Cessna Skyhawk Owner's Manual page 20

BEFORE TAKE-OFF.
WARM-UP.
"
o
4
woo
-
If
the
engine accelerates smoothly,
the
airplane
is ready for
take-off.
---
Since
the
engine is closely
cowled for
efficient
in-flight engine
cooling,
precautions should
be
taken to
avoid
overheating
during prolonged engine
operation on
the
ground. Also, long periods of idling may cause
fouled
spark
plugs.
MAGNETO
CHECK.
o
The magneto check should be made at
1700
RPM as follows: Move
ignition switch
first
to
"R"
position,
and note RPM. Next move switch
o o
back
to
"BOTH"
to
clear
the
other set of plugs. Then
move
switch
to
the
"L" position and note RPM. RPM
drop should
not
exceed 125
RPM
on
either magneto or show
greater than
50
RPM
differential
between
magnetos. If
there
is
a doubt
concerning operation of
the
ignition system,
RPM checks at higher engine speeds will usually
confirm
whether a
deficiency exists.
An
absence of RPM drop may
be an
indication
of
faulty grounding of
I
g
... ....
one side of
the
ignition system or should be
cause
for suspicion
that the
Zo
z
magneto
timing
is set in advance
of
the
setting
specified.
Oo
TAKE-OFF.
POWER
CHECK-
It is important
to
check
full-throttle
engine operation early in
the
take-off
run. Any signs of rough engine operation or sluggish engine
acceleration is good cause for discontinuing
the take-off.
If
this
occurs,
you are justified in making a
thorough
full-throttle,
static
runup before
another
take-off
is attempted.
The
engine should
run smoothly and
turn
approximately 2260
to 2360
RPM with carburetor heat off. °
NOTE
Carburetor heat
should not be used during
take-off
gg
-'
=
x
unless it is absolutely necessary for obtaining
smooth
engine acceleration.
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