2-48. PROPELLER LEVERS.
Two propeller levers on the control pedestal (fig,
2-10), placarded PROP, are used to regulate propeller
speeds. Each lever controls a primary governor, which
acts to regulate propeller speeds within the normal
operation range. The full forward position of the levers is
placarded TAKEOFF, LANDING AND REVERSE and
also HIGH RPM. The full aft position of the levers is
placarded FEATHER. When a lever is placed at HIGH
RPM, the propeller may attain a static RPM of 2,000
depending upon power lever position. As a lever is
moved aft, passing through the propeller governing range,
but stopping at the feathering detent, propeller RPM will
correspondingly decrease to the lowest limit. Moving a
propeller lever aft past the detent into FEATHER will
feather the propeller.
2-49. PROPELLER REVERSING.
Do not move the power levers into
reverse range without the engine
running. Damage to the reverse
linkage mechanisms will occur.
Propeller reversing on unimproved
surfaces should be accomplished
erosion from reversed airflow and,
in dusty conditions, to prevent
obscuring the operator's vision.
To prevent an asymmetrical thrust
condition, propeller levers must be
in HIGH RPM position prior to
The propeller blade angle may be reversed to
shorten landing roll. To reverse, propeller levers must be
positioned at HIGH RPM (full forward), and the power
levers are lifted up to pass over the IDLE detent, then
pulled aft into REVERSE setting. One yellow caution
caution/advisory annunciator panel, alerts the pilot not to
reverse the propellers. This light illuminates only when
the landing gear handle is down, and if propeller levers
are not at HIGH RPM (full forward). This circuit is
protected by a 5ampere circuit breaker, placarded
LANDING GEAR RELAY, located on the overhead circuit
breaker panel (fig. 2-26).
2-50. PROPELLER TACHOMETERS.
Two tachometers on the instrument panel register
propeller speed in hundreds of RPM (fig. 2-28). Each
indicator is slaved to a tachometer generator unit
attached to the corresponding engine.
Section VII. UTILITY SYSTEMS
2-51. DEFROSTING/DEFOGGING SYSTEM.
Description. The defrosting/defogging system is
an integral part of the heating and ventilation system.
The system consists of two warm air outlets connected by
ducts to the heating system. One outlet is just below the
pilot's windshield and the other is below the copilot's
windshield. A push-pull control, placarded DEFROST
AIR, on the pilot's subpanel, manually controls airflow to
the windshield. When pulled out, defrosting air is ducted
to the windshield. As the control is pushed in, there is a
corresponding decrease in airflow.
Vent blower switches As required.
Cabin temperature mode selector switch
Cabin temperature control As required.
Cabin air, copilot air, pilot air, and defrost
air controls As required.
Maximum Windshield Defrosting.
Pilot air, copilot air IN.
Cabin air and defrost air controls Out
Cabin temperature mode selector
switch MAN HEAT.
Cold air outlets As required.
Manual temperature switch As required.
Manual Operation. If the automatic temperature