Cessna 172SPHUSR05 Pilot Operating Handbook page 132

SECTION 4
NORMAL PROCEDURES
Speci a l consi d erati o n shoul d be gi v en to the operati o n of the
airpl a ne fuel system duri n g the wi n ter season or pri o r to any flight in
col d temperatures. Proper preflight draining of the fuel system is
especi a l l y important and will elimi n ate any free water accumulati o n.
The use of addi t i v es such as i s opropyl al c ohol or di e thyl e ne gl y col
mono methyl ether may al s o be desirable. Refer to Secti o n
information on the proper use of addi t i v es.
Col d weather often causes condi t ions whi c h require special care
duri n g airpl a ne operati o ns. Even small accumulati o ns of frost, i c e,
or snow must be removed, parti c ularl y from wing, tail and all control
surfaces to assure sati s factory fli g ht performance and handling.
Al s o, control surfaces must be free of any internal accumulati o ns of
ice or snow.
If snow or sl u sh covers the takeoff surface, allowance must be
made for takeoff di s tances which will be increasingl y extended as
the snow or slush depth increases. The depth and consi s tency of
thi s cover can, in fact, prevent takeoff in many instances.
I
WH E N PU LLING THE
HAND , TREAT IT AS IF THE IGNITION SWITCH IS
TU R N E D ON. A LOOSE O R BROKEN GROUND
WI R E ON EITHER MAGNETO COULD CAUSE
THE ENGINE TO FIRE.
Prior to starting on col d mornings, i t i s advi s abl e to pull the
propeller through several times by hand to "break l o ose" or
"limber" the oil, thus conserving battery energy.
When air temperatures are bel o w 20°F (-6°C), the use of an
external preheater and an external power source are recommended
whenever possible to obtain posi t i v e starti n g and to reduce wear
and abuse to the engine and el e ctri c al system. Preheat will thaw the
oil trapped in the oil cool e r, whi c h probably will be congeal e d pri o r
to starti n g in extremel y col d temperatures.
14-34
WAR N I NG
THROUGH BY
CESSNA
MODEL 1 72S
for
8
Revi s i o n 4