Fresh setback for Boeing's 737 MAX

[Bill Sloman]

On Saturday, June 29, 2019 at 12:49:05 PM UTC+2, DecadentLinux...@decadence..org wrote:

Bill Sloman <bill.sloman@ieee.org> wrote in
news:8105193b-33ee-4d19-b8b6-d885395c0735@googlegroups.com:

On Friday, June 28, 2019 at 9:27:18 PM UTC+2, Cursitor Doom wrote:
On Wed, 26 Jun 2019 16:42:36 -0700, Rick C wrote:

On Wednesday, June 26, 2019 at 7:27:32 PM UTC-4, Cursitor Doom
wrote:
Similar fault to last time found in software:


https://tinyurl.com/y4dcqwnb

Here is the link for the actual report rather than having to
read the ZeroHedge interpretation.

https://www.cnn.com/2019/06/26/politics/boeing-737-max-
flaw/inde
x.html

Ah, so CNN is pure news with no <cough> "interpretation" then.
Nice to know.
;-

It does lack the kind of "interpretation" that rabid right wingers
expect to get with their daily dose of propaganda, but services
like CNN do present stuff in a way the main stream of the
population finds acceptable.

That how the free market works. CNN is primarily serving an
American audience, so their slant is slightly more right wing than
the British BBC or the Australian ABC, but it isn't a gross
difference, and you have to look hard to find an example of a
perceptible difference.


One of the few things I find to be a gain in the crapstorm DJT has
caused is that it makes it easier to spot the extreme idiots as they
come out of the woodwork with their "fake news" declarations.

I have never seen a more immature bunch of sheep.

I strive for whirled peas.

There are degrees of gullibiltiy. Cursitor Doom will beleive any right-wing nonsense, and John Larkin wil believe any climate change denial propaganda..

Krw believes a lot of similarly nonsencial things, but he isn't actually gullible - he can't absorb any kind of new idea, and the nonsense he now beleives all dates back to the time when he could still learn stuff, back when Joseph MacCarthy still had credibility.

--
Bill Sloman, Sydney

 

I remember when you "quit" this group because there was not enough posts about electronics. You lectured the group about how boring the group had become (or some such thing) and you are and have always been the creator of trolling content [actually it is not really trolling content because nobody bites on it]. Not that I mind off topic stuff or trolls, I think it adds to an otherwise narrowly focused group.... I am just saying that I remember your high and mighty Opus......what i can't remember is how long it lasted.

 

On Sunday, June 30, 2019 at 10:58:45 PM UTC-4, DLUNU wrote:

trader4@optonline.net wrote in
news:d07712b8-5854-48b8-9b9e-fb4d56aedd86@googlegroups.com:

On Sunday, June 30, 2019 at 1:52:19 PM UTC-4,
DecadentLinuxUserNumeroUno wrote:
trader4@optonline.net wrote in news:d8a03c6e-8f6f-4862-a0e1-
4af302ecf43b@googlegroups.com:

And then factor in the added failure modes and possible
scenarios introduced by all that additional complexity.

Nope. Just a motor to crank the cockpit dials. That leaves all
the
original mechanicals in place, which is the stuff that WAS
engineered properly.

IDK how you can say it was engineered properly

The dial crank cockpit trim adjust device has been in place long
before MCAS got incorporated into this model.

Of course, that's why I said I don't know how you can say that the system
was engineered properly. The manual hand crank system has been in 737s
since they first rolled out and from all indications, if those planes
suffered a runaway trim that put the plane into a steep nose down, it
would be difficult to impossible for the pilots to be able to manually
turn the wheels and to do so in time to avoid a crash too. I would assume
that the reason we haven't seen crashes before is that true runaway trim
is very rare.

when if the trim
runs away signifcantly,

No. MCAS dialed the trim to its extent in one direction and the
pilots in these cases did not override the faulty MCAS operation in
time.

That is runaway trim. Trim, where for whatever reasons, the system that
uses electric motors runs has a failure that causes the trim to go to
some incorrect position.

The stabilizer trim dials work fine and are not merely on Boeing
airframes.

