power allglass instrument panels.
You'll find dual electrical systems like this as
standard on many factory airplanes with EFIS
cockpits: Beechcraft G36 Bonanzas and G58 Baron
twins; Cirrus Aircraft SR20 and SR22 models; current
production Mooneys; even the modest Cessna
singles, the 172, 182 and 206 sport dual buses.
Many of these sport dual everything: alternators,
to produce electrical power; batteries and
regulators, to control the output and sharing of
power from the two alternators; and dual buses.
For glass-panel aircraft lacking these capabilities,
avenues exist for some aircraft to add them.
Depending on the airframe, supplemental type
certificates may provide the path to adding a second
alternator and a regulator capable of handling both
the main and second generating source.
Several vendors offer packages that add a
standby alternator, some driven off the engine
accessory drive normally used to power the nowunneeded suction or pressure pump, along with
the regulator capable of controlling both - including
picking up the load when the main alternator fails.
B&C Specialty Products offers standby alternator
packages for many popular aircraft, including a
regulator capable of handling the changeover. Both
belt-driven and gear-driven options are available,
and the company holds STCs for many aircraft. B&C
also holds STCs and offers kits to fit its standby
alternator systems in various aircraft, among them
the Beechcraft Bonanza, Cessna 210 and Piper
PA32.

Basic Aircraft Products also offers STCs for its
ram-air turbine-powered standby alternators for
several airframes. In essence, the ram-air turbine
pops out where airflow through turbine blades drives
an alternator.
Fourteen-volt systems available from BAP include
most Aeronca models, short-wing Pipers through the
Super Cub, Taylorcraft BC 12-D, the Luscombe 8
series and Boeing Stearman.
Another avenue for adding alternate electrical
power involves using the field approval approach to
add a second bus and a standby battery. But other
avenues exist to assure power continues to flow to
digital panels.
EFIS with integral standby power
In many instances, avionics manufacturers offer
integral standby power in or for today's modern
EFIS gear.
Avidyne, Aspen Avionics, Dynon and Garmin offer
the option of a standby battery for their systems.
For example, Aspen's Evolution line of PFDs and
MFDs come standard with both a standby battery
and a GPS navigation receiver.
For VFR-only pilots, Aspen's certified VFR PFD
offers an inexpensive path to adding modern solidstate indications for the entire six-pack of analog
flight instruments in a standard panel for about
$4,000 plus installation. And that includes the
standby battery and GPS.
Aspen's higher IFR-approved PFD and its line
of MFDs also include the standby features as
standard - and the battery satisfies the regulatory
requirement for that instrument.
Garmin offers the option of a standby battery for
both its new G600 TXi and G500 TXi PFDs, also
satisfying the emergency-power requirement.
Ditto for Garmin's G5 instrument, which is
approved as a replacement attitude indicator and, in
a second unit, a DG and HSI - with a GPS interface
as an option. The G5 can be equipped with its own
integral standby battery to keep the units working
for more than two hours in the event of the loss of
main-ship power.
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Table of Contents for the Digital Edition of AEA Pilot's Guide 2018-2019