Boeing 737 Max design error

[Jan Panteltje]

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.

Using those for absolute position like inertia based navigation is harder,
I have published some drift test about that in an other group,
then some university did a lot better some years ago.,
but that is not the issue here.
The issue is seeing the nose already pointing down, if so do not continue pointing it more down.

Angle-of-attack vane sensors actually measure the angle of passage of
air around the airframe relative to the inclination of the airframe and
consequently offer information which can't reliably be measured or
calculated otherwise, which is precisely why they use fragile external
sensors to measure it.

Mechanical sensors exposed to the plane's outside are vulnerable to many things,
from birds to ice to what have you.
redundancy is then a must.
As somebody already pointed out the pitot tube issue has also killed many many people,
not so long ago a plane fell out of the sky here due to that, wrong airspeed.
Some years ago I was experimenting here with ultrasonic air speed measurements (wind speed and direction),
more just for fun, a second system using a different measurement system could make things safer I'd think.

Almost look like things are stuck... FAA needs an overhaul and leave beaten paths,

 

gnuarm.deletethisbit@gmail.com wrote in
news:f89a7717-773a-46e9-94a2-587ec64b5ca3@googlegroups.com:

On Monday, May 6, 2019 at 3:52:38 AM UTC-4, bitrex wrote:
On 5/6/19 3:28 AM, Jan Panteltje wrote:
On a sunny day (Sun, 5 May 2019 23:13:13 -0700) it happened
Banders <snap@mailchute.com> wrote in
qaoj9p$1jpn$1@gioia.aioe.org>:

On 05/05/2019 08:25 PM, omnilobe@gmail.com wrote:
Weight and Balance of the 737 Max.

I looked at photos of 737 and 737 Max. The 737 has the front
of the engine at the front of the wing. The Max has the rear
of the engine at the front of the wing. That makes it stall
easily.
Actually, tail-heavy makes for an easy stall, and nose-heavy
makes for a dive. The crash planes weren't stalling, the AOA
sensors just thought they were. So you have it backward.

This photo should put your mind at ease.
https://www.colombotelegraph.com/wp-
content/uploads/2019/03/Cr
ash-Animation-of-Ethiopian-Airlines-flight-ET302-Boeing-737-
Max
-pl ane.jpg

Normally software is tested and debugged, crashes happen,
bit of a nono to debug it in flights that carry people.

My opinion is that such software should be written by pilots,
not by spaced out no flying experience people.

I have bluntly refused to write code for things that I could
not use myself.

Ever write the code for an artificially intelligent sex-robot
that replicates the sensation of making love to a barely-legal
Asian college student majoring in microbiology? Asking for a
friend.

You are too funny! "Asking for a friend"... lol

So are these really available??? Instead of microbiology, do they
come in liberal arts majors? Asking for a friend...

This group does not give any friends away. They must be earned.
And then too, the very definition of the word is askew here.

So do not bother to ask for a friend, because they are rarely
available by request.

 

gnuarm.deletethisbit@gmail.com wrote in
news:731fc8c7-f451-451a-b753-7d4af5ae9551@googlegroups.com:

On Monday, May 6, 2019 at 4:57:15 AM UTC-4, Cursitor Doom wrote:
On Mon, 06 May 2019 08:30:50 +0000, Jan Panteltje wrote:

Like Trump University, normally somebody would get jailed for
running a fake university and handing out fake certificates?

Dunno about that, but I *do* know Obama posted a crudely-forged
birth certificate on the WH website, so maybe Trump is simply
following a recently-established precedent. :-D

What do you expect? If you aren't of this Earth, you have to
produce some sort of document.

Asking for an alien confirmation?

 

Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote in news:qapnfn$din$2
@dont-email.me:

> Indeed, software developer for embedded is also a hardware developer,

Yeah... TraderTard4 does not have any clue about real world
electrically controlled system development.

He is real good at reading up on things though, so he is all filled
up on recent 'findings' etc.

Maybe he'll figure out what 'software' means at some point. And
then... maybe... he'll figure that the authers are not just sit on
their ass pencil chewing desk jockeys.

Hey FatAssTraderTard4... how much do you weigh?

 

trader4@optonline.net wrote in news:20104676-2e55-4f19-be8e-
91be4d27d66b@googlegroups.com:

Get it near
neutral, where you know it belongs,

Easy for you to say.

