In-Flight Engine Failure

[O. Sami Saydjari]

Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
3 months and the engine failed during climb out on Tuesday. Altitude
was 4400 feet. Luckily, the engine did not entirely quit and I made it
to an airport within 10 miles. TBO was 1000 hours away. Dissapointing!
When we cut the oil filter, it was full of fairly large aluminum and
steel bits of metal. Arg!

(1) Upon examination, the wire into the left magneto was found to be
broken off, just at its connection to the magneto. A mechanic theorized
that it could have grounded to the magento housing. He said that that
could have actually caused a grounding of both magnetos and could have
fouled up the engine firing, and could have contributed to the failure.
Later, he said that he thought that it was just a coincidence that the
left mag wire happened to have been broken when the engine failed due to
some other reason. What do you folks think? Could the two have been
tied togehter?

(2) Now I am faced with having to have the engine overhauled. Growl!
The engine has brand new cylinders on it (well, they have about 100
hours on them) put on by the previous owner. So, I think we want to do
a custom overall of this particular engine. Does that make sense? Are
there different places who do this sort of thing with different
reputations for quality of work? If so, I would like to hear about
recommendations (the engine is a TCM TSIO-360-FB) or perhaps criteria to
use in making a judgement. Also, are there different quality parts or
methods in doing the overhaul that are options that I need to specify
when I ask for the overhaul. In other words, if I can pay 10% more and
get more reliability, then I might like to have the option to do
that...but often, you have to be knowledgeable enough to ask for the
right things.

[Dave Butler]

O. Sami Saydjari wrote:
> Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
> 3 months and the engine failed during climb out on Tuesday. Altitude
> was 4400 feet. Luckily, the engine did not entirely quit and I made it
> to an airport within 10 miles. TBO was 1000 hours away. Dissapointing!

Way to go. I had a similar engine failure once and was able to make a nearby
airport under partial power with mucho vibration. It's an unforgettable experience.

> When we cut the oil filter, it was full of fairly large aluminum and
> steel bits of metal. Arg!
>
> (1) Upon examination, the wire into the left magneto was found to be
> broken off, just at its connection to the magneto. A mechanic theorized

What wire, the P-lead?

> that it could have grounded to the magento housing. He said that that
> could have actually caused a grounding of both magnetos and could have
> fouled up the engine firing, and could have contributed to the failure.

Seems kinda far-fetched.

> Later, he said that he thought that it was just a coincidence that the
> left mag wire happened to have been broken when the engine failed due to
> some other reason. What do you folks think? Could the two have been
> tied togehter?

I don't want to say it's impossible, but it seems unlikely to me. What do I know?

Suppose the magneto could have come loose and spun around, breaking off the
wire, causing gross ignition mistiming and detonation, and leading to the
failure? I dunno, I'm just brainstorming.

>
> (2) Now I am faced with having to have the engine overhauled. Growl!
> The engine has brand new cylinders on it (well, they have about 100
> hours on them) put on by the previous owner. So, I think we want to do
> a custom overall of this particular engine. Does that make sense? Are
> there different places who do this sort of thing with different
> reputations for quality of work? If so, I would like to hear about

See if you find a copy of "The Major Overhaul", by Kas Thomas. It's out of
print. You might contact Kas himself and ask him where to get a copy.

> recommendations (the engine is a TCM TSIO-360-FB) or perhaps criteria to
> use in making a judgement. Also, are there different quality parts or
> methods in doing the overhaul that are options that I need to specify
> when I ask for the overhaul. In other words, if I can pay 10% more and
> get more reliability, then I might like to have the option to do
> that...but often, you have to be knowledgeable enough to ask for the
> right things.

[G.R. Patterson III]

"O. Sami Saydjari" wrote:
>
> (1) Upon examination, the wire into the left magneto was found to be
> broken off, just at its connection to the magneto. A mechanic theorized
> that it could have grounded to the magento housing. He said that that
> could have actually caused a grounding of both magnetos and could have
> fouled up the engine firing, and could have contributed to the failure.

If we're talking about the P-lead, I don't see how grounding one would ground out
both mags. In any case, if both mags had been grounded, the engine would not run at
all.

> Later, he said that he thought that it was just a coincidence that the
> left mag wire happened to have been broken when the engine failed due to
> some other reason. What do you folks think? Could the two have been
> tied togehter?

I doubt it. Magneto grounding doesn't cause chunks of metal in the oil filter.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

[Orval Fairbairn]

In article >,
"O. Sami Saydjari" > wrote:

> Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
> 3 months and the engine failed during climb out on Tuesday. Altitude
> was 4400 feet. Luckily, the engine did not entirely quit and I made it
> to an airport within 10 miles. TBO was 1000 hours away. Dissapointing!
> When we cut the oil filter, it was full of fairly large aluminum and
> steel bits of metal. Arg!
>
> (1) Upon examination, the wire into the left magneto was found to be
> broken off, just at its connection to the magneto. A mechanic theorized
> that it could have grounded to the magento housing. He said that that
> could have actually caused a grounding of both magnetos and could have
> fouled up the engine firing, and could have contributed to the failure.
> Later, he said that he thought that it was just a coincidence that the
> left mag wire happened to have been broken when the engine failed due to
> some other reason. What do you folks think? Could the two have been
> tied togehter?


Very unlikely -- all the P-lead break does is prevent you from shutting
down that mag. It is a good idea to pefrorm a "both off" check when
doing a mag check. That way, you will be able to find a broken P-lead.

You did not state whether or not the engine ran roughly or smoothely
after the failure. From your description of the metal chunks, it would
appear that you had a valve failure, in which case the engine would have
vibrated pretty badly.


> (2) Now I am faced with having to have the engine overhauled. Growl!
> The engine has brand new cylinders on it (well, they have about 100
> hours on them) put on by the previous owner. So, I think we want to do
> a custom overall of this particular engine. Does that make sense? Are
> there different places who do this sort of thing with different
> reputations for quality of work? If so, I would like to hear about
> recommendations (the engine is a TCM TSIO-360-FB) or perhaps criteria to
> use in making a judgement. Also, are there different quality parts or
> methods in doing the overhaul that are options that I need to specify
> when I ask for the overhaul. In other words, if I can pay 10% more and
> get more reliability, then I might like to have the option to do
> that...but often, you have to be knowledgeable enough to ask for the
> right things.
>

[O. Sami Saydjari]

>> (1) Upon examination, the wire into the left magneto was found to be
>> broken off, just at its connection to the magneto. A mechanic theorized
>
>
> What wire, the P-lead?
>

Yes, the P-lead.

[O. Sami Saydjari]

> Congrats on your cool head and piloting job.....

Thank you. I am a better pilot today because of this experience. The
good news is that I have my (hopefully) once-in-a-flying-career engine
failure behind me :)

> IF you ever have a *zero* mag drop. Don't congratulate
> yourself on the condition of the electrical system.... it means you
> have a broken "P" lead. A dangerous condition.

