AOPA Pilot Magazine - June 2022 - 96

RUDDER & WRENCH
SWITCH
AND
SAVE
manufacturers. I presented the results of a
five-year study of GA engine-failure accident
data from the NTSB showing that the
greatest risk of an engine-failure accident
exists when an engine is young, not when
it's old.
" We should worry more about engine
failure during the first 200 hours after the
engine is overhauled or rebuilt than during
the first 200 hours past recommended
TBO, " Whit explained. " Very few enginefailure
accidents involve engines beyond
TBO and 80 percent of those are due to
maintenance errors rather than to any
age-related cause. "
Whit recommended that Unruly
1%
Cash Back1
on Every
Other Purchase
CASH BACK1
APPLIED AS STATEMENT CREDIT.
QUARTERLY BONUS POINT CAP OF 2,500 POINTS*
Switch today to the AOPA
World Mastercard®, and stop
paying too much on your
aviation purchases.
Visit
AOPA.org/creditcard
to learn more
enroll its Skyhawk in my company's managed
maintenance program where we
help owners maintain their aircraft using
this on-condition philosophy, working
directly with their shops and mechanics.
The board approved. One of my most
experienced account managers-Eric
Svelmoe, an A&P with inspection authorization-was
assigned to Unruly's airplane.
The journey begins
The Skyhawk was averaging 300 flight
hours per year and had flown as much
as 600 hours in prior years. Unruly had
acquired the airplane in 1998 with 500
hours since new, and had the Air Plains
supplemental type certificate installed to
upgrade the engine from 160 to 180 horsepower.
The airplane was hangared and
maintained by the local FBO.
Whit told Svelmoe that the club's
primary maintenance concern was that
the Skyhawk's factory-rebuilt Lycoming
IO-360 had more than 2,000 hours. For
Unruly to continue flying it a thorough
condition monitoring program would
need to be implemented. " The FBO isn't
much of a believer in borescopes, " Whit
explained. " They've got an old clunky
one that they hardly ever use, so we really
don't know what our exhaust valves or
cylinder barrels look like. "
*Certain points and purchase restrictions apply; see full Rewards
Terms and Conditions for full details at AOPA.org/creditcard
editcard.
1 Rewards points can be redeemed for Cash Back or other items provided
through AOPA Pilot Rewards. A Cash Back redemption is applied
as a statement credit. The statement credit will reduce your balance
but you are still required to make at least your minimum payment. A
minimum of 2,500 points is needed to redeem for Cash Back. Values
for non-cash back redemption items such as merchandise, gift cards
and travel may vary.
Bulletproof...almost
Svelmoe-who has decades of experience
overhauling and maintaining Lycoming
engines-told Whit that the Lycoming
IO-360 is relatively bulletproof, but does
have a few vulnerabilities that need to
96
AOPA PILOT / June 2022
be monitored closely. One involves the
engine's hollow-stem, sodium-filled
exhaust valves, which have a history of
becoming eroded, pitted, and vulnerable
to breakage after a couple of thousand
hours. Another is the cam and lifters,
which have a history of spalling if corrosion
occurs during periods of disuse.
Svelmoe believed Unruly's Skyhawk
was flying so regularly that this probably
wouldn't occur. He suggested switching
from Aeroshell 15W-50 to Phillips X/C 20W50
and adding ASL CamGuard for improved
protection against corrosion and wear.
A third vulnerability is sticking exhaust
valves, a longstanding problem with
Lycomings. Svelmoe recommended doing
the exhaust valve " wobble test " every 400
hours per Lycoming Mandatory Service
Bulletin No. 388C. He also urged that club
members be trained to recognize " morning
sickness " -rough running when the
engine is started cold that smooths out
once the engine warms up-and to report
this immediately so that the valve guide
can be reamed before sticking gets serious.
Annual inspection
The Skyhawk's 2012 annual inspection
began January 30. Engine time was now
about 2,500 hours. The compression test
went smoothly with all cylinders in the 70s.
However, the borescope inspection was a
big disappointment because the FBO's
borescope-a Snap-On BK5500-was (in
Whit's words) " pretty much of a joke. "
The resolution and lighting were horrible,
and there was no way to manipulate
the camera to view the condition of the
exhaust valve stems, so it was necessary to
drop the exhaust system to inspect them.
The Snap-On BK5500 (above) was " pretty
much of a joke " so the club acquired a
$250 Vividia Ablescope VA-400, which was
a huge improvement.
SUPPLIED BY THE AUTHOR
http://www.AOPA.org/creditcard http://www.AOPA.org/creditcard
AOPA Pilot Magazine - June 2022

Table of Contents for the Digital Edition of AOPA Pilot Magazine - June 2022
