
Why Investigators Fear the Two Boeing 737s Crashed for Similar Reasons - ejstronge
https://www.nytimes.com/interactive/2019/03/13/world/boeing-737-crash-investigation.html
======
ycombonator
From pilot forums..

 _Actually Boeing sent out a memo to the pilots of the MAX after Lion Air
crash explaining what may have caused it and what to do. Here is basically
what is happening. Upon climb out the pilot will engage the autopilot with it
in NAV mode. At this time flaps are still extended for climb out and the
aircraft maintains the climb as indicated on the FMS to the assigned altitude.
Once the flaps are fully retracted the MCAS engages. At this point the MCAS
looks at several things but one being the Vertical Pitch Indicator to either
adjust the trim up or down as needed for climb or possibly level flight if
needed at this point. The Vertical Pitch Indicator is reading on some MAX 8 's
10-20 degrees higher than what the aircraft actually is pitched at. This
engages the MCAS to lower the Trim to level the aircraft as needed. Well at
this point the plane over pitches nose down because the Vertical Pitch
Indicator is saying the plane is pitched up, which it is not. The pilot then
will use the Trim on the yoke to trim up also pull back on the yoke and both
the MCAS and the pilot are fighting to keep the plane level. Once the pilot
stops with the trim adjustment the MCAS goes to full trim down due to adjust
for the 10-20 degree increase in the Vertical PItch Indicator it was getting,
which is incorrect. At this point the aircraft is sadly most likely in
downward angle and unable to recover from it. Boeing did say in a memo what
could be done to help stop this during flight. The pilot's can manually
override all autopilot functions including MCAS, either first or at that point
put the Flaps extended one notch to disengage the MCAS. _

~~~
bshipp
The manufacturer is telling pilots to extend flaps to disengage MCAS? How is
there not a tactile illuminated button in all those 3,000 knobs and switches
that the pilot can simply flip to disengage that system? This is just getting
weirder and weirder.

~~~
danielvf
That seems quite wrong - maybe got garbled somewhere. Boeing’s official
instructions to to all operators after the Lion air crash was to follow
existing stabilizer runaway procedures by flipping two switches in the center
of the aircraft to disable electronic control of the stabilizer.

(You can see a video of this procedure from a few years ago:
[https://www.youtube.com/watch?v=3pPRuFHR1co&t=154](https://www.youtube.com/watch?v=3pPRuFHR1co&t=154))

~~~
bshipp
Thanks, that makes much more sense. Maybe they figure it's faster in an
emergency to simply pop out the flaps one notch instead of the pilot
attempting to find a button which they rarely press.

Although, truth be told, I imagine every 737 pilot is keenly aware of that
button's location now...

~~~
matt-attack
I would have thought that was true after the _first_ crash. I'm honestly
baffled how it could happen again. If _I_ was aware of this issue from the
Lion Air crash, wouldn't every pilot in the world know about it?

I mean, if a plane crashes, doesn't every pilot in the world inquire about
what caused it? I wouldn't think that would escape a single pilot. Or do I
have it wrong? Do they not perceive crashes the same way the general public
does?

~~~
londons_explore
Investigations tend to keep things hush till they have final conclusions, and
everyone involved is scared of lawsuits so doesn't want to talk about problems
or workarounds on-record. Talking about a workaround or distributing a fix
before it's vetted by all the right people and procedures could also be
legally risky if the workaround causes other issues.

That tends to mean a lot of issues re-occur multiple times before they're
resolved.

~~~
Joakal
Hush? It's an airplane. Shouldn't the same models be grounded?

Of course, it didn't help if Boeing blamed the pilots (if it was true?). This
would imply to other pilots that everything is ok with the planes.

~~~
londons_explore
Even a plane with a bunch of faults is much safer than a typical journey by
car.

Ground a few planes, and the extra car journeys caused by people choosing to
drive due to disruption to their travel plans easily causes more deaths.

Humans are particularly bad at handling unlikely events (such as the risk of a
plane crash), and in those cases, their 'gut reaction' frequently is the wrong
one.