The point is that they do not work fine if the trim runs away to a steep
nose down setting. We have the Ethiopian crash that, by all indications,
shows that. We also have Sully saying that he had trouble trying to recover
in a simulator from the same situation, even knowing what was coming.
Once the trim runs far enough and the plane is pitching down and gaining
speed, it becomes near impossible or impossible for the pilots to get it
back to where it needs to be quickly enough or even move it at all.

puts the plane into a steep dive that
increases the necessary force, a pilot doesn't have enough strength
to overcome it.

Still MCAS to blame not the cockpit connection to the stabilizer.
That hard connection is the last resort in a failure and has been in
the basic design book for a long time. Long before 737Max8.

And again, had any of those earlier planes suffered a stuck switch or a
short, that caused the electric motors to force full nose down trim,
it would have produced the same result as the MCAS failure doing it.
Actually, a worse result! Because with MCAS, the electric trim still
worked, the pilots could use the trim buttons to undo what MCAS just
did. With a short running the electric motors full nose down, the
pilots would have had no electric option to reverse it.

What's interesting is that apparently it hasn't
been a problem in the last half century, where trim ran away to
that extent, until now.

Trim never 'ran away to that extent' before.

Exactly. But that doesn't mean that it could not have. It just means
we were lucky. And Boeing knew that too. In the early 737 manuals
they described the procedure to deal with that, ie the case where the
trim forces hard nose down and the trim wheels can't be turned. The
manual said the procedure was to push the controls forward, the opposite
of what you would normally do, which would help relieve the force required
to turn the trim wheels. Over time that was removed from the manuals.

 

On Monday, July 1, 2019 at 8:52:08 PM UTC-4, Lasse Langwadt Christensen wrote:

tirsdag den 2. juli 2019 kl. 02.02.23 UTC+2 skrev Chris:
On 07/01/19 18:55, Lasse Langwadt Christensen wrote:
mandag den 1. juli 2019 kl. 19.42.50 UTC+2 skrev Chris:
On 07/01/19 03:58, DLUNU wrote:


No. MCAS dialed the trim to its extent in one direction and the
pilots in these cases did not override the faulty MCAS operation in
time.

The stabilizer trim dials work fine and are not merely on Boeing
airframes.



Not quite. Because of the increased surface area on the max and
aerodynamic load at high speeds, the force required to counteract
the runaway mcas trim exceeds that which can be manually corrected
with the trim wheel. That's why both crashes were unrecoverable.

the surface area and the trim isn't different on the MAX

Not according to people who actually fly them and others who
should know about such things.

everything I've heard from 737 pilots is that the difference between
MAX and NG is the engines and their position



and aerodynamic load at high speed exceeding what you can correct
with the trimwheel can happen on any 737, it is even described in the manual

https://theaircurrent.com/wp-content/uploads/2019/04/1981-737-roller-coaster-recovery-1240x1903.jpg

Perhaps, but in the case of both crashes, mcas forced the nose down
at low altitude, where there was not enough height for recovery by
the roller coaster method.

sure, but runaway trim could have caused a similar situation on any 737


There's a long running set of threads on this at the pprune site
here, going back ages: https://www.pprune.org/rumours-news-13/.
Worth having a look at to see how bad the situation really is...

yes it it pretty bad when a simple system failure can cause a unrecoverable
situation if you don't have lots of altitude to spare

Agree, I haven't seen anything where it's been stated that the difficulty
in turning the trim wheels is worse with the MAx than any other 737.
And only one crash, Ethiopia, was apparently due to that. No indication
that the Lion Air flight the pilots even followed the runaway trim
procedure and tried to trim manually.

 

[Lasse Langwadt Christense]

tirsdag den 2. juli 2019 kl. 17.10.41 UTC+2 skrev tra...@optonline.net:

On Monday, July 1, 2019 at 1:42:50 PM UTC-4, Chris wrote:
On 07/01/19 03:58, DLUNU wrote:


No. MCAS dialed the trim to its extent in one direction and the
pilots in these cases did not override the faulty MCAS operation in
time.

The stabilizer trim dials work fine and are not merely on Boeing
airframes.



