Cessna T188C - Page 274

MODEL
188
& T188
SERIES
SERVICE
MANUAL
f.
Install
spacers
and
spinner
support
on
propeller
13-14.
REMOVAL.
cylinder.
If
spacers
are
not centered
mechanically
a.
Remove
cowling
and engine
baffles
as required
(piloted),
visually
center
and
hold them
until
spinner
for access
to governor.
support
is
forced firmly
in
place.
b. Disconnect
governor
control
from
governor
arm
g.
Hold spinner
snug
against
spinner
support
and
or
extension
arm.
check
alignment
of
holes
in spinner
with
holes
in
spinner
bulkhead.
Add or
remove
spacers
from
pro-
NOTE
peller
cylinder
until holes
are
within
.050 of
align-
ment.
Note
position
of
all washers
so that
washers
h.
Push
hard
on spinner
to align
holes
and
install
may
be installed
in the
same
position
on
re-
screws
and
washers(if
required)
in 3 or
more
equal
installation.
spaces
around
the spinner
bulkhead.
Relax
pressure
on
the spinner
and install
the remaining
screws
and
c.
Remove
four
sets
of nuts
and
washers
securing
washers
(if
required).
governor
to engine
and
pull
governor
from
mounting
i.
Tighten
all screws
uniformly
around
the
spinner,
studs.
d. Remove
gasket
from
between
governor
and
engine
13-10.
TIME
BETWEEN
OVERHAUL
(TBO).
Pro-
mounting
pad.
peller
overhaul
shall
coincide
with
engine
overhaul,
but interval
shall
not exceed
1200
hours,
Refer
to
13-15.
INSTALLATION.
Sections
11,
11A,
and
11B
for
engine
overhaul
rec-
a. Wipe
governor
and
engine
mounting
pad
clean
ommendatlons.
b.
Install
a
new gasket
on the
mounting
studs.
In-
stall gasket
with
raised
surface
of the
gasket
screen
13-11.
PROPELLER
GOVERNOR.
toward
the
governor.
13-12.
DESCRIPTION.
The
propeller
governor
is
a
single-acting,
centrifugal
type,
which
boosts
oil pres-
WARNING
sure from
the engine and
directs it to the
propeller
where the
oil is used to
increase blade
pitch. A
Be sure
magneto is
grounded before
turning
single-acting governor uses oil pressure to effect a engine.
pitch
change in one
direction only;
a pitch change
in
the
opposite direction
results from
a combination
of c.
Position governor
on mounting
studs, aligning
centrifugal
twisting moment
of rotating
blades and
governor
drive splines
with splines in the
engine and
compressed
springs.
Oil
pressure
is boosted
in
the
install
mounting
nuts
and washers.
Do not
force
governor
by
a gear
type oil
pump.
A pilot valve,
fly
spline
engagement.
Rotate
engine
crankshaft
slightly
weight
and speeder
spring act together
to open
and and
splines will engage
smoothly
when properly
close governor oil passages as required to maintain aligned.
a constant engine
speed.
d. Connect governor
control to governor arm
or
arm extension and rig control as outlined in paragraph
NOTE
13-16.
e. Reinstall
all items
removed for
access.
Outward
physical
appearance
of
specific
gov-
ernors is the same,
but internal parts deter-
13-16. HIGH-RPM
STOP ADJUSTMENT.
mine whether
it uses oil
pressure to increase
a. Remove
engine cowling
and baffle as
required
or
decrease
blade pitch.
The
propellers
used
for
access.
on these aircraft require governors which b. Remove safety wire and loosen the high-speed
"sense" in a certain manner. "Sensing" is stop screw locknut.
determined by the type
pilot valve installed
c. Turn the stop screw
IN to decrease maximum
inside the governor. Since the basic governor rpm and OUT to increase maximum rpm. One full
may
be set to "sense" oppositely,
it is impor- turn of
the stop screw causes a change
of approxi-
tant to ascertain
that the governor
is correct -
mately 25 rpm.
for the propeller being used. d. Tighten stop screw locknut and make propeller
control
Linkage
adjustment
as
necessary
to maintain
13-13. TROUBLE SHOOTING. When trouble shoot- full travel.
ing the propeller-governor combination, it is recom- e. Install baffle and cowling.
mended that
a governor known to be in
good condition f. Test
operate propeller and governor.
be
installed
to
check whether
the propeller
or the
governor
is at
fault.
Removal
and
replacement,
rig-
NOTE
ging,
high-speed
stop
adjustment,
desludging
and
re-
placement
of the
governor
mounting
gasket
are
not
It is
possible
for either
the
propeller
low
major
repairs
and
may be
accomplished
in
the field.
pitch
(high-rpm)
stop
or the
governor
high-
Repairs
to
piopeller
governors
are
classed
as
pro-
rpm
stop
to
be the
high-rpm
limiting
factor.
peller
major
repairs
in
Federal
Aviation
Regulations,
It is desirable
for
the
governor
stop
to
which
also
define
who
may
accomplish
such
repairs.
limit
the
high-rpm
at the
maximum
rated
13-12
Revision
1