~~~
notfromhere
Cars have a lot of issues, but those issues are more forgiving than a similar
issue in a plane.

If my cars engine has issues, I can pull over. If a plane's engine has issues,
there's a good chance its going to kill everyone on board

------
cletus
Ok, so disclaimer: not a pilot. At all. But a comment someone made here in
relation to the A380 being retired sprang to mind.

The question came up of why not drop from 4 engines to 2 (on the A380)?
Someone answered that as soon as you change the engines you have to redesign
the wing. As soon as you do that you have to redesign the fuselage. At that
point you may as well just design a brand new plane.

So, my understanding of the 737 Max design is essentially that Boeing recycled
the aging 737 design by putting more powerful engines on it. To make this
work, they had to move the engines (and maybe the wings) forward? Is that
right?

So the MCAS system seems, at least to me, designed to compensate for an
engine, wing and frame configuration that was never designed for.

Add to that that Boeing _seems_ to have cut corners here and given what I
think is called a common rating to the 737 Max (with existing 737 models) and
not really educating pilots on what MCAS is, why its necessary, when it might
kick in and how to override that if the plane is behaving incorrectly.

So, complete non-pilot and non-aeronautical engineer that I am, that seems...
bad.

What's more, Boeing's reaction to the two crashes seems woefully tone deaf.
Two crashes of new aircraft within 6 months of each other in perfect
weather... caution would seem to dictate to ground them. I mean they grounded
early 787s when they found an issue causing batteries to catch fire. What's
different now and then? That issue I don't believe led to any total loss of
the aircraft and those board, not even once let alone twice.

Add to that that the AOA sensor (from what I've read) doesn't have any
redundancy and it just seems like a bad time is inevitable.

Could Boeing really have cut corners in this way? If so, that seems woefully
shortsighted.

~~~
sesteel
We're not going to solve this problem in a HN forum. Planes have a ton of
hours put on them before a passenger ever steps onboard. This is a heavily
regulated industry; and a lot of trust is placed in Boeing and the FAA to only
build and certify safe planes. People make mistakes and that is why so many
people are involved using best practices in the development of complex systems
such as these.

~~~
Theodores
The Space Shuttle had a tonne of hours put on it before we learned of the
O-ring problem catastrophically.

Everyone was trying their hardest and did their best, everything was built to
spec but there were organisational and communication problems. The message
that the dreaded O-rings weren't good for a cold weather launch was not heard
or understood. No malice was involved but, when you have a schedule and
deadlines with lots of large organisation hubris these things happen.

In only the broadest strokes is the current Boeing situation analogous to the
sad fate of the Space Shuttle, however, just because a lot of testing has gone
on and just because there is a lot of regulation does not mean that the layman
appreciation of the situation is wrong. The layman understanding can be big
picture rather than bogged down by intricacy of details.

~~~
sesteel
These calls always seem easy in the aftermath, when you have the benefit of
hindsight. In both of these cases, billions of dollars are on the line, but
the truth is, there is always some risk. There is, as we've all heard, a
greater risk of us dying in our car than any type of air catastrophe. Yet we
still drive. How many flights have these planes taken? I can almost guarantee
that Boeing did not build this sensor; the sensor has a spec sheet, its
operational capability was verified in a laboratory and the FAA approved it.
If the problem was not recoverable, they would have grounded the planes after
the first accident; it appeared to be a training issue. Anyway, we can only
make decisions with the information we have; it was the satellite data that
suggested there was a link. It was then that the direction was clear and the
call was made; this system is too dangerous as it is.

Making decisions based on fear is a fools errand. It is how you spend
trillions of dollars waging wars combating terrorism when the risk of a terror
related death is the US is lower than getting struck by lightening.

~~~
hyeonwho4
But the choice here is not "fly or drive", the choice here is "fly 737 MAX or
fly another plane". I expect very few fliers have the budget and time to
change flights, and those who can, will.

