MD-80
Roger Duncan
under a Chinees Contract. They are checking to see if any couldbe
involved.
You to could be flying in a kit under construction.
Spehro Pefhany
> I just heard on TV that some parts for Douglas Aircraft were made
> under a Chinees Contract. They are checking to see if any couldbe
> involved.
Parts of 747's too, IIRC. This is an election year, isn't it? Why does
this sound like the first chapter of Tom Clancy novel?
--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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sp...@interlog.com
Fax:(905) 271-9838 (small micro system devt hw/sw + mfg)
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PLAlbrecht
under a Chinees Contract.
But they have ISO 9001 certification! <g>
Pete
foxeye
your replacement parts for front line fighters and other U.S.A.F.
aircraft.........hell, even the shit made in the USA don't work half
the time, so I guess third world is no worse. Example..Relay for the
fire control radar on F16 acft. costs over $125.00 each (about 1/2" x
1" x 1" size 24 volt) and 9 out of 10 fail in minutes after
energizing it. We routinely use 6 or 7 just to get one to work.....and
the engineers say they are working on it..yea, right........
PLAlbrecht
>under a Chinees Contract.
Here we go.
>>FAA administrator Jane Garvey on Sunday responded to a U.S. News and World
Report article that said Flight 261's horizontal stabilizer was made in China,
and that quoted a spokesman for the International Association of Machinists and
Aerospace Workers as saying FAA oversight of foreign parts manufacturers is
inadequate.
>>Garvey said on CNN that the international organization that oversees aviation
manufacturing ``has some very high standards.'' But she added, ``I think that's
going to be an issue that the NTSB will look at and we may make some changes.''
>>Boeing spokesman John Thom said Sunday that the manufacturer of the part used
on Flight 261 had not yet been determined.
No matter where the parts are built, they meet the same stringent
specifications, Thom said. ``We insist on that. We'd be stupid if we didn't.''
================
Question: can a crappy Chinese 3-in-1s make jackscrews?
Pete
mull...@advinc.com
> > involved.
>
> Parts of 747's too, IIRC. This is an election year, isn't it? Why
does
> this sound like the first chapter of Tom Clancy novel?
Nah, this is Nevil Shute. He's already been there and got the
T-shirt!
Jim
Sent via Deja.com http://www.deja.com/
Before you buy.
Bruce Simpson
>>>I just heard on TV that some parts for Douglas Aircraft were made
>under a Chinees Contract.
>
>But they have ISO 9001 certification! <g>
Meaning that regardless of the quality of the finished product -- the
paperwork is *perfect* :-)
---------------------------------
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boris beizer
news:B4A9DC798178F629.DA9F9AD6...@lp.airnews.net...
> On 14 Feb 2000 03:57:19 GMT, plalb...@aol.com (PLAlbrecht) wrote:
>
> >>>I just heard on TV that some parts for Douglas Aircraft were made
> >under a Chinees Contract.
> >
> >But they have ISO 9001 certification! <g>
>
> Meaning that regardless of the quality of the finished product -- the
> paperwork is *perfect*
Not quite correct. It means that the paperwork that describes their process
is perfect. Whether that process works or not is immaterial, as long as it
is properly documented.
I know that it is way off topic, but I highly recommend the book by
John Seddon "In Pursuit of Quality -- the Case Against ISO 9000" Oak Tree
Press, London, ISBN 1-86076-042-2.
Now the real question, to get back to the ng topic is: are the
rejected jackscrews being used as lead screws on their machine tools, or is
that the rejected lead screws are being used for the MD-80 jackscrews?
Boris
--
-------------------------------------
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TEL: 215-572-5580
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Email direct: bbe...@sprintmail.com
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dave_fr...@myremarq.com.invalid
to McDonnel Douglas by Harbor Freight!!
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Gary Coffman
> Now the real question, to get back to the ng topic is: are the
>rejected jackscrews being used as lead screws on their machine tools, or is
>that the rejected lead screws are being used for the MD-80 jackscrews?
That doesn't seem to be the relevant question. The exact TPI and uniformity
of a jackscrew is relatively unimportant. What matters is the metallurgy of
the screw, which determines if it will fail under design loading or not. That's
the essence of the matter. It is also why there are such great concerns about
counterfeit parts. To first order, the quality of the machining is irrelevant. As
long as the screw conforms roughly to the print, and fits its mating nut, the
machining is satisfactory. It is the quality of the materials, and their heat
treatment if any, that matters. That's usually where corners are cut to save
cost.
Gary
Gary Coffman KE4ZV | You make it |mail to ke...@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |
boris beizer
news:3j+oOBhm6N+JAf...@4ax.com...
> On Mon, 14 Feb 2000 15:43:06 GMT, "boris beizer" <bbe...@sprintmail.com>
wrote:
> > Now the real question, to get back to the ng topic is: are the
> >rejected jackscrews being used as lead screws on their machine tools, or
is
> >that the rejected lead screws are being used for the MD-80 jackscrews?
