Lycoming Loses Big Lawsuit / Indemnity Claim Squashed

("Gene Kearns" wrote)
the TIO-540 and LTIO-540 engines...


http://tinyurl.com/65b9u


(From the story)
The case revolves around a number of small airplane engine failures that
occurred when the airplanes' crankshafts broke in flight. Between 2000 and
2002, there were 24 failures and 12 deaths in Cessnas, Pipers and other
airplanes with Lycoming aircraft engines. Interstate Southwest supplied
Lycoming with the crankshaft forgings for those engines.

Following the failures, Lycoming launched an investigation aimed at
determining the cause. Its conclusion was that Interstate Southwest had
overheated the forgings, weakening the steel.

But attorneys for Interstate, Mr. Rose and Hal Walker of Rose Walker in
Dallas, found a different cause. Their experts were able to determine that
Lycoming's design for the crankshafts, which dates back to smaller, lower
horsepower engines from 40 years ago, was inadequate for the larger, higher
horsepower engines that failed.

They also found that by adding Vanadium to the steel -- something Lycoming
decided to do just before the failures began -- the company further limited
the amount of stress the crankshafts could withstand. Lycoming had added
Vanadium to make the steel harder and reduce the number of machining
operations, ultimately saving the company money.

Ultimately, jurors agreed with lawyers for Interstate, and found that even
Lycoming's investigation of the crankshaft failures was fraudulent.

"The jurors found the combination of poor design and Vanadium pushed these
crankshafts beyond their limits," says Hal Walker. "That's why these planes
crashed, and not, as Lycoming claimed, because Interstate overheated the
forgings."

Montblack

A lot of highly stressed shafts etc (like in a transmission) are made
of AISI 6150 steel which is probably similar to what Lycoming
specified. I understood that Lycoming also nitrided their finished
shafts, which should further increase the fatigue strength as well as
provide an excellent wear surface on the journals. (The hinges of hell
are nitrided.)

As a Mech Engr I thought adding Vanadium did only good things to steel.
I don't see how they could save any machining costs by adding
vanadium. Surely they didn't add vanadium just so they could skip
nitriding?

It is interesting that it appears to be only the turbo models that are
involved. I wonder what the condition of the harmonic damper
assemblies and their associated pins and bushings etc was for each
failure.

I'll bet it is appealed..... I sure hope so at least.

As a Mech Engr I thought adding Vanadium did only good things to
steel.
I don't see how they could save any machining costs by adding
vanadium. Surely they didn't add vanadium just so they could skip
nitriding?

As a mechanical engineer, what the hell do you know? I f you want to
know
how much Vanadium to add, ask a jury.

Bill Hale

"nrp" wrote in message
oups.com...
[...]
It is interesting that it appears to be only the turbo models that are
involved. I wonder what the condition of the harmonic damper
assemblies and their associated pins and bushings etc was for each
failure.

I'll bet it is appealed..... I sure hope so at least.


Betcha $100 to a nickel that the verdict will be appealed, and that the
punitive damages part of the judgment is drastically reduced. The
appellate courts of Texas are not plaintiff-friendly unless Texas is the
plaintiff pushing to hurry death by lethal injection.

On the issues of the crank failures this litigation is not over. Biggest
damages will go to the estates of people killed, that is, if juries find
that Lycoming and/or other parties are at fault.

I make no judgments here, don't know the details, and take no sides; but the
Founders argued that in a true democratic republic the petit jury is the
Palladium of Liberty. See the _Federalist Papers_ for details. If you
don't like jury decisions see your representative about a constitutional
amendment.

Gene Kearns -

A designer really has his back to the stress wall if he has to use
4340/4350 steels. It doesn't make sense to compromise the fatigue
capability for machinability in a part like this.

Don't all the Lycomings from 100 hp thru the big 540s (or even 720s?)
have the same OD on their crank and rod journals?

