Real stats on engine failures?

On Tue, 25 Nov 2003 23:31:50 +1000
"B" wrote:

Night VFR engine failu

1. turn on landing lights,

2. if you don't like what you see, turn them back off!


You may want to shut off the master with an engine failure, unless you're
sure it's ok to leave it on.


Hope this helps,
Peter

On 25 Nov 2003 05:56:17 -0800
(Captain Wubba) wrote:

"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


Actually I'd really like to know that too. When I delve more deeply
into the NTSB stuff, I'll break out fatalities. And it does
relate....I am most concerned with IFR and night flying, with this
specific question. An engine loss at altitude in day VFR should almost
never be fatal; it probably shouldn't even bend the plane very often.
But at night or in hard IFR I'd expect the fatality rate to be rather
high. What it is exactly will be interesting to find out. Certainly it
is easier to find out fatalities than it is total engine failures. If
I can glean these numbers from the NTSB database, I'll let you know.
Since this is mostly aboiut risk management, it will be interesting to
really know the risks *after* the engine failure as well.


I wonder if the ASF Air Safety Foundation can help out here? They live
and breathe this stuff.

I'd expect the number of hours flown per failure that resulted in a fatal to
be very high and of course decreasing with worsening conditions. But it
may be hard to find out the cause as others have said. It seems like
you're interested in hard and unexpected failures. I think in a lot
of ways we, as pilots, are fortunate to have so much data to look to
but it can be misleading if it's not comprehensive enough. So far the
data's pretty good and it's useful still. But I have never looked at
car crash data much to improve how I drive. Although I know more accidents
occur in the slow lane and fewer in the fast lane so I try to avoid the
slow lane but I didn't really need accident data to reach that conclusion.
My point is just that we like to know how people paid down their mortgage,
early and suddenly as a reminder that it happens and to learn from and
avoid the same mistake.



Rick


Cheers,

Cap

"Tom S." wrote in message news:...

"Mike Rapoport" wrote in message
link.net...

http://www.ntsb.gov/NTSB/brief.asp?e...12X20796&key=1

In sum...

"The National Transportation Safety Board determines the probable cause(s)
of this incident as follows:

The failure of a number one cylinder connecting rod bolt due to
under-torquing during engine major overhaul. "

"Mike Rapoport" wrote in message
link.net...
[...] 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".

Well, granted, the engines on your plane require a much more specialized
maintenance crew than the one Lycoming on mine. But in spite of the very
real possibility of human error during maintenance, as far as I know more
engine failures are prevented by maintenance than are caused by it. I would
be very surprised if you could find statistics to the contrary.

Pete

(Michael) wrote

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.
[...]
Gyro failure is not a big deal if you train properly.

Well, for those of us less studly than this, I'd still take an engine
failure over gyro failure in IMC under most conditions. Maybe given
the time/money to train "properly" gyro failure isn't such a major
emergency. But I don't have either the time or the money, so this
instrument-rated pilot isn't flying IFR till he gets a plane with
backup gyros or electric AI.

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

Good point. Climbout is a really horrible time for an engine failure.
In cruise I'm still much more afraid of gyro failure though. As I
said in another post on this subject, some of the reason for this is
that it often happens (and did to me) with little or now warning.

Jim Rosinski
N3825Q

(Michael) wrote in message . com...

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. .... Gyro failure is not a big deal if you train properly.

I really don't want to restart that whole thread but FWIW:

One observation from the recent ASF/FAA vacuum failure study
was that pilots who lost only their AI (electric HSI did not
fail) did not lose control of the airplane, while a significant
number of pilots (same aircraft) lost control when they lost
both. There was no correlation to time in type or total time.

This result suggests to me that it might be a mistake to
extrapolate from "lose AI no problem" to "lose gyros no
problem".

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

No argument there. But certainly there are a number of pilots
who have found vacuum system failure in night IMC to be fatally
ugly.

There are currently no "real stats" which prove or disprove
the contention that this ugliness is entirely due to improper
training.

Them's the facts,
Sydney

ost (Ditch) wrote in message ...
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.

In a SE airplane w/ an engine powered vacuum pump and w/out a backup
electric pump or backup electric gyros, engine failure will become
gyro failure in a minute or so.

Sydney

(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

On 24 Nov 2003 11:31:57 -0800, (Captain Wubba)
wrote:



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.


There are variations depending on the engine and aircraft. Whether these
are significant is unknown, as the universe is too small to afford
significance to the statistics.

Last year, in the March and June issues (2002) Aviation Consumer published
studies on accidents in light and heavy single engine a/c of the type most
of us here fly.

The total accident rate from all causes was on the order of 3.8/100,000 hrs
and the fatal accident rate from all causes was on the order of 1.1/100,000
hrs.

Engine failures (NOT including fuel exhaustion) comprised about 21% of the
accidents so, since fatal accidents are likely all reported to the NTSB, I
think one could assume a fatal engine failure accident rate on the order of
1/500,000 hrs in this group of aircraft.




Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

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


Did they? I see pilots take off all the time with no preflight. I see
plenty of aircraft takeoff without having had their pilots sample the
fuel, look at the oil, do a runup...even take a quick look in the
tanks. No just pattern flights either. Just the other day, when I
flying to Nashville, I saw a guy who I knew was headed to Charleston,
SC in an A36 just show up at the airport, pile his wife and kid in the
plane and go. They were late, apparently...no time for a preflight. In
a single-engine plane, over mountains, at night. He trusted the FBO to
have filled up his tanks...he trusted that his oil level was where it
should have been...he trusted that there was no water in his tanks, or
that they were not accidently filled with Jet-A. You might be
right...he might have thought he was managing the risks, but obviously
he wasn't. It just didn't catch up to him *this* time.

Paul Craig's excellent book 'The Killing Zone: How & Why Pilots Die'
talks about 'creeping complacency'. When we were student pilots we
used pre-flight checklists all the time. Checked everything. AFter a
few hundred hours, many non-professional pilots have allowed
themselves to truncate their preflight to a quick walk around, oil
check, and tank level. Many don't even do that.

To me, this is about risk management. I *can* manage the risks of
running out of gas. I *can* manage the risks of fuel contamination.
Just by being diligent about my preflights. But I can't preflight my
way out of a thrown rod...which is why I'd like to know more about
their liklihood.

Cheers,

Cap



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