Lycoming crankshafts

Ya got to be kidding me... There are a couple of dozen flyers dead
already resulting from their " CERTIFIED", overpriced, traceable, FAA
approved cranks.
************************************************** *****************************

Do you have AD's for this statement? URL's? NTSB findings?

I see no crank AD's on Lycomings for the past 30 years...

denny - willing to learn

Ya got to be kidding me... There are a couple of dozen flyers dead
already resulting from their " CERTIFIED", overpriced, traceable, FAA
approved cranks.

************************************************** **************************
***

Do you have AD's for this statement? URL's? NTSB findings?

This took all of 3 seconds to find. Don't you people know how to use the
internet ?

http://www.ntsb.gov/ntsb/brief.asp?e...08X01353&key=1

I made a factually correct statement about Lycoming crankshafts...
I suggest that you look up the engine make in a Malibu...


denny

Reference:
http://www.airweb.faa.gov/Regulatory...light=98-02-08

From the Preamble to AD 98-02-08:

SUPPLEMENTARY INFORMATION: On October 18, 1993, the Civil Aviation
Authority (CAA), which is the airworthiness authority of the United
Kingdom (UK), received a report that a Piper PA-28-161 aircraft, with a
Textron Lycoming O-320-D3G reciprocating engine installed, executed a
forced landing due to an engine crankshaft failure which caused the
propeller to separate from the aircraft. The cause of the crankshaft
failure was determined to be due to a high cycle fatigue mechanism that
had initiated from a number of corrosion pits in the crankshaft bore.
After the cracks had progressed through a substantial proportion of the
crankshaft section, the rate of advance had increased until the
remaining unseparated portion had failed as a result of overload. The
cracking occurred in high cycle fatigue and it had progressed over an
extended period of service. At the time of the accident the engine had
operated for 1,950 hours time in service (TIS) since overhaul and had
accumulated 4,429 hours total time since new over a period of 16 years.
In addition, the Federal Aviation Administration (FAA) has confirmed
that four other failures in the United States and 10 in foreign
countries were due to cracks initiating from corrosion pits in the
crankshaft bore on certain Textron Lycoming 320 and 360 reciprocating
engines with ratings of 160 horsepower or greater. Of the 10 failures
in foreign countries, four resulted in the propeller separating from
the aircraft inflight. Three of these four were from 1993 to 1996. The
FAA utilized metallurgical failure analysis reports and other
information to conclude that these failures were due to cracks
originating from corrosion pits. This condition, if not corrected,
could result in crankshaft failure, which can result in engine failure,
propeller separation, forced landing, and possible damage to the
aircraft.

Ref:
http://www.airweb.faa.gov/Regulatory...ght=2005-19-11

From the Preamble to AD 2005-19-11:
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Lycoming Engines (formerly Textron Lycoming) AEIO-360, IO-360,
O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 series
reciprocating engines rated at 300 horsepower (HP) or lower. This AD
requires replacing certain crankshafts. This AD results from reports of
12 crankshaft failures in Lycoming 360 and 540 series engines rated at
300 HP or lower. We are issuing this AD to prevent failure of the
crankshaft, which could result in total engine power loss, in-flight
engine failure, and possible loss of the aircraft.

Dan

I stand corrected, I should have done the search before replying... A
couple-three years back when the Continental crankshaft failures were
the topic of discussion I had done an AD search on Lycoming crankshafts
(since a have a pair of them) and the FAA web site did not show any for
Lycoming since the early 70's... I hadn't repeated the search
recently... My bad...

But, the topic of metallurgy failures is not limited to Lycoming and
Continental... Both Superior and ECI has massive recalls on cylinders
for early wear and cracking, including failures in flight...
Continental big bores are famous for the rocker arm bushings wearing
out every 900 hours (I've been through a couple of early top overhauls
over this)...
Lycoming parallel valve cylinders are famous for lack of cooling oil to
the valve stems leading to morning sickness (been there, done that,
got the tee shirt, now I use AVBLEND)...

The problem is more than just Lyconsaurus being dinosauers... Airplane
engines are highly stressed machinery... If they were engines pumping
water from the mines, or turning dynomotors for municipal electric
plants, or pushing 900 foot container ships, we would just make the
parts so heavy and thick they could never fail, but that is not an
option with airplanes.. It seems that every major player in the
aircraft engine market has been bitten by the metallurgy bug... Is it
the stress on the engine parts, or the FAA regs, or bad metallurgy? I
don't know the answers but there do not appear to be simple
solutions... Every company producing engines/parts has bright people
working for them, so if there were solutions they would have been
implemented and we would not be having this discussion...

denny

I remember reading about this some years ago. There was a picture of
the failed UK crank front journal bearing ID taken thru the front plug
hole. It was solid crud where the crud ID appeared to be about 1/4
inch diameter. That engine must have been filthy inside & operated in
some very abusive and corrosive conditions. It is interesting that it
had been overhauled once & was near TBO again. Who did the magnaflux
at the first overhaul?

I remember reading about this some years ago. There was a picture of
the failed UK crank front journal bearing ID taken thru the front plug
hole. It was solid crud where the crud ID appeared to be about 1/4
inch diameter. That engine must have been filthy inside & operated in
some very abusive and corrosive conditions. It is interesting that it
had been overhauled once & was near TBO again. Who did the magnaflux
at the first overhaul?

That crud is usually a product of condensation mixing with
the oil. The condensation comes from blowby gases, water being one of
combustion's byproducts. Sludge results from the mixing, along with
acidic compounds formed from hydrogen present in both water and oil,
and sulfur, chlorine and nitrogen from the oil. The presence of
aluminum doesn't help any, either.
Since the front of the crank runs fairly cold due to the cooling effect
of the prop, condensation is a bigger problem inside the crank nose.
The acids pit the inside of the crank, creating stress risers, and it
eventually fails. Magnafluxing at the previous overhaul doesn't prevent
it.
Short flights don't let the oil get hot enough to boil off
the condensates formed when the engine is cold. Running up the engine
without flying it does more damage than leaving it alone.

Dan

Note that there is no discrimination between crank failures used for
aerobatic and nonaerobatic flight/aircraft.

From the Preamble to AD 2005-19-11:
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Lycoming Engines (formerly Textron Lycoming) AEIO-360, IO-360,
O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 series
reciprocating engines rated at 300 horsepower (HP) or lower. This AD
requires replacing certain crankshafts. This AD results from reports of
12 crankshaft failures in Lycoming 360 and 540 series engines rated at
300 HP or lower. We are issuing this AD to prevent failure of the
crankshaft, which could result in total engine power loss, in-flight
engine failure, and possible loss of the aircraft.

"George" wrote in message news:UJbWf.17503

This took all of 3 seconds to find. Don't you people know how to use the
internet ?

http://www.ntsb.gov/ntsb/brief.asp?e...08X01353&key=1


These three people died because the pilot failed to follow procedures and
[apparently] stalled the airplane. The crankshaft was a factor, but an
eminently survivable one.


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

The pilot's failure to maintain airspeed above stall speed...... A factor to
the accident was ......the fatigue failure of the crankshaft.'

("George" wrote)
Do you have AD's for this statement? URL's? NTSB findings?

This took all of 3 seconds to find. Don't you people know how to use the
internet ?

http://www.ntsb.gov/ntsb/brief.asp?e...08X01353&key=1


Yes, wait for someone to provide a link, them click on it. g


Montblack
'The Internet is the greatest library the world has ever known .
Unfortunately, all of the books are in a pile in the middle of the floor.'
:-)