Textron Cessna C172S PIM, Pilot Operating Handbook

Page: 117 / 322

CESSNA SECTION 3
MODEL 172S NAV III EMERGENCY PROCEDURES
GFC 700 AFCS
U.S.
HIGH CARBON MONOXIDE (CO) LEVEL
ANNUNCIATION
Carbon monoxide (CO) is a colorless, odorless, tasteless product of an
internal combustion engine and is always present in exhaust fumes.
Even minute quantities of carbon monoxide breathed over a long
period of time may lead to dire consequences. The symptoms of
carbon monoxide poisoning are difficult to detect by the person affected
and may include blurred thinking, a feeling of uneasiness, dizziness,
headache, and loss of consciousness.
The cabin heater system operates by allowing ambient air to flow
through an exhaust shroud where it is heated before being ducted into
the cabin. If an exhaust leak, caused by a crack in the exhaust pipe,
occurs in the area surrounded by this shroud it would allow exhaust
fumes to mix with the heated ambient air being ducted into the cabin.
Therefore, if anyone in the cabin smells exhaust fumes, experiences
any of the symptoms mentioned above, or the CO LVL HIGH warning
annunciation comes on when using the cabin heater, immediately turn
off the cabin heater and preform the emergency items for High Carbon
Monoxide (CO) Level Advisory.
When the CO detection system senses a CO level of 50 parts per
million (PPM) by volume or greater, the alarm turns on a flashing
warning annunciation CO LVL HIGH in the annunciation window on the
PFD with a continuous tone until the PFD softkey below WARNING is
pushed. It then remains on steady until the CO level drops below 50
PPM and automatically resets the alarm.
OTHER EMERGENCIES
WINDSHIELD DAMAGE
If a bird strike or other incident should damage the windshield in flight to
the point of creating an opening, a significant loss in performance may
be expected. This loss may be minimized in some cases (depending on
amount of damage, altitude, etc.) by opening the side windows while
the airplane is maneuvered for a landing at the nearest airport. If
airplane performance or other adverse conditions prevent landing at an
airport, prepare for an off airport landing in accordance with the
Precautionary Landing With Engine Power or Ditching checklists.
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