
737 MAX crashes “linked” by satellite track data, FAA says - close04
https://arstechnica.com/information-technology/2019/03/faa-acting-chief-says-satellite-data-provided-link-between-boeing-crashes/
======
_s
Many aviation enthusiasts / pilots first go to is to have a look at the flight
data - usually available on FlightAware / FlightRadar24 and a few other
websites, plus LiveATC usually can provide recordings of the flights
communications to towers as well.

Most immediately saw parallels with the Lion Air crash - but as always, we as
laymen should refrain from coming to conclusions until after a thorough
investigation has been completed.

The fleet has been grounded, and reports / data will slowly trickle out as
more conclusions are made.

~~~
rootusrootus
It is/was a real stretch to draw any parallels based on the amount of ADS-B
data we got out of FR24. The plane went out of range of the nearest FR24 ADS-B
receiver just a few minutes after taking off. People see what they want to
see.

It sure is an impatient world we live in. Probably attributable to the
Internet, our insatiable need for more information _NOW_. Everyone ripping on
the FAA for not making a grounding decision until yesterday, even though the
crash itself happened just four days ago.

~~~
duado
I rip the FAA for that. The level of air safety we have is because we have
traditionally protected it fiercely. Within minutes of the second plane going
down, the type should have been grounded until the FAA could figure out
whether they were related. If not, they can unground them later.

~~~
rootusrootus
There is a good reason we teach kids the allegory about the boy who cried
wolf. If the FAA panics that easily they will destroy their creditability just
as quickly as if they take too long. If they really did get new evidence
yesterday and it prompted their decision, then I think they deserve more
credit than the other world agencies that freaked out in a matter of hours. I
want our regulators to be cold and analytical.

~~~
threeseed
It is not panicking or freaking out to err on the side of caution and ground
flights.

In fact it seems quite prudent for a regulator to do this.

~~~
ncallaway
> It is not panicking or freaking out to err on the side of caution and ground
> flights.

It can be, though.

There is a risk inherent to air travel. The _safest_ thing to do would be to
ground all flights of all aircraft permanently.

That wouldn't be prudent, though, because we can mitigate the risk until the
benefit of air travel outweighs the risk of dying during air travel.

The prudent thing to do is to carefully evaluate the risks, and make a
determination when the risks become too great.

~~~
FartyMcFarter
A statistically unlikely pair of crashes or the same model of plane, same
phase of flight, same consequences, and similar altitude variations would seem
to be enough justification for a prudent grounding.

If a company releases a new version of their software and it crashes twice in
similar ways (much more frequently than the previous version), that is also
enough reason to rollback the release and investigate, especially if the
software has any critical use cases.

~~~
snowwrestler
If you release a software update and only 2 out of thousands of nodes are
experiencing problems, would you honestly take the whole application offline
over that? Most software companies would not, in my experience. They would
take a close look at those two nodes first.

Obviously commercial aviation has much higher standards than software vendors
generally do. Airline tickets don’t generally come with 5,000 word EULAs with
all-caps provisions like “THIS SOFTWARE IS NOT FIT FOR PURPOSE AND SHOULD NOT
BE USED FOR ANY REASON AND YOU ASSUME ALL RESPONSIBILITY FOR ANY NEGATIVE
OUTCOMES OF ANY KIND” etc.

Two crashes in close succession seems like an obvious abnormality. But because
standards are so high, to commercial aviation providers and regulators, _every
single crash_ is treated as a significant abnormality. So the question is, why
don’t they ground all models of a certain plane after a single crash? Once you
understand that, the same logic applies to two crashes.

~~~
dmichulke
The first fallacy in this is that (as I understand it) you only think about
probabilities, while in fact it's about probability (of something bad
happening) times the cost of that bad thing.

Clearly, a chance for a bug losing you 300$ is much less of a problem than a
chance for a bug killing 300 people.

The second thing is that a software update may render previous knowledge
useless.