Not quite. Because of the increased surface area on the max and
aerodynamic load at high speeds, the force required to counteract
the runaway mcas trim exceeds that which can be manually corrected
with the trim wheel. That's why both crashes were unrecoverable.

Chris

I agree it looks like that is why ONE crash, the Ethiopian one, was
unrecoverable. There the co-pilot said he was trying to move the trim,
but could not do so. It's not absolutely clear what he was doing and
what he meant, but it looks like he was trying to turn the trim wheel
manually and could not move it.

The other crash, the crew was just lost in the wilderness. AFAIK, there
is no indication that they even followed the runaway trim procedure at all.
They flew around for about 5 minutes, with MCAS commanding nose down,
then the pilot reversing it with the trim buttons. The plane could have
flown for hours like that, until it ran out of fuel, but the pilot handed
control over to the co-pilot and when MCAS did the next nose down, the
co-pilot only applied a weak nose up and then nothing more. Had they
used the trim buttons as they were doing to get the trim near where it
should be, then followed the runaway trim procedure, turn off the switches
and trim manually, the plane would have flown fine. That's pretty much
what happened the day before with the same plane.

I also haven't seen anything where it says that the difficulty of using the
manual wheels is worse in the Max than previous 737s. I have seen where
Boeing recognized from the earliest 737s that with enough nose down runaway
trim, the wheels might be difficult to impossible to move. They described
a procedure in the manuals for pilots to push forward on the controls,
which would temporarily make the dive even steeper, but would relieve some
of the pressure from the control surface and make the trim wheels easier
to turn. That process was later dropped from the manuals, has been gone
for decades.

I've one guy talk about FAA might also be looking at the 737NG
because when it was made the trim wheels were made smaller than
on the classic 737 to make room for the instrumentation upgrade

 

On Monday, July 1, 2019 at 1:42:50 PM UTC-4, Chris wrote:

On 07/01/19 03:58, DLUNU wrote:


No. MCAS dialed the trim to its extent in one direction and the
pilots in these cases did not override the faulty MCAS operation in
time.

The stabilizer trim dials work fine and are not merely on Boeing
airframes.



Not quite. Because of the increased surface area on the max and
aerodynamic load at high speeds, the force required to counteract
the runaway mcas trim exceeds that which can be manually corrected
with the trim wheel. That's why both crashes were unrecoverable.

Chris

I agree it looks like that is why ONE crash, the Ethiopian one, was
unrecoverable. There the co-pilot said he was trying to move the trim,
but could not do so. It's not absolutely clear what he was doing and
what he meant, but it looks like he was trying to turn the trim wheel
manually and could not move it.

The other crash, the crew was just lost in the wilderness. AFAIK, there
is no indication that they even followed the runaway trim procedure at all.
They flew around for about 5 minutes, with MCAS commanding nose down,
then the pilot reversing it with the trim buttons. The plane could have
flown for hours like that, until it ran out of fuel, but the pilot handed
control over to the co-pilot and when MCAS did the next nose down, the
co-pilot only applied a weak nose up and then nothing more. Had they
used the trim buttons as they were doing to get the trim near where it
should be, then followed the runaway trim procedure, turn off the switches
and trim manually, the plane would have flown fine. That's pretty much
what happened the day before with the same plane.

I also haven't seen anything where it says that the difficulty of using the
manual wheels is worse in the Max than previous 737s. I have seen where
Boeing recognized from the earliest 737s that with enough nose down runaway
trim, the wheels might be difficult to impossible to move. They described
a procedure in the manuals for pilots to push forward on the controls,
which would temporarily make the dive even steeper, but would relieve some
of the pressure from the control surface and make the trim wheels easier
to turn. That process was later dropped from the manuals, has been gone
for decades.

 

[Bill Sloman]

On Tuesday, July 2, 2019 at 2:06:18 PM UTC+2, bule...@columbus.rr.com wrote:
> I remember when you "quit" this group because there was not enough posts about electronics. You lectured the group about how boring the group had become (or some such thing) and you are and have always been the creator of trolling content [actually it is not really trolling content because nobody bites on it]. Not that I mind off topic stuff or trolls, I think it adds to an otherwise narrowly focused group.... I am just saying that I remember your high and mighty Opus......what i can't remember is how long it lasted.

