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back to "BOTH" to clear the other set
position, note RPM and return the switch to the "BOTH" position. RPM
drop should not exceed 150 RPM on either magneto or show greater than
50 RPM differential between magnetos.
operation of the ignition system, RPM checks at higher engine speeds will
u sually confirm whether a deficiency exists.
An absence
one side
the ignition system or should be cause for suspicion that the
of
magneto timing is set in advance
ALTERNATOR CHECK.
Prior to flights where verification of proper alternator and voltage
regulator operation is essential (such as night or instrument flights), a
positive verification can be made by loading the electrical system momen
tarily (3 to 5 seconds) with the landing light during the erigine runup (1700
RPM). The ammeter will remain within a needle width of zero if the
ternator and voltage regulator are operating properly.
TAKE-OFF.
is important to check full-throttle engine operation early in the take
It
off
Any signs of rough engine operation or sluggish engine accelera
run.
tion is good cause for discontinuing the take-off.
Full throttle runups over loose gravel are especially harmful to
propeller tips. When take-offs must be made over a gravel surface, it is
very important that the throttle be advanced slowly. This allows the air
plane to start rolling before high RPM is developed, and the gravel will be
blown back of the propeller rather than pulled into it.
After
throttle is applied, adjust the throttle friction lock clock
full
prevent the throttle from creeping back from a maximum power
wise
to
position. Similar friction lock adjustments should be made a s require d
in other flight conditions to maintain a fixed throttle setting.
Normal take-oUs are accomplished with wing flaps 0° to 20°, cowl
flaps open, full throttle, and 2600 RPM. Reduce power to 23 inches of
manifold pressure and 2450 RPM
wear.
Using 20° wing flaps reduces the ground run
2-12
RPM drop may be an indication
of
plugs. Then move switch to
of
there is a doubt concerning
If
the setting specified.
of
soon as practical to minimize engine
as
and
faulty grounding of
of
total distance over
"L"
al
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