 

trader4@optonline.net wrote in
news:c6b72f5a-7630-453a-a7f9-80adb2e33097@googlegroups.com:

One way would be to look at other data, eg airspeed and attitude
and see if that's consistent with a stall.

How many times a day do you contradict yourself?

You have more than once declared both to be non factors.

And you forgot your always wrong sig.

 

trader4@optonline.net wrote in
news:bc496342-1823-4eb9-9b07-ab96aae6321f@googlegroups.com:

Altitude would not seem to be a parameter in determining if the
plane is stalling or not.

Technically, no, but tons of plane, in the real world, attitude and
airspeed is a huge indicator of "stable flight" or a possible lack
thereof.

Since, genearally, we fly passenger planes non-inverted, and with all
the gravity and inertia 'on the hat', those two indications can tell a
person a lot about how the plane is flying.

 

trader4@optonline.net wrote in
news:bc496342-1823-4eb9-9b07-ab96aae6321f@googlegroups.com:

Incorrect. There are two clearly marked cutoff switches for the
electric trim, located right at the large trim wheels that are
spinning back and forth beside the pilots. Turned off, MCAS can't
do anything.

The problem is that when finally turned off, the movement MCAS
ALREADY DID perform placed the tail in an unstable position, and
required a SLOW, MANUAL, PILOT INITIATED RETURN.

There needs to be a system that once deativated, allow full IMMEDIATE
restore of pilot control, WITHOUT a SLOW, MANUAL EFFECTOR POSITION
MOVEMENT REQIUISITE.

 

trader4@optonline.net wrote in
news:c9077654-80c6-423c-9d4f-43839263f95f@googlegroups.com:

On Monday, May 6, 2019 at 4:12:17 AM UTC-4,
DecadentLinux...@decadence.org wrote:
omnilobe@gmail.com wrote in
news:c53fb380-eaac-4408-9422-959a9d1f8d3f@googlegroups.com:

Boeing is updating its software so the giant engines can
unbalance the airplane the same way as in the two crashes. Do
you want to fly a plane that only software is used to prevent
stalling? Without software it stalls.

The software was for IF the plane stalled, which it did not.
It was
a sensor error.

It is because the pilot does not always have a sense of a stall
situation, which the craft never get into anyway unless the pilot
and copilot are sleeping.

That's incorrect. The pilots know that a stall is approaching
with the STICK SHAKER and audible alerts.





A stalling plane is pilot error, not airplane error.

The issue with the 737 Max is that at high levels of AOA, the
plane has a tendency to nose up even further. Part of the
certification process is that if you release the controls the
plane is supposed to head in a stable direction, not toward
instability. That is why MCAS was added.





The biggest issue to me is that there was no release switch to
return
pilot control.

Wrong again, as proven by the first Lion Air flight that had the
same problem the day before the crash. The pilot in the jump
seat, who was not one of the crew, correctly identified the
runaway trim problem, told the two pilots flying what to do. They
turned off the electric trim, used manual trim and the plane flew
on to it's destination.

Manual recovery from a positioner is NOT "reset and release".
Instead of a slow, manual dial back method, it needs a full release
of the positioner arm on the tail.

I do not need to discuss symantics with a retard sporting reading
comprehension issues in previous posts. You're a goddamned idiot,
and stuck on krw's "always wrong" BABY BULLSHIT. YOU need to grow
the fuck up, boy.

> Wrong, always wrong.

Yes, you are, dumbfuck4.

You are thick, boy! I said the PILOT sense. Not the plane
feeding back to his hand, which is also reliant on the PLANE'S
sensor, BTW, you fucking retard.

 

Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote in
news:qapdk2$flj$1@dont-email.me:

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.

'and it had no redundancy' which the dopey tradertard4 dipshit will
use to claim he is right.

I said software a long time ago, like the day after it happened.

It was, however there are notable hardware issues which I would
also have done differently.

IOW software change alone could fix it, however there would still
be a chance of the manipulator getting at the end of its travel and
requiring manual reset to the zero trim point. The entire idea has
striong issues where a pilot needs to know how and when a detachment
of this system would be needed to restore pilot control in a
situation where the system was malfucntioning.

They likely needed to install a method to detach the hydraulic arm
completely from the elevator (tail) to 'give back' pilot control if
'requested'. These were not trim tabs, this thing moves the entire
elevator, a pilot's nightmare, IMO.