------
aberoham
Did anybody notice this 737 Max-7 test on Tuesday? Quite an interesting
altitude and speed pattern --

[https://flightaware.com/live/flight/BOE1/history/20190312/16...](https://flightaware.com/live/flight/BOE1/history/20190312/1630Z/KBFI/KBFI)

~~~
bcyn
Could you explain to a layman like me the interesting parts?

~~~
jen729w
Check the 'detailed track log' \- you have to click to show it on mobile - for
the altitude & speed graphs.

A normal flight
([https://flightaware.com/live/flight/QFA804](https://flightaware.com/live/flight/QFA804))
goes up smoothly. This one very much does not, and the patterns shown bear a
resemblance to a layman like me to the published flight patterns of the Lion
Air flight.

Note the very steep climb on this flight also. Who knows what that means.

People who know way more than I do, please step in!

~~~
samstave
I would assume they were testing flight overide logic... which takes some
balls...

~~~
yjftsjthsd-h
Yeah, I can hardly imagine being the crazy/gutsy person actually doing a test
of failure modes on a plane _in the air_. I mean, what exactly are your
options if it goes wrong? _Maybe_ you can parachute, but seems like a long
shot given altitude and the plane itself (just aim it at an uninhabited area
before you jump?)

I'm just... gonna go back to my office job, I think.

~~~
bwilliams18
The type of error that this appears to be is solved if you know what it is,
you can just turn the MCAS system off and hand-trim the plane no problem. So
testing the failure at a high altitude is of a relatively low risk, you've
specifically briefed and likely practiced in a simulator exactly how to turn
these systems off. The pilot not flying the plane almost certainly has their
hands right on the switches and or fuses.

~~~
samstave
Serious question:

WHY has not Boeing turned every single aircraft of theirs into a drone-capable
device?

They should have a person, like we have with air traffic control, sitting
monitoring all planes in flight, but that person is sitting in a pit on the
ground.

They have to monitor X number of craft - and in the event of any anomolous
data.... be ready to take over control of the machine in the air.

Imagine if all pilots had a life sensor on them, and should they fail -
control of the craft auto switches to ground control.

We can already kill millions of people with dron pilots in nevada. Why not
make drone pilots fly airliners.

Heck, in a few years - you just need a few technicians in the cock pit to be
sure there are not physical issues - and let the ground pilots do all the work
- but the air pilots can take over if the ground connection is lost...

~~~
CamperBob2
Arguably this should be possible for cars as well, as a transitional stage
towards full self-driving capability.

With planes you could argue that the additional complexity of implementing
something like this would be a safety liability in itself. It's not 100% clear
what problem it would solve. On the other hand, plenty of people would pay to
not have to do the driving themselves.

~~~
samstave
I freaking love this idea with cars.

Pay disabled people to GTA 5 you home....

(aside: japanese cafes are employing disabled-driven robots....)

------
bshipp
Out of all the previous Canadian Minister's of Transport we've had over the
years, Garneau's opinion is one I'd actually pay attention to. He flew on the
space shuttle three times, was in space for 30 hours, and has a doctorate in
Electrical Engineering. Not that he's an expert in this, but if there's any
Canadian politician in the past few years who would be able to question their
public servants and make sure the data supported the decision, it's likely
him.

Canada's two largest carriers, Air Canada and Westjet, have a combined 37 Max
8s in their fleets, so I'm sure this wasn't a position Garneau took likely.

[https://www.theglobeandmail.com/business/article-
grounding-o...](https://www.theglobeandmail.com/business/article-grounding-
of-737-max-8-spells-turbulence-for-air-canada-and-westjet/)

~~~
rkagerer
This guy handed me my degree when I graduated, and I share your respect for
his accomplishments. But I do expect he took some PR flak, considering just
two days ago he spoke fairly strongly against a ban (stating he would board a
737 MAX "without hesitation") even as other countries including the EU
implemented one, and despite the Air Canada Pilots Association calling on him
to "to take proactive action to ensure the safety of the Canadian travelling
public".

Not disputing your point, or even criticising his actions (I don't know enough
about the situation to do so, aside from having a stake by being booked on an
affected flight). Just filling in a bit more of the story.