I agree. But distinguishing between a 25 RPM mag drop and a zero mag
drop, especially when the RPM needle normally is vibrating a bit, can be
hard (at least for me).

Just out of curiosity, other than having a hot mag (a bad thing, I know,
because the engine can start when turned over by a person...or the
wind), what other failures can be induced by such a problem?

>
>
>
> Yeah, BUT.... those 100 hour cylinders might be trash. Can you give
> us more information on what actually broke?

Not yet. I am not sure how I will find this out until I am actually
into the overhaul itself. Is there some other diagnostic procedure I
should try?

> If a cylinder ingested a
> valve, all cylinders on that side are now suspect, perhaps more if you
> have a crossover tube. A bent connecting rod may also be possible.
> Too many questions.....

Well, all cylinders seemed to have good pressure when it was tested.
because there was both aluminum and steel metal chunks in the oil
filter, the A&P on the spot said that he thought it might have been "the
bearings."

My A&P is going out there to pull the engine on Monday. I should know
more then.

[O. Sami Saydjari]

> It is a good idea to pefrorm a "both off" check when
> doing a mag check. That way, you will be able to find a broken P-lead.

Interesting. I never was taught to do that, but it makes a lot of
sense. Thanks.
>
> You did not state whether or not the engine ran roughly or smoothely
> after the failure. From your description of the metal chunks, it would
> appear that you had a valve failure, in which case the engine would have
> vibrated pretty badly.

Well, here is a little more detail. First, I experienced a 200 RPM
drop. No other obvious symptoms. Then, within 2 minutes, the RPM
dropped another 200 and MP pressure seemed to drop. I boosted throttle.
At that point, I was getting vectors to the nearest airport. Within
about 2 more minutes, I was down into the "yellow arc" of RPM...I think
it was about 2000 RPM. At that point the engine began running rough,
although the vibration was not that bad...just sounded very rough. Then
within about 5 miles of the airport, the oil pressure began dropping
into the yellow arc...35 PSI or so...and dropping. On turning final,
the engine was quite rough, and oil pressure was down to around 10-15
PSI (bottom of the yellow arc), after pulling off the run way, the oil
pressure was at the very bottom of the yellow arc...maybe 5 PSI. I
immediately shutdown. Does that help?
>
>
>
>>(2) Now I am faced with having to have the engine overhauled. Growl!
>>The engine has brand new cylinders on it (well, they have about 100
>>hours on them) put on by the previous owner. So, I think we want to do
>>a custom overall of this particular engine. Does that make sense? Are
>>there different places who do this sort of thing with different
>>reputations for quality of work? If so, I would like to hear about
>>recommendations (the engine is a TCM TSIO-360-FB) or perhaps criteria to
>>use in making a judgement. Also, are there different quality parts or
>>methods in doing the overhaul that are options that I need to specify
>>when I ask for the overhaul. In other words, if I can pay 10% more and
>>get more reliability, then I might like to have the option to do
>>that...but often, you have to be knowledgeable enough to ask for the
>>right things.
>>

[Frank Ch. Eigler]

Orval Fairbairn > writes:

> [...] all the P-lead break does is prevent you from shutting down
> that mag. It is a good idea to pefrorm a "both off" check when
> doing a mag check. That way, you will be able to find a broken
> P-lead.

I've heard mechanics advising against doing this test casually. If
done at even moderate power, it can apparently cause backfiring, which
can in turn create induction system damage. I've seen a C172, one
cylinder of which was burned out shortly after such an episode, due to
extreme lean running resulting from induction cracks.

- FChE

[kage]

What brand of cylinders are they?

I don't know about the "360" series cylinders, but I would NEVER put
Continentals on if there were any alternative. Continental makes only junk
at this time and their reps are just paid liars.

Karl

[O. Sami Saydjari]

I presume they are TCM, but I am not certain. I left the logs with the
mechanic. In my appraisal, it says "8/20/02 Installation of six factor
new cylinder assemblies, part number 654970A4BP. Installed by
Maintenance Express."

-Sami

kage wrote:

> What brand of cylinders are they?
>
> I don't know about the "360" series cylinders, but I would NEVER put
> Continentals on if there were any alternative. Continental makes only junk
> at this time and their reps are just paid liars.
>
> Karl
>
>

[Bill Hale]

"O. Sami Saydjari" > wrote in message >...
> Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
> 3 months and the engine failed during climb out on Tuesday. Altitude
> was 4400 feet. Luckily, the engine did not entirely quit and I made it
> to an airport within 10 miles. TBO was 1000 hours away. Dissapointing!
> When we cut the oil filter, it was full of fairly large aluminum and
> steel bits of metal. Arg!

What is wrong with this engine? The symptoms surely don't relate to
P leads or magneto wires.

Why not run a compression check on it? Take off the valve cover on
any suspicious cylinders. What's in there?

Take off the cylinder, if you figure out
that it's only one. See what's going on. What's the cam look like?

With the cylinder off, you can look inside the case for clues.

There are a lot of failures where you could do a repair and be back
in business--unless something got loose and whanged around inside.
The oil filter probably kept stuff out of the bearings.

It wouldn't be much of an investment in time to investigate. Plus,
we all want to know what busted!! Heck, you can even do this yourself.

It's a hard running engine.

Bill H

[O. Sami Saydjari]

Oops..that should have said "8/20/03...."

O. Sami Saydjari wrote:

> I presume they are TCM, but I am not certain. I left the logs with the
> mechanic. In my appraisal, it says "8/20/02 Installation of six factor
> new cylinder assemblies, part number 654970A4BP. Installed by
> Maintenance Express."
>
> -Sami
>
> kage wrote:
>
>> What brand of cylinders are they?
>>
>> I don't know about the "360" series cylinders, but I would NEVER put
>> Continentals on if there were any alternative. Continental makes only
>> junk
>> at this time and their reps are just paid liars.
>>
>> Karl
>>
>>
>

[O. Sami Saydjari]

>
> Why not run a compression check on it? Take off the valve cover on
> any suspicious cylinders. What's in there?

Well, I was traveling on business when the failure happened, I could
only spend the next morning with it before I had to be flown home
(commercially, arg!). Also the shop where I was had several fires
happening simultaneously and were short handed, so they were unwilling
to investigate beyond pull the spark plugs and cutting the oil filter.


>
> Take off the cylinder, if you figure out
> that it's only one. See what's going on. What's the cam look like?

Well, I am sending my A&P out there on Monday and I hope to learn these
details from him. I will report back. My skill level is not at the
point I could have easily done these things myself. Sorry to tease you
with scant description and not be able to provide the details.

>
> With the cylinder off, you can look inside the case for clues.
>
> There are a lot of failures where you could do a repair and be back
> in business--unless something got loose and whanged around inside.
> The oil filter probably kept stuff out of the bearings.