Just because the old software ran successfully on 100k nodes, it might still
be the case that 2 out of 1000 new versions fail, so then you have 0.2%
failure rate. That doesn't mean you should take out all 100k nodes but it
means you might want to stop the 1k nodes in accordance with the principles
laid out above.

Finally, I am not even sure why this is a yes/no question. How about: You're
allowed to use the plane but you cannot rely on a defense of "the FAA said it
was ok" if something happens, so talk to your insurance before.

------
cjbprime
This data's been available for several days at the least, right? Are they just
trying to come up with an explanation for why they now support a grounding
that they opposed yesterday that isn't "the President told us to"?

~~~
root_axis
I was unaware that the president was involved in the decision making process,
do you have any more details on that?

~~~
Bud
There's zero evidence so far that Trump had anything to do with that.
Certainly he shouldn't.

But of course, we _should_ have a fully-functioning and fully-staffed FAA,
too. But we don't, because of Trump intentionally hamstringing it, and because
of antics like trying to get his personal pilot named head of FAA when he came
into office.

~~~
dagoat
John Dunkin is the pilot you refer to. Do you think that he should be excluded
from the job based on his Trump affiliation - or are there specific things he
lacks that would mean he would be unsuitable for the job?

It appears that Mr. Dunkin has decades of experience as a pilot and has no
previous affiliation with the FAA.

~~~
bdavisx
Decades of non-management experience in the same field qualifies you to run a
30,000 employee agency?

I've got decades of non-management software dev experience, perhaps I should
be in charge of Microsoft?

~~~
dagoat
Good point. And I think that is an important consideration.

However, to be clear, he does have smaller scale management experience - most
likely consistently, but at the very least during the Trump campaign.

Perhaps he would be wrong for the job, but certainly there are examples of
both experienced and less experienced/inexperienced persons doing awful jobs
at the helm of agencies, companies, and even countries.

I would also add that being in charge of such a massive organization often
means you do not get to make off the cuff or unilateral decisions so easily as
you would, say, at a 50 person organization. You do certainly get to steer,
but there are many other hands on the wheel.

As for you being CEO of MS, Satya is doing a decent enough job + I know
nothing of your background and you come off as under confident in your ability
to do the job. So I'll go with no :p

------
alexandercrohde
It's interesting to note that, as emotionally salient this is for HN, in terms
of significance compared to other problems out there it might be lower.

It's a bit of a flaw in human nature that easily-pictured problems scare us
much more than abstract/distant problems.

Is it silly to press for a moral value of striving to make our morality align
with numeric measure of significance rather than sensational emotions?

~~~
oliveshell
I think this 737 MAX issue resonates with the HN crowd because, along with the
emotional factors, it’s a high-stakes technical problem.

The two fatal crashes were caused by an interplay of hardware, software
design, and human factors, and studying things like this is fascinating to
those of us who are interested in building systems so that catastrophes don’t
happen.

~~~
karthikb
It's a high stakes technical problem that is _caused by not addressing
technical debt_ \- something that the many of the HN readership sees on a
daily basis in other domains.

MCAS was created as a way to compensate for instability caused by strapping
large engines onto an aircraft not originally designed for it, as opposed to
doing a redesign.

~~~
madeofpalk
Also there's the "sales/business people made the problem worse" angle as well
that developers just love.

------
jdsully
How is it we have such precise satellite location data on these crashes - but
MH370 can just disappear.

~~~
tus87
Didn't you read the part about the transponder being switched off?

~~~
sowbug
Please see the "In Comments" section of
[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html).
Writing "The transponder was switched off" would contribute the same substance
to the conversation but without the insinuation.

------
d1str0
It says the damaged flight recorder was sent to France. Do they have a better
recovery/repair team than, say, the US’ FAA and NTSB, or is it more likely
just because France is much closer to the crash site?

~~~
agumonkey
I don't recall why but I think MH370 recorder was also sent to France.
Probably to avoid conflict of interests ?

