Rockwell Commander 112 - Propeller Governor Installation

SECTION IV
POWER PLANT
AND PROPELLER
MAINTENANCE MANUAL
ROCKWELL
COMMANDER
112/B/TC/TCA
MODEL
LOW
PITCH
HIGH PITCH
112
23
0
(::0.1
0
)
28
0
- 30
0
112B
11. 6
0
(.:to. 1
0
)
30
0
112TC, 112TCA
15
0
(:!-0.1
0
)
30
0
Figure 4·14. Propeller Pitch Settings
c . Remove attaching nuts and washers and remove
governor assembly mounting pad.
d. Remove gasket between governor and engine pad.
PROPELLER GOVERNOR INSTALLATION
a. Wipe governor and engine mounting pad clean.
b . Install new gasket on mounting studs. Install
gasket with raised surface of gasket screen toward
governor.
c. Position governor on mounting studs, aligning
governor splines and splines in engine, and install
mounting nuts and washers. Do not force spline en-
gagement. Rotate engine crankshaft slightly and
splines will engage smoothly when properly aligned.
d. Connect governor control to governor and rig.
e. Reinstall all parts removed for access.
NOIE
It is possible for either the propeller
low pitch (high rpm) stop, or the gover-
nor high rpm stop to be the high rpm
limiting factor. It is desirable for the
governor stop to limit the high rpm at
the maximum rated rpm for a particular
aircraft. Due to climatic conditions,
field elevation, low pitch blade angle and
other considerations, an engine may not
reach rated rpm on the ground. It may be
necessary to readjust the governor stop
after test flying to obtain maximum rated
rpm when airborne.
HIGH RPM STOP ADJUSTMENT
a. Remove upper engine cowling for access to
governor.
b. Loosen high- speed stop screw jam nut.
c. Turn stop screw in to decrease maximum rpm
and out to increase maximum rpm. One full revolu-
tion of stop screw causes a change of approximately
25 rpm.
d. Tighten stop screw jam nut and make propeller
control linkage adjustment as necessary to maintain
full travel.
4-30
(
ZERO PROPELLER
PROTRACTOR
30-INCH
STATION
Figure 4·15. Checking Blade Angle
e. Re- rig disconnected controls and reinstall
cowling.
f.
Perform propeller and governor operational test.
Check for smoothness and full range of operation.
PROPELLER GOVERNOR CONTROL RIGGING
a. Disconnect control end from governor.
b. Place propeller control in cabin full forward,
then pull back approximately 1/8-inch and lock in
position. This will allow a cushion to assure full
contact with governor high rpm stop screw.
c. Place governor arm against high rpm stop screw.
d. Loosen jam nut and adjust control rod until at-
taching holes align while governor arm is against
high rpm stop screw. Be sure to maintain sufficient
thread engagement of the control and the rod end. If
necessary, shift the control in its clamps.
e. Attach control rod end to governor, tighten
jam nut, and install all safeties.
f. Inspect propeller control for full travel.
TROUBLE-SHOOTING
The best method of trouble- shooting is to decide on
the various causes of a given trouble and then to eli-
minate causes one by one, beginning with the most
probable. The following trouble-shooting figure lists
some of the most common troubles, which may be
encountered in maintaining the power plant system,
its probable causes and remedies. (see Figure 4-16).
Change 2
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**unofficial copy**