 

[Martin Brown]

On 07/05/2019 05:17, Riley Angel wrote:

On 2019-05-06 06:46, trader4@optonline.net wrote:

The issue with the 737 Max is that at high levels of AOA, the plane has
a tendency to nose up even further. Part of the certification process
is that if you release the controls the plane is supposed to head in
a stable direction, not toward instability. That is why MCAS was added.

This is incorrect.

In what way is it incorrect? His description is a fairly succinct
explanation of the problem that MCAS was intended to address. Namely
that the physically bigger engines and shifted centre of gravity made
the plane tend towards an AoA stall condition if left to its own
devices. (but only in some fairly rare edge cases)

The AoA sensor and MCAS was meant to intervene before this happened.

In reality if the AoA sensor went bad MCAS would force the plane nose
down into a steep power dive and generate non-sensical stall warnings.
Worse it was able to reset and do it again and again making far more
significant adjustments to the trim than implied by its specification.

FAA were clearly asleep on the job - their responsibility to do an
independent check that Boeing safety system engineering was sound.

--
Regards,
Martin Brown

 

Tom Gardner <spamjunk@blueyonder.co.uk> wrote in
news:Gb_zE.286379$da5.124498@fx13.am4:

On 06/05/19 15:26, trader4@optonline.net wrote:
Altitude would not seem to be a parameter in determining if the
plane is stalling or not.

You can stall a plane at any attitude and any speed.
I've done that, many times.

It is particularly intense when you enter a spin
at 100ft AGL.

Was it in a multi-Decaton aircraft?

Define all these declarations to the parameters of flight we are
going to be seeing these craft involved in.

"enter a spin"? Please.

 

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:466ef7dc-0503-4b47-8485-71d8825dd7c5@googlegroups.com:

The biggest issue to me is that there was no release switch to
return
pilot control.

there is, two switches to turn off electric trim and the pilots
are supposed to know how to handle run away trim by memory

I know what is there. You do not understand my statement.

I do not like an actuator arm locked onto my elevator. That
removes my control and an emergency cicumstance does not restore
control, it merely gives up as the controlling element. The pilot
still then must manually actuate a mecahnism at a much slower rate
than needed, to get back to stick control.

If there is one, it needs to have a FULL release and not be a
manual screw requiring manual return. If it gets released fully,
the pilot's elevator control return is a mere stick push.

 

[Sylvia Else]

On 7/05/2019 9:38 pm, DecadentLinuxUserNumeroUno@decadence.org wrote:

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:466ef7dc-0503-4b47-8485-71d8825dd7c5@googlegroups.com:

The biggest issue to me is that there was no release switch to
return
pilot control.

there is, two switches to turn off electric trim and the pilots
are supposed to know how to handle run away trim by memory


I know what is there. You do not understand my statement.

I do not like an actuator arm locked onto my elevator. That
removes my control and an emergency cicumstance does not restore
control, it merely gives up as the controlling element. The pilot
still then must manually actuate a mecahnism at a much slower rate
than needed, to get back to stick control.

If there is one, it needs to have a FULL release and not be a
manual screw requiring manual return. If it gets released fully,
the pilot's elevator control return is a mere stick push.

The trim is a normal part of the aircraft's control system, and it
doesn't have a fixed correct position to which it could be restored. It
has to be adjusted frequently during the flight depending on many
factors. In the 737, the trim is adjusted by having the tailplane driven
by a jackscrew. The only way that the trim can be restored to its
currently correct state after something has driven wrongly it is to turn
the jackscrew the other way. Once you've disabled the power to the
jackscrew motor, human power is the only way it can be done.

Anything more complicated just introduces other failure modes, and as
has been abundantly demonstrated, you don't want things messing with the
position of the tailplane.

Sylvia.

 

[Sylvia Else]

On 7/05/2019 9:15 pm, DecadentLinuxUserNumeroUno@decadence.org wrote:

trader4@optonline.net wrote in
news:bc496342-1823-4eb9-9b07-ab96aae6321f@googlegroups.com:


Incorrect. There are two clearly marked cutoff switches for the
electric trim, located right at the large trim wheels that are
spinning back and forth beside the pilots. Turned off, MCAS can't
do anything.



The problem is that when finally turned off, the movement MCAS
ALREADY DID perform placed the tail in an unstable position, and
required a SLOW, MANUAL, PILOT INITIATED RETURN.

There needs to be a system that once deativated, allow full IMMEDIATE
restore of pilot control, WITHOUT a SLOW, MANUAL EFFECTOR POSITION
MOVEMENT REQIUISITE.