That would be nice. My A&P suspects that the bearings are likely
fouled, but we will find out.
>
> It wouldn't be much of an investment in time to investigate. Plus,
> we all want to know what busted!! Heck, you can even do this yourself.

Would it were so. Perhaps in a few years :)

>
> It's a hard running engine.
>
> Bill H

[G.R. Patterson III]

"O. Sami Saydjari" wrote:
>
> Well, here is a little more detail. First, I experienced a 200 RPM
> drop. No other obvious symptoms. Then, within 2 minutes, the RPM
> dropped another 200 and MP pressure seemed to drop. I boosted throttle.
> At that point, I was getting vectors to the nearest airport. Within
> about 2 more minutes, I was down into the "yellow arc" of RPM...I think
> it was about 2000 RPM. At that point the engine began running rough,
> although the vibration was not that bad...just sounded very rough. Then
> within about 5 miles of the airport, the oil pressure began dropping
> into the yellow arc...35 PSI or so...and dropping. On turning final,
> the engine was quite rough, and oil pressure was down to around 10-15
> PSI (bottom of the yellow arc), after pulling off the run way, the oil
> pressure was at the very bottom of the yellow arc...maybe 5 PSI. I
> immediately shutdown. Does that help?

Well, you can rule out magneto problems being a factor here. If the temperatures were
going up at the same time, something in that engine was binding, and it was getting
ready to seize. The pressure drop would be caused either by a serious oil leak (you
would've noticed that) or rapid clogging of oil passages by metal particles. I think
it would not have kept running much longer.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

[O. Sami Saydjari]

> If the temperatures were
> going up at the same time, something in that engine was binding, and it was getting
> ready to seize.

As I recall, the temperature remained in the green.

> The pressure drop would be caused either by a serious oil leak (you
> would've noticed that) or rapid clogging of oil passages by metal particles.

Right. I immediately checked the oil after landing and it was at 7.5
quarts, just where it was on take-off.

> I think
> it would not have kept running much longer.

Good to know :)

>
> George Patterson
> This marriage is off to a shaky start. The groom just asked the band to
> play "Your cheatin' heart", and the bride just requested "Don't come home
> a'drinkin' with lovin' on your mind".

[Ray Andraka]

Why,

If you check the left and then the right mag, you know that both of them will
ground out properly without risking damage due to a backfire. The only thing
that individually checking the mags won't find is a switch that is defective
in the off position only, pretty unlikely. If you are that paranoid about the
switch, you can check it with an ohmmeter with the engine stopped.

Orval Fairbairn wrote:

> Very unlikely -- all the P-lead break does is prevent you from shutting
> down that mag. It is a good idea to pefrorm a "both off" check when
> doing a mag check. That way, you will be able to find a broken P-lead.

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[Ray Andraka]

If it were me, and knowing that the oil pressure dropped off to near zero, plus all the metal, I would not
opt for anything less than a complete overhaul. Even if the obvious damage is isolated to one cylinder, you
don't know what damage the low oil pressure and all that metal did elsewhere. It would really suck to spend
a bunch of cash on a fix only to have it happen again. Besides, right now, the cost of an overhaul is
relatively low compared to the prices over the last few years. If there were no metal, and the oil pressure
hadn't dropped, then maybe, but not under those circumstances.

Bill Hale wrote:

>
> There are a lot of failures where you could do a repair and be back
> in business--unless something got loose and whanged around inside.
> The oil filter probably kept stuff out of the bearings.
>
> It wouldn't be much of an investment in time to investigate. Plus,
> we all want to know what busted!! Heck, you can even do this yourself.
>
> It's a hard running engine.
>
> Bill H

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[Dave Butler]

Ray Andraka wrote:
> Why,
>
> If you check the left and then the right mag, you know that both of them will
> ground out properly without risking damage due to a backfire. The only thing
> that individually checking the mags won't find is a switch that is defective
> in the off position only, pretty unlikely. If you are that paranoid about the
> switch, you can check it with an ohmmeter with the engine stopped.

Many (OK, some) ignition switches have an AD with a recurring inspection
requirement that requires testing the OFF position every 100 hours. AD 76-07-12

>
> Orval Fairbairn wrote:
>
>
>>Very unlikely -- all the P-lead break does is prevent you from shutting
>>down that mag. It is a good idea to pefrorm a "both off" check when
>>doing a mag check. That way, you will be able to find a broken P-lead.
>
>
> --
> --Ray Andraka, P.E.
> President, the Andraka Consulting Group, Inc.
> 401/884-7930 Fax 401/884-7950
> email
> http://www.andraka.com
>
> "They that give up essential liberty to obtain a little
> temporary safety deserve neither liberty nor safety."
> -Benjamin Franklin, 1759
>
>


--
Dave Butler, software engineer 919-392-4367

[Nathan Young]

On Thu, 08 Apr 2004 10:44:20 -0500, "O. Sami Saydjari"
> wrote:

>
>
>> Congrats on your cool head and piloting job.....
>
>Thank you. I am a better pilot today because of this experience. The
>good news is that I have my (hopefully) once-in-a-flying-career engine
>failure behind me :)
>
>> IF you ever have a *zero* mag drop. Don't congratulate
>> yourself on the condition of the electrical system.... it means you
>> have a broken "P" lead. A dangerous condition.
>
>I agree. But distinguishing between a 25 RPM mag drop and a zero mag
>drop, especially when the RPM needle normally is vibrating a bit, can be
> hard (at least for me).

In addition to the RPM - you should be able to hear the mag drop - not
a precise indicator but certainly enough to confirm whether or not the
mag is grounded.

-Nathan

[Nathan Young]

On Fri, 09 Apr 2004 09:01:16 -0400, Dave Butler
> wrote:

>Ray Andraka wrote:
>> Why,
>>
>> If you check the left and then the right mag, you know that both of them will
>> ground out properly without risking damage due to a backfire. The only thing
>> that individually checking the mags won't find is a switch that is defective
>> in the off position only, pretty unlikely. If you are that paranoid about the
>> switch, you can check it with an ohmmeter with the engine stopped.
>
>Many (OK, some) ignition switches have an AD with a recurring inspection
>requirement that requires testing the OFF position every 100 hours. AD 76-07-12

Yep, and you can tell when the mechanic is testing the Bendix switch
by the backfires outside his hangar.

[Nathan Young]

On Thu, 08 Apr 2004 08:41:44 -0500, "O. Sami Saydjari"
> wrote:

>Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
>3 months and the engine failed during climb out on Tuesday. Altitude
>was 4400 feet. Luckily, the engine did not entirely quit and I made it
>to an airport within 10 miles.

Glad to hear you made it safely. You are based in Wisconsin, right?
Where was the failure? Northern Wisconsin can be an unforgiving area
for an off-airport landing (miles and miles of dense forests).

