Cessna 172P - Page 230

2
AIR,
CONDITIONING
SYSTEM
MODEL
1?2P
PILOT'S
OPETìATING
HANDBOOK
Ê¡UPPLEMENT
1.
Check
compÌessor
drive
belt for tightness,
a,nd compressor
for
condition.
2.
Check
tunnel
from
firewall
to
condenSer
air scoop
for
damage,
Iooseness
and
evidence
of
line
leakage.
3.
Check
condenser
air
scoop for
blockage,
condition, and
evidence
of
system
leakage.
4.
Check
that
return
air openings
in top
of
aft baggage
area are
clean
and
not
blocked
by baggage.
Also,
check area
for evidence
of
system
leakage.
5.
Check
that condensate
drain is not damaged
or blocked.
should
reveal
oil
streaks or drops
of oil
in the aft
b
e
ground,
do
not
operate
the
air conditioning
system
u
ked
by service
personnel.
OPER,ATION
ON
GROUND
After
preflight
inspection
and engine
start, use the following
proce-
dures
for
best utilization
of the
system
prior
to flight.
1.
Cabin Doors
and
ït¡indows
--
CLOSED.
2.
Cabin Air
Control Knob
--
PUSHED
IN.
3. Wing
Root Ventilators --
CLOSED.
4.
AIR TEMP
Control
Knob
--
MAX.
5. FAN
Control
Knob
--
HI.
6.
After
Initia,l
Cooldown
--
REPOSITION AIR TEMP and FAN
control
knobs as required to
maintain
desired
temperature.
NOTE
A
high
pressure
switch
in
the air conditioning system
disengages
the compressorclutch and
stops system
opera-
tion
in the
event
the system
becomes overhea,ted
during
periods
of
idling at low RPM. The
system
will cyole on
and
off
under
these circumstences a,nd
is
not malfunctioning.
If
this
oocurs,
head
the airplane into the
wind
and increase
engine
nPM,
if
practical.
BEFOR,E
TAKEOFF'
1. AIR TEMP
Control Knob
--
OFF.
2.
FAN
Control Knob
--
AS DESIRED
TAKEOFF
Because of
the
effect of the air
conditioning system on
climb
perfor-
mance, flaps are
not
approved
for
takeoff whenever
the airplane is
4
g0
May 1980