Whoever Bulegoge is, he hasn't got enough sense to include enough of the post he's reacting to make it clear who it is.

I had to go to eternal september to find out that he was talking about me.

I do remember taking a break from the group a year or so ago. I don't recall saying anything about electronic content or trolling at the time - perhaps Bulegoge could use Google to find the post?

I suspect that his memory is playing him false. Since he doesn't ever seem to have ever posted anything worth paying attention to - I certainly can't recall anything - I really shouldn't have bothered responding to this worthless crud either.

--
Bill Sloman, Sydney

 

[Phil Allison]

Bill Sloman wrote:

Whoever Bulegoge is, he hasn't got enough sense to include enough of the post he's reacting to make it clear who it is.

I had to go to eternal september to find out that he was talking about me.

I do remember taking a break from the group a year or so ago. I don't recall saying anything about electronic content or trolling at the time - perhaps Bulegoge could use Google to find the post?

I suspect that his memory is playing him false. Since he doesn't ever seem to have ever posted anything worth paying attention to - I certainly can't recall anything - I really shouldn't have bothered responding to this worthless crud either.

** I agree - posters who use stupid handles and post abuse in mid air ( no context or quotes ) are the worst kind of trolls.

IMO that makes them fair game for anything you are to say about them - so I do.

And don't little shits squeal about it.



..... Phil

 

On Tuesday, July 2, 2019 at 7:58:41 PM UTC-4, DLUNU wrote:

Chris <xxx.syseng.yyy@gfsys.co.uk> wrote in news:qfe6u9$2ev$1
@gioia.aioe.org:

Perhaps, but in the case of both crashes, mcas forced the nose down
at low altitude, where there was not enough height for recovery by
the roller coaster method.

Roller coaster is not was not NEVER was a "method", ya dope. It is a
description of what was recovered from not the method of recovery.

It is an outcome of a control method (cockpit actuation) which has the
HUGE problem of being too slow, and the loading increases on ALL craft
experiencing such an issue.

The "roller coaster" method he's referring to is Boeing's method for
extreme runaway trim recovery that was in the 737 manuals decades ago.
If the trim goes far out the pilots may not be able to turn the trim
wheels manually. So the procedure was to push the controls forward,
put the plane into a steeper dive to relieve the pressure so that the
trim wheels could be turned.

 

[DLUNU]

Chris <xxx.syseng.yyy@gfsys.co.uk> wrote in news:qfdgmk$td9$1
@gioia.aioe.org:

On 07/01/19 03:58, DLUNU wrote:


No. MCAS dialed the trim to its extent in one direction and
the
pilots in these cases did not override the faulty MCAS operation
in
time.

The stabilizer trim dials work fine and are not merely on
Boeing
airframes.



Not quite. Because of the increased surface area on the max and
aerodynamic load at high speeds, the force required to counteract
the runaway mcas trim exceeds that which can be manually corrected
with the trim wheel. That's why both crashes were unrecoverable.

Chris

The system I suggest RELEASES MCAS and dials from the cockpit using
cockpit installed MOTORS, which are more powerful than humans. IF
that fails or is also 'down', THEN the pilot uses the dials.

And YES THEY (cockpit stab trim dials) WERE around BEFORE the MCAS
system.

STAB TRIM has been around for DECADES.

 

[DLUNU]

bulegoge@columbus.rr.com wrote in
news:41e79378-15bc-4a95-84f7-ecfa9b7a0423@googlegroups.com:

I remember when you "quit" this group because there was not enough
posts about electronics. You lectured the group about how boring
the group had become (or some such thing) and you are and have
always been the creator of trolling content [actually it is not
really trolling content because nobody bites on it]. Not that I
mind off topic stuff or trolls, I think it adds to an otherwise
narrowly focused group.... I am just saying that I remember your
high and mighty Opus......what i can't remember is how long it
lasted.

Damn. This guy is so stupid, he not only does not even know what
a troll is, the dope thinks that he DOES!

Dude... YOU are the troll.