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. If those are not the switches
that already disable the electric trim, then which should the pilots
trip when they have a trim issue, bearing in mind that time is of the
essence.

So perhaps they trip them all, and the re-enable the trim recovery
system, with the intention of getting things back in order, only to
discover that that's the system causing the trouble when it makes it
even worse.

An out of trim state is perfectly manageable, provided it's not allowed
to go too far, and the fact that the manual trim is slow doesn't matter.

Sylvia.

 

bitrex <user@example.net> wrote in news:Vy_zE.16$s85.5@fx34.iad:

I propose a psychological phenomena called "Transient Reactive
Incompetence" - when faced with a combination of unfamiliar
situation or high stress levels, and presented with a set of
options, humans will tend to pick the least advantageous options
despite the information they already know that suggests to do
otherwise

In that case no human should be piloting any passenger plane. It
should all be computers.

No. SOME humans are really bad in panic situations and they do
panic. Some humans react differntly to panic situations.

Same thing in billiards. One has shot 5 of 7 balls, and the last
two appear to be impossibly hidden at the other end of the table,
behind all of the opponents balls.

Do NOT panic. Your 5th ball shot may get your cue ball down
ther... or not. The odds that the other guy is not going to run
out on you are in your favor slighly. Although you got all of your
balls off the table and out of his way, he may still have been
dazzled by your first 5 shots and will choke from fear at some
point.

 

Sylvia Else <sylvia@email.invalid> wrote in news:gjdbgdFo8vtU1
@mid.individual.net:

> Anything more complicated just introduces other failure modes,

I said nothing about something more complicated.

Having motors turn jacks screws and then expecting pilots to crank
them back manually is ludicrous.

Hell if anything, they should have an "invert switch" on it, so the
pilot could throw that and the plane would reverse it's manipulation
and then flip it back and turn it off at the center point restoring
immediate and even assisted full control. TIME IS OF THE ESSENCE when
an automated control system malfucntions.

It should be hydraulic and releaseable. Not simply "hand resetable"
to your magic 'needs to be here to resume' location. Let it control,
and if it screws up, REMOVE it 100% from control with no manual dial
back requisite. Real simple. Not complex.

 

Sylvia Else <sylvia@email.invalid> wrote in
news:gjdbgdFo8vtU1@mid.individual.net:

and as
has been abundantly demonstrated, you don't want things messing
with the position of the tailplane.

Wake up! That is what MCAS does. It does not move a trim tab. It
moves the entire tailplane (elevator).

 

On Tuesday, May 7, 2019 at 7:15:36 AM UTC-4, DecadentLinux...@decadence.org wrote:

trader4@optonline.net wrote in
news:bc496342-1823-4eb9-9b07-ab96aae6321f@googlegroups.com:


Incorrect. There are two clearly marked cutoff switches for the
electric trim, located right at the large trim wheels that are
spinning back and forth beside the pilots. Turned off, MCAS can't
do anything.



The problem is that when finally turned off, the movement MCAS
ALREADY DID perform placed the tail in an unstable position, and
required a SLOW, MANUAL, PILOT INITIATED RETURN.

That's true, but the simple solution to that is the pilots could have
used the trim buttons to get the trim back close to neutral and then
turn off the electric trim. Even you should be able to understand that.

There needs to be a system that once deativated, allow full IMMEDIATE
restore of pilot control, WITHOUT a SLOW, MANUAL EFFECTOR POSITION
MOVEMENT REQIUISITE.

And how many more failure modes do you think that will introduce, trying
to solve a problem that Boeing already has the solution to? All planes
with electric trim are subject to possible runaway trim. That's why it's
supposed to be understood and committed to memory. Sadly, most of these
pilots couldn't identify it or deal with it. But if using the mechanical
trim was such a big problem and serious issue, it's rather odd that we
all the accident data, it hasn't shown up as being significant, or at all.
Even these crashes, if the pilots had correctly identified the runaway
trim problem and responded, there would have been no crashes. For proof
of that we have the one flight the day before with LA.

 

trader4@optonline.net wrote in
news:c3425dd2-d12c-46e5-a123-b6b50690dac9@googlegroups.com:

And how many more failure modes do you think that will introduce,
trying to solve a problem that Boeing already has the solution to?

Go away, little boy. You keep answering my posts as if I speak of
what IS in place, when clearly your inablity to interpret what you read
is glaring as I have been talking about what I think SHOULD BE in
place.

God DAMN, you are stupid, you putz motherfucker.