Rockwell Commander 112 - SYSTEM AND COMPONENT SERVICING

SECTION IT
SERVICING
MAINTENANCE MANUAL
ROCKWELL
COMMANDER
112/B/TC/TCA
AND INSPECTION
STARTING HOT ENGINE
a. Mixture control lever - full LEAN.
b. Propeller control lever - ill RPM.
c. Throttle control - FULL
d. Induction air heat control - OFF.
e. Master battery switch - ON (alternator side of
switch
OFF if external power is used).
I WARNING I
Propeller area must be clear of person-
nel, work benches and equipment prior
to engaging starter.
f. Ignition switch - START and then to BOTH
when engine starts.
NOIE
Cranking should be limited to 30 seconds,
and several minutes allowed between crank-
ing periods to permit the starter to cool.
g. Mixture control lever - full RICH.
h. Throttle control - desired IDLE speed.
i. Check oil pressure gage for an indication of oil
pressure. If oil pressure is not indicated within 30
seconds after engine start, stop engine and determine
causeD
j. After engine has started, disconnect external
power source if used, and place alternator master
switch to ALT (on).
NOIE
The battery switch should be left ON
until the alternator is turned on and
stabilized.
ENGINE OPERATIONAL CHECK
After engine start, allow engine to warm up at 1000-
1200
rpm to ensure adequate cooling and engine lubri-
cation. At completion of warm up period proceed with
the engine ope
rational cheCk.
INSTRUMENTS. With engine stabilized at 2200 rpm,
check all engine instruments, ammeter, voltmeter
(optional) and vacuum (optional).
I
IGNITION. Check ignition switch grounding by retard-
ing throttle to IDLE and turn ignition switch OFF, to
check that engine will stop running. After rpm has
dropped 100 to 200 rpm, turn ignition switch to BOTH.
2- 6
If magneto switches remain OFF for
longer than a few seconds, after-firing
may occur when magnetos are switched
back to BOTH. If the engine continues
to run with the ignition switch off, stop
engine by placing mixture control lever
in IDLE CUTOFF and check magneto ground.
PROPELLER. With engine at 2200 rpm, exercise •
propeller by slowly moving pro pelle r control lever aft
to reduce rpm to 1500. Return control lever full for- •
ward (ill RPM) and note any indication of sluggish or
erratic operation. Refer to Section IV if propeller
does not operate properly.
Do not allow cylinder head and oil temp-
peratures to exceed operating limits.
MAGNETO CHECK. Advance throttle to 2200 rpm •
and rotate ignition switch from BOTH to L (left) poSi-
tion and note rpm drop. Rotate switch back to BOTH
pOSition
to clear the engine. Rotate switch to R (right)
pOSition and note rpm drop. Drop should not exceed
175 rpm on either magneto and should not exceed 50
rpm variation between the two magnetos.
FULL POWER. With propeller in HI RPM and •
mixture control in full RICH, advance throttle to
FULL open position. Tachometer should read 2700
rpm, and manifold pressure (at sea level) should be
28.6 inches mercury.
IDLE SPEED. Retard throttle lever to IDLE pOSition.
Engine should run smoothly at 600 (+50, -0) rpm,
without any tendency to load up.
ENGINE
SHUTDOWN. Stop engine by placing mixture
control lever in IDLE CUTOFF position. As soon as I
propeller has stopped turning, place ignition switch
in OFF position, then turn all other electrical switches
OFF.
SYSTEM AND COMPONENT SERVICING
Servicing procedures contained in this section are
confined to those maintenance actions that occur with
routine frequency and require a reasonable short period
of time to accomplish (see Figure 2-4). Servicing
practices and maintenance to aircraft systems and
components which require less frequent attention are
contained in the appropriate section of this manual.
HYDRAULIC SYSTEM
HYDRAULIC POWER PACK. The hydraulic power
pack is located in the left forward area of the aft fuse-
lage section (see Figure 2-5). An access pal1ellocated
in the baggage compartment on the left aft side affords
easy access for servicing. Before removing the fill
port screw, wipe fill port area with a shop towel •
to remove dirt that could fall into the reservoir. Never
allow reservoir to remain uncapped any longer than
necessary. If reservoir is low and hydraulic fluid is
not immediately available reinstall fill port screw •
until hydraulic fluid is obtained. Service hydraulic
reservoir as follows:
Change 3
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**unofficial copy**