>(2) Now I am faced with having to have the engine overhauled. Growl!
>The engine has brand new cylinders on it (well, they have about 100
>hours on them) put on by the previous owner. So, I think we want to do
>a custom overall of this particular engine. Does that make sense?

It is too early to tell what you need to do. With that amount of
metal - I would tear the engine down and inspect the crank/bearings,
etc. You may be able to reuse the cylinders.

-Nathan

[O. Sami Saydjari]

>
>
> Glad to hear you made it safely. You are based in Wisconsin, right?

Right. Central Wisconsin.

> Where was the failure? Northern Wisconsin can be an unforgiving area
> for an off-airport landing (miles and miles of dense forests).
>

I was on a business trip in Washington D.C., so I was out of a small
airport called Tipton Field (FME). I ended up landing at Gaithersburg.

[PaulH]

Had a prop interference overhaul done at Poplar Grove, IL a couple of
years ago. I visited the shop when the had the engine apart and was
really impressed.

[Ray Andraka]

Again, my contention is that you are better off checking one mag at a time, to
verify the mags ground out properly, and then check the off position of the switch
using an ohmmeter rather than causing the engine to backfire.

The other alternative I guess is to leave the switch in the off position once you
put it there, let the engine shut down completely, then restart it and shut it down
normally.

Dave Butler wrote:

> Ray Andraka wrote:
> > Why,
> >
> > If you check the left and then the right mag, you know that both of them will
> > ground out properly without risking damage due to a backfire. The only thing
> > that individually checking the mags won't find is a switch that is defective
> > in the off position only, pretty unlikely. If you are that paranoid about the
> > switch, you can check it with an ohmmeter with the engine stopped.
>
> Many (OK, some) ignition switches have an AD with a recurring inspection
> requirement that requires testing the OFF position every 100 hours. AD 76-07-12
>
> >
> > Orval Fairbairn wrote:
> >
> >
> >>Very unlikely -- all the P-lead break does is prevent you from shutting
> >>down that mag. It is a good idea to pefrorm a "both off" check when
> >>doing a mag check. That way, you will be able to find a broken P-lead.
> >
> >
> > --
> > --Ray Andraka, P.E.
> > President, the Andraka Consulting Group, Inc.
> > 401/884-7930 Fax 401/884-7950
> > email
> > http://www.andraka.com
> >
> > "They that give up essential liberty to obtain a little
> > temporary safety deserve neither liberty nor safety."
> > -Benjamin Franklin, 1759
> >
> >
>
> --
> Dave Butler, software engineer 919-392-4367

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[Ray Andraka]

Tipton (FME) is small? That's a pretty big field. Suburban (W18) which is
about 3 miles away is a small airport (2300'x25' with trees at both ends
and a significant slope to the runway). Tipton, also has more of a big
airport feel with the staff, not nearly as friendly.

"O. Sami Saydjari" wrote:

> >
> >
> > Glad to hear you made it safely. You are based in Wisconsin, right?
>
> Right. Central Wisconsin.
>
> > Where was the failure? Northern Wisconsin can be an unforgiving area
> > for an off-airport landing (miles and miles of dense forests).
> >
>
> I was on a business trip in Washington D.C., so I was out of a small
> airport called Tipton Field (FME). I ended up landing at Gaithersburg.

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[O. Sami Saydjari]

Good point. I just meant that it was not a BWI or a tower controller
airport, for example. I should have beem more specific.

-Sami

Ray Andraka wrote:

> Tipton (FME) is small? That's a pretty big field. Suburban (W18) which is
> about 3 miles away is a small airport (2300'x25' with trees at both ends
> and a significant slope to the runway). Tipton, also has more of a big
> airport feel with the staff, not nearly as friendly.
>
> "O. Sami Saydjari" wrote:
>
>
>>>
>>>Glad to hear you made it safely. You are based in Wisconsin, right?
>>
>>Right. Central Wisconsin.
>>
>>
>>>Where was the failure? Northern Wisconsin can be an unforgiving area
>>>for an off-airport landing (miles and miles of dense forests).
>>>
>>
>>I was on a business trip in Washington D.C., so I was out of a small
>>airport called Tipton Field (FME). I ended up landing at Gaithersburg.
>
>
> --
> --Ray Andraka, P.E.
> President, the Andraka Consulting Group, Inc.
> 401/884-7930 Fax 401/884-7950
> email
> http://www.andraka.com
>
> "They that give up essential liberty to obtain a little
> temporary safety deserve neither liberty nor safety."
> -Benjamin Franklin, 1759
>
>

[O. Sami Saydjari]

Yeah, that is where my A&P just recommended that I send it. Your
endorsement makes me fee all the better! Thanks.

PaulH wrote:

> Had a prop interference overhaul done at Poplar Grove, IL a couple of
> years ago. I visited the shop when the had the engine apart and was
> really impressed.

[Dan Thomas]

(Bill Hale) wrote in message >...
> "O. Sami Saydjari" > wrote in message >...
> > Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
> > 3 months and the engine failed during climb out on Tuesday. Altitude
> > was 4400 feet. Luckily, the engine did not entirely quit and I made it
> > to an airport within 10 miles. TBO was 1000 hours away. Dissapointing!
> > When we cut the oil filter, it was full of fairly large aluminum and
> > steel bits of metal. Arg!
>
> What is wrong with this engine? The symptoms surely don't relate to
> P leads or magneto wires.
>
> Why not run a compression check on it? Take off the valve cover on
> any suspicious cylinders. What's in there?
>
> Take off the cylinder, if you figure out
> that it's only one. See what's going on. What's the cam look like?
>
> With the cylinder off, you can look inside the case for clues.
>
> There are a lot of failures where you could do a repair and be back
> in business--unless something got loose and whanged around inside.
> The oil filter probably kept stuff out of the bearings.

Sure, it kept the stuff out of the bearings. But the oil pump
is upstream of the filter, and all that metal garbage went through it
and chewed it up. "Fixing up" the engine is spending money on an
engine that will fail again very shortly, if it generates any oil
pressure at all. Nothing less than complete teardown is necessary
here.

Dan

[O. Sami Saydjari]

> Sure, it kept the stuff out of the bearings. But the oil pump
> is upstream of the filter, and all that metal garbage went through it
> and chewed it up. "Fixing up" the engine is spending money on an
> engine that will fail again very shortly, if it generates any oil
> pressure at all. Nothing less than complete teardown is necessary
> here.
>

Yes, seems reasonable, painful as that conclusion is.
Price tag: $21K (plus labor). Gulp.

[Roy Smith]

In article >,
"O. Sami Saydjari" > wrote:

> > Sure, it kept the stuff out of the bearings. But the oil pump
> > is upstream of the filter, and all that metal garbage went through it
> > and chewed it up. "Fixing up" the engine is spending money on an
> > engine that will fail again very shortly, if it generates any oil
> > pressure at all. Nothing less than complete teardown is necessary
> > here.
> >
>
> Yes, seems reasonable, painful as that conclusion is.
> Price tag: $21K (plus labor). Gulp.

