AOPA Pilot Magazine - December 2021 - 89

RUDDER & WRENCH
Savvy Maintenance coverage sponsored by AIRCRAFT SPRUCE
SAVVY MA INTENANCE /OPINION
Balky alternator
Chasing down an elusive charging
system gremlin
BY MIKE BUSCH
APPLY NOW FOR
AOPA'S FLEXIBLE
AVIATION LOAN
DO YOU WANT QUICK & EASY?
Fill out a quick online application and be
approved in one business day.
I NTER M I T TENT P R O B L EMS A R E the
worst. They always seem to happen at the
most inconvenient time, like when you're
in the middle of nowhere. They never
seem to happen when you want them to
happen, like when you're trying to show
them to your A&P so he can troubleshoot
and fix them.
Case in point: Nearly 30 years ago,
not long after I bought my Cessna 310, I
was in the middle of a 4,000-mile crosscountry
that took me from California
to Illinois, Kansas, Oklahoma, and back
home to California. I was not an A&P at
the time, simply a maintenance-involved
airplane owner. (The A&P would come a
decade later.)
The first sign of trouble occurred as
I was starting engines at Champaign,
Illinois, headed for Wichita, Kansas.
With both engines running, I noted that
the amber warning light marked " ALT
FAILURE: R ALT " did not go out the way
it should have. I didn't know whether this
was a genuine alternator failure or just a
malfunctioning idiot light, but figured I'd
better try to find out.
I shut off the known good alternator
(the left one) to see what would happen.
What I observed was (1) the righthand
alternator output current read zero amps,
(2) the battery ammeter showed a discharge,
(3) the bus voltage dropped from 28
to 24 volts, and (4) the red " LOW VOLT "
light illuminated. That pretty much settled
it: The right alternator was kaput. (This
diagnostic routine took about 10 seconds.)
Go or no-go? The conservative decision
would have been to shut down the
engines and try to find a mechanic. That
also would have been the FAA-approved
thing to do. Both alternators are required
equipment so per FAR 91.213(d) my
Cessna 310 with one non-functioning
alternator was legally unairworthy.
On the other hand, doing this would
probably mean that I'd have to cancel
my appointments in Wichita and
Independence, Kansas, and Tulsa,
Oklahoma. Wichita also seemed like
a much better place to deal with this
issue, since it's home to one of the
best twin Cessna shops in the country
(Yingling Aviation) as well as the
world's best supply of Cessna parts. The
weather was severe VFR, so I didn't
consider a flight with one alternator
inoperative to be even slightly risky.
AOPA PILOT / December 2021
89
DO YOU WANT AFFORDABLE?
A $10,000 flight training loan with monthly
payments as low as $250 a month. AOPA
Member rates starting at WSJ Prime +5%.
DO YOU WANT FLEXIBILITY?
You can borrow as much as 3x your monthly
income (up to a max of $100k).
Go to
aopa.org/financemytraining
to apply today.
AOPA's Flexible Aviation Loan can be put
to work right now to get you on your way as
a better trained, more proficient pilot.
http://www.aopa.org/financemytraining
AOPA Pilot Magazine - December 2021

Table of Contents for the Digital Edition of AOPA Pilot Magazine - December 2021
