Real stats on engine failures?

(Rich Stowell) wrote
Sorry I can't point you to the "harder" data you're looking for, but
here's perhaps a little perspective on the issue:

According to one NTSB Study, pilots with fewer than either 500 hours
total time, or 100 hours in type, are more likely to encounter an
inadvertent stall/spin than to have a genuine engine failure (i.e.: a
random-event engine failure, not one attributed to such pilot errors
as fuel mismanagement).

Really? If that were true, then there would be hard data.

What the NTSB study REALLY says is that these low time pilots are more
likely to encounter an inadvertent stall/spin LEADING TO AN ACCIDENT
than to have a genuine engine failure LEADING TO AN ACCIDENT. This is
because an engine failure rarely leads to an accident (at least if the
ones known to me are any indication) but an inadvertent stall/spin
usually leads to an accident.

For that matter, most engine failure fatalities in light singles are
not the result of collision with terrain (which is usually survivable)
but of failure to maintain flying speed (which usually isn't). That's
basically a stall/spin anyway.

In my case, over 6,400 hours ...
... two legitimate engine failures as follows:

2 in 6400 hours is very much consistent with my experience. It's also
very much consistent with the 1 in 1000 to 1 in 10000 number the FAA
provides.

Michael

Michael wrote:

True but I would assume that they thought that they had given the subject
adequate consideration. It is arogant to believe that everyone else is a
fool and you are not. My fovorite ezample are those pilots who are
confident that they could handle an IMC gyro failure when the record shows
that many (most?) cannot.

Yeah, I've heard that song before. Even believed it. Then I had my
AI tumble. At night. In IMC. On the climbout. While being
rerouted. In spite of what everyone told me, it was a complete
non-event.

Thanks for the narrative -- it's useful information.

I'm curious where the statistics are that show that most pilots cannot
handle an AI failure in IMC. This FAA report

http://www1.faa.gov/fsdo/orl/files/advcir/P874052.TXT

states that vacuum failures are a factor in an average of 2 accidents per
year, and that there is an average of one vacuum-related accident for every
40,000 to 50,000 GA IFR flight plans filed. That doesn't tell us much,
though, since we don't know how many non-fatal vacuum failures occurred
during those flights.


All the best,


David

ost (Ditch) wrote

My fovorite ezample are those pilots who are
confident that they could handle an IMC gyro failure when the record shows
that many (most?) cannot.

Give me an engine failure any day. Gyro failure is my worst nightmare.

Big-time ditto from me on this. Couple years ago I had a complete
gyro failure at night, fortunately not IFR. No warning, no nothing.
Just failed completely and instantly. Subsequent investigation of the
literature showed that this is not an uncommon failure mode.

I don't fly IFR any more, and probably won't till I'm flying a plane
with backup gyros. That's one nice thing about the new Cessnas,
they've got backups.

Jim Rosinski
N3825Q

"Ron Natalie" wrote in message
. ..
Lack of use is the big killer. People base a lot of things on how many
hours
in service an engine has, but they accumulate problems while sitting as
well.

Which is why I stipulated both an "hours of operation" and a "calendar time"
measure. Either one is significant, you are correct.

I don't particularly enjoy flying with an engine that's just had some major
work, but I'd sure take that over flying with an engine that's NEVER had ANY
work. And an engine that's gotten a few hours under its belt after
maintenance looks better every flight.

Pete

"Mike Rapoport" wrote in message
link.net...
Presumably all the pilots who had engine failures believed the same thing.

And presumably, all the pilots who had engine failures engaged the same
level of preflight diligence.

"Mike Rapoport" wrote in message
hlink.net...
True but I would assume that they thought that they had given the subject
adequate consideration.

That would be a bad assumption.

It is arogant to believe that everyone else is a
fool and you are not.

That's true.

My fovorite ezample are those pilots who are
confident that they could handle an IMC gyro failure when the record shows
that many (most?) cannot.

And how many have actually practiced this situation frequently?

What people believe and what they are capable of are to different things.
For example, in a survey a few years back, a bunch of people were polled on
their driving ability. Almost all (like 95%) said "superior", even those
with extensive driving citations. When taken out on test tracks, it was even
worse; most could not handle even the most routine emergencies. Then, how
often have any of us ever gone back to a driving school aften getting our
license when we turned sixteen?


Mike
MU-2


"Peter Duniho" wrote in message
...
"Mike Rapoport" wrote in message
link.net...
Presumably all the pilots who had engine failures believed the same
thing.

It's safest to assume that, but I suspect that in reality, only some
small
subset even bothered to think hard enough about the issues to believe
the
same thing.

I guess I don't agree. My experience is that maitenance creates many
problems. I agree that the engine will last longer if you change the oil
more frequently but changing the oil doesn't prevent failures. Routine
maitenance doesn't detect impending connecting rod failures, turbo bearing
about the sieze ect. I have seen and heard of too many oil leaks, fuel
leaks, rubbing tubes and various parts coming loose or falling off...all
caused by "maitenance".

Mike
MU-2

"Peter Duniho" wrote in message
...
"Mike Rapoport" wrote in message
hlink.net...
You are probably more likely to have an engine failure from maitenance
than
from lack of maitenance.

Cute. But not really all that true, IMHO.

It depends on over how long a period of time you're talking about. If you
mean the instant after some maintenance is done, well sure...it's true
(but
obviously so, and not interestingly so). But if you look at the same
question over 2000 hours of operation or one or two decades, I suspect
that
lack of maintenance will show up as much more of an issue. The lack of
oil
changes alone are likely to be a major problem, never mind the myriad of
fixable problems that would normally be detected during routine
maintenance.