I can only offer my own experience. My club had an Archer which showed
metal in the oil filter. The engine had about 1300 SMOH, and this was
the third run on the engine. We tried pulling cylinders and opening the
oil pump trying to find the problem and ended up just throwing a lot of
good money after bad. In the end, we racked up a lot of shop bills and
still had to get a new engine.

IHMO, the aviation gods have smiled upon you. They made the engine last
long enough to get you safely on the ground so you could write that $21k
check. The alternative could have been much worse.

[Ray Andraka]

Ouch. I paid 20K and change for a Penn Yann O-540 rebuild to new limits
with everything new except the case and crank last summer. Yours is a 4
banger, right? I guess the turbo adds a bunch to it?

"O. Sami Saydjari" wrote:

> Yes, seems reasonable, painful as that conclusion is.
> Price tag: $21K (plus labor). Gulp.

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[O. Sami Saydjari]

6 cylinders.

Ray Andraka wrote:

> Ouch. I paid 20K and change for a Penn Yann O-540 rebuild to new limits
> with everything new except the case and crank last summer. Yours is a 4
> banger, right? I guess the turbo adds a bunch to it?
>
> "O. Sami Saydjari" wrote:
>
>
>>Yes, seems reasonable, painful as that conclusion is.
>>Price tag: $21K (plus labor). Gulp.
>
>
> --
> --Ray Andraka, P.E.
> President, the Andraka Consulting Group, Inc.
> 401/884-7930 Fax 401/884-7950
> email
> http://www.andraka.com
>
> "They that give up essential liberty to obtain a little
> temporary safety deserve neither liberty nor safety."
> -Benjamin Franklin, 1759
>
>

[O. Sami Saydjari]

>
> IHMO, the aviation gods have smiled upon you. They made the engine last
> long enough to get you safely on the ground so you could write that $21k
> check. The alternative could have been much worse.

I definitely agree.

[Dave Stadt]

I will back-up that recommendation although I am not totally unbiased as I
work at the airport. Tour the engine shop if you get a chance.

"O. Sami Saydjari" > wrote in message
...
> Yeah, that is where my A&P just recommended that I send it. Your
> endorsement makes me fee all the better! Thanks.
>
> PaulH wrote:
>
> > Had a prop interference overhaul done at Poplar Grove, IL a couple of
> > years ago. I visited the shop when the had the engine apart and was
> > really impressed.
>

[PaulaJay1]

In article >, Nathan Young
> writes:

>Many (OK, some) ignition switches have an AD with a recurring inspection
>>requirement that requires testing the OFF position every 100 hours. AD
>76-07-12
>
>Yep, and you can tell when the mechanic is testing the Bendix switch
>by the backfires outside his hangar.

Question. If you let the engine come to a stop and then restarted it, would
that be better? Would it possibly cause a manifold fire? It would prevent the
backfire.

Chuck

[ilana]

"O. Sami Saydjari" > wrote in message >...
> Yeah, that is where my A&P just recommended that I send it. Your
> endorsement makes me fee all the better! Thanks.



> I had to change a cranckshaft bolt by an AD on a AEIO 540 on an extra 300L.
'EXTRA' distributor and 'lycoming' estimated the labor time to be
somwhere in the 30 Hrs,While pulling the engine of the aircraft was
the only way to perform the job.
The guys in POPLAR GROVE did it in 12 hrs,whitout even removing the
engine,
they are experts,and $$$ savers compare to the others mentioned above,
I am back there again when engine work needed(hope never).
Good luck with the overhaul,and safe flying - soon.



> PaulH wrote:
>
> > Had a prop interference overhaul done at Poplar Grove, IL a couple of
> > years ago. I visited the shop when the had the engine apart and was
> > really impressed.

[McGregor]

For a rebuild on the TSIO360 I guess you can go to (in personal order of
preference):

*) Western Skyways
*) TCM
*) Victor Engines

If you didn't have the "FB" version before, you can get the upgrade
(pushrods I think) and have an 1800 TBO.

"O. Sami Saydjari" > wrote in message
...
> Well, it happended. I have owned the plane (Piper Turbo Arrow III) for
> 3 months and the engine failed during climb out on Tuesday. Altitude
> was 4400 feet. Luckily, the engine did not entirely quit and I made it
> to an airport within 10 miles. TBO was 1000 hours away. Dissapointing!
> When we cut the oil filter, it was full of fairly large aluminum and
> steel bits of metal. Arg!
>
> (1) Upon examination, the wire into the left magneto was found to be
> broken off, just at its connection to the magneto. A mechanic theorized
> that it could have grounded to the magento housing. He said that that
> could have actually caused a grounding of both magnetos and could have
> fouled up the engine firing, and could have contributed to the failure.
> Later, he said that he thought that it was just a coincidence that the
> left mag wire happened to have been broken when the engine failed due to
> some other reason. What do you folks think? Could the two have been
> tied togehter?
>
> (2) Now I am faced with having to have the engine overhauled. Growl!
> The engine has brand new cylinders on it (well, they have about 100
> hours on them) put on by the previous owner. So, I think we want to do
> a custom overall of this particular engine. Does that make sense? Are
> there different places who do this sort of thing with different
> reputations for quality of work? If so, I would like to hear about
> recommendations (the engine is a TCM TSIO-360-FB) or perhaps criteria to
> use in making a judgement. Also, are there different quality parts or
> methods in doing the overhaul that are options that I need to specify
> when I ask for the overhaul. In other words, if I can pay 10% more and
> get more reliability, then I might like to have the option to do
> that...but often, you have to be knowledgeable enough to ask for the
> right things.
>

[O. Sami Saydjari]

Update: The crank shaft broke! That means I was operating on just a
couple of cylinders. The overhaul folks said that have only seen this
happen one other time; apparently it is quite rare.

I am going to visit my engine tomorrow to see the damage for myself, see
if we can conclude what caused it, and learn as much as I can from
seeing my engine splayed out on a workbench.

Seems like a great learning opportunity. Any suggestions on good
questions to ask, or something special I should try to learn from seeing
my engine in this state?

-Sami
N2057M, Piper Turbo Arrow III (in surgery)

[kage]

Did this engine ever have a prop strike?

Karl


"O. Sami Saydjari" > wrote in message
...
> Update: The crank shaft broke! That means I was operating on just a
> couple of cylinders. The overhaul folks said that have only seen this
> happen one other time; apparently it is quite rare.
>
> I am going to visit my engine tomorrow to see the damage for myself, see
> if we can conclude what caused it, and learn as much as I can from
> seeing my engine splayed out on a workbench.
>
> Seems like a great learning opportunity. Any suggestions on good
> questions to ask, or something special I should try to learn from seeing
> my engine in this state?
>
> -Sami
> N2057M, Piper Turbo Arrow III (in surgery)
>

[Aaron Coolidge]

kage > wrote:
: Did this engine ever have a prop strike?

