Boeing 737 Max design error

trader4@optonline.net wrote in
news:5f688044-7858-4b7f-9c9a-660e94878eb5@googlegroups.com:

Bingo. And to fix a mostly non-existent problem. It's almost
certain that another add-on, which would add cost and complexity,
would reduce reliability, not increase it. Electric trim, the
cutoff switches, trimming manually has been around for a very long
time and I'd like to see data that shows what he wants would have
made any difference.

It is not an add on, dipshit.

It is "Remove screw jack and replace with hydraulic jack".

The hydraulic jack design is such that if placed in "open" mode,
the cylinder slides without damping. That is recovery mode 1. If
that fails, it could have an elbow release. I should not have to
explain how that works. It could also have a release at the
attachment end... either attachment end.

What you know about what would or would not make a difference
matters not. You are an idiot, and you whimpering about a system
that has been in place for deacdes is stupid because OBVIOUSLY
manually cranking a tail plane jack screw by hand is a LITTLE BIT
TOO SLOW. Regardless of what you think, TraderTard4 times over.

 

Sylvia Else <sylvia@email.invalid> wrote in
news:gjdgu4Fpd55U1@mid.individual.net:

Anyway, I don't know where you're getting that from. Different
aircraft use different arrangements for longitudinal trim. The
trim on a 737 works by adjusting the tailplane.

Right, which means they still used the term, but moving an entire
control surface is not "trim". It is wresting full control of a
critical surface. One does not use "trim" to avert an impending
stall.
They use the 'electric trim system', becuase it is a part of that,
but the term itself is a misnomer here. Trim is a term used to
describe SMALL elements which were incorporated into planes so that
a flight can be adjusted out to reduce pilot stress and nowadays to
increase fuel economy. So now it is being used to describe any
adjustment surfaces so that a standard "released stick" does not
cause a sudden change in flight characteristics. IOW, the pilot no
longer had to hold the stick at a certain position to maintain
'level flight'. he could adjust it out such that a 'released stick'
does not cause a sudden change to the current flight circumstances.

And we are not talking about 'different aircraft' on my
suggestion, I was referring specifically to this plane.

 

Sylvia Else <sylvia@email.invalid> wrote in news:gjdgu4Fpd55U1
@mid.individual.net:

The MCAS system here moves the entire elevator on the plane.

It doesn't touch the elevators.

The entire tailplane IS the elevator. Standard aircraft element
nomenclature.

 

trader4@optonline.net wrote in
news:80d34090-d67d-418b-8552-4316f23526fc@googlegroups.com:

Yes, great idea. McDonald Douglas used that idea in the DC-10.
Instead of a jackscrew to drive the flaps, they used a hydraulic
PISTON. Which of course is what we actually call it. In 1979 a
DC-10 full of passengers taking off from O'Hare had an engine fall
off, which in turn damaged the hydraulic lines in the wing. The
flaps retracted. Guess what happened next.

Wrong, always wrong.

You are a goddamned idiot.

Flaps on large passenger planes, for your information, ARE actuated
by hydraulic cylinders.

That is whay airplanes have hydraulic systems in them.

You need to grow the fuck up, you childish little piece of shit.

 

trader4@optonline.net wrote in news:de422837-121d-4ec2-a304-
6f0397665697@googlegroups.com:

one of which is that you could
not exert enough force to turn it by hand.

More proof that you are an idiot. A screw is a very precise
engineering design. The threads utilize the shear strength of the
material they are cut on to move huge elements requiring huge forces
with a mere rotational force. Screw threads impart linear change in
a per turn manner. Each rotation moves the screw one thread pitch
further. Tons of linear force and movement force IS applied and it
does not require tons of force in the screw's rotation.

You prove over and over that you do not have the mechanical
aptitude to even be in the discussion.

IF there were your special "hydraulic assist" mechanisms in place,
then there would be no need for the manual dial at all. The pilot
could merely activate the recovery switch and hold it until the
dial back finishes.

That would actually work.

But you certainly do not know enough about the mechanical realm to
even make valid speculations. You failed to keep your weight
down... You failed at 'trading'. You have absolutely zero grasp of
physics. What is next, child? You gonna give the whole group a
primer on how hard it is to turn a screw?

 

[Sylvia Else]

On 8/05/2019 8:08 am, DecadentLinuxUserNumeroUno@decadence.org wrote:

Sylvia Else <sylvia@email.invalid> wrote in news:gjdgu4Fpd55U1
@mid.individual.net:

The MCAS system here moves the entire elevator on the plane.