I still wonder about the condition of the damper system(s). I'm sure
Lycoming would have checked that out, but maybe a nasty service
bulletin or AD will be coming?

NRP

What is interesting about this suit is it's not the estates suing. This is
case of corporate defamation.

Textron Cessna Lycoming passed blame on to these guys for what is really
their responsibility. I don't know how covering their collective arses
affected the suits Lycoming by the estates, but I bet it pretty much closed
down Interstate. Perhaps interstate screwed up, or maybe they did not.
What's for sure as that Lycoming didn't test and inspect.

There are almost always reduction settlements from what I hear, so either it
will get appealed or settled. The insurance companies are big on settling
anyway, and the interstate guys likely just want enough money to start over.




"Gene Kearns" wrote in message
...


the TIO-540 and LTIO-540 engines...


http://tinyurl.com/65b9u
--

Homepage
http://myworkshop.idleplay.net/

Betcha $100 to a nickel that the verdict will be appealed, and that the
punitive damages part of the judgment is drastically reduced. The
appellate courts of Texas are not plaintiff-friendly unless Texas is the
plaintiff pushing to hurry death by lethal injection.

The Appellate structure in Texas is two tiered: Criminal (such as your
death penalty appeals) takes one route and Civil (such as this case)
takes a separate but parallel route.

Something to keep in mind, is that the venue was in Anderson, Texas, the
county seat of Grimes County, Texas and Interstate Forging's home
county. Never heard of it? Most havent. Its small. The whole county was
loosely populated enough to be covered by 3 ambulances (thats where my
knowledge of their territory comes in). I've walked in the 100 year old
courthouse in the past, where this trial was held.

What I am getting at is, hometown company in a small county where
everyone knows everyone else (literally) is likely to get a favorable
jury when in a civil matter against the behemoth from out of town. So,
yea, the punitive damages may get overturned but here's the nice thing.
The trial, all of the metallurgy data, etc.. is now public record. Other
experts can go over it. It may be introduced in other trials. If the
engineering WAS (and probably IS) faulty, then its clear that one of
several things will happen, the most favorable being the redesign of the
cranks. In any event, the rotary auto engine I'm fitting right now just
took a big increase in value in my eyes.

(on a side note I dont intend to debate further, how is a 10+ year
appeal process "hurrying to death" with lethal injection" The latest
appeals have said the long wait amounted to cruel and unusual
punishment.. isn't that a hoot)

I don't think it would be the static HP that would be the problem. I
get less than 5 KSI shear stress for a solid or near solid shaft
transmitting 400 HP at 2700 RPM. A complex section like a crankshaft
of 4340 heat treated, blessed by the Pope etc, and nitrided should be
good for maybe +/- 40 to 50 KSI.

Obviously the fatigue problem is completely dominated by the dynamics,
which in turn are dominated by the damper integrity(s). Mechanics have
to realize how important these gadgets are. I'd hate to have to
explain to a jury how they work though.

Another minor stress factor could be gyroscopic loads in an aerobatic
A/C.


Dunno.... guess we'll wait and see...

Yep!

NRP

Sad thing is tht there was probably an engineer that said to his boss
"Sir, the crank is undersize for this increase in horsepower. We
should up the diameter and change the crankcase accordingly".
Management reply: "That would cost too much and marketing says we need
this engine ready next month. No time or money for re-tooling or a new
casting. Make it work"

I hear this kind of warped logic all the time where I am now.....

Bob

wrote in message
ups.com...
Sad thing is tht there was probably an engineer that said to his boss
"Sir, the crank is undersize for this increase in horsepower. We
should up the diameter and change the crankcase accordingly".
Management reply: "That would cost too much and marketing says we need
this engine ready next month. No time or money for re-tooling or a new
casting. Make it work"

I hear this kind of warped logic all the time where I am now.....


Hmmm...Colin Kingsbury (in this group) says that sort of thing is common in
software development and infers that it's a _good thing_.