Cessna 172R, Operating Handbook

Page: 95 / 500

CESSNA
MODEL 172R
SECTION 3
EMERGENCY PROCEDURES
INSUFFICIENT RATE OF CHARGE
NOTE
The low
voltage
annunciator (VOLTS) may come on and
I
ammeter discharge
indications
may occur during low RPM
conditions with an electrical load
on
the
system,
such as
during a low RPM taxi. Under these conditions, the
■
annuciator will go off at higher RPM.
I
If the overvoltage sensor should shut down the alternator
and trip
the alternator circuit breaker
(ALT FLD),
or
if the alternator
output
is|
low, a discharge rate will
be
shown on the
ammeter
followed by
illumination of the low voltage annunciator (VOLTS).
Since
thisl
may
be a "nuisance"
trip
out,
an
attempt
should
be made
to
reactivate the alternator
system.
To reactivate,
set
the
avionics!
master
switch to the OFF position,
check that the alternator
circuit!
breaker
(ALT FLD) is in, then
set
both sides of the
master
switch
tol
the OFF position and then
to the ON position. If the problem
no|
longer exists, normal alternator charging will
resume
and the low
voltage annunciator
(VOLTS) will go off. The avionics
master switch
I
may then be returned
to the
ON position.
|
If the annunciator illuminates again, a
malfunction
is
confirmed.!
In this
event,
the flight should
be terminated and/or the
current
drain on the
battery minimized because the battery can
supply the
electrical
system for only a limited period
of time. Battery power
must be
conserved for later operation
of the wing flaps
and, if the
emergency occurs
at
night,
for
possible use
of the landing lights
during landing.
OTHER
EMERGENCIES
WINDSHIELD DAMAGE
If
a
bird strike or other incident
should damage the windshield in
flight to the point of
creating
an
opening, a significant
loss in
performance may be expected. This loss
may be minimized
in
some
cases (depending on
amount
of damage, altitude,
etc.) by
opening the
side windows while the airplane is maneuvered
for
a
landing at the
nearest airport. If airplane performance or other
adverse conditions
preclude landing
at an airport, prepare for an
"off airport" landing in accordance
with
the
Precautionary Landing
With Engine Power or Ditching
checklists.
Revision
7
3-23/3-24