It doesn't touch the elevators.


The entire tailplane IS the elevator. Standard aircraft element
nomenclature.

I don't know what's wrong with you.

<https://www.alamy.com/stock-photo-plane-tail-unit-tui-fly-boeing-737-35079500.html>

Note the hinged section. That's the elevator.

Sylvia.

 

Boeing 737 Max Fun Edition:

http://www.skybuck.org/Boeing/NewBoeing737FunEdition.jpg

!!! >=D

Bye,
Skyfun.

 

[Sylvia Else]

On 7/05/2019 11:00 pm, DecadentLinuxUserNumeroUno@decadence.org wrote:

Sylvia Else <sylvia@email.invalid> wrote in
news:gjdaubFo46rU1@mid.individual.net:


The problem here is that you're talking about another piece of
equipment that can control the trim, and which might do so when it
shouldn't. It would then require switches to disable it.

Same equipment, except that instead of a screw jack, it would be a
hydraulic cylinder, and THAT cylinder can be made to be 'freed' either
in the cylinder valving and design itself or by attachment point or
both.

The jackscrew controls the angle of the tailplane. If it were 'freed'
the tailplane would be left flapping in the breeze.

That happened once, to an MD-83, and the result wasn't pretty.

https://en.wikipedia.org/wiki/Alaska_Airlines_Flight_261

Sylvia.

 

[Sylvia Else]

On 8/05/2019 8:15 am, DecadentLinuxUserNumeroUno@decadence.org wrote:

trader4@optonline.net wrote in
news:d6cd5150-70ee-4ac7-b5c3-4f72a40d4da7@googlegroups.com:

That is EXACTLY what is there now. In all these planes, the
electric trim buttons on the controls were working and were used
many times to move the trim back to where it should be. Is it
rocket science to get it near normal and then turn off the cutoff
switches? Geez.

Nice convenient ignorance of the time factor, AGAIN.

Obviously a pilot decided change cannot be implemented fast enough,
or we would not be discussing crashes, we would be discussing a huge
error found by a complaining pilot.

Unless we're just talking about gross pilot incompetence.

Sylvia.

 

[Sylvia Else]

On 7/05/2019 10:55 pm, trader4@optonline.net wrote:

On Monday, May 6, 2019 at 11:57:11 PM UTC-4, Sylvia Else wrote:
On 7/05/2019 12:01 am, trader4@optonline.net wrote:
It would seem most likely that he was trying to turn
the wheel, but could not. If so, that would be another huge problem,
one that could extend to all 737s. Is it possible with extreme trim
and enough airspeed that you can't turn the wheel?

There is some Boeing documentation on this. Mentour Pilot discusses this
in one of his videos - possibly this one.

https://www.youtube.com/watch?v=xixM_cwSLcQ&t=1217s

Certainly the load on the trim jackscrew increases as the aircraft is
further out of trim, and this can reach the level where the pilots are
not strong enough to turn the trim wheels. Boeing suggest briefly
unloading the control column to allow the trim wheels to be turned, and
then loading the control column again to recover the flight path, and do
this repeatedly, until the situation improves.

Of course, to get into that position the pilots have to fail to address
the deteriorating trim situation.

Sylvia.

It makes sense that the forces required to turn the jackscrew increase with
speed, but as I thought the jackscrew was driven by hydraulics and the what
the pilots were trying to turn was linked to that and used it for power assist?
In which case you'd think that whatever turns the jackscrew would have enough
power to move it worst case. The procedure you outline makes sense, but for
a runaway trim, that really goes to the limits, many times you would not
have the luxury of enough time and altitude to follow it.

Clearly, it's not a happy place to be.

But from a design perspective, the question is going to be how to
balance the needs of the pilots in a 'normal' runaway trim scenario
against the needs of pilots who've let things get out of hand.

Increasing the turn ratio to make it easier to turn the wheels in the
extreme out of trim case makes life harder for those pilots who have to
manually operate the trim to fly the aircraft to a suitable landing
place after they've dealt with a runaway trim properly.

Boeing obviously don't want to write in the handbook - "You and your
passengers are doomed - you should have got more training", so they
offer up something, but it stills comes down to "How on Earth did you
get here in the first place?"

Sylvia.

 

[Riley Angel]

On 2019-05-07 11:11, trader4@optonline.net wrote:

There are no CoG problems with 737 Max 8, or stability problems, or
anything else of that ilk which the press seem to be peddling with abandon.
It is true that it has larger engines whch are mounted further aft

That is wrong, the engines are mounted further forward.\

Correct, I had a braino while editing.