: Karl

That was going to be my question! Even a prop strike on something "soft"
such as snow can lead to a later crank failure. Did you see any mention of
a prop overhaul/replacement in the logs?
--
Aaron Coolidge

[O. Sami Saydjari]

I have only had the plane for 3 months. No strike while I have had it.
The logs, of course, do not say whether a prop strike happended, but
the last major overhaul was 12 years ago, which was only about 318 tach
hours ago.

-Sami

kage wrote:
> Did this engine ever have a prop strike?
>
> Karl
>
>
> "O. Sami Saydjari" > wrote in message
> ...
>
>>Update: The crank shaft broke! That means I was operating on just a
>>couple of cylinders. The overhaul folks said that have only seen this
>>happen one other time; apparently it is quite rare.
>>
>>I am going to visit my engine tomorrow to see the damage for myself, see
>>if we can conclude what caused it, and learn as much as I can from
>>seeing my engine splayed out on a workbench.
>>
>>Seems like a great learning opportunity. Any suggestions on good
>>questions to ask, or something special I should try to learn from seeing
>>my engine in this state?
>>
>>-Sami
>>N2057M, Piper Turbo Arrow III (in surgery)
>>
>
>
>

[O. Sami Saydjari]

I will double check the logs when I see them on Monday, but I do not
recall seeing such an entry when I read through it for the purchase.

My understanding is that any prop strike *requires* a major overhaul for
this very reason. Is that not the case?

-Sami

Aaron Coolidge wrote:
> kage > wrote:
> : Did this engine ever have a prop strike?
>
> : Karl
>
> That was going to be my question! Even a prop strike on something "soft"
> such as snow can lead to a later crank failure. Did you see any mention of
> a prop overhaul/replacement in the logs?

[G.R. Patterson III]

"O. Sami Saydjari" wrote:
>
> My understanding is that any prop strike *requires* a major overhaul for
> this very reason. Is that not the case?

Don't think so. It requires that the engine be disassembled and checked for damage
but not overhauled. Many owners would take the opportunity to major the engine,
though.

George Patterson
If you don't tell lies, you never have to remember what you said.

[Roy Smith]

In article >,
"G.R. Patterson III" > wrote:

> "O. Sami Saydjari" wrote:
> >
> > My understanding is that any prop strike *requires* a major overhaul for
> > this very reason. Is that not the case?
>
> Don't think so. It requires that the engine be disassembled and checked for
> damage
> but not overhauled. Many owners would take the opportunity to major the
> engine,
> though.

Once you've got the thing taken apart, why would you do anything else?

[G.R. Patterson III]

Roy Smith wrote:
>
> Once you've got the thing taken apart, why would you do anything else?

If I had it overhauled a few hundred hours ago, I would not do it again. Teardown,
damage check, and reassembly is much cheaper than an overhaul.

George Patterson
If you don't tell lies, you never have to remember what you said.

[O. Sami Saydjari]

Is there a way to test a crank after a prop strike to absolutely assure
that it has no micro-fractures or hidden fatigue points? That seems
like a pretty big gamble to me. -Sami

G.R. Patterson III wrote:
>
> Roy Smith wrote:
>
>>Once you've got the thing taken apart, why would you do anything else?
>
>
> If I had it overhauled a few hundred hours ago, I would not do it again. Teardown,
> damage check, and reassembly is much cheaper than an overhaul.
>
> George Patterson
> If you don't tell lies, you never have to remember what you said.

[John Theune]

"O. Sami Saydjari" > wrote in
:

> I have only had the plane for 3 months. No strike while I have had
> it.
> The logs, of course, do not say whether a prop strike happended, but
> the last major overhaul was 12 years ago, which was only about 318
> tach hours ago.
>
> -Sami
>
> kage wrote:
>> Did this engine ever have a prop strike?
>>
>> Karl
>>
>>
>> "O. Sami Saydjari" > wrote in message
>> ...
>>
>>>Update: The crank shaft broke! That means I was operating on just a
>>>couple of cylinders. The overhaul folks said that have only seen
>>>this happen one other time; apparently it is quite rare.
>>>
>>>I am going to visit my engine tomorrow to see the damage for myself,
>>>see if we can conclude what caused it, and learn as much as I can
>>>from seeing my engine splayed out on a workbench.
>>>
>>>Seems like a great learning opportunity. Any suggestions on good
>>>questions to ask, or something special I should try to learn from
>>>seeing my engine in this state?
>>>
>>>-Sami
>>>N2057M, Piper Turbo Arrow III (in surgery)
>>>
>>
>>
>>
>
>

I have not followed this entire thread, but from your comment above
about engine usage, I'm not suprised that you had a failure of one kind
or another. < 35 hours per year or run time is not very good for a
engine. I'm just glad your here to complain about it! Having the fan
stop turning is a bad thing.

[Dave Stadt]

"O. Sami Saydjari" > wrote in message
...
> I will double check the logs when I see them on Monday, but I do not
> recall seeing such an entry when I read through it for the purchase.
>
> My understanding is that any prop strike *requires* a major overhaul for
> this very reason. Is that not the case?
>
> -Sami

There is no such requirement. Even if there were such a requirement there
is no guarantee the engine teardown would be done. Just because there is no
prop strike in the log book does not mean it did not happen.

[John]

Both Contenal and Lycoming have had crank shaft breakage problems a
few years ago on some engines when they outsourced production.
You might want to look into the AD's and service letters on this. Some
engines were grounded for a long time since there was a shortage of
crankshafts.
John

On Tue, 27 Apr 2004 16:47:06 -0500, "O. Sami Saydjari"
> wrote:

>Update: The crank shaft broke! That means I was operating on just a
>couple of cylinders. The overhaul folks said that have only seen this
>happen one other time; apparently it is quite rare.
>
>I am going to visit my engine tomorrow to see the damage for myself, see
>if we can conclude what caused it, and learn as much as I can from
>seeing my engine splayed out on a workbench.
>
>Seems like a great learning opportunity. Any suggestions on good
>questions to ask, or something special I should try to learn from seeing
>my engine in this state?
>
>-Sami
>N2057M, Piper Turbo Arrow III (in surgery)

[G.R. Patterson III]

"O. Sami Saydjari" wrote:
>
> Is there a way to test a crank after a prop strike to absolutely assure
> that it has no micro-fractures or hidden fatigue points?

Yes. IIRC, it's called magnafluxing.

George Patterson
If you don't tell lies, you never have to remember what you said.

[Ron Natalie]

"Dave Stadt" > wrote in message m...

