Textron 172R180HP, Pilot Operating Handbook

Page: 80 / 396

SECTION 3
EMERGENCY PROCEDURES
CESSNA
MODEL 172A (180 HP)
3. Cautiously apply elevator back pressure to slowly reduce the
airspeed to 80 KIAS.
4. Adjust the elevator trim control to maintain an 80 KIAS glide.
5. Keep hands off the control wheel, using rudder control to hold
a straight heading.
6. Clear engine occasionally, but avoid using enough power to
disturb the trimmed glide.
7. Upon breaking out of clouds, resume normal cruising flight.
INADVERTENT FLIGHT INTO ICING CONDITIONS
Flight into icing conditions is prohibited and extremely
dangerous. An inadvertent encounter with these conditions can best
be handled using the checklist procedures. The best procedure, of
course, is to turn back or change altitude to escape icing conditions.
During these encounters, an unexplained loss in engine speed
could be caused by ice blocking the air intake filter, or, in extremely
rare instances, ice completely blocking the fuel injection air
reference tubes. In either case, the throttle should be positioned to
obtain maximum RPM (in some instances, the throttle may need to
be retarded for maximum power). The mixture should then be
adjusted, as required, to obtain maximum RPM.
STATIC SOURCE BLOCKED
If erroneous readings of the static source instruments (airspeed,
altimeter and vertical speed) are suspected, the static pressure
alternate source valve should be pulled on, thereby supplying static
pressure to these instruments from the cabin.
I
With the alternate static source on, refer to the Alternate Static
Source Airspeed Calibration table in Section 5 for additional details.
I
Maximum airspeed and altimeter variation from normal is 4 knots
and 30 feet over the normal operating range with the window(s)
closed. See Section 5 tables for airspeed calibration data.
3-18 Oct 4/01