Real stats on engine failures?

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.

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

Presumably all the pilots who had engine failures believed the same thing.

Mike
MU-2


"Captain Wubba" wrote in message
om...
Andrew Rowley wrote in message
. ..
studentpilot wrote:

Know a bloke well with over 15'000 hours, he has had no engine
failures.
He has had however 4 self inficted engine failures, these were fuel
system failures. Mostly failure to put enough in, failure to check
for water contamination properly, failure to know the aircraft fuel
system. This blokes expirence is all single engine, going from little
Lyc's to Radial's and turbine.

Why do you exclude fuel exhaustion, fuel contamination etc? Don't they
happen if you're IFR?

If you're IFR or at night it doesn't really matter WHY it stops.

Because I can control these problems. If I do a proper preflight, the
probability of fuel contamination is very, very low. If I do the
proper fuel calculations and check the fuel levels and carry proper
reserves, I'm not going to run out of gas.

This is about risk management. I can manage the risks of fuel
contamination or exhaustion very easily, if I exercise diligence and
care. If those are no longer concerns, the primary engine-related
concern becomes mechanical failure, and that's what I'm looking at.


Cap

(Captain Wubba) wrote
Indeed. Interesting. But I'd still like to see some hard data.

Me too.

Since a big part of flying is risk
management, it would be very helpful to *really* know the risks
involved. If the odds of losing an engine are 1 in 50,000 hours, then
night/hard-IFR single-engine flying becomes a great deal more
appealing than if it is 1 in 10,000 hours.

And what if it's 1 in 1000 hours? Then night/hard-IFR single-engine
flying becomes foolhardy.

I'll try to go over the NTSB data more thoroughly, I think a
reasonable extrapolation would be that at least 1 in 4 in-flight
engine failures (probably more) would end up in the NTSB database.

That doesn't seem at all consistent with my experience. Of all my
acquaintances who have had engine failures, only one wound up in the
NTSB database because he died and took his passengers with him. One
severely damaged the airplane but walked away and contrary to
regulation never reported it. The plane was eventually rebuilt. The
others made safe landings.

Based on my experience, the it's more like 1 in 10 to 1 in 100.

Michael

"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.

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).


In my case, over 6,400 hours with 5,600+ hours of instruction given
(mostly doing spin, emergency maneuver, aerobatic, and tailwheel
training -- the type of flying that might be considered harder on an
engine than more routine types of flying), I've had several
non-critical engine anomalies that were successfully dealt with,
including:

Prop stoppages during spins due to a couple of students hanging on so
tight to the throttle that it choked off the engine -- we call that
"fright idle";

Clogged fuel injectors during take-off that only revealed themselves
at full throttle;

Primer controls that were not truly "in and locked" which has lead to
prop stoppages during idle power landings.


In addition, two legitimate engine failures as follows:

The first, a fuel injector failure as we entered the traffic pattern
(after practicing off field landings, no less!) -- landed without
further incident;

The second, carb ice in a Champ during a flight review choked off the
engine during a touch and go -- touched down on the taxiway abeam the
departure end of the runway, hit a parked Porshe, bent the airplane,
walked away without so much as a scratch.

Rich
http://www.richstowell.com



(Captain Wubba) wrote in message . com...
Indeed. Interesting. But I'd still like to see some hard data. This is
the kind of problem I run into...most of your pilot friends report
that they have had a failure, but the majority of mine report none.
And none of the 2000+ hour CFI types I asked (I asked 4 of them) have
ever experienced an engine failure. My dad was a pilot with well over
12,000 hours and never had one. Another relative had fewer than 500
hours total in his flying carrer and lost one on his first solo XC.

I asked another A&P I ran into at the airport tonight, and he said he
thought it should be at least 40,000 hours per in-flight engine
failure, but really wasn't sure. Since a big part of flying is risk
management, it would be very helpful to *really* know the risks
involved. If the odds of losing an engine are 1 in 50,000 hours, then
night/hard-IFR single-engine flying becomes a great deal more
appealing than if it is 1 in 10,000 hours.

I'll try to go over the NTSB data more thoroughly, I think a
reasonable extrapolation would be that at least 1 in 4 in-flight
engine failures (probably more) would end up in the NTSB database.
But the cursory review I made earlier made me think the numbers were
much less negative than I had considered before. And the opinions of
these A&Ps are very interesting, because while failure might not
require a total overhaul, it will require *something* to be done by a
mechanic...and if these guys are seeing 30-40 engines make it to TBO
for every one needing repair due to an in-flight failure, that might
well support the 40,000 to 50,000 hour hypothesis.