~~~
gdpgreg
With all due respect to Garneau, I don't think the statement that he wouldn't
hesitate to get on a max 8 doesn't really mean much considering he willingly
flew 3 times on the most deadliest aircraft of the modern era.

~~~
victor106
I would respect anyone who changes their opinion after seeing new facts.

I don’t understand this ridiculous burden we place on our politicians. Why
can’t they change their opinion on things when new facts come to light? I am
not saying changing principles but opinions.

Like someone asked “I see new facts and change my opinion. What do you do?”

------
olliej
There's nothing new here - it's rehashing the same "these are similar so may
be the same cause" as every other article on the topic.

~~~
rootusrootus
Not sure why you're getting downvoted. You are exactly right, this article
contains zero new information. It's just another opportunity for HN "experts"
to pontificate about airplanes using mostly incorrect armchair analysis.

~~~
freddie_mercury
> It's just another opportunity for HN "experts" to pontificate about [X]
> using mostly incorrect armchair analysis.

Isn't this just classic Gell-Mann amnesia? All HN threads are like this.
(Probably all threads everywhere on the internet are like this.)

The next time you read a thread on [to skim the current front page] Facebook
data, consensus protocols, Google hardware, facial recognition, death metal,
or the British coastline...before reading the comments remind yourself

"this is just another opportunity for HN 'experts' to pontificate about [X]
using mostly incorrect armchair analysis"

~~~
mherdeg
> Isn't this just classic Gell-Mann amnesia?

My favorite-thing about the Gell-Mann amnesia effect is that the coiner of the
term himself, in the very speech where he coined the term, fell victim to that
effect.

To Michael Crichton's great credit, in the 2002 talk where he defines the
term, he gives us an extremely specific, testable hypothesis we can use to
evaluate his idea.

He says that the "effect" is as follows: it is not worth your time to read the
newspaper and all newspaper stories which contain any kind of "speculation" or
"predicting" have no predictive value.

The example he chooses is the 2002 United States steel tariffs. Most
mainstream newspapers he reads have quoted experts whose consensus is that the
then-contemporary 2002 tariffs will negatively affect GDP. His hypothesis is
as follows: we will find in retrospect that these predictions were useless and
US GDP will not clearly be damaged by the 2002 tariffs.

Was he right? Well... Years later, there is consensus among experts that US
GDP was in fact negatively affected by 2002 steel tariffs (links to sources at
[https://en.wikipedia.org/wiki/2002_United_States_steel_tarif...](https://en.wikipedia.org/wiki/2002_United_States_steel_tariff)
).

Driven to attack the idea of trusting any experts who predict the future,
Crichton's key example was readily disproven.

I have often re-read Crichton's talk and have found myself wanting to project
extra layers of meaning on top of his ideas; I find myself arguing on his
behalf to try to change what he is saying to make it "more true". The words he
uses are carefully chosen and seem like they add up to an interesting idea.

It is true that people seem to believe information without factual basis when
it's presented in the "news" format; it's also true that people seem to
believe opinions they already agree with when presented to them in any format;
and it is certainly true that people asked to make predictions with incomplete
information sometimes guess wrong, yet their "best guess" predictions are
sometimes presented without robust explanations of the uncertainty and what it
means.

All that is true. But it doesn't change the fact that the "Gell-Mann Amnesia
Effect" was introduced by saying that the untrustworthy lamestream media needs
to stop yammering already about those steel tariffs hurting GDP, which there
is no way they could predict. (It appears the media was right on that one.)
Worse than relying on anecdata, though, his talk does not propose a robust way
of actually measuring whether media predictions are accurate -- he doesn't
even try to measure that, let alone present results.