>
> That doesn't seem to be the relevant question. The exact TPI and
uniformity
> of a jackscrew is relatively unimportant. What matters is the metallurgy
of
> the screw, which determines if it will fail under design loading or not.
That's
> the essence of the matter. It is also why there are such great concerns
about
> counterfeit parts. To first order, the quality of the machining is
irrelevant. As
> long as the screw conforms roughly to the print, and fits its mating nut,
the
> machining is satisfactory. It is the quality of the materials, and their
heat
> treatment if any, that matters. That's usually where corners are cut to
save cost.
Okay. A serious answer to my fascecious question. The metalurgy point is
pertinent. I bought the Phase II toolpost from Dave Ficken at Cabin Fever.
I asked him what does the Aloris, say, toolpost do or offer that the Phase
II doesn't. His response paraphrased was (If I've misquoted you Dave, or
misattributed this, apologies all around: " Metallurgy. The import
(Chinese, Indian, etc.) may start out as accurate, but it won't stand up to
the wear. For typical hobbyist use, it will probably last a lifetime,
though."
tonyp
PLAlbrecht <plalb...@aol.com> wrote in part:
> Question: can a crappy Chinese 3-in-1s make jackscrews?
Other question: did good old Americans using good old Bridgeports and
Monarchs ever produce parts that failed in airplanes? I seem to recall
planes crashing before Alaska Air but I can't site a source on the web for
that.
--
Tony Prentakis
Consumer of time, occupier of space, producer of Z-stages
"How can I know what I think until I hear what I have to say?"
PLAlbrecht
>Monarchs ever produce parts that failed in airplanes? I seem to recall
>planes crashing before Alaska Air but I can't site a source on the web for
that.
I'm sure they did. And will continue to do so. But the question remains, why
did the Alaska jet crash? Was it the jackscrew, or some other part of the
Chinese-made assembly? What was wrong with it? And would a domestically made
part have been subjected to better manufacturing or quality control methods?
What entered into the decision to use a Chinese-made part?
Pete
Sonny B. Pickles
>
> I wonder if the Jackscrews were made by Pittsburg Forge and sold
> to McDonnel Douglas by Harbor Freight!!
>
>
You're some kind of sicko fuck head!
Gerald Miller
--
Gerry
London, Canada
Sonny B. Pickles <sbpic...@sciti.com> wrote in message
news:38A8543B...@sciti.com...
Fitch R. Williams
>You're some kind of sicko f***k head!
"plonk"
Fitch
In So. Cal.
The FAQ for RCM is: http://w3.uwyo.edu/~metal
Metal Web News at http://www.mindspring.com/~wgray1/
The "Drop Box" is at http://www.metalworking.com/
SteveK
flight surface, that has a single point failure". It's one thing to trust
the wings not to break, but it's a whole different problem when your talking
about a control actuator. Things that move can fail. The jack screw and nut
have two motors that drive either end, even this is bothersome, it is not
tri-plex, just dual. The jamming of the nut or what I hypothesize happened,
was the nut-screw failure acted like a sprag mechanism. The pilot "fuddled"
with the trim, and could only run the shaft in one direction. The drive
motors did not have enough torque to rotate against the frictional forces.
And they ran it to the end limit. Unfortunately this was an "unflyable" trim
condition. Macdonald Douglas has similar problems with single point failures
in other air frames like the DC11 tail rotor burst that took out all 3
hydraulic elevator actuators. The only thing that allowed the pilot to fly
the airplane, was there still was cables that ran direct from his control
wheel, he lost the "power steering" (the crew had to apply 200-300 lbs. of
force to the control wheel to fly the airplane). This design error should
have been seen, and it is a design error. These are "flight critical
systems" i.e. their failure results in the inability to maintain safe flight
and landing of the airframe. The regulatory agency (FAA and JAA) require a
safety analysis to show that the probability of failure that could result in
a "loss of life" must be greater then 1 per billion hours. Generally a
single channel (electronic) system can only get you 4000 hours (I don't know
what the number is for a "properly" designed mechanical component, but it's
a similar number). So a dual system can get you 16000000 hours. So for
critical systems, you need at least three redundant paths to get you past a
billion hours. This all assumes that they are independent of one another.
They don't fail at the same time, and a failure of one doesn't inhibit the
other paths of control.
It's interesting that military airplanes are only concerned with completing
the mission, and safe flight and landing are not required, i.e. the crew and
airframe are expendable.
Just recently the Boeing 737 airplane exceed 100 million hours total fleet
flight hours. So getting to a billion hours of experience it tough. And this
airframe has had accidents via the rudder actuator (possibly) going hard
over.