It's not clear that anyone went out of their box, unless you know what
exactly happened during the design and changes at Boeing.

Other than them apparently being able to self-certify this component,
and by some accounts having ultimately allowed it several times more
trim authority than originally designed for and documented, I know
nothing about it more than I have read from public sources. Just a big
systems engineering failure all round.

 

[Riley Angel]

On 2019-05-07 11:46, trader4@optonline.net wrote:

I looked into how it's designed. Looks like the cables from the trim
wheels drive the trim mechanism directly, as do a motor. So you're
right.

The 737 can be flown manually; literally with only the forces generated
by the pilot. It is one of the few aircraft where the primary controls
are still mechanical and connected directly to the control surfaces -
albeit with additional actuators such as the trim jackscrews for
automatic control where required - because it's so old.

 

[Banders]

On 05/07/2019 03:08 PM, DecadentLinuxUserNumeroUno@decadence.org wrote:

Sylvia Else <sylvia@email.invalid> wrote in news:gjdgu4Fpd55U1
@mid.individual.net:

The MCAS system here moves the entire elevator on the plane.

It doesn't touch the elevators.


The entire tailplane IS the elevator. Standard aircraft element
nomenclature.

No, it isn't. And when it is, that's called a Stabilator.

The "tailplane" referred to is the Horizontal Stabilizer. Or "Stab".

A vertical stabilizer is a "Fin". Because vertical stabilizer just
sounds stupid.

An elevator is a smaller piece behind the stabilizer, and a trim tab is
another even smaller piece behind the elevator.

Trim is trim, whether it's done gracefully with a dinky tab on the
elevator, or by forcefully wrenching the entire stabilizer.

 

[Jan Panteltje]

On a sunny day (Tue, 7 May 2019 19:57:26 +0100) it happened Tom Gardner
<spamjunk@blueyonder.co.uk> wrote in <rykAE.631834$XN1.553522@fx23.am4>:

On 07/05/19 09:37, Jan Panteltje wrote:
On a sunny day (Mon, 6 May 2019 21:52:18 -0700) it happened Riley Angel
4736angel@pm.me> wrote in <HMqdncp446aekkzBnZ2dnUU7-N3NnZ2d@supernews.com>:

On 2019-05-06 06:42, Jan Panteltje wrote:
I have read lately it was, it is anyways in the sense that it did not detect the output to ever tilt the thing more and
more.
Looks like the dumbest loop you can ever write.
It did not check angular position (I think they added that now, only takes a 1$ MEMS chip),
and it had no redundancy.

Swing a $1 MEMS chip round your head. Which angular position is which
now? An aircraft in flight is essentially a free body with only gravity
as a reference, which can be confused by any other sort of acceleration
force.

Most toy drones, including mine a bit less toy now, use these chips
and keep perfectly horizontal, so know about attitude.
Calibrated before takeoff, like an pressure based altimeter.

Now put the aircraft in, say, a turn where it is pulling 1G.
What direction does the MEMS sensor indicate is "down"?

I've done turns at 3G for a minute or so, and "down"
definitely wasn't towards the earth!

It is irrelevant AFAIK because it is not about up/down
but about difference between left right , and front back, pitch roll.
I for example am using the MPU6050
https://store.invensense.com/datasheets/invensense/MPU-6050_DataSheet_V3%204.pdf
basically a 3 axis gyroscope and 3 axis accelerometer in one chip with i2c bus.
Notice the 'gyroscope' part.

Wrote drivers for it and played around with it, even wrote a open GL based demo not sure where it is...

For the gyroscope part the acceleration Gs you make do not affect it,
but the accelerometer part will show you their magnitude and direction.


The interesting issue for me was if I could use it as inertia based navigation system, so to replace GPS basically.
There the long term drift becomes an issue, mainly due to stresses on the PCB and chip due to temperature fluctuations.
You'd have to put the whole chip and board in an oven to get anywhere usable results...

I think by now there are many more of these type of chips.

You can make zero G with a drone too (have it fall a few tens of meters),
and pull some when going up or on an angle, thing stays neatly horizontal.

 

[Martin Brown]

On 06/05/2019 20:47, trader4@optonline.net wrote:

On Monday, May 6, 2019 at 10:44:25 AM UTC-4, gnuarm.de...@gmail.com
wrote:
On Monday, May 6, 2019 at 5:00:14 AM UTC-4, Sylvia Else wrote:

The effect of the software behaviour, as was, was to trim the
aircraft forward for no good reason.

