Real stats on engine failures?

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

In article , Captain
Wubba wrote:

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?

The real question is, "How do you determine when it it your turn?" :-)))

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.

Most Iv'e come across in the last 25 years aviating have had no
problems, usually if there are it's a maintaince issue or operator
induced.


--
studentpilot
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

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.

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

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 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/

(Captain Wubba) wrote in message . com...
Andrew Rowley wrote in message . ..
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.

"Cap",

Just curious.

When you fill the tanks after each cross country flight, do you
calculate the fuel you actually had remaining, and compare it
to your calculated fuel reserve?

If so, have they ever disagreed?

I really don't want to go there again either -- this topic has been
thrashed out previously and anyone who cares could go Google for it,
but there are a number of factors which make fuel calculations for
a GA aircraft somewhat more uncertain than most pilots would apparently
like to believe.

These uncertainties include:
*aircraft parked on a slope while refueling
*aircraft tachometer not calibrated and no fuel flow meter
*leakage of fuel in flight
*OAT colder than expected or charted and pilot doesn't compensate
*and so forth

We've had our "ulp" moment where we landed safely and fueled,
and while we had legal reserves we in fact had considerably
less fuel than our proper calculations and preflight checking
led us to expect (for one or more of the above reasons), and
it would have bitten us on the butt if we'd had to exercise
"Plan B".

I don't disagree at all with the philosophy that one should
exercise control to minimize whatever risks one can.

I just feel that it's a mistake to conclude that no pilot
who runs out of fuel in flight did so, or that no pilot
who does so will ever run out of fuel in flight.

Regards,
Sydney

"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).

I have about 3000 hrs over 45 years.
Three failures which I had no contribution to (I did not precipitate the
failure).
One total power loss - carburetor malfunction - landed off airport.
One partial power loss - turbo charger induction failure
One damn near total power loss on takeoff - turbo charger failure

I've had others, but they were due to "unusual circumstances".

One complete failure of a magneto. Didn't count that as an engine failure,
but the reduction in power is sure noticeable at night.

Just to put some perspective on the equipment. Two out of the three
were in airplanes less than a year old.



In article ,
(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