Real stats on engine failures?

"Kyler Laird" wrote in message
...
(Captain Wubba) writes:

So what is it? If the engine-failure rate is one failure for every
50,000 flight hours, I'll feel much less reticent about night/IFR
single-engine flying than if it is one in 10,000 hours. Anybody have
any facts or hard data, or have any idea where I might be able to
track some down?

Don't forget that you're safest with a single-cylinder engine. If
you have a six-cylinder, you're *six* times as likely to have a
failure.

...or at least that's what I've learned from some of the geniuses
who talk about twins vs. singles.

Not so, smart ass. You don't have six oil pumps, six crank seals, six fuel
pumps, six alternators, six crankshafts, 12 magnetos, 6 carbs, ect, ect, on
that six cylinder engine, do you?
--
Jim in NC

"Morgans" writes:

Don't forget that you're safest with a single-cylinder engine. If
you have a six-cylinder, you're *six* times as likely to have a
failure.

...or at least that's what I've learned from some of the geniuses
who talk about twins vs. singles.

Not so, smart ass. You don't have six oil pumps, six crank seals, six fuel
pumps, six alternators, six crankshafts, 12 magnetos, 6 carbs, ect, ect, on
that six cylinder engine, do you?

Correct, genius. Similarly, there are engine problems that are quite
independent of the number of engines on a plane.

--kyler

"Kyler Laird" wrote in message
...
Correct, genius. Similarly, there are engine problems that are quite
independent of the number of engines on a plane.

Such as? Other than fuel exhaustion, I'm at a loss to think of any.

"Peter Duniho" writes:

"Kyler Laird" wrote in message
...
Correct, genius. Similarly, there are engine problems that are quite
independent of the number of engines on a plane.

Such as? Other than fuel exhaustion, I'm at a loss to think of any.

Fuel exhaustion certainly accounts for a lot, but there's also
misfueling, fuel contamination, and intake clogging by widespread
particulates. All are as about likely to take out one as they are
several.

BTW, one of the things I like about a twin is the slight
difference in when such a loss is likely to happen. If one
engine runs out of fuel, runs into bad fuel, or gets socked with
ice/ash/..., at least I usually have a few seconds/minutes of power
on the other one before it experiences the same thing. It might
not seem like much, but it can be quite an advantage in sticky
situations. (Yes, yes...and if I decide to be stupid, it also
makes flipping the airplane over even easier - just like stalling a
single upon loss of power.)

--kyler

"Kyler Laird" wrote in message
...
Fuel exhaustion certainly accounts for a lot, but there's also
misfueling, fuel contamination, and intake clogging by widespread
particulates.

What's "misfueling"? Sounds like fuel exhaustion to me. As for the others,
you're right to the extent that all engines are run from the same fuel
supply. Many twins have separate tanks for each engine and may or may not
suffer the same problems.

In any case, the incidence of those failures is extremely low, compared to
the total number of failures (not counting fuel exhaustion of course which,
if I recall correctly, is the number one cause of engine failures).

The fact remains, having a second engine *does* significantly increase your
chances of an engine failure, just as having extra cylinders increases your
chance of having a cylinder failure. In most cases, it's a worthwhile
tradeoff, but one shouldn't pretend the tradeoff doesn't exist.

Pete

Peter Duniho wrote:

"Kyler Laird" wrote in message
...
Fuel exhaustion certainly accounts for a lot, but there's also
misfueling, fuel contamination, and intake clogging by widespread
particulates.

What's "misfueling"?

Putting jet-A in a gasoline burner (or vice-versa).

George Patterson
Some people think they hear a call to the priesthood when what they really
hear is a tiny voice whispering "It's indoor work with no heavy lifting".

"G.R. Patterson III" wrote in message
...
What's "misfueling"?

Putting jet-A in a gasoline burner (or vice-versa).

Ahh, okay. Still, quite uncommon relative to other kinds of engine failure,
especially with respect to in-flight failures.

"Peter Duniho" writes:

"Kyler Laird" wrote in message
...
Fuel exhaustion certainly accounts for a lot, but there's also
misfueling, fuel contamination, and intake clogging by widespread
particulates.

What's "misfueling"?

I was thinking of getting a fuel that will not burn effectively in
the plane's engine(s)

Sounds like fuel exhaustion to me.

I welcome suggestions on how I could have stated it more clearly.

As for the others,
you're right to the extent that all engines are run from the same fuel
supply.

Packing ice/ash/... into the _air_ intake has little to do with the
fuel supply. (Again, I think I was not clear.)

Many twins have separate tanks for each engine and may or may not
suffer the same problems.

If the lineman fuels the plane from the wrong (Jet A) truck, it's
unlikely to matter which tanks feed which engines unless you did
not fill all of the tanks.

In any case, the incidence of those failures is extremely low,

Great. I don't need to worry about all of those stories I heard of
getting JetA in an airplane marked "Turbo." Thanks.

The fact remains, having a second engine *does* significantly increase your
chances of an engine failure, just as having extra cylinders increases your
chance of having a cylinder failure. In most cases, it's a worthwhile
tradeoff, but one shouldn't pretend the tradeoff doesn't exist.

Agreed. I don't think anyone pretends the tradeoff doesn't exist.
Some do pretend that it is a linear relationship thus ignoring what
you describe as the most popular failures (along with the others
that I listed).

--kyler

"Kyler Laird" wrote in message
...
Sounds like fuel exhaustion to me.

I welcome suggestions on how I could have stated it more clearly.

Sorry, can't help you there. The screw up was mine.

Packing ice/ash/... into the _air_ intake has little to do with the
fuel supply. (Again, I think I was not clear.)

I don't consider that a "failure" any more than I consider flying into the
side of a mountain a structural failure. Particulates dense enough to shut
down an engine are dense enough that the pilot had no business flying into
them in the first place (or was unfortunate enough to be overtaken by a
cloud).

In any case, the incidence of those failures is extremely low,

Great. I don't need to worry about all of those stories I heard of
getting JetA in an airplane marked "Turbo." Thanks.

I'd hazard a guess that you don't. I've owned my turbocharged aircraft for
nearly ten years now, and have NEVER had any sort of confusion regarding
what kind of fuel it takes. The filler holes are clearly marked 100LL, I
supervise all fueling, and in any case, *real* turbine aircraft don't have
"turbo" written on the side.

I've heard those same stories, but have never seen any evidence that they
were anything more than apocryphal. I can believe it might have happened
once or twice, but it hardly sounds like something that happens often enough
to skew engine failure statistics, especially when one is only considering
in-flight engine failures.

Agreed. I don't think anyone pretends the tradeoff doesn't exist.
Some do pretend that it is a linear relationship thus ignoring what
you describe as the most popular failures (along with the others
that I listed).

Well, even ignoring the factors you've mentioned, it's not actually a linear
relationship. It's just *nearly* linear, near enough that the
generalization is reasonably true. The other factors that you've mentioned
don't really change that relationship, IMHO. It's still *nearly* true, just
as it is without considering them.

Bottom line: the more stuff you have, the more likely something will go
wrong with some of your stuff.

Pete