For our piston aircraft engines, we have
a marvelous multiplicity of condition-
monitoring tools at our disposal, including:
• Oil filter visual inspection
• Oil filter scanning electron
microscopy
• Spectrographic oil analysis
• Digital engine monitor data analysis
• Borescope inspection
• Differential compression test
• Visual crankcase inspection
• Visual cylinder head inspection
• Oil consumption trend analysis
• Oil pressure trend analysis
If we use all these tools on an appro-
priately frequent basis and understand
how to interpret the results, we can be
confident that we know whether the
engine is healthy or not—and if not, what
kind of maintenance action is necessary
to restore it to health.
USE THOSE TOOLS!
The moment you abandon the TBO concept and decide to make your
maintenance decisions on-condition,
you take on an obligation to use these
tools—all of them—and pay close attention to what they’re telling you.
Unfortunately, many owners and
mechanics don’t understand how to use
these tools appropriately or interpret
the results properly.
Just today, for example, I received an
e-mail from the owner of a 2002 Beechcraft
A36 Bonanza which said in part:
“My engine has 1,700 hours [it’s at
TBO] and is running fine. It uses only
2 to 3 quarts of oil per 50-hour oil-
change interval. I send in an oil sample
information@polyfiber.com
polyfiber.com
800-362-3490
