Cessna 172P - Page 329

PILOT'S
OPERATING
HANDBOOK
SUPPLEMEIVT
19
CESSNA SOOA AUTOPII,OT
(TYPE
AF-39õA)
SUPPLEMENT
CESSNA NAVOMATIC
3OOA
AUTOPILOT
(Type
AF-39541
sEcTtoN
I
GENERAL
The
Cessna
8004
Navomatic is an all
electric,
single-axis
(aileron
control)
autopilot
system that
provides
added lateral and
directional
stability.
Components &re & computer-a¡nplifier, a turn coordinator,
a
directional
glfro,
&n
aileron
actuator and a
course
deviation indicator(s)
incorlrorating
a localizer reversed
(BC)
indicator light.
Roll and
yaw
motions of the airplane are sensed by the turn coordina-
tor
gyro.
Deviations
from the selectod heading aro sensed bythe direction-
al
gyro.
The
computer-amplifier
eloctroniaally computes tho
necessary
correction
and
signals the actuator to move the ailerons to maintain
the
airplane
in
the
commanded
lateral
a,ttitude or heading.
The
actuator
includes
a thermoetatic
switch which monitors
the
operating
temperature
of the motor. If
the
temperature
becomes abnormal,
the
thermostatic
switch opens and
disengages
the autopilot
to remove
power
from
the
actuator. After
approximately
10
minutes, the switch wiII
automatically
close
to reapply
power
to the actua,tor and a,utopilot system.
The
3004
Navomatic will also íntercept
and track a VOR or localizer
course
using
signals from
a VHF navigation
receiver.
The
operating
controls
for the
Cessna
3004
Navomatic are
located on
the
front
panel
of the
computer-amplifier and
on
tho
directional
gyro,
shown
in Figure
1.
The
primary
function
pushbuttons
(HDG
SEL, NAV
INT,
and
NAV TRK),
are
interlocked so that
only
one
function oan
be
selected
at a
time. The
HI
SENS and BACK CIìS
pushbuttons
are not
interlocked
so
that either
or both
of
these
funotions
can be selected
at
any
time.
30
May 1980
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