 

[DLUNU]

Chris <xxx.syseng.yyy@gfsys.co.uk> wrote in news:qfe6u9$2ev$1
@gioia.aioe.org:

Perhaps, but in the case of both crashes, mcas forced the nose down
at low altitude, where there was not enough height for recovery by
the roller coaster method.

Roller coaster is not was not NEVER was a "method", ya dope. It is a
description of what was recovered from not the method of recovery.

It is an outcome of a control method (cockpit actuation) which has the
HUGE problem of being too slow, and the loading increases on ALL craft
experiencing such an issue.

 

[Lasse Langwadt Christense]

onsdag den 3. juli 2019 kl. 01.58.41 UTC+2 skrev DLUNU:

Chris <xxx.syseng.yyy@gfsys.co.uk> wrote in news:qfe6u9$2ev$1
@gioia.aioe.org:

Perhaps, but in the case of both crashes, mcas forced the nose down
at low altitude, where there was not enough height for recovery by
the roller coaster method.

Roller coaster is not was not NEVER was a "method", ya dope. It is a
description of what was recovered from not the method of recovery.

from the horses mouth, https://theaircurrent.com/wp-content/uploads/2019/04/1981-737-roller-coaster-recovery-1240x1903.jpg

 

[DLUNU]

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:a08193b5-88ad-43ed-9011-a738faf23b29@googlegroups.com:

tirsdag den 2. juli 2019 kl. 03.59.56 UTC+2 skrev Rick C:
On Monday, July 1, 2019 at 1:42:50 PM UTC-4, Chris wrote:
On 07/01/19 03:58, DLUNU wrote:


No. MCAS dialed the trim to its extent in one direction
and the
pilots in these cases did not override the faulty MCAS
operation in time.

The stabilizer trim dials work fine and are not merely on
Boeing
airframes.



Not quite. Because of the increased surface area on the max and
aerodynamic load at high speeds, the force required to
counteract the runaway mcas trim exceeds that which can be
manually corrected with the trim wheel. That's why both crashes
were unrecoverable.

Doesn't the aerodynamic load tend to restore the elevator to the
neutral position? That's why some planes pivot the elevator near
the center of loading. No?


doesn't help if the load is so high the screw binds up

Sounds like a better screw thread design should have been used.
Sounds like good ol' square thread was chosen by the $9.00
'engineers'.

Should have used precision caged ball screw assembly for the least
back force imposition while having a high transition per turn rate.

 

[DLUNU]

trader4@optonline.net wrote in
news:3688aa24-10ba-42f3-b7cc-6b1b09577449@googlegroups.com:

On Sunday, June 30, 2019 at 10:58:45 PM UTC-4, DLUNU wrote:
trader4@optonline.net wrote in
news:d07712b8-5854-48b8-9b9e-fb4d56aedd86@googlegroups.com:

On Sunday, June 30, 2019 at 1:52:19 PM UTC-4,
DecadentLinuxUserNumeroUno wrote:
trader4@optonline.net wrote in news:d8a03c6e-8f6f-4862-a0e1-
4af302ecf43b@googlegroups.com:

And then factor in the added failure modes and possible
scenarios introduced by all that additional complexity.

Nope. Just a motor to crank the cockpit dials. That leaves
all the
original mechanicals in place, which is the stuff that WAS
engineered properly.

IDK how you can say it was engineered properly

The dial crank cockpit trim adjust device has been in place long
before MCAS got incorporated into this model.

Of course, that's why I said I don't know how you can say that the
system was engineered properly. The manual hand crank system has
been in 737s since they first rolled out and from all indications,
if those planes suffered a runaway trim that put the plane into a
steep nose down, it would be difficult to impossible for the pilots
to be able to manually turn the wheels and to do so in time to
avoid a crash too. I would assume that the reason we haven't seen
crashes before is that true runaway trim is very rare.







when if the trim
runs away signifcantly,

No. MCAS dialed the trim to its extent in one direction and the
pilots in these cases did not override the faulty MCAS operation
in time.

That is runaway trim. Trim, where for whatever reasons, the system
that uses electric motors runs has a failure that causes the trim
to go to some incorrect position.





