AOPA Pilot Magazine - May 2013 - 71

As time went on, Hall began to get
suspicious of all sorts of other potential
weak points in the electrical system,
including the voltage regulator, the wiring,
and all of the other components.

HALL’S CURENT PANEL

is a far cry from where he
began a few years ago
(below left). A Garmin
G500 anchors the
workspace, with a
Garmin GNS 530 and 430
providing communication
and navigation. Ever
the professional, Hall
includes even more
back-up support with
a yoke-mounted
Garmin 696. If the
primary alternator were
to fail, an annunciator
light would come on,
indicating to the pilot
that the standby
alternator has
automatically come
on line (far left).

When Hall—based at the Ithaca
Tompkins Regional Airport in Ithaca, New
York—purchased the Mooney in 2000, it
was well configured, but more or less stock.
Almost from the beginning he began looking for backups to all his systems. He put in
a loran receiver to back up the Garmin GNS
530 and VOR navigators, and he installed a
Mid-Continent Lifesaver—an electric attitude indicator with a self-contained battery
backup—to provide redundancy for his attitude indicator.
That attitude indicator was his first
step forward into an all-electric cockpit.
The Lifesaver replaced his turn coordinator, an instrument he never liked anyway.
“That turn coordinator tended to look like
a bird flapping its wings,” he said. With that
upgrade he had two attitude instruments—
one vacuum powered, and one electrically
powered. “I felt like I pushed reliability forward,” he said. “But the weakest system all
along was the alternator.”
QUEST FOR REDUNDANCY. With that
assumption in mind, Hall went on a search
for the best and most reliable system he
could find. He tried two different brands,
neither of which made him happy. He even
carried an extra alternator with him in the
baggage compartment, so that if he ever got
stuck somewhere, he at least would have the
part. As time went on, however, he began to
get suspicious of all sorts of other potential
weak points in the electrical system, including the voltage regulator, the wiring, and all
of the other components.

Hall’s quest for redundancy became
even more critical when he upgraded to
a Garmin G500 primary flight and multifunction display. He now had a glass
airplane with one primary electrical
source. “And this doesn’t seem like such a
good idea,” he said. “Now if I lose the alternator, I’m going to lose a lot more than I did
before.” So he started to look at a dual electrical system.
Unless the engine has an additional
accessory pad and can accept a second alternator, the vacuum system first
must be removed, and an alternator is
then installed in its place. And this is the
tricky part—adding additional systems
usually is easier than taking factory systems away. According to Todd Adams, the
manager at Lancaster Avionics in Lititz,
Pennsylvania, the first place to look is the
aircraft’s type certificate data sheet. If
this document lists the vacuum pump as
required equipment, the approval process
is more complicated—not impossible, but
not easy, either. If the vacuum pump isn’t
listed, taking it out and replacing it could
be as easy as getting the shop to sign off on
a Form 337 as a field approval and going
on your way.
Unfortunately for Hall, clearly listed
in black and white on page 38 of the
Mooney’s type certificate data sheet are
five acceptable vacuum pumps, one of
which must be installed, or the aircraft
is considered VFR only. Hope seems to
come in the form of a note stating that
removal of the vacuum pump is possible

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AOPA Pilot Magazine - May 2013

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