Hi Jim,
Welcome!
Your question is legitimate, but suggests your concerns have arisen
from unintentional oversimplification of a much more complex issue.
The rate of failure is quite low, considering the number active.
Reliability of the little Continentals is dependent upon multiple
factors. An accident related to loss of power is NOT necessarily an
"engine issue". There is clearly nothing "wrong" with their
fundamental design. These engines continue to reliably power the
majority of the two place general aviation fleet, even though they must
today digest a fuel containing four times the lead they were designed
for (which requires a certain amount of pilot awareness and proficiency
to mitigate for maximum reliability).
Fuel flow ceasing because the pilot did not properly verify that tanks
were filled, or in-flight fuel consumption such that fuel was exhausted
in flight are not engine-specific. Neither would be a quick drain
coming out of a gascolator or wing tank, a fuel line rupturing in
flight due to metal fatigue (or way too old rubber). Neither would
ignoring the nose tank gauge after fuel (transfer) pump failure in
flight, or fuel flow blockage due to tank slosh coming loose and
blocking fuel filter screens.
For whatever reason, Ercoupes not used for rental or flight instruction
generally fly less than 100 hours a year. That would suggest that the
average engine goes fifteen plus years between overhauls, which is way
more than the factory prefers. This is the reason that poor
compression and/or oil leaks tends to require top overhauls "after a
few hundred hours".
If an engine is not properly broken in (and few are), they could use a
"top" as soon as the piston rings cease progressive "mating" to their
cylinder walls which results in good compression and low oil
consumption for the "long term". If an engine is not flown (not just
run, but actually operated up in the air for a half hour or more), it
should be preserved; and almost no one does this because the decision
not to fly is seldom a conscious one.
Failures such as a broken crankshaft in flight are so rare as to be as
statistically insignificant as they are attention-getting. In
addition, in reality a "factory new" part is an untested part ;<)
These engines are definitely not being "over-driven" inasmuch as they
are used in racing at much greater output and found acceptably reliable
even in that usage. If oil is not being changed properly, how would
that affect Continentals differently than, say, Lycomings, Franklins,
or Pratt and Whitneys? No piston engine is as reliable as the average
kerosene burner of today.
I cannot think of an engine or an aircraft that you could be
"comfortable with", given the basic thrust of your question and the
personal perspective it suggests. Flying a privately owned aircraft is
safe, but it is not without great responsibility and, yes, a measure of
risk most of us find easy to accept.
Those 16 fatalities in the last decade include two persons in Florida
and another two in California (?) that came apart due to exceeding
airframe design structural limits, possibly as a result of unauthorized
aerobatics. That leaves just over one a year for an operational fleet
of 1500-1600.
If each of 1500 flew 50 hours, that would be 75,000 operational hours;
and so one's individual risk would be two hundreths of a percent per
hour flown. A similar evaluation of driving a the average car,
including all the junkers on the road, would likely reveal much worse
odds.
If you take the time to purchase a good Ercoupe, learn it well and
bring it up to top condition, it is my personal opinion that there
exists no other aircraft that will carry you from point A to point B in
greater safety with anywhere near equal enjoyment or economy of
operation.
Regards,
William R. Bayne
.____|-(o)-|____.
(Copyright 2010)
--
On May 8, 2010, at 11:36, Jim wrote:
Given who I'm writing to, I realize this may generate some heated
discussion. Nonetheless, I really am looking for helpful input.
I've been considering buying an Ercoupe for over a year. What has
kept me from doing it? Frankly, what appears to be poor engine
reliability. Many of the planes for sale have had major overhauls or
top overhauls long before the TBO. In some cases, top overhauls have
been required after a few hundred hours.
Then, there are the in-flight problems and outright failures.
According to the NTSB investigation database, there have been 76
Ercoupe accidents in the last decade accounting for 16 fatalities. Of
those, accidents, 58 were engine related and accounted for 14 of the
16 fatalities. That means that, on average, there are almost 8 Ercoupe
accidents a year, 6 of which can be attributed to engine issues that
result in more than 1 death. In addition, we know there are engine
problems that don't result in accidents, such as the guy who reported
that his prop fell off (broken crankshaft) but he was close enough to
his destination airport to land safely.
So, why are these engines having problems? Are they being
over-driven? Is the oil not being changed often enough? Is it the lack
of factory-new parts, i.e. used parts that are beyond their safe life?
I really want to understand what's going on 1) so that if I buy an
Ercoupe, I can be reasonably sure the engine won't, given proper care,
quit on me, and 2) so I know what kind of use and care the engine
needs to keep it reliable? Or, are these C-75 and C-85 engines just
not reliable no matter what you do, due to design or age or whatever?
Regards,
Jim Hart