Cheers,

Cap


(Michael) wrote in message om...
(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 only vaguely official number that I've ever seen came from a UK
accident report for a US-built twin. The UK investigators queried the
FAA on engine failure rates for the relevant engine, and the only
answer they got was that piston engines have failure rates on the
order of 1 in 1000 to 1 in 10000 hours. This is consistent with my
experience. I've had one non-fuel-related engine failure (partial,
but engine could only produce 20-30% power) in 1600+ hrs. Most people
I know with over 1500 GA hours have had an engine failure.

50,000 hours is not realistic. Excluding a few airline pilots (who
have ALL had engine failures) all my pilot friends together don't have
50,000 hours, and quite a few of them have had engine failures.

I've heard the maintenance shop thing before, but you need to realize
that most engine failures do not result in a major overhaul. Stuck
valves and cracked jugs mean that only a single jug is replaced;
failure of the carb or fuel injection system (my problem) affects only
that component. And oil loss will often seize an engine and make it
not worth overhauling.

There are no real stats on engine failures because engine
manufacturers and the FAA don't want those stats to exist. The FAA
could create those stats simply by requiring pilots to report engine
failures for other than fuel exhaustion/contamination reasons, but
will not.

The truth is, FAA certification requirements have frozen aircraft
piston engines in the past, and now they're less reliable than
automotive engines (not to mention ridiculously expensive).

Michael

"Captain Wubba" wrote in message
om...

This is about risk management. I can manage the risks of fuel
contamination or exhaustion very easily, if I exercise diligence and
care. If those are no longer concerns, the primary engine-related
concern becomes mechanical failure, and that's what I'm looking at.



I'm with you.
I'm most interested in anything which forces me down. Included
in that would be carburetor failure, fuel line breaks, engine fire,
as well as the engine deciding to punch a hole in the case...
stuff that I could never protect against by a thorough preflight.

I'd also be interested in survival statistics for forced landings at
night, over mountainous terrain, in cold weather etc. for *any*
reason (including self-induced fuel exhaustion). Then it is
easy to work out the risks.

--
Dr. Tony Cox
Citrus Controls Inc.
e-mail:
http://CitrusControls.com/

"studentpilot" wrote in message ...

Know a bloke well with over 15'000 hours, he has had no engine failures.

My airplane has about 5500 hours over 50 years on it. It's had two fairly
major engine failures to my knowledge. I had the (mis)fortune of having
the second one which put an end to this engine (it's sitting in my basement
a new zero-time replacement is now installed).

Knowing *NOTHING* about turbocharged engines, I was wondering. Would a loss
of the turbocharger still allow the engine to produce the same power as a
non-turbo engine of the same size at the same altitude? From the examples
I've read in this thread so far, 3 out of 4 are turbocharger failures.
Interesting.


"Bob Gardner" wrote in message
news:G_vwb.294669$Tr4.929561@attbi_s03...
In 7000 hours I had one engine "failure," which was just a loose hose
between the turbocharger and intake manifold. Engine didn't really fail,
it
just lost boost on that side. I've had some engine anomalies, but nothing
that would meet the definition of failure. I would tend to agree that
honest-to-goodness failures are very rare when considered in the context
of
total operating hours for all powered aircraft.

Bob Gardner

"Captain Wubba" wrote in message
om...
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

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.

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.

It depends on the type of turbo failure. The typical failure is the bearing
in which case the engine will not make much, if any power.

Mike
MU-2


"Jeff Franks" wrote in message
...
Knowing *NOTHING* about turbocharged engines, I was wondering. Would a
loss
of the turbocharger still allow the engine to produce the same power as a
non-turbo engine of the same size at the same altitude? From the
examples
I've read in this thread so far, 3 out of 4 are turbocharger failures.
Interesting.


"Bob Gardner" wrote in message
news:G_vwb.294669$Tr4.929561@attbi_s03...
In 7000 hours I had one engine "failure," which was just a loose hose
between the turbocharger and intake manifold. Engine didn't really fail,
it
just lost boost on that side. I've had some engine anomalies, but
nothing
that would meet the definition of failure. I would tend to agree that
honest-to-goodness failures are very rare when considered in the context
of
total operating hours for all powered aircraft.

Bob Gardner

"Captain Wubba" wrote in message
om...
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