Lycoming YO-233-B2A Maintenance Manual page 68

(4) If deposits get into the engine oil, engine malfunction and/or failure can occur from
abrasive wear.
(5) However, if during flight, the engine is in a particulate-laden atmosphere, do the
following:
(a) Monitor the engine temperature during flight. (Damaged or blocked cooling baffles or
heavy deposits on engine cooling surfaces can decrease cooling efficiency and cause
the engine to overheat.)
(b) If the engine is not operating smoothly in flight, make a safe landing as soon as
possible. Identify and repair the cause of rough operation.
(6) In the event that the engine has been in particulate-laden atmospheres, especially volcanic
ash clouds or with ash on the ground, Lycoming recommends that you complete the
standard actions shown in Table 2.
Maintenance after flight...
Wear personal protective equipment (gloves,
respiratory, and eye protection). Per the
airframe manufacturer's instructions,
thoroughly remove the ash or particulate from
the aircraft by hand brushing or air/vacuum.
Make sure that all ash is removed from the
engine, nacelle and cowling.
Complete the post-flight inspection.
Particularly, examine the induction filters,
induction system, and engine baffles for
blockage or damage.
Immediately, complete an oil change, collect an
oil sample and have a spectrographic analysis
done on the oil sample. Compare this analysis
with past oil analyses to determine engine wear
or contamination.
Replace the oil filter and intake air filter to
remove any internal contamination that can
cause premature wear because of the highly
abrasive effects of most solid particles.
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Page 48
DO NOT USE WATER INITIALLY TO REMOVE VOLCANIC ASH.
WHEN VOLCANIC ASH COMES INTO CONTACT WITH WATER IT
CAN BECOME A HARDENED, CORROSIVE COMPOUND.
Action to Take in Volcanic Ash Conditions
YO-233-B2A Engine Maintenance Manual
TEO-540-A1A Engine Maintenance Manual
Table 2
Maintenance after 10 hours of operation or
the next flight...
Wear personal protective equipment. Examine
the external engine, cowling, and nacelle for
any particulate or ash residue. Remove any
particulate or ash residue per the airframe
manufacturer's instructions.
Complete the pre-flight inspection.
Complete the oil change and collect another oil
sample for spectrographic analysis. Compare
the results against the last oil sample to identify
engine wear or effects of contamination. As a
precaution, complete another oil change and
analysis of a sample again, as necessary.
Replace the oil filter and intake air filter as a
precaution to be sure there are no effects of
particulate contamination. Replace these
components again after the next flight, as
necessary.
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February 2021