EAA Sport Aviation - February 2012

so we can gather data more rapidly. More often than not, the elevated wear metal values wind up self-resolving over the next 50 to 100 hours and no follow-up action is necessary.

Even if the oil analysis results keep getting worse, we never suggest grounding the airplane or taking the engine apart based solely on oil analysis results alone. Keep in mind that what oil analysis is reporting on is microscopic wear metal particles that are too small to see and too small to be caught in the oil filter. Metal particles that small certainly do not represent any sort of safety-of-flight hazard. No matter how ugly the oil report looks, we’re not going to do anything drastic.

A series of deteriorating oil analysis
reports simply tells us that we need to
start looking more aggressively using
other condition-monitoring tools at our
disposal. For example,
we might perform a
borescope inspection
of all the cylinders to
see if we can spot any-
thing wrong (scored
barrel, burned exhaust
valve, etc.). Or we
might send the oil fil-
ter media out to a lab
for scanning electron
microscope evalua-
tion, which will tell us
the shape and alloy of
the metal, and often
will provide a good
indication of where it’s
coming from. Or we might dump the
engine monitor data and analyze it to see
if we can spot any combustion anomalies,
oil pressure fluctuations, etc.

Similarly, if we cut open an oil filter
and spot a significant amount of metal, we
won’t ground the aircraft unless the
amount of metal found is huge (e.g., a

“Breakfast in New York, Lunch in Chicago, Dinner in Denver”
Test Fly the
Flight Design
CTLS & see
why the World’s
Best Selling LSA
delivers real
Cross-Country
Performance
& Comfort!
Cavernous 49” Cabin
Tremendous Visibility
Long 830nm Legs