The stabilizer trim dials work fine and are not merely on Boeing
airframes.

The point is that they do not work fine if the trim runs away to a
steep nose down setting. We have the Ethiopian crash that, by all
indications, shows that. We also have Sully saying that he had
trouble trying to recover in a simulator from the same situation,
even knowing what was coming. Once the trim runs far enough and the
plane is pitching down and gaining speed, it becomes near
impossible or impossible for the pilots to get it back to where it
needs to be quickly enough or even move it at all.








puts the plane into a steep dive that
increases the necessary force, a pilot doesn't have enough
strength to overcome it.

Still MCAS to blame not the cockpit connection to the
stabilizer.
That hard connection is the last resort in a failure and has been
in the basic design book for a long time. Long before 737Max8.

And again, had any of those earlier planes suffered a stuck switch
or a short, that caused the electric motors to force full nose down
trim, it would have produced the same result as the MCAS failure
doing it. Actually, a worse result! Because with MCAS, the
electric trim still worked, the pilots could use the trim buttons
to undo what MCAS just did. With a short running the electric
motors full nose down, the pilots would have had no electric option
to reverse it.







What's interesting is that apparently it hasn't
been a problem in the last half century, where trim ran away to
that extent, until now.

Trim never 'ran away to that extent' before.

Exactly. But that doesn't mean that it could not have. It just
means we were lucky. And Boeing knew that too. In the early 737
manuals they described the procedure to deal with that, ie the case
where the trim forces hard nose down and the trim wheels can't be
turned. The manual said the procedure was to push the controls
forward, the opposite of what you would normally do, which would
help relieve the force required to turn the trim wheels. Over time
that was removed from the manuals.


Simple solve with the cockpit assist motors.

The problem is with the speed of actuation. Period.
Subsequent difficulty in manually turning the dials and doing so in a
timely manner. Not possible, as we have seen demonstrated
tragically.

Hence the cockpit assist motor suggestion.

We already know what happened, yet you guys keep coming back
spouting off what you read as if no one else did.

So, What The Fuck Is up with That?

 

[DLUNU]

trader4@optonline.net wrote in news:b6ce2956-2152-498c-9d9f-
77af75dadb6d@googlegroups.com:

> I agree it looks like that is why ONE crash, the Ethiopian one,

Got you pegged. A copy and paste savant wannabe. With plenty of your
own bent perspective sprinkled in.

 

[DLUNU]

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in news:7df5b14a-
e72b-40f0-9288-e6d08c66d52f@googlegroups.com:

when it was made the trim wheels were made smaller than
on the classic 737

Hand application of torque on smaller wheels is more difficult than on
the larger diameter.

The connection of said wheels to whatever actuation shaft matters too.
Is there a ratio, etc.

 

[DLUNU]

Phil Allison <pallison49@gmail.com> wrote in
news:9af9e413-a38b-4f92-b0f4-12e92807db43@googlegroups.com:

** I agree - posters who use stupid handles and post abuse in mid
air ( no context or quotes ) are the worst kind of trolls.

IMO that makes them fair game for anything you are to say about
them - so I do.

Which actually makes you worse than the trolls. Doh!

 

On Tuesday, July 2, 2019 at 9:13:10 PM UTC-4, DLUNU wrote:

trader4@optonline.net wrote in
news:3688aa24-10ba-42f3-b7cc-6b1b09577449@googlegroups.com:

On Sunday, June 30, 2019 at 10:58:45 PM UTC-4, DLUNU wrote:
trader4@optonline.net wrote in
news:d07712b8-5854-48b8-9b9e-fb4d56aedd86@googlegroups.com:

On Sunday, June 30, 2019 at 1:52:19 PM UTC-4,
DecadentLinuxUserNumeroUno wrote:
trader4@optonline.net wrote in news:d8a03c6e-8f6f-4862-a0e1-
4af302ecf43b@googlegroups.com:

And then factor in the added failure modes and possible
scenarios introduced by all that additional complexity.

Nope. Just a motor to crank the cockpit dials. That leaves
all the
original mechanicals in place, which is the stuff that WAS
engineered properly.

