Recovery From Spi R Al Di V E I N The Clouds; I Nadv E Rtent Flight Into Icing Con Ditions; Stati C Source Bl O Cked - Cessna 172SPHUSR05 Pilot Operating Handbook

SECTION 3
EMERGENCY PROCEDURES
R ECOVERY FROM SPIRAL DIVE IN T H E C LO U DS
If a spi r al is encountered in the cl o uds, proceed as follows:
Retard throttle to i d l e posi t ion.
2. Stop the turn by using coordinated ail e ron and rudder control
1 .
to align the symboli c airpl a ne i n the turn coordinator wi t h the
hori z on reference line.
3. Cautiousl y appl y elevator back pressure to slowl y reduce the
airspeed to 80 KI A S.
Adjust the elevator trim control to maintai n an 80 KIAS gli d e.
5. Keep hands off the control wheel, using rudder control to hold
4.
a strai g ht heading.
6. Cl e ar engine occasi o nal l y , but avoi d usi n g enough power to
di s turb the trimmed gl i de.
7. Upon breaking out of clouds, resume normal cruising flight.

I NADV E RTENT FLIGHT INTO ICING CON DITIONS

Flight into i c i n g condi t i o ns i s
dangerous. An inadvertent encounter with these condi t i o ns can best
I
be handl e d using the checkl i st procedures. The best procedure, of
course, i s to turn back or change al t i t ude to escape i c i n g condi t ions.
During these encounters, an unexplained loss in engine speed
coul d be caused by i c e bl o cking the ai r intake fil t er, or, i n extremel y
rare instances, i c e compl e tel y bl o cking the fuel injection air
reference tubes. In either case, the throttle should be posi t ioned to
obtai n maximum RPM (in some i n stances, the throttl e may need to
be retarded for maximum power). The mixture shoul d then be
adjusted, as required, to obtai n maximum RPM.
STATI C SOU RCE B LOCKED
If erroneous readings of the static source instruments (airspeed,
al t imeter and verti c al speed) are suspected, the stati c pressure
lal t ernate source val v e shoul d be pulled ON, thereby suppl y i n g stati c
pressure to these instruments from the cabin.
3-1 8
MODEL 1 72S
and extremely
prohibited
CESSNA
Revi s ion
4