Pete

"Mike Rapoport" wrote in message
link.net...
I don't have any personally but I have a friend that has had three in
3500hrs. One connecting rod failure in a 210. A crankshaft failure in an
Azetec and I forget the details of the third failure. It has been
estimated
that 10% of Malibus have had inflight engine failures of some kind.


It'd be interesting to know the maintenance history of those birds that did
have failures (skimped maintenance, etc).

It's also be interesting to know the total operating hours of the Malibu
fleet, Lycoming vs. Continental...

I have also had a gyro fail (in a Turbo Lance that had only one AI) in IMC
flight along with an partial electrical failure (lost the alternator) and
managed to get to my destination after shooting a localizer approach to
pretty much minimiums with a Garmin 12XL that I had to program the approach
waypoints into while flying partial panel AND it was in freezing rain. No
****, this really happened. Every emergency I have ever had was on that one
flight which happened to be my first serious IFR flight after getting the IR
(accross the Sierra From Minden to San Jose in a major blizzard)

That experience doesn't convince me that there are not plenty of senarios
where it wouldn't have had a happy ending.

Mike
MU-2


"Michael" wrote in message
om...
"Mike Rapoport" wrote
True but I would assume that they thought that they had given the
subject
adequate consideration. It is arogant to believe that everyone else is
a
fool and you are not. My fovorite ezample are those pilots who are
confident that they could handle an IMC gyro failure when the record
shows
that many (most?) cannot.

Yeah, I've heard that song before. Even believed it. Then I had my
AI tumble. At night. In IMC. On the climbout. While being
rerouted. In spite of what everyone told me, it was a complete
non-event. Used the copilot side AI for a while, but quickly decided
it was too much hassle, and flying partial panel was easier. Since I
still had the copilot side AI, I was legal to continue the flight -
and I did. Shot the NDB at my destination, but the weather was crap
and the runway lights were inop, so I couldn't get in. Wound up
shooting the ILS to near mins in the rain at my alternate. No big
deal. Gyro failure is not a big deal if you train properly. I could
even argue that without the backup AI, I would have been safer that
night because I would have had to turn back and land.

On the other hand, an engine failure in a single engine airplane under
the same conditions would have been very, very ugly.

Michael

On Tue, 25 Nov 2003 14:40:02 GMT
"Mike Rapoport" wrote:

No you are not making much sense. If you live and fly in the Midwest then
the chances of survival after an engine failure are very different than
flying over rough terrain.


I'd like to see the stats from the Capt. Wubba. Unless you are privvy to
some, can you share it here? Or is this from your experience?

For example I heard a stat that surprised me as it was counter-intuitive.
There are more fatal accidents by teen and early twenties car drivers in
rural areas then in urban areas. But once I had the explanatin it made more
sense. The fatality rate goes up since the speed goes way up out in the
country.



R. Hubbell




Mike
MU-2


"R. Hubbell" wrote in message
news:%oDwb.3381$ZE1.73@fed1read04...
On 24 Nov 2003 11:31:57 -0800
(Captain Wubba) wrote:

Howdy. I was discussing with a friend of mine my concerns about flying
single-engine planes at night or in hard IFR, due to the possibility
of engine failure. My buddy is a CFI/CFII/ATP as well as an A&P, about
3500 hours, and been around airplanes for a long time, so I tend to
give credence to his experiences. He asked me how often I thought a
piston engine had an in-flight engine failure. I guestimated once
every 10,000 hours or so. He said that was *dramatically*
over-estimating the failure rate. He said that in his experience it is
at least 40,000 to 50,000 hours per in-flight engine failure. The
place where he works sometimes as a mechanic has plenty of planes come
in for overhauls and annuals, and he estimates that for every plane
that has had an engine failure before TBO, at least 20-30 make it to
TBO without any failure (which would extrapolate to a similar figure).
The flight school he teaches at has 7 Cessnas used for primary
training and rental that have flown at least 40,000 hours total in the
six years he has been there, and they have not experienced a single
engine failure.

I emailed Lycoming, and (unsurprisingly) they told me they did not
keep records about engine failure rates.

So I'd like to find out if anyone has done any objective analysis of
certificated, piston-engine failure rates in light airplanes. I have
seen all kinds of 'guesses', but little in the way of objective facts.
After analyzing NTSB accident data and comparing to annual GA
flight-hours, I'm starting to think my friend is on the right track,
but that is a relatively small sample, and has some methodologial
flaws. It's funny. I know 20,000 hour CFIs who have never had an
engine failure, and I also know 300 hour PP-ASELs who have had engine
failures.

Just for giggles, I asked 8 pilot friends/relatives if they had ever
had an engine failure. The only 'yes' was a relative who lost an
engine after takeoff on his first solo cross-country in 1958. And I
know one other pilot who had an engine failure, who I wasn't able to
talk to.

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?

Thanks,

Cap


I think it's a reasonable question to ask bnut to me it's more important
to
know how many engine failures resulted in fatalities since if the engine
failed and they walked away from it then who the hell cares what failed
as long as you live to fly again. Am I making any sense? The stat I'm
tinking of would be engine failures where a fatality resulted and that
number will be many more hours than just a engine failure and that's
the number that I'll live close to if I have to live close to some fear
factor. Even if I'm carried away on a stretcher it beats paying the
down mortgage. The engine will just be the last thing I'd think of.

Do you know what that does to your numbers when you include fatals?


R. Hubbell