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Figure 2-9. Standard hand signals.
Ch 02.qxd 5/7/04 6:22 AM Page 2-7
2-8
When activating the starter, one hand should be kept
on the throttle. This allows prompt response if the
engine falters during starting, and allows the pilot to
rapidly retard the throttle if revolutions per minute
(r.p.m.) are excessive after starting. A low r.p.m.
setting (800 to 1,000) is recommended immediately
following engine start. It is highly undesirable to allow
the r.p.m. to race immediately after start, as there will
be insufficient lubrication until the oil pressure rises.
In freezing temperatures, the engine will also be
exposed to potential mechanical distress until it warms
and normal internal operating clearances are assumed.
As soon as the engine is operating smoothly, the oil
pressure should be checked. If it does not rise to the
manufacturer’s specified value, the engine may not be
receiving proper lubrication and should be shut down
immediately to prevent serious damage.
Although quite rare, the starter motor may remain on
and engaged after the engine starts. This can be
detected by a continuous very high current draw on the
ammeter. Some airplanes also have a starter engaged
warning light specifically for this purpose. The engine
should be shut down immediately should this occur.
Starters are small electric motors designed to draw
large amounts of current for short periods of cranking.
Should the engine fail to start readily, avoid
continuous starter operation for periods longer than 30
seconds without a cool down period of at least 30
seconds to a minute (some AFM/POH specify even
longer). Their service life is drastically shortened from
high heat through overuse.
HAND PROPPING
Even though most airplanes are equipped with electric
starters, it is helpful if a pilot is familiar with the procedures
and dangers involved in starting an engine by
turning the propeller by hand (hand propping). Due to
the associated hazards, this method of starting should
be used only when absolutely necessary and when
proper precautions have been taken.
An engine should not be hand propped unless two
people, both familiar with the airplane and hand
propping techniques, are available to perform the
procedure. The person pulling the propeller blades
through directs all activity and is in charge of the
procedure. The other person, thoroughly familiar
with the controls, must be seated in the airplane with
the brakes set. As an additional precaution, chocks
may be placed in front of the main wheels. If this is
not feasible, the airplane’s tail may be securely tied.
Never allow a person unfamiliar with the controls to
occupy the pilot’s seat when hand propping. The
procedure should never be attempted alone.
When hand propping is necessary, the ground surface
near the propeller should be stable and free of debris.
Unless a firm footing is available, consider relocating
the airplane. Loose gravel, wet grass, mud, oil, ice, or
snow might cause the person pulling the propeller
through to slip into the rotating blades as the engine
starts.
Both participants should discuss the procedure and
agree on voice commands and expected action. To
begin the procedure, the fuel system and engine
controls (tank selector, primer, pump, throttle, and
mixture) are set for a normal start. The ignition/
magneto switch should be checked to be sure that it is
OFF. Then the descending propeller blade should be
rotated so that it assumes a position slightly above the
horizontal. The person doing the hand propping should
face the descending blade squarely and stand slightly
less than one arm’s length from the blade. If a stance
too far away were assumed, it would be necessary to
lean forward in an unbalanced condition to reach the
blade. This may cause the person to fall forward into
the rotating blades when the engine starts.
The procedure and commands for hand propping are:
Person out front says, “GAS ON, SWITCH OFF,
THROTTLE CLOSED, BRAKES SET.”
Pilot seat occupant, after making sure the fuel is
ON, mixture is RICH, ignition/magneto switch is
OFF, throttle is CLOSED, and brakes SET, says,
“GAS ON, SWITCH OFF, THROTTLE
CLOSED, BRAKES SET.”
Person out front, after pulling the propeller
through to prime the engine says, “BRAKES
AND CONTACT.”
Pilot seat occupant checks the brakes SET and
turns the ignition switch ON, then says,
“BRAKES AND CONTACT.”
The propeller is swung by forcing the blade downward
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AIRPLANE FLYING HANDBOOK 飞机飞行手册上(17)