> There is no such requirement. Even if there were such a requirement there
> is no guarantee the engine teardown would be done. Just because there is no
> prop strike in the log book does not mean it did not happen.
>
There is no regulatory requirement, but both Lycoming and Continental "require"
a tear down inspection after any sort of prop strike. For us small operators, it's
just a very strong suggestion from the manufacturer. After my engine failure which
had a very small scuffing of the prop blades, the insurance company didn't even bat
an eye on paying for the teardown. Ran about $3K if I recall.

[Bill Hale]

"G.R. Patterson III" > wrote in message >...
> "O. Sami Saydjari" wrote:
> >
> > Is there a way to test a crank after a prop strike to absolutely assure
> > that it has no micro-fractures or hidden fatigue points?
>
> Yes. IIRC, it's called magnafluxing.
>
> George Patterson
> If you don't tell lies, you never have to remember what you said.

I've wondered about this. Mangnafluxing will detect cracks. Will it
positively detect damage from a prop strike that might cause a failure
much later?

I've always been nervous about this WRT factory re-man engines. How do
you know for sure that there was never a prop strike?

Incidentally, on the subject IO-360 engine, is there an improved crank
like there is for the IO520s that has the fillet at each cheek? On the
520s, those are the 520BBs; without the improved crank, they were -B or -BA.
I know there were failures with the older design.

In the Bonanza & Baron Proficiency courses, we've flown about 80,000 hours
and have had 7 engine failures AT THE CLINICS! These aren't doggy airplanes!
It's made me much more conservative. Fortunately, only one resulted in injury.

Bill Hale

[O. Sami Saydjari]

Updated update: I was just down at the overhaul shop today )Poplar
Grove). The crank broke just in front of the rear main bearing. So the
front 5 cyclinders were running the prop and the rear-most cylinder was
running the gearing to the rest of the engine. They said the whole shop
stopped to come take a look at the engine! They were astounded that it
ran 10 minutes after the crank broke (which is exactly the time I needed
to get to the nearest airport and land safely).

The collateral damage was minimal. Some gear teeth on the back of the
crank need replacing because they got worn from the crank wobling (so
they will just relace both gears). Similarly, the rear bearing is shot,
and the place where the bearing sits needs to be welded and resurfaced.
The cam shaft got a little bit of wear on it from a piece hitting it.
One cylinder is stuck as a result of some of the wear, but they think
they can get it out without problem.

Theories on cause? Well, so far, the shop thinks that maybe it was
overboosted before I got it. On the last one of these failures they
saw, he said the overboost relief valve was stuck and did not perform
its function. He said that these valves are rarely checked on annuals
(if ever). He has no alternative theory at the moment. We will have to
check the valve later because it is still with the plane out in
Gaithersburg, MD.

So, it looks I need to buy a new crank shaft and some other minor parts.

The shop visit was very interesting. I learned a lot and the folks at
Poplar Grove (Ill.) seem really on top of things. Their shop seems top
notch. I got a great tour.

I took pictures of the broken crank shaft. I will try to post them to a
web site in the next few days and post a pointer to them.

At the end, one of the shop workers suggested that I immediately go out
and buy a lottery ticket, because luck was definitely with me.

-Sami
N2057M, Piper Turbo Arrow III


O. Sami Saydjari wrote:
> Update: The crank shaft broke! That means I was operating on just a
> couple of cylinders. The overhaul folks said that have only seen this
> happen one other time; apparently it is quite rare.
>
> I am going to visit my engine tomorrow to see the damage for myself, see
> if we can conclude what caused it, and learn as much as I can from
> seeing my engine splayed out on a workbench.
>
> Seems like a great learning opportunity. Any suggestions on good
> questions to ask, or something special I should try to learn from seeing
> my engine in this state?
>
> -Sami
> N2057M, Piper Turbo Arrow III (in surgery)
>

[O. Sami Saydjari]

OK. Here are the pics for those interested. They are at:
www.swc-alps.org/DSCN3368.JPG
www.swc-alps.org/DSCN3370.JPG

-Sami
N2057M, Piper Turbo Arrow III

O. Sami Saydjari wrote:

> Updated update: I was just down at the overhaul shop today )Poplar
> Grove). The crank broke just in front of the rear main bearing. So the
> front 5 cyclinders were running the prop and the rear-most cylinder was
> running the gearing to the rest of the engine. They said the whole shop
> stopped to come take a look at the engine! They were astounded that it
> ran 10 minutes after the crank broke (which is exactly the time I needed
> to get to the nearest airport and land safely).
>
> The collateral damage was minimal. Some gear teeth on the back of the
> crank need replacing because they got worn from the crank wobling (so
> they will just relace both gears). Similarly, the rear bearing is shot,
> and the place where the bearing sits needs to be welded and resurfaced.
> The cam shaft got a little bit of wear on it from a piece hitting it.
> One cylinder is stuck as a result of some of the wear, but they think
> they can get it out without problem.
>
> Theories on cause? Well, so far, the shop thinks that maybe it was
> overboosted before I got it. On the last one of these failures they
> saw, he said the overboost relief valve was stuck and did not perform
> its function. He said that these valves are rarely checked on annuals
> (if ever). He has no alternative theory at the moment. We will have to
> check the valve later because it is still with the plane out in
> Gaithersburg, MD.
>
> So, it looks I need to buy a new crank shaft and some other minor parts.
>
> The shop visit was very interesting. I learned a lot and the folks at
> Poplar Grove (Ill.) seem really on top of things. Their shop seems top
> notch. I got a great tour.
>
> I took pictures of the broken crank shaft. I will try to post them to a
> web site in the next few days and post a pointer to them.
>
> At the end, one of the shop workers suggested that I immediately go out
> and buy a lottery ticket, because luck was definitely with me.
>
> -Sami
> N2057M, Piper Turbo Arrow III
>
>
> O. Sami Saydjari wrote:
>
>> Update: The crank shaft broke! That means I was operating on just a
>> couple of cylinders. The overhaul folks said that have only seen this
>> happen one other time; apparently it is quite rare.
>>
>> I am going to visit my engine tomorrow to see the damage for myself,
>> see if we can conclude what caused it, and learn as much as I can from
>> seeing my engine splayed out on a workbench.
>>
>> Seems like a great learning opportunity. Any suggestions on good
>> questions to ask, or something special I should try to learn from
>> seeing my engine in this state?
>>
>> -Sami
>> N2057M, Piper Turbo Arrow III (in surgery)
>>
>

[James M. Knox]

"O. Sami Saydjari" > wrote in
:

> So, it looks I need to buy a new crank shaft and some other minor
> parts.

Have you checked with your insurance agent on this? I'm wondering what
part of the total cost they will pay, if any. Basically they are on the
hook for any damage which is NOT the original problem. For example, prop
fall off and you make an emergency landing in a corn field, damaging some
aluminum. They won't pay for the prop, but will pay for all damage to the
airframe.