I think the story on the billion hour requirement, is that if you plot
probability of death versus age, you get a minimum at age ten of one per
million hours. They wanted the probability to be 1000 times better then
this, and numerically achievable.
SteveK
"Mark Kinsler" <kin...@frognet.net> wrote in message
news:W%3q4.45112$ox5.11...@tw11.nn.bcandid.com...
> A couple of thoughts on the MD-80 and its stabilizer:
>
> The jackscrew I saw on the evening news used a ballscrew. The covered
> channels through which the balls recirculate were clearly visible on the
> outside of the assembly.
>
> Counterfeit parts are a big problem. A Chinese part isn't necessarily a
> counterfeit part: Chinese factories are perfectly capable of making
> high-quality and very expensive parts. A counterfeit part could have been
> made in a shop staffed by a bunch of goons in the USA, or anywhere else.
>
> One of the more comprehensive books on the subject of where airplanes are
> made and which parts are made where is a novel called _Airframe_ by
> Michael Crichton. It's a book that's more in the tradition of Arthur
> Hailey or the aforementioned Nevil Shute than Tom Clancy's more popular
> military/conspiracy stuff.
>
> M Kinsler
> --
>
............................................................................
> 114 Columbia Ave. Athens, Ohio USA 45701 voice740.594.3737 fax740.592.3059
> Home of the "How Things Work" engineering program for adults and kids.
> See http://www.frognet.net/~kinsler
Eastburn
Jack screw with bronze strings wrapped around it...
Nut - maybe 12" long - two piece double flange type - almost a clean hole
were threads should be.
Sounds to me that the tail is being over torque and the pressure is
being plied on the threads.
Are they overloaded jets and since they have powerful jets - put the
jet on its tail ? and crank on the power ?
Whatever - it looks like nut failure to me - not jackscrew.
Nut likely make you know where - out of odd alloy. That might be it.
Martin
--
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
Martin Eastburn, Barbara Eastburn
@ home on our computer old...@pacbell.net
tto...@ix.netcom.com
as the MD-80 and have been in use since the first Jet airliners and probably
long before that but my experience only goes back to the first 707 Boeing -80 .
If you seen what is in a Cessna you would never get in one.
Tom
Licensed A&P
eberlein
house, killing sleezo lame duck president and sleezo advisors. First Lady
escapes (on a political trip to York, England) and asks Jack Ryan (now retired)
to investigate the cause of the fatal crash. 600 pages later we learn that alien
invaders landing in Roswell, NM , 1947 have spent the last 50+ years deliberately
subverting the metal fabricating and aerospace industries of the world to prevent
construction of a true interplanetary drive system that needs a special "T-nut"
for successful operation. Seems as if the "T-nut" can only be fabricated by one
with a combination of mechanical appitude with machine tools and and well
developed mental telepathy abilities....I'd tell the rest, but why ruin a good
book.
Mike Eberlein 2/14/99
Mark Kinsler
Larry Phillips
>
> What you should know is that all the big planes have basically the same system
> as the MD-80 and have been in use since the first Jet airliners and probably
> long before that but my experience only goes back to the first 707 Boeing -80 .
> If you seen what is in a Cessna you would never get in one.
> Tom
> Licensed A&P
I've seen what's in a Cessna, and I'd rather fly in a Cessna than any MD
aircraft of more recent vintage than the DC-9.
--
Hukt on fonix werkt fer me!
Steve Rayner
I have to disagree with your last statement! I have seen what is in a
Cessna! And I flew it! I agree that the control rigging is not very
impressive to look at though.
tto...@ix.netcom.com wrote:
: What you should know is that all the big planes have basically the same system
: as the MD-80 and have been in use since the first Jet airliners and probably
: long before that but my experience only goes back to the first 707 Boeing -80 .
: If you seen what is in a Cessna you would never get in one.
: Tom
: Licensed A&P
: SteveK wrote:
: > > A couple of thoughts on the MD-80 and its stabilizer:
--
I'm a Canadian eh! Steve.
**************************************************************************
The FAQ for rec.crafts.metalworking is at: http://w3.uwyo.edu/~metal
The metalworking drop box is at http://www.metalworking.com
or http://208.213.200.132
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************* Tu ne cede malis, sed contra audentior ito. ****************
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Rich Osman
have an impressive appearance. That control system does have an impressive
reliability record, though.
Steve Rayner wrote:
--
mailto:Ri...@Osman.com http://www.rich.osman.com
Rich Osman; POB 93167;
Southlake, TX 76092 (Near DFW Airport) ARS: WB0HUQ
Ken & Teresa Lilja
Rich Osman wrote:
> Steve, I agree with you. The Cessna's virtue is simplicity, and simple things rarely
> have an impressive appearance. That control system does have an impressive
> reliability record, though.
>
On the Cessna 210 the aileron cables hold the wings on. Sorta. If the cable tension is
too low the ailerons can flutter and cause a wing to fail outboard of the flaps.
