AOPA Turbine Pilot Magazine - August 2024 - 93

breakdown assistance service and so
he called Savvy's 24/7 hotline for help.
Within a few minutes, he received a
phone call from Tom Cooper A&P/IA, one
of Savvy's most experienced account managers.
Mark told Tom about his in-flight
CHT number 2 runaway and everything
that had transpired since then.
" Instruct the shop to stop work immebulletin
applied to only 300 cylinders identified
by lot number. Finally, head cracks
in this area are common and have never
caused any sort of in-flight failure, incident,
or accident.
Tom consulted with Eric Svelmoe,
diately, " Tom told Mark. " They're clearly
on a fishing expedition to find every discrepancy
they can. We can't let them do
that. We need to instruct them to confine
their activity to the problem you had with
the number 2 cylinder. "
Mark called the shop to tell them to
stop work on his airplane and told them to
expect to hear from Tom. As it happened,
Savvy had worked with this shop before, so
they were already set up in Savvy's online
ticket system. Tom began communicating
with the DOM via the ticket system, creating
a contemporaneous written record of
communications among the DOM, Mark,
and Tom.
Show me the evidence
Tom asked the DOM to post the borescope
images of cylinder number 2 so he could
look at them. The DOM posted three excellent
images, one of the heads of both valves
(exhaust and intake), one of just the exhaust
valve, and a third showing the face of the
exhaust valve when it was wide open.
Tom reviewed these borescope images
and asked several other members of the
Savvy team to do so. All of us agreed that
the valves looked perfectly normal. Tom
also obtained the engine monitor data for
the incident flight and asked Savvy data
analyst Stephanie Schledorn, an A&P/IA,
to review it. Stephanie reported that CHT
number 3 never exceeded 429 degrees F-
not even close to Continental's redline of
460 degrees F-and that the EGT had
been stable, suggesting that no detonation
had occurred in the cylinder.
Tom asked the DOM if they had a borescope
image of the piston crown-where
detonation signatures would first show up-
but the shop hadn't taken any images of the
piston. Tom also asked the DOM if the shop
had inspected the number 2 fuel nozzle and
was told this had not been done. Tom asked
Fluorescent dye penetrant inspection.
This might or might not be a crack. If it is a
crack, it doesn't present a safety issue.
about the condition of the top spark plug-
the next place one would look for evidence
of detonation-and was told it looked fine.
Tom concluded the shop had found no valid
evidence of detonation, and that the " white "
exhaust valve was a red herring.
Exhaust deposits on the exhaust valve
can be any combination of brown, red,
orange, yellow, white, and even green. The
color isn't important. What's important is
whether the deposit pattern appears symmetrical.
Tom sent the shop a copy of the
AOPA poster " Anatomy of a Valve Failure "
to help them understand how to distinguish
normal and abnormal exhaust valves,
and why we were convinced that Mark's
number 2 exhaust valve looked normal.
Cylinder head cracks?
Tom asked the DOM why the shop was
concerned about cylinder head cracks.
The shop cited Continental service bulletin
MSB09-1B, which dealt with head
cracks between the top spark plug and
fuel nozzle bosses. The DOM insisted the
cylinders with cracked heads had to be
replaced. The shop sent Tom some photographs
showing fluorescent dye penetrant
inspection results of several cylinders.
Some of those photos revealed nothing
of interest, but a couple showed features
that could be cracks.
Tom had several problems with the
position the shop was taking. First, neither
Mark nor Tom had authorized the
shop to inspect the cylinders for cracks.
Second, the Continental service bulletin
was just a service bulletin, so as a Part 91
operator Mark was not obligated to comply
with it. Third, the Continental service
A&P/IA, Savvy's manager of quality assurance
and training. This was Eric's take on
the situation: " This shop is not performing
an annual inspection, so their opinion about
the engine's airworthiness is irrelevant.
So is Continental's service bulletin at the
moment. None of the cracks in the pictures
are ever going to cause a cylinder failure so
there is no safety concern. I'm not seeing any
problems with the turbochargers, based on
the photographs provided by the shop. The
oil found in one turbocharger is undoubtedly
caused by a slightly leaky check valve
and can be dealt with at Mark's convenience.
Mark should simply instruct the shop to
put his aircraft back together so he can fly it
home, and not remove any cylinders, even
if the shop considers those cylinders to be
unairworthy. Let's get Mark's airplane out
of jail and get it home for its annual inspection.
A ferry permit shouldn't be necessary
because the shop can't declare the aircraft
to be unairworthy since they haven't been
authorized to inspect it. "
Borescope images of the number 2 exhaust
valve appeared perfectly normal.
Getting out of jail
Tom asked the DOM how much disassembly
had been done. The shop indicated
that they'd removed the top cowling,
removed the left-hand intercooler to gain
access to the number 2 cylinder, removed
the top spark plug to allow the cylinder to
be borescoped, but had not yet removed
AOPA PILOT / August 2024
93
AOPA Turbine Pilot Magazine - August 2024

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