/I don't question Bob's assessment of the essential bus,
/but I do have an experience to share here.
>If the job is done right, the probability of a fuse opening
>is very close to zero . . . when it does, there's something
>broke . . . and there's no value in fiddling with it it flight.
/That's ALMOST always true. I once had an intermittent short in
/my panel wiring ground out my panel lights while I was IMC at
/night shortly after departure from San Diego (in a Grumman Yankee).
/The momentary grounding blew the fuse. I flew the airplane thru the
/overcast using a flashlight in my teeth to see the panel (that's why
/I always keep the flashlight on a string hanging from my neck... easy
/to find).
/After I was thru the overcast I replaced the fuse, and found that
/the panel lights worked OK for the approach back into Los Angeles.
/It was a lot easier with working panel lights than with just a flashlight.
/The next day I found the abraded wiring and made sure it was properly
insulated.
/Given that experience I'll likely opt to keep my fuses/breakers
/within reach. In general, however, if a fuse blows it'll probably
/blow again if replaced, 'cause it blew for a reason.
But you didn't read the article . . . #1 on the essential bus
list of goodies is panel lighting . . . not 5 amps of post lights
and internally lit gizmos but a simple panel flood . . . a maximum
of .16 amps. How about a goose-neck mounted map light that can
point into your lap hands free for map reading and be twisted
to cover the panel during alternator out and/or situations like you
describe above? The proscription is if someting is essential,
have a backup for it. If not essential, don't worry about it. But in
either case, don't be a mechanic in flight. Flashlights are
not my idea of backup for normal panel lighting. It's rediculously
EASY to have TWO systems . . . one fancy on the main bus and one
simple system on the essential bus.
I'll suggest that the thoughtfully designed system should never
present you with a good reason for fiddling with fuses or breakers
in flight.
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