
Boeing Knew the AOA Disagree Alert on the 737 Max Didn’t Work - samrohn
https://www.aviationtoday.com/2019/05/06/boeing-angle-of-attack-disagree-alert/
======
Deimorz
This is blogspam from over a month ago.

Here's the official release from Boeing that this is just reiterating (from
May 5): [https://boeing.mediaroom.com/news-releases-
statements?item=1...](https://boeing.mediaroom.com/news-releases-
statements?item=130431)

NYTimes article:
[https://www.nytimes.com/2019/05/05/business/boeing-737-max-w...](https://www.nytimes.com/2019/05/05/business/boeing-737-max-
warning-light.html)

HN discussion of that article:
[https://news.ycombinator.com/item?id=19835608](https://news.ycombinator.com/item?id=19835608)

~~~
acqq
More important than "the execs believed all planes have the feature" is that
the claim after the Lion Air's crash was that at least these companies which
did pay for the "extra" would be able to not fly the dangerous planes, as the
technicians would discover that one of AoA vanes is not working while the
plane is still on the ground. But that was also a lie (from the NYT article):

"“We were told that if the A.O.A. vane, like on Lion Air, was in a massive
difference, we would receive an alert on the ground and therefore not even
take off,” said Dennis Tajer, a spokesman for the union representing American
Airlines pilots. “That gave us additional confidence in continuing to fly that
aircraft.”

But in the last several weeks, Boeing has been saying something different. Mr.
Tajer said the company recently told American pilots that the system would not
alert pilots about any sensor disagreement until the aircraft is 400 feet
above the ground."

------
aaronbrethorst
_" Senior company leadership was not involved in the review and first became
aware of this issue in the aftermath of the Lion Air accident."_

i.e. the buck stops somewhere else!

~~~
raverbashing
And the damning thing was that they still thought it was ok to keep it absent

There are a couple of reasons why "the existing functionality was acceptable"
is a poor excuse:

\- It was present on early models (it was not an optional feature)

\- Its triggering indicate to the pilots that something is amiss. Especially
after the 1st accident there should have been an association "AOA problems ->
potential MCAS problems"

------
jandeboevrie
First line: In 2017, Boeing learned that the angle-of-attack (AOA) disagree
alert — a standard feature on all 737 MAX aircraft — didn't work on the
majority of the planes. The company determined that the alert was not
necessary for safe operation, so it did not inform operators or the FAA.

So all those lives could have been saved and they knew it in 2017? And they
let two crashes happen? Explain that to the ones who got left behind...

~~~
ealexhudson
Previously, the thinking was that most airline pilots weren't using the AOA
information anyway - they had included the feature because some airlines had
ex-military staff who were used to having it, but most didn't. So the AOA
being wrong wouldn't necessarily be that urgent a problem, if it was only the
pilot we were talking about.

Unfortunately, it wasn't only used by a small number of pilots, but also by
MCAS. It seems that MCAS kicks in during scenarios that weren't originally
intended - i.e. take-offs as well as stall scenarios - and they got two other
things wrong:

* MCAS was revised to be more aggressive toward the end of testing;

* MCAS has a bug / design flaw that allowed the system to command an increasingly steep nose-down each time a pilot overrode it.

There were lots of little signs all over the place that there was a problem.
Unfortunately, they didn't seem to join the dots, and each seemingly-
reasonable decision they made when taken together added up to a dangerous
scenario.

~~~
m_mueller
Or alternatively they didn't _want_ to join the dots.

~~~
hvindin
I would be sceptical that anyone wouldn't want to join the dots if it meant
that their most popular product stayed popular and they didnt end up with
blood on their hands after many many people died because those dots remained
unjoined.

At _worst_ it might be plausible that in a very specific scenario some people
knew about enough of those dots that they knew it would be a PITA to go back
and make everything right, but they almost certainly _didn 't_ know about
enough of those dots to actually understand the scale of their fuck up there.

In which case I would say it's still a matter of someone not joining the dots,
it's just makes them moderately more culpible, then steeply more incompetent
the more of those dots they knew about but still didn't flag as problems.

~~~
cottsak
That's possible but unlikely.

I'd be willing to bet there are engineers who are experiencing a lot of guilt
about this right now. Not many.. but maybe even a handful. These are people
who might not have been able to do anything about the problem had they
realised the true scale of the risk. But I'd guarantee they exist, even if
only in a number one can count on one hand.

It's a failing of the company culture where these engineers were not made safe
to speak up; a missing facility for those who knew, to get the message to
those who __would __do something about it had they known. It was likely a
function of unhealthy (toxic?) company culture which precluded this
psychological safety.

I bet these folks feel pretty bad.. maybe even responsible. They won't speak
up tho, lest being labelled or even targeted with the full blame. They will
suffer in silence, in some ways like the many soldiers ordered to do things
they didn't think were right, but did anyway.

------
josefrichter
I'd be curious to read more about those cases when MCAS was engaged, but the
pilots were able to recover. There were a number of them.

~~~
philjohn
IIRC there was one on the Lion Air plane that crashed, but because they had a
737 instructor aboard helping aleviate the pressures when things started going
wrong they were able to land.

------
CamperBob2
This is an interesting point. Some will argue that the AOA disagree indicator
wouldn't have made any difference in either crash. But it seems like it
_would_ have caused Lion Air to take their aircraft out of service and fix the
problem after it occurred on the penultimate flight.

Of course, the fact that they kept the aircraft in service without bothering
to diagnose the issue that almost got everyone killed on the previous flight
is a counterargument in itself. There's more than enough gross negligence to
go around in this case, unfortunately.

Edit: actually, it appears that Lion didn't spring for the "optional" warning
indicator feature in the first place.