~~~
yoramv
You mean MH17?? MH370 was never found.

~~~
agumonkey
maybe it was the potential piece of fuselage found later then ?

------
Animats
It's early. The graphs show a dive after takeoff while speed is increasing.
That's a loss of control; nobody does that on purpose. More info is needed to
know _why_. Uncommanded nosedown? Actual stall? Something else?

------
everdev
How does the theory of a faulty AoA sensor align with eye witness accounts of
smoke coming from the plane?

Also, the altitude data seems to cut out at it's peak. Was the decent so rapid
it couldn't be tracked?

~~~
MichaelApproved
> _How does the theory of a faulty AoA sensor align with eye witness accounts
> of smoke coming from the plane?_

They don't need to align. Eyewitness accounts are so bad, it's surprising
they're allowed in court.

"Why Science Tells Us Not to Rely on Eyewitness Accounts - Eyewitness
testimony is fickle and, all too often, shockingly inaccurate"

> _Many researchers have created false memories in normal individuals; what is
> more, many of these subjects are certain that the memories are real._

> _In one well-known study, Loftus and her colleague Jacqueline Pickrell gave
> subjects written accounts of four events, three of which they had actually
> experienced. The fourth story was fiction; it centered on the subject being
> lost in a mall or another public place when he or she was between four and
> six years old. A relative provided realistic details for the false story,
> such as a description of the mall at which the subject’s parents shopped._

> _After reading each story, subjects were asked to write down what else they
> remembered about the incident or to indicate that they did not remember it
> at all. Remarkably about one third of the subjects reported partially or
> fully remembering the false event. In two follow-up interviews, 25 percent
> still claimed that they remembered the untrue story, a figure consistent
> with the findings of similar studies._

[https://www.scientificamerican.com/article/do-the-eyes-
have-...](https://www.scientificamerican.com/article/do-the-eyes-have-it/)

~~~
refurb
You example is subjects believing a _false story given to them_. That's
different than someone reporting something that they believed they saw with no
prompting from anyone else.

~~~
semi-extrinsic
We don't know whether that happened in this case. Maybe journalist (who was
there hours later) asked the eye witnesses "did you see smoke or hear strange
sounds?" \- if so, all bets are off.

------
bittweeker
A Pilot who hitched a ride in cockpit saved doomed Lion Air Boeing 737 Max day
before it crashed. As the Lion Air crew fought to control their diving Boeing
737 Max 8, they got help from an unexpected source: an off-duty pilot who
happened to be riding in the cockpit.

That extra pilot, who was seated in the cockpit jumpseat, correctly diagnosed
the problem and told the crew how to disable a malfunctioning flight-control
system and save the plane, two people familiar with Indonesia’s investigation
told Bloomberg.

Why wasn't this information passed on to all Lion Air pilots?

------
bittweeker
Sound like Air Bus A330 nose dive problem, they had with the software 3 years
back, sounds a lot like the Boeing 737 MAX 8 problem that is burning up the
news channels. Did AIR BUS ground their A330 world wide fleet when this
happened? How did Air Bus handle this?

------
WhuzzupDomal
I've seen many discussions about whether the groundings of the MAX (especially
the earliest ones) are hysterical/political or is it based on any facts. The
facts is two of these BRAND NEW planes crashed within 5 months under very
similar circumstances. Doesn't that alone seems statistically justified to
ground the MAX? The chances of human error and/or environmental factor
striking twice within such short period seems infinitesimally low, no? Just
curious how that math works out.

------
js2
I don't see anything in this article that wasn't already in the FAA's
Emergency Order of Prohibition[1]:

 _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._

This article is further missing the "new information from the wreckage
concerning the aircraft's configuration" piece, which is in the NPR
interview[2]: _And that, coupled with some physical evidence we found at the
crash site led us to believe that the similarities were too great not to
consider that there was a common thread._

So it wasn't just the flight path, which indeed was sufficient for other
countries, but the addition of physical evidence as well:

 _And when you have a common thread between two accidents, then the argument
for grounding becomes necessary. Grounding becomes necessary, and so that 's
what we did. We didn't have that link until yesterday morning, yesterday
afternoon about midday.