(I have giggled at this before -
[https://news.ycombinator.com/item?id=18005236](https://news.ycombinator.com/item?id=18005236)
)

~~~
perl4ever
"He says that the "effect" is as follows: it is not worth your time to read
the newspaper and all newspaper stories which contain any kind of
"speculation" or "predicting" have no predictive value."

To me, "no predictive value" is consistent with sometimes being right,
possibly by chance. It means being wrong enough that you can't assume either
positive or negative correlation with the truth. It's easy to hide statements
which are true and should be obvious in a sea of confusing nonsense.

------
jey
AFAICS, the "new satellite data" is just the usual ADS-B data that led
everyone else to the same conclusion, but picked up by a global network of
satellites[1]. (Sites like FlightAware24 are instead based on data contributed
by a global network of volunteers listening to ADS-B broadcasts in their local
area.)

1\. [https://aireon.com/resources/overview-materials/its-just-
ads...](https://aireon.com/resources/overview-materials/its-just-ads-b/)

------
mcguire
" _The oscillation of roughly 15 to 20 seconds is a telltale sign that
suggests the M.C.A.S. system may have been involved, said R. John Hansman Jr.,
a professor of aeronautics and astronautics at the Massachusetts Institute of
Technology._

" _Planes like the Boeing 737 oscillate naturally, he said, because of
turbulence and and other effects. But those swings have different time spans:
either between five and eight seconds, or a minute or longer. The variations
in the intermediate range of 15 or so seconds have no other obvious
explanation, he said._ "

Both planes porpoised with periods of~20 seconds during their flight.

~~~
selimthegrim
Assuming this is a phugoid oscillation?

------
js2
Here’s the FAA Emergency Order of Prohibition:

[https://www.faa.gov/news/updates/media/Emergency_Order.pdf](https://www.faa.gov/news/updates/media/Emergency_Order.pdf)

 _On March 13, 2019, the investigation of the ET302 crash developed new
information from the wreckage concerning the aircraft 's configuration just
after takeoff that, taken together with newly refined data from satellite-
based tracking of the aircraft's flight path, indicates some similarities
between the ET302 and JT610 accidents that warrant further investigation of
the possibility of a shared cause for the two incidents that needs to be
better understood and addressed. Accordingly, the Acting Administrator is
ordering all Boeing 737 MAX airplanes to be grounded pending further
investigation._

I’m curious about “the wreckage concerning the aircraft's configuration just
after takeoff“ part as that’s the first I’ve heard about aircraft
configuration having been recovered from the crash site. Maybe something about
the horizontal stabilizer positon when the crash occurred?

~~~
chopin
Afaik the horizontal stabilizer is deflected by a worm gear. Even with a
totally destroyed fuselage I think it would be possible to recover parts of
the gear which allow judging its position at time of impact. As well it is in
the aft part of the plane where also the flight recorders are placed as they
have there the best chance of survival.

------
trhway
Besides the engines moved forward those are 2x higher bypass engines and thus
point of thrust is moved even more forward resulting in even more of pitching
torque - basically the plane seems to be like a Hayabusa bike lifting the
front wheel up at the good throttle.

------
crb002
Similar reasons would be better news. Different reasons could mean they are
hunting two fatal bugs.

------
gabrielblack
In this list of 737 accidents, correct me if I'm wrong, seems that the crashes
for similar reasons (shortly after takeoff) are 3 , not 2. There is other one
(May 18, 2018 ) involving a 737-100/200 that seems strictly related to the
other two by time and dynamic:
[https://en.wikipedia.org/wiki/List_of_accidents_and_incident...](https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_the_Boeing_737)

~~~
kayfox
In that case it was a really old aircraft that stalled in the way that MCAS is
designed to prevent.

One thing to note is that this flight is very similar to the previous
Ethiopian crash.

------
known
How did Boeing QA sign off this anomaly
[https://en.wikipedia.org/wiki/2019_Boeing_737_MAX_groundings...](https://en.wikipedia.org/wiki/2019_Boeing_737_MAX_groundings#737_MAX_design_issues)

------
m_mueller
Tried to read on Android Chrome, cannot click away cookie policy. Am I the
only one? Miss safari reader mode...

~~~
victor9000
Android Firefox has a solid reader mode

~~~
yjftsjthsd-h
And ublock/umatrix, which are also helpful for making things usable.