IDK how you can say it was engineered properly

The dial crank cockpit trim adjust device has been in place long
before MCAS got incorporated into this model.

Of course, that's why I said I don't know how you can say that the
system was engineered properly. The manual hand crank system has
been in 737s since they first rolled out and from all indications,
if those planes suffered a runaway trim that put the plane into a
steep nose down, it would be difficult to impossible for the pilots
to be able to manually turn the wheels and to do so in time to
avoid a crash too. I would assume that the reason we haven't seen
crashes before is that true runaway trim is very rare.







when if the trim
runs away signifcantly,

No. MCAS dialed the trim to its extent in one direction and the
pilots in these cases did not override the faulty MCAS operation
in time.

That is runaway trim. Trim, where for whatever reasons, the system
that uses electric motors runs has a failure that causes the trim
to go to some incorrect position.





The stabilizer trim dials work fine and are not merely on Boeing
airframes.

The point is that they do not work fine if the trim runs away to a
steep nose down setting. We have the Ethiopian crash that, by all
indications, shows that. We also have Sully saying that he had
trouble trying to recover in a simulator from the same situation,
even knowing what was coming. Once the trim runs far enough and the
plane is pitching down and gaining speed, it becomes near
impossible or impossible for the pilots to get it back to where it
needs to be quickly enough or even move it at all.








puts the plane into a steep dive that
increases the necessary force, a pilot doesn't have enough
strength to overcome it.

Still MCAS to blame not the cockpit connection to the
stabilizer.
That hard connection is the last resort in a failure and has been
in the basic design book for a long time. Long before 737Max8.

And again, had any of those earlier planes suffered a stuck switch
or a short, that caused the electric motors to force full nose down
trim, it would have produced the same result as the MCAS failure
doing it. Actually, a worse result! Because with MCAS, the
electric trim still worked, the pilots could use the trim buttons
to undo what MCAS just did. With a short running the electric
motors full nose down, the pilots would have had no electric option
to reverse it.







What's interesting is that apparently it hasn't
been a problem in the last half century, where trim ran away to
that extent, until now.

Trim never 'ran away to that extent' before.

Exactly. But that doesn't mean that it could not have. It just
means we were lucky. And Boeing knew that too. In the early 737
manuals they described the procedure to deal with that, ie the case
where the trim forces hard nose down and the trim wheels can't be
turned. The manual said the procedure was to push the controls
forward, the opposite of what you would normally do, which would
help relieve the force required to turn the trim wheels. Over time
that was removed from the manuals.


Simple solve with the cockpit assist motors.

Which then introduce their own potential failure scenarios.
And if this is a problem in the Max, then it's a problem in all
737s. Are you proposing they all be retrofitted, when there are
other measures being implemented to prevent MCAS from causing
runaway trim? Once that is done, the Max should be no more likely
to experience runaway trim than any other 737.

The problem is with the speed of actuation. Period.
Subsequent difficulty in manually turning the dials and doing so in a
timely manner. Not possible, as we have seen demonstrated
tragically.

It's obviously possible, that was proven by the crew on the LA flight
the previous day. Same thing happened, the pilot just riding in the
jump seat had to tell the other pilots what to do, ie follow the runaway
trim procedure. They did and the plane flew on to it's destination.

Also, the LA flight that crashed, had they followed the runaway trim
procedure that plane would not have crashed either. They flew around
for about 6 mins, using the trim buttons to counter what MCAS was
doing. They never did the runaway trim procedure, but the flight profile
suggests that had they done it, it would have worked as it did the day
before.

Hence the cockpit assist motor suggestion.

We already know what happened, yet you guys keep coming back
spouting off what you read as if no one else did.

So, What The Fuck Is up with That?

You keep making incorrect assertions?

 

[DLUNU]

trader4@optonline.net wrote in news:513bbc83-4475-4460-90dd-
aaa4861b42af@googlegroups.com:

> Which then introduce their own potential failure scenarios.

Only one. It not energizing when the pilot flips the switch.

As I said, the pilot hand method is the last resort.

All systems have failure modes and many are virtually unrecoverable.

So MULTIPLE systems get introduced.

Nit pick BS.