GREENE: But isn't this something that analysts and experts have been saying
for days now, that these two crashes appeared similar?

ELWELL: Yeah. Many were saying it, but nobody had data to act on it. It was
all conjecture. And in aviation, the FAA in the U.S. has always acted on data.
We're a data-driven organization. We have the safety record we have today
based on science, risk analysis and data._

1\.
[https://www.faa.gov/news/updates/media/Emergency_Order.pdf](https://www.faa.gov/news/updates/media/Emergency_Order.pdf)

2\. [https://www.npr.org/2019/03/14/703298739/faa-acting-head-
dan...](https://www.npr.org/2019/03/14/703298739/faa-acting-head-dan-elwell-
on-boeing-decision)

------
ashnyc
If these two crash had happened in USA or Western Europe . Would the FAA have
grounded the 737 right away . Or would they have waited before taking that
decision

~~~
philpem
Turning that around a bit...

If it was a pair of Airbus aircraft (A320, A330, pick any you like) which
suffered these two crashes, would the FAA have demanded the whole fleet
grounded?

------
drawkbox
How strange that they both had issues at around 6000-8500 feet, briefly
recovering, then nose diving.

Even more interesting is the recent 767 Amazon cargo flight crash in Texas
also did a node dive at around 8000 feet which somehow has escaped the news
with this new crash [1]. The pilots decided on a path around weather, were at
11-12000 feet, descended 3000+ feet and then the plane essentially did a
similar nose dive. Is this a data problem?

> _As the plane passed through 12,000 feet at a ground speed of 290 knots (340
> mph), the pilots indicated they preferred the westerly route option ATC had
> given them around the rain; air traffic control told them they would need to
> descend quickly to 3,000 feet to do so, and radar data reveals the Boeing
> turned to a heading of 270º as requested and descended through 8,500 feet.
> One minute later, the controller told the crew they would be past the bad
> weather in about 18 miles, and to expect a turn to the north. The crew
> responded "Sounds good" and "Okay," according to the NTSB, and the plane
> leveled out at 6,200 feet before rising 100 feet more._

> _That, apparently, is when things went haywire. The aircraft began what the
> NTSB report described as "small vertical accelerations consistent with the
> airplane entering turbulence," according to the flight data recorders
> recovered from the accident scene. Seconds later, with the plane holding
> steading at 230 knots (265 mph), the engines went to full power, and the
> nose of the plane rose four degrees...then the aircraft pitched nose-down
> for the next 18 seconds, reaching a maximum pitch of –49º in response to the
> plane's elevator inputs. _

The Ethiopia 737 Max has almost the same issue [2]

> _ADS-B data recorded for ET302 by FlightRadar24 shows that the aircraft,
> after reaching an altitude of 8,025 feet above sea level, suddenly dipped,
> plunging 400 feet before recovering briefly. But the aircraft 's vertical
> speed remained unstable, and a few minutes later it dove into the ground.
> For reference, the airport the flight took off from is at 7,631 feet above
> sea level—so the aircraft never reached more than 500 feet above the ground,
> not leaving much room for correction._

All of these planes had issues in the 6000-8500 feet range and then both
suffered the same plunging fate after briefly recovering from a dip / nose
stabilization issue.

Hopefully the ADS system is secure and not susceptible to infiltration/hacks
causing the plane to react to incorrect data at a range that is not
recoverable.

[1] [http://www.thedrive.com/news/26933/amazon-
boeing-767-cargo-p...](http://www.thedrive.com/news/26933/amazon-
boeing-767-cargo-plane-was-going-almost-500-mph-in-texas-crash-ntsb-says)

[2] [https://arstechnica.com/information-
technology/2019/03/faa-a...](https://arstechnica.com/information-
technology/2019/03/faa-acting-chief-says-satellite-data-provided-link-between-
boeing-crashes/)

~~~
xmly
I guess the correlation here is the stalling problem often happens during this
height range. Both 737 were in the ascending process, while the 767 is during
normal flying.