I once repaired a Cessna 150 that had landed with it's rudder laying over at a 45 degree
angle to the fin - the top hinge bolt had worked it's way out. Three hinges would have
prevented this.
Ken
Gary Coffman
>Lets look at the facts we have.
>
>Jack screw with bronze strings wrapped around it...
>
>Nut - maybe 12" long - two piece double flange type - almost a clean hole
>were threads should be.
>
>Sounds to me that the tail is being over torque and the pressure is
>being plied on the threads.
So, it might be a design error, it might be inferior metallurgy, or it might
be pilot error, ie flying the aircraft outside its design envelope.
>Are they overloaded jets and since they have powerful jets - put the
>jet on its tail ? and crank on the power ?
They have to fly noise abatement profiles on take off and landing. That
may not have been contemplated when the aircraft was designed. So
it might be design error. OTOH, those profiles should be inside the
design envelope of the aircraft, or the FAA is culpable for setting
profiles not safely achievable by the commercial fleet. I don't think
that likely, however.
I'm still of the opinion that it will turn out to be inferior metallurgy.
It is possible, however, that the problem is improper maintenance.
That was the case with the DC-10 engine pylons. It could be the
case here too.
Esther Heller
eberlein wrote in message <38A8B0DA...@usit.net>...
>It is! Flying rent-a wreck 747 loses control over DC and plummets into
White
>house, killing sleezo lame duck president and sleezo advisors. First Lady
>escapes (on a political trip to York, England) and asks Jack Ryan (now
retired)
>to investigate the cause of the fatal crash. 600 pages later we learn that
alien
>invaders landing in Roswell, NM , 1947 have spent the last 50+ years
deliberately
>subverting the metal fabricating and aerospace industries of the world to
prevent
>construction of a true interplanetary drive system that needs a special
"T-nut"
>for successful operation. Seems as if the "T-nut" can only be fabricated
by one
>with a combination of mechanical appitude with machine tools and and well
>developed mental telepathy abilities....I'd tell the rest, but why ruin a
good
>book.
>
>Mike Eberlein 2/14/99
>
One minor correction, the first lady was on a political trip to upstate
New York, not York England. (I am from upstate NY, ask me how I know?)
Esther
eoh at kodak...
Orrin B. Iseminger
such a profound post. Einstein, move over. We have found someone to share
your throne.
Orrin
In article <38A8543B...@sciti.com>, sbpic...@sciti.com says...
>
>dav...@myremarq.com wrote:
>>
>> I wonder if the Jackscrews were made by Pittsburg Forge and sold
>> to McDonnel Douglas by Harbor Freight!!
>>
>>
>
>You're some kind of sicko fuck head!
Edward Haas
experienced by this aircraft. Shuttling from Alaska in winter to Acapulco
must have some effect long-term. One wonders how much thermal cycling of
this nature had occurred B4 the accident occurred and whether or not these
conditions were anticipated by those responsible for the original design.
--
"Steamboat Ed" Haas : Just another fart in
Watch link rot in action! : the Elevator of Life...
http://www.nmpproducts.com
---Decks a-wash in a sea of words---
Howard R. Garner
Every flight up to the 20-30 thousand foot altitude
undergoes more of a thermal change then just driving on the
surface from Alaska to Mexico.
Now back to lurk mode.
Paul Koning
>
>
>
> I have to disagree with your last statement! I have seen what is in a
> Cessna! And I flew it! I agree that the control rigging is not very
> impressive to look at though.
The term that comes to mind is "elegant". Wire cable is also
nice in that it has lots of redundancy... If it starts to fail
that's rather obvious (fraying).
Then again, usually when I'm in a Cessna I have a parachute on... :-)
So I only worry during the take-off.
paul
Chuck Sherwood
> at a 45 degree angle to the fin - the top hinge bolt had worked it's way
> out. Three hinges would have prevented this.
A GOOD preflight inspection might have caught it too.
Good maintenace helps too.
chuck who use to own a 150
Ron Bean
"CLatham" <chris....@neinsppammomajiq.com> writes:
>I really wonder if it's possible to have zero crashes. Mother Nature's a
>bitch, Murphy was an optimist, and Shit Happens! Planes crash, buildings
>fall down, bridges twist off, Space Shuttles blow up! Put enough parts in
>something and every once in awhile a critical one will break and all the
>hindsight in the world won't keep the next critical part from
>self-destructing underwater, on the ground or in the air! Life causes
>death! We all just keep trying to avoid this inescapable fact.
The idea is not to have zero crashes-- the idea is to avoid
having a bunch of crashes for the *same reason*. The first time
may be an accident, but the second time is not...
BTW Murphy wasn't an optimist, he was an engineer (apparently
some time around WWII-- unfortunately I've lost the reference
for this). His "law&q