The pilots should have treated it as a runaway trim, and acted
accordingly. Then the crashes would not have occurred.

I have not seen anything clear or athoritative, but it appears the
situation is not so simple to diagnose as was initially indicated.
When you have a cockpit full of instruments and controls and
"something" is wrong and the plane is behaving very erratically, it
seems not so simple to do the right thing and know that it was
right in the face of the airplane continuing to fly improperly.

It is simple. The trim wheels are spinning right next to your leg.
Something is pushing it way nose down. You push it back up with the
trim button. Five seconds later, *something* is pushing it back
down again. How hard is it to identify that as a problem with the
electric trim? That the plane can;t fly with full nose down trim,
but it flies every other day with small trim? Hello? It doesn't
matter what is causing the electric trim motor to turn and do
something abnormal. It could be a stuck switch, a short, it doesn't
matter that it was MCAS. And the procedure is to turn it off using
the switches right above the trim wheels and then trim manually. We
know it works, because that's what the pilots on LA did the day
before.

But only when instructed to do so by the third pilot who was just along
for the ride and obviously he did not want to die. He figured it out and
told them how to regain control. The implication is that whatever the
sequence of events was on the flight deck when MCAS goes rogue it is
sufficient to overwhelm a two man flight crew with alerts and alarms. I
suspect that bad HCI user interface has played a part in these crashes.
(including making the AoA sensors disagree indicator an optional extra)

The guy who saved the earlier Lion Air flight leg from disaster should
be a very important witness in the crash enquiry into MCAS behaviour.

This is very, very basic flight principles and training that is
supposed to be committed to memory, precisely because in an
emergency, with runaway trim, you have to do the right thing and do
it quickly.

More so when taking off from a high altitude airport with less lift.

It seems likely that Boeing expected that that would happen in
the event that this non-redundant computer system misbehaved.

Yet in both cases the pilots let the aircraft get itself
seriously out of trim. So much so, that in the case of the second
crash, when the the pilots did eventually disable the electric
trim, the aircraft was so far out of trim that the pilots were
not strong enough to turn the trim wheels (or they didn't try -
it's rather unclear at the moment).

There is the main point. It is too early to be making judgements.

I agree it's too early to make final judgments, but there is plenty
out there already to make some judgments, including that the pilots
bear some of the blame. It's similar to most of these, which is why
crashes are so rare. It's rarely just one thing, it's a whole series
of things that have to go wrong for it to result in a crash, all of
them low

I'm not sure the second crew ever stood much of a chance as they were
already in thin air at take off and surrounded by even higher mountains.

probability. Speaking of probabilities, I'm still mystified as to
why there has been nothing about the root cause of the incorrect AOA
reading.

That is also surprising. I guess we have to wait for the final report.

--
Regards,
Martin Brown

 

[Tom Gardner]

On 08/05/19 15:07, trader4@optonline.net wrote:

On Tuesday, May 7, 2019 at 3:54:41 PM UTC-4, Tom Gardner wrote:
On 07/05/19 19:58, trader4@optonline.net wrote:
On Tuesday, May 7, 2019 at 2:47:55 PM UTC-4, Tom Gardner wrote:
On 07/05/19 18:45, Banders wrote:
On 05/07/2019 05:57 AM, trader4@optonline.net wrote:
On Tuesday, May 7, 2019 at 12:33:45 AM UTC-4, Banders wrote:
On 05/06/2019 11:55 AM, trader4@optonline.net wrote:

Mushing has nothing to do with what I stated.  Explain to us how a 737
that's been going 300 MPH in level flight for 30 seconds can be stalling.
It can't.

Not during those 30 seconds perhaps, but wind shear can change things in
an instant.

Again, explain to us how any wind shear on this planet, can cause a plane
that is in level flight, at 300 MPH, for the last 30 seconds to stall.

Does this link work?
https://en.wikipedia.org/wiki/Supercell#/media/File:Supercell.svg

You would be lucky to have the wings stall rather than be torn off.

Bear in mind that trader4 appears not to have any
experience of flying aircraft, and hence no experience
of the strange unexpected meteorological effects that
can be encountered.

So then explain to us how a 737 that's been flying for 30 secs
at 300 MPH in level flight can suddenly stall, requiring MCAS to activate.
Cite for us when this has happened.




Even with my limited experience, I've been in situations
which have surprised co-pilots that have been an instructor
for over half a century.

But I'm sure trader4 won't let that reality deter him
from his confident announcements about how aircraft
do (and don't) fly.