For me, the 767 hit with some kind of strange turbulence then the engines went
to max and caused a typical stall crash. You could google about the stall
crash, such as : [https://www.dw.com/en/why-do-airplanes-stall-and-why-is-
it-s...](https://www.dw.com/en/why-do-airplanes-stall-and-why-is-it-so-
dangerous/a-47869837)

For both 737 max, their MCAS system thought they had a stall potential and
triggered on nose dive while the airplanes were actually in the perfectly
normal situation.

For 767, they do not have this autonomous system and the stall warning was not
even triggered. So it was a purely manual operation. If they have a perfectly
functioned MCAS like the 737 max has, they may have survived.

So a working MCAS could save plane from crash like 767 had. Just the MCAS on
737 max was not working correctly and MAY potentially have caused the tragedy.

~~~
drawkbox
> _Both 737 were in the ascending process, while the 767 is during normal
> flying._

It might not have anything to do with ascent/descent but the range / altitude
and how systems react at that altitude. Maybe the systems are designed to be
more reactive at this height because there is less chance to recover than if
you are cruising at 30k feet.

What is most interesting to me is how the Amazon cargo plane 767 crash made
almost zero news and has quickly been replaced in the news with the 737 Max
8/9 issues. Though all situations are very similar, straight nose dives that
were sudden at the 6000-8500 feet range. There has to be something to that.

767 crashes and emergencies are EXTREMELY rare [1].

Most are related to human intervention such as terrorism, pilot error, fuel
error and only a very small amount are mechanical errors. Of the 12 problems,
only 5 were mechanical error.

[1]
[https://en.wikipedia.org/wiki/Category:Accidents_and_inciden...](https://en.wikipedia.org/wiki/Category:Accidents_and_incidents_involving_the_Boeing_767)

~~~
xmly
That is probably because 767 is a plane with quite a long history without any
major upgrade. And it is cargo, so no passengers.

The first 737 Max crashed in Indonesia, it did not have quite media coverage
as well. The second one got much more attention because that is quite rare
that two brand new flights crashed in such a short period. Everyone suspected
it is caused by design or system flaws.

~~~
drawkbox
> _That is probably because 767 is a plane with quite a long history without
> any major upgrade. And it is cargo, so no passengers._

767 is a passenger and cargo plane.

I assume you mean the Amazon 767 was a cargo plane [1], in which case yes it
got less attention as only the pilots/cargo crew were on board. However, a 767
crashing in the US seems like it would have gotten more focus.

Other 767s are passenger planes including two infamous ones American Airlines
Flight 11 (Boeing 767-223ER) and United Airlines Flight 175 (Boeing 767-200)
that were the two planes that crashed into the World Trade Center tower 1 & 2
on 9/11 [2][3].

For the most part these planes don't crash and a straight nose dive is a freak
occurrence. Most of the other issues that weren't crashes with 767 were
landing gear, short fuel related and terrorism.

It is very strange and eerie that this 767 from Amazon crashed almost
similarly to the 737 Max 8/9 in Indonesia and Ethiopia recently, with such a
long history of nothing like this.

[1]
[https://en.wikipedia.org/wiki/Atlas_Air_Flight_3591](https://en.wikipedia.org/wiki/Atlas_Air_Flight_3591)

[2]
[https://en.wikipedia.org/wiki/American_Airlines_Flight_11](https://en.wikipedia.org/wiki/American_Airlines_Flight_11)

[3]
[https://en.wikipedia.org/wiki/United_Airlines_Flight_175](https://en.wikipedia.org/wiki/United_Airlines_Flight_175)