~~~
mormegil
> actually, it appears that Lion didn't spring for the "optional" warning
> indicator feature in the first place.

AIUI, there was no "optional warning indicator feature" at all. The AOA
disagree warning should have been a standard feature. Only the indicator of
the current AOA was the optional feature.

------
frostburg
Boeing should be fined enough that "shareholder value" would be roughly zero
after all the assets are sold to pay the fine.

That (besides any personal penalty that might be appropriate, of course) might
realign the incentives for the next set of managers facing similar choices
somewhere else, but it won't happen.

~~~
dahdum
It might feel good to do that, but you’d be putting tens of thousands out of
work, and handing the industry over to Airbus, which last I read, had an ever
so slightly worse safety record (though both are quite good). That’s bad for
cost and safety long term.

By all means I support axing those responsible and criminal charges where/if
appropriate, but a company death sentence does not serve the public interest.

~~~
MarkSweep
I think the argument for making it a corporate death sentence is that future
companies and shareholders will know it is in their interest to make airplanes
that don't kill people.

More abstractly, if you value human life at a high enough dollar value and
make corporations liable for loss thereof, they will expend effort to preserve
human life. It appears that currently the externality of killing people is
priced at a level where Boeing does not mind killing people.

I don't know if lawsuit liability is the best way to police corporate
behavior, but it is big part of the system we currently have in the USA.

~~~
briandear
They do make airplanes that don’t kill people. More people die per mile in
cars than have ever died in airplanes. The train fatality rate in the United
States is higher than that of airplanes — the majority of those airplanes
being Boeing. More people died in cars yesterday than in all of 2018 for
Boeing. And given fatalities per mile, air travel on Boeing airplanes is safer
than any other form of transportation. Suggesting that Boeing makes planes
that “kill people,” is about as ridiculous as saying that Specialized makes
bikes that kill people. The safety record of American aviation is unmatched —
and most of those planes are Boeing. Let’s tamp down on the hyperbole.

~~~
cf498
Because its relative. You cant get car traffic as safe as airplanes. Its not
reasonable to hold Boeing to the same standards as automotive traffic.
Automotive traffic is simply far more dangerous then flying. You also wouldnt
be ok with people dying from bread as long as its fewer then the amount of
people dying to e.coli or fish poisoning. The question is always how easy it
is to prevent deaths not how many are acceptable for a given branch.

------
basicplus2
<The company said that a Boeing-convened safety review board affirmed in
December that the absence of the AOA disagree alert from flight displays would
not have presented a safety issue.

The FAA confirmed the discussion and that it deemed the issue "low risk" at
the time.>

So the FAA is culpable as well as Boeing

~~~
briandear
How is the FAA culpable? No American planes crashed? The FAA doesn’t control
regulations for Indonesia do they? Indonesian maintenance standards are
atrocious. Look at Lion Air’s record. Is it a coincidence that one of the
world’s worst airlines also happen to crash the 737 and yet Southwest Airlines
that flew an order of magnitude more flights on the Max never had even a
scratch? Lion Air knew they had a problem on the penultimate flight — but they
ignored it. The FAA would never allow that level of negligence in the US: that
plane would have been grounded. The FAA has a better safety record than anyone
else — and that includes the Europeans.

~~~
salawat
Doesn't matter. The design itself was unsafe. The reason the FAA has
historically been so highly regarded is that it has fostered a design
environment of generally implicit design safety.

Ironically, however, Europe has called the FAA to task before on several
models of Boeing aircraft that weren't implicitly design safe. See the D.P.
Davies Interview w.r.t the Boeing 727 certification process.

They cut corners, and did not inform pilots of the inherent risk that existed
in a manner concomitant with the severity of the result. This originated in a
desire to submit an aerodynamically deviant aircraft, yet attain type
airworthyness certification with minimal friction.

Lion Air may be last in safely operating aircraft, but the design standards
were generally written in such a way where even the _worst_ operators stood a
good chance of going up, and getting back down free of harm.

Obviously, that is no longer the case.

------
dfeojm-zlib
Still wondering about why 737 NGs (-600,-700,-800,-900) are still deemed
"airworthy" despite the 2010 investigative report on Boeing's intentional
deception and cover-up of Ducommun's absurdly dangerous and substandard
critical structural fuselage components. Several passengers have already died
from fuselage breakups from hard landings and runway overruns when previous
aircraft have survived similar situations intact; plus the possibility of
aircraft catastrophically breaking up in heavy turbulence.

------
afarrell
Boeing has over 100,000 employees. What does it mean when a sentence says that
"Boeing knew X"?

~~~
maltalex
This was my question too. The real question isn't whether _someone_ in the
company knew. It's whether someone with decision power knew, and who was that
person? And also, if people with decision power did not know - then why?

~~~
cottsak
I tend to agree.

And if this can be traced to someone with influence, how was it possible for
the company to be structured so that a single point of failure was possible -
that speaks to a larger problem and then puts the senior exec on the chopping
block too.

------
jdsully
It’s not clear the AOA disagree light would have saved the two flights, so
waiting for the next release was reasonable.

The critical jump pilots had to make was that this was a trim runaway event.
AOA indicators were not connected to the trim system before.

~~~
pauljurczak
> It’s not clear the AOA disagree light would have saved the two flights

Unless you change it to "It’s certain the AOA disagree light would not have
saved the two flights", you are basically arguing for presence of AOA disagree
light.

~~~
jdsully
The FAA provides time to fix issues if its deemed to not be a critical issue -
because if every problem results in grounding planes then people just won't
report issues. The added stress of millions in losses could also result in
subpar fixes that cause more problems.

In this case I agree with the FAA's initial decision for this indicator. Its
extremely unlikely having it working would have prevented the two crashes. The
mere fact that it might have helped doesn't make the original decision
incorrect.