You're just sore because I have the facts and also hold the pilots
partly responsible for what happened. Out of 7, at least 4 could not
identify a runaway trim problem and take the simple steps, that are
supposed to be a memory item, to deal with it.

I'm not sore, but I don't have the time to educate you in
how aircraft do (and don't) fly.

It would help if you had some experience of flying aircraft.

It would help if you had been taught by competent instructors
that require you to recover after an aircraft has "departed
controlled flight", because such conditions can easily be
encountered, must be recognised, and dealt with.

*Since you have neither, trying to educate you would be a
waste of our time.*

*If you are prepared to educate yourself*, I suggest
Wolfgang Langewiesche's "Stick and Rudder; An
Explanation of the Art of Flying".

Still waiting for the simple answer from the alleged expert:

A 737 has been flying level for 30 secs at 300mph. Explain to us
how it can suddenly be stalling.

I am not an expert, but I do know more about how
aircraft fly than you do.

The reason I do not respond to this particular question
of yours is because:
- it is not an important question
- if I did, you would just move on to another unimportant
question based on a poor understanding of how aircraft fly

 

On Tuesday, May 7, 2019 at 3:54:41 PM UTC-4, Tom Gardner wrote:

On 07/05/19 19:58, trader4@optonline.net wrote:
On Tuesday, May 7, 2019 at 2:47:55 PM UTC-4, Tom Gardner wrote:
On 07/05/19 18:45, Banders wrote:
On 05/07/2019 05:57 AM, trader4@optonline.net wrote:
On Tuesday, May 7, 2019 at 12:33:45 AM UTC-4, Banders wrote:
On 05/06/2019 11:55 AM, trader4@optonline.net wrote:

Mushing has nothing to do with what I stated.  Explain to us how a 737
that's been going 300 MPH in level flight for 30 seconds can be stalling.
It can't.

Not during those 30 seconds perhaps, but wind shear can change things in
an instant.

Again, explain to us how any wind shear on this planet, can cause a plane
that is in level flight, at 300 MPH, for the last 30 seconds to stall.

Does this link work?
https://en.wikipedia.org/wiki/Supercell#/media/File:Supercell.svg

You would be lucky to have the wings stall rather than be torn off.

Bear in mind that trader4 appears not to have any
experience of flying aircraft, and hence no experience
of the strange unexpected meteorological effects that
can be encountered.

So then explain to us how a 737 that's been flying for 30 secs
at 300 MPH in level flight can suddenly stall, requiring MCAS to activate.
Cite for us when this has happened.




Even with my limited experience, I've been in situations
which have surprised co-pilots that have been an instructor
for over half a century.

But I'm sure trader4 won't let that reality deter him
from his confident announcements about how aircraft
do (and don't) fly.

You're just sore because I have the facts and also hold the pilots
partly responsible for what happened. Out of 7, at least 4 could not
identify a runaway trim problem and take the simple steps, that are
supposed to be a memory item, to deal with it.

I'm not sore, but I don't have the time to educate you in
how aircraft do (and don't) fly.

It would help if you had some experience of flying aircraft.

It would help if you had been taught by competent instructors
that require you to recover after an aircraft has "departed
controlled flight", because such conditions can easily be
encountered, must be recognised, and dealt with.

*Since you have neither, trying to educate you would be a
waste of our time.*

*If you are prepared to educate yourself*, I suggest
Wolfgang Langewiesche's "Stick and Rudder; An
Explanation of the Art of Flying".

Still waiting for the simple answer from the alleged expert:

A 737 has been flying level for 30 secs at 300mph. Explain to us
how it can suddenly be stalling.

 

On Tuesday, May 7, 2019 at 6:08:00 PM UTC-4, DecadentLinux...@decadence.org wrote:

Sylvia Else <sylvia@email.invalid> wrote in
news:gjdgu4Fpd55U1@mid.individual.net:

Anyway, I don't know where you're getting that from. Different
aircraft use different arrangements for longitudinal trim. The
trim on a 737 works by adjusting the tailplane.


Right, which means they still used the term, but moving an entire
control surface is not "trim". It is wresting full control of a
critical surface. One does not use "trim" to avert an impending
stall.

Wrong, always wrong. Here you are, the village idiot, coming up with
stupid solutions, when anyone who has followed this Boeing MCAS problem
knows that it does use trim and not the full elevator. It's abundantly
obvious, for example Boeing put out the procedure to deal with the
same thing happening again. IT's to follow the runaway TRIM PROCEDURE,
which is shutting off two switches that turn of the TRIM MOTORS and
then TRIMMING MANUALLY.

