Textron Cessna C172S PIM, Руководство по эксплуатации для пилотов

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CESSNA SECTION 3
MODEL 172S NAV III EMERGENCY PROCEDURES
GFC 700 AFCS
U.S.
ROUGH ENGINE OPERATION OR LOSS OF POWER
SPARK PLUG FOULING
A slight engine roughness in flight may be caused by one or more spark
plugs becoming fouled by carbon or lead deposits. This may be verified
by turning the MAGNETOS switch momentarily from BOTH to either L
or R position. An obvious power loss in single magneto operation is
evidence of spark plug or magneto trouble. Since spark plugs are the
more likely cause, lean the mixture to the recommended lean setting for
cruising flight. If the problem does not clear up in several minutes,
determine if a richer mixture setting will produce smoother operation. If
not, proceed to the nearest airport for repairs using the BOTH position
of the MAGNETOS switch unless extreme roughness makes the use of
a single MAGNETO position necessary.
MAGNETO MALFUNCTION
Sudden engine roughness or misfiring is usually a sign of a magneto
problem. Changing the MAGNETOS switch from BOTH to the L and R
switch positions will identify which magneto is malfunctioning. Select
different power settings and enrichen the mixture to determine if
continued operation on BOTH magnetos is possible. If not, change to
the good magneto and continue to the nearest airport for repairs.
IDLE POWER ENGINE ROUGHNESS
(As Required by AD 2001-06-17, Paragraph (d)(3))
An excessively rich idle fuel flow may cause low speed engine
roughness during flight. During most in-flight low engine speeds (power
off stalls, approach to landing, etc.), the mixture control is normally in
the full-rich position. However, to improve engine roughness (caused
by an improperly adjusted fuel servo) during low engine speeds while in
flight, you should rotate the vernier mixture control (leaning of fuel
mixture). You may also have to lean the fuel mixture if this low engine
speed results in power loss and you need to restart the engine during
flight. In all cases, you should land the airplane at the nearest airport for
repairs if low speed engine roughness requires you to adjust the fuel
mixture control to improve engine operation.
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