Beechcraft C23 SUNDOWNER 180 Pilot Operating Handbook page 266

Section X BEECHCRAFT
Safety
Information
haze, etc.) the illusions predominate. Only through
awareness of these illusions, and proficiency
in
instrument flight
procedures, can an airplane
be
operated safety in
a
low
visibility
environment.
Flying
in fog,
dense haze or dust, cloud
banks,
or
very
low
visibility,
with
strobe lights or
rotating
beacons
turned on can contribute to
vertigo.
They
should
be
turned off
in
these conditions, particularly
at night.
All pilots should check the
weather
and use
good
judgment
in
planning
flights.
The VFR
pilot should
use extra caution in avoiding
low
visibility
conditions.
Motion sickness often precedes or accompanies
disorientation and may
further
jeopardize
the
flight.
Disorientation
in low
visibility
conditions is not
limited to VFR
pilots.
Although IFR pilots are
trained to look
at
their
instruments
to gain an
artificial
visual reference
as a
replacement
for
the
loss of
a visual
horizon, they do not always do
so.
This can happen
when
the pilot's
physical
condition
will
not permit him
to concentrate
on his
instruments;
when
the
pilot
is not proficient in flying
instrument conditions in the airplane he
is flying;
or,
when
the pilot's
work
load of
flying
by
reference
to
10-36
March, 1981