In this case the crankshaft is definitely YOURS... that's what broke. But
I wonder if they will pay for any "consequential" {remember that word}
damage to the rest of the engine?

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

[Aaron Coolidge]

O. Sami Saydjari > wrote:
: OK. Here are the pics for those interested. They are at:
: www.swc-alps.org/DSCN3368.JPG
: www.swc-alps.org/DSCN3370.JPG

In picture 3370, it looks like there are two distinct types of fractures.
The top of the fracture, through the vibration damper mounting holes, appears
to be dark and have a rough surface, which typically means a fatigue failure.
The remainder of the fracture has a shiny, smooth surface, which typically
means an instantaneous overload type of fracture.
Interesting.
--
Aaron Coolidge

[Bill Hale]

"O. Sami Saydjari" > wrote in message >...
> Updated update: I was just down at the overhaul shop today )Poplar
> Grove). The crank broke just in front of the rear main bearing. So the
> front 5 cyclinders were running the prop and the rear-most cylinder was
> running the gearing to the rest of the engine. They said the whole shop
> stopped to come take a look at the engine! They were astounded that it
> ran 10 minutes after the crank broke (which is exactly the time I needed
> to get to the nearest airport and land safely).

How can this be?? The crank drives the camshaft then the mags run from
gears that mesh with the cam gear... at least it's like that on every
other continental I've seen.

So the cam and maqs and oil pump quit working if the crank breaks.

It would windmill, however. Until it locks due to lack of oil.

What don't I understand? If there was metal in the oil filter, the
oil pump must have been running.

Bill Hale

[O. Sami Saydjari]

First, I must say that I am not a mechanic by any stretch. I am just
learning this stuff, so I might have misunderstood what the shop was
telling me. Hopefully, an expert will chime in here soon and explain
this a bit better.

That said, I am not sure I understand what is you did not understand.
It seems to me that if the crank shaft breaks, you end up with
essentially two engines: a set of cylinders running one side of the
shaft break and the rest running the other side of the shaft break. So,
it would seem that some cylinders are running the engine parts (oil
pump, magnetos, etc) and the others are running the prop. Of course, if
the break occurs right next to the prop, then the prop would stop. If
it breaks behind the main rear bearing, then all of the engine
accessories stop (and thus the engine stops soon after). Also, I should
point out that the shop speculated that even though the shaft broke,
that in might have been partially connected through friction (since the
break was not a 90 degree shear break).

Now, I will hasten to add that my understanding of crank shaft operation
may be overly simplistic, so again, I will defer to expert opinion as it
comes in. I am sharing all of this to get as much out of it as a
learning experience as I can.

-Sami
N2057M, Piper Turbo Arrow III

Bill Hale wrote:
> "O. Sami Saydjari" > wrote in message >...
>
>>Updated update: I was just down at the overhaul shop today )Poplar
>>Grove). The crank broke just in front of the rear main bearing. So the
>>front 5 cyclinders were running the prop and the rear-most cylinder was
>>running the gearing to the rest of the engine. They said the whole shop
>>stopped to come take a look at the engine! They were astounded that it
>>ran 10 minutes after the crank broke (which is exactly the time I needed
>>to get to the nearest airport and land safely).
>
>
> How can this be?? The crank drives the camshaft then the mags run from
> gears that mesh with the cam gear... at least it's like that on every
> other continental I've seen.
>
> So the cam and maqs and oil pump quit working if the crank breaks.
>
> It would windmill, however. Until it locks due to lack of oil.
>
> What don't I understand? If there was metal in the oil filter, the
> oil pump must have been running.
>
> Bill Hale

[Dave Butler]

O. Sami Saydjari wrote:
> First, I must say that I am not a mechanic by any stretch. I am just
> learning this stuff, so I might have misunderstood what the shop was
> telling me. Hopefully, an expert will chime in here soon and explain
> this a bit better.
>
> That said, I am not sure I understand what is you did not understand. It
> seems to me that if the crank shaft breaks, you end up with essentially
> two engines: a set of cylinders running one side of the shaft break and
> the rest running the other side of the shaft break. So, it would seem
> that some cylinders are running the engine parts (oil pump, magnetos,
> etc) and the others are running the prop. Of course, if the break
> occurs right next to the prop, then the prop would stop. If it breaks
> behind the main rear bearing, then all of the engine accessories stop
> (and thus the engine stops soon after). Also, I should point out that
> the shop speculated that even though the shaft broke, that in might have
> been partially connected through friction (since the break was not a 90
> degree shear break).

Seems likely to me that the front and rear parts were fairly strongly connected
if you were able to get enough power out of the engine to keep flying for a few
minutes, as I think you said you did. The rear part of the crank would have the
drive gear that turns the cam (and in turn, the magnetos) and the front part of
the engine is not going to make much power unless the cam and magnetos are
pretty well synchronized with it.

It doesn't bother me that part of the shear looks like fatigue cracking and the
rest looks like a catastrophic failure. The fatigue crack weakened the shaft to
the point where it could finally fail catastrophically, no?

>
> Now, I will hasten to add that my understanding of crank shaft operation
> may be overly simplistic, so again, I will defer to expert opinion as it
> comes in. I am sharing all of this to get as much out of it as a
> learning experience as I can.
>
> -Sami
> N2057M, Piper Turbo Arrow III
>
> Bill Hale wrote:
>
>> "O. Sami Saydjari" > wrote in message
>> >...
>>
>>> Updated update: I was just down at the overhaul shop today )Poplar
>>> Grove). The crank broke just in front of the rear main bearing. So
>>> the front 5 cyclinders were running the prop and the rear-most
>>> cylinder was running the gearing to the rest of the engine. They
>>> said the whole shop stopped to come take a look at the engine! They
>>> were astounded that it ran 10 minutes after the crank broke (which is
>>> exactly the time I needed to get to the nearest airport and land
>>> safely).
>>
>>
>>
>> How can this be?? The crank drives the camshaft then the mags run from
>> gears that mesh with the cam gear... at least it's like that on every
>> other continental I've seen.
>>
>> So the cam and maqs and oil pump quit working if the crank breaks.
>>
>> It would windmill, however. Until it locks due to lack of oil.
>>
>> What don't I understand? If there was metal in the oil filter, the
>> oil pump must have been running.
>>
>> Bill Hale
>
>


--
Dave Butler, software engineer 919-392-4367

[Kai Glaesner]

Aaaron,
> The top of the fracture, through the vibration damper mounting holes,
appears
> to be dark and have a rough surface, which typically means a fatigue
failure.
> The remainder of the fracture has a shiny, smooth surface, which typically
> means an instantaneous overload type of fracture.
> Interesting.

Not so much, the fatigue (dark part) may start small and grow until the
"good" material left can no longer bear the load and breaks suddenly (shiny
smooth part)

Regards,

Kai