This engine was a low-time factory-new
engine, so the owner figured that the severe
engine damage would be covered under
TCM’s warranty. I advised him not to bother
filing a warranty claim, because I’ve never
known TCM to give warranty consideration
for a destructive detonation or pre-ignition
event. TCM considers this to be operational
abuse, not a defect in materials or
workmanship, and therefore not covered by
warranty. (For what it’s worth, I agree with
TCM on this.)
The owner didn’t believe me and filed a
warranty claim anyway. TCM promptly and
unequivocally denied the claim.
A similar case occurred to another TCM-powered airplane shortly after takeoff. The
annotated J. P. Instruments (JPI) data for
this event is courtesy of General Aviation
Modifications Inc.
This time, it was the No. 5 cylinder that
experienced thermal runaway and pre-ignition. It was an even more severe event
Within minutes, the airplane was back on the
ground, engine destroyed. A forensic post-flight
evaluation revealed that the magnetos had been
timed approximately 10 degrees advanced from the
proper timing...
than the one suffered by the Cirrus, and it took only two minutes
from the application of takeoff power to the complete destruction of
the No. 5 piston, which wound up with a large hole melted through
the piston crown.
In yet another case (for which I unfortunately have no photos), a
drop-dead gorgeous Lancair IV-P kit plane powered by a fire-breathing 350-hp TCM TSIO-550 engine went up for its first test
flight after 1 0 years of laborious building time by the owner. Within
minutes, the airplane was back on the ground, engine destroyed. A
forensic post-flight evaluation revealed that the magnetos had been
timed approximately 10 degrees advanced from the proper timing,
which turned out to be a $50,000 mistake.