Geeez, if you spent just a fraction of the time learning that you do
posting, you might improve. The above is easily verfiable online.
And not a single person in this thread agrees with the BS you just
posted either.

They use the 'electric trim system', becuase it is a part of that,
but the term itself is a misnomer here. Trim is a term used to
describe SMALL elements which were incorporated into planes so that
a flight can be adjusted out to reduce pilot stress and nowadays to
increase fuel economy. So now it is being used to describe any
adjustment surfaces so that a standard "released stick" does not
cause a sudden change in flight characteristics.

That another lie. Wrong, always wrong. The trim on the tail is a small
element and it is used to neutralize the forces on the controls.




IOW, the pilot no

longer had to hold the stick at a certain position to maintain
'level flight'. he could adjust it out such that a 'released stick'
does not cause a sudden change to the current flight circumstances.

Bingo. And that's what MCAS uses, the TRIM, to point the nose down.

Geeez.

And we are not talking about 'different aircraft' on my
suggestion, I was referring specifically to this plane.

Irrelevant of course, because it's all wrong.

 

On Tuesday, May 7, 2019 at 5:57:28 PM UTC-4, DecadentLinux...@decadence.org wrote:

trader4@optonline.net wrote in
news:5f688044-7858-4b7f-9c9a-660e94878eb5@googlegroups.com:

Bingo. And to fix a mostly non-existent problem. It's almost
certain that another add-on, which would add cost and complexity,
would reduce reliability, not increase it. Electric trim, the
cutoff switches, trimming manually has been around for a very long
time and I'd like to see data that shows what he wants would have
made any difference.


It is not an add on, dipshit.

It is "Remove screw jack and replace with hydraulic jack".

The hydraulic jack design is such that if placed in "open" mode,
the cylinder slides without damping. That is recovery mode 1. If
that fails, it could have an elbow release. I should not have to
explain how that works. It could also have a release at the
attachment end... either attachment end.

All that is indeed adding. All to solve a problem that is pretty much
non-existent.

What you know about what would or would not make a difference
matters not. You are an idiot, and you whimpering about a system
that has been in place for deacdes is stupid because OBVIOUSLY
manually cranking a tail plane jack screw by hand is a LITTLE BIT
TOO SLOW. Regardless of what you think, TraderTard4 times over.

So show us all the accident reports over the last 50 years, where
manual trim being too slow was the cause or a major factor in the
crash. That is what aircraft designers and FAA look at before
making huge changes in systems that already work. And then, we
don't know that your new hydraulic system is any better. Boeing
thought their improvement of MCAS made the plane safer too.
And I cited for you what happens with a hydraulic piston driven
actuator when a hydraulic line fails. We saw that with the American
Airlines DC-10 at O'Hare, 1979.

 

On Tuesday, May 7, 2019 at 5:50:53 PM UTC-4, DecadentLinux...@decadence.org wrote:

trader4@optonline.net wrote in news:de422837-121d-4ec2-a304-
6f0397665697@googlegroups.com:

one of which is that you could
not exert enough force to turn it by hand.

More proof that you are an idiot. A screw is a very precise
engineering design. The threads utilize the shear strength of the
material they are cut on to move huge elements requiring huge forces
with a mere rotational force. Screw threads impart linear change in
a per turn manner. Each rotation moves the screw one thread pitch
further. Tons of linear force and movement force IS applied and it
does not require tons of force in the screw's rotation.

Woooah there Pilgrim! Neither I nor any of the other adults here discussing
this said that it required "tons of force" to turn the trim wheels.
Only that:

A - The co-pilot in the Ethiopian crash said he was trying to manually
move the trim and could not. That is fact

B - Someone posted that part of the procedure for moving the trim manually
is that if there is too much speed and too much trim, then the 737 trim
wheels may require both pilots strength to move and could still be
impossible to move, without changing the airplane speed and/or attitude.


It' quite amazing how you get things totally twisted and wrong. Sure,
we all know how leverage works, but all it does is allow lesser force
over a longer distance to do the same work. That doesn't mean that
the force needed can be supplied by a human hand.

But you certainly do not know enough about the mechanical realm to
even make valid speculations. You failed to keep your weight
down... You failed at 'trading'. You have absolutely zero grasp of
physics. What is next, child? You gonna give the whole group a
primer on how hard it is to turn a screw?

Sure, after you posted the above nonsense.