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737 MAX crashes “linked” by satellite track data, FAA says

228 points| close04 | 7 years ago |arstechnica.com | reply

150 comments

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[+] _s|7 years ago|reply
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|7 years ago|reply
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.

[+] _verandaguy|7 years ago|reply
To be clear, Flightradar24 and other ADS-B-based online services do not provide enough data to come to a meaningful conclusion about these kinds of accident. The resolution is often too coarse to even see how quickly a plane would've pitched down, assuming it did so quickly.
[+] nonbel|7 years ago|reply
> "we as laymen should refrain from coming to conclusions until after a thorough investigation has been completed"

People say this, but why? It seems to go against human nature. People love to speculate based on limited information and/or understanding.

[+] cjbprime|7 years ago|reply
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"?
[+] Someone1234|7 years ago|reply
I'd argue yes.

It is identical data from ADS-B that we've had for days. People keep reiterating their "verified" line, but that had no basis when they said it, repeating it doesn't add to its legitimacy. The data today is the same data we had then.

It is essentially a way to ignore the data until it is politically expedient.

[+] root_axis|7 years ago|reply
I was unaware that the president was involved in the decision making process, do you have any more details on that?
[+] alexandercrohde|7 years ago|reply
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|7 years ago|reply
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.

[+] asdff|7 years ago|reply
People love catastrophe and ignore larger problems all the time. During the 2017-2018 flu season, almost a million people were hospitalized and ~80,000 people died from the disease (1), a record high and a huge burdon on healthcare for everyone sick or not, yet we aren't getting 2-3 threads a day on influenza popping up on HN like we are with these 150 or so tragic deaths. Maybe part of it is who died. In the case of this flight, it was people affluent enough to afford jet travel. The news is filled with stories of their lives cut short and the tragedy of it all. In the case of deaths from the flu, it is often the old and those in poor health like the homeless who die from the disease, an invisible population for most people. We wont be seeing any articles in national news documenting the lives of those 80,000.

1. https://www.cdc.gov/flu/about/burden/2017-2018.htm

[+] rdiddly|7 years ago|reply
Not sure if I know which thing you mean. You mean plane crashes themselves (which kill far fewer people than the cars people drive every day), or this new "link" between the two crashes (which I agree seems spurious at first glance but they may yet confirm it)?
[+] FakeComments|7 years ago|reply
If you do that last thing, you may be a psychopath.

Edit:

The basis for the “trolley problem” is precisely how you handle accounting for the numeracy of death versus the emotional involvement and personal culpability.

People who rationally perform cost benefit analysis about lives and well-being seem to have more psychopaths: see CEOs and other leaders. This isn’t necessarily bad, but it’s worth noting.

[+] jdsully|7 years ago|reply
How is it we have such precise satellite location data on these crashes - but MH370 can just disappear.
[+] jimktrains2|7 years ago|reply
It was my understanding that all/most/all-controllable radios were shutoff at some point. There was some maintenance data from the engines that factored into the search location, but otherwise it wasn't transmitting anything.

I havn't followed very closely, so take that with salt, but it's a starting place if anything.

[+] Retric|7 years ago|reply
A flight data recorder provides a lot of information. https://en.m.wikipedia.org/wiki/Flight_recorder

We could stream this information via satellite uplink. Instead Radar and transponders is used to keep a close enough location to make recovery generally strait forward.

It’s really turning off the transponder while over the middle of the ocean that’s the issue for MH370.

[+] tus87|7 years ago|reply
Didn't you read the part about the transponder being switched off?
[+] d1str0|7 years ago|reply
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?
[+] overlordalex|7 years ago|reply
I've read that they don't want to send it to the USA because of the possibility of Boeing to unduly influence the investigation.

http://fortune.com/2019/03/13/ethiopian-air-crash-black-boxe... > but Ethiopian authorities would prefer to work with the U.K.’s Air Accidents Investigation Branch to ensure that U.S. experts won’t have undue influence in the probe of the American-made plane.

https://www.bloomberg.com/news/articles/2019-03-13/ethiopia-... > The choice of Europe over the U.S. National Transportation Safety Board for the analysis of the black boxes is a strategic decision for Ethiopian Airlines and the nation’s government, said Asrat Begashaw, the carrier’s public relations director.

[+] DevX101|7 years ago|reply
I absolutely agree with not giving the blackbox to the U.S. There is definitely a possibility of a conflict of interest with the F.A.A. not being fully forthcoming. U.S. politicians have a strong interest to keep the U.S. aviation industry strong and Id be surprised if there was absolutely zero interference between politicians and the F.A.A. conducting a fair investigation.

Also, the F.A.A. has already been aware that there were issues with this plane (software fixes were being worked on), but the planes continued to fly. If it turns out that the information already known to them BEFORE the latest crash should have been sufficient to call for a grounding, I could see them attempting to cover their ass.

[+] Mr_Shiba|7 years ago|reply
Can't blame them. US institutions have been slowly poisoned by the cancer call lobbying. You have regulators with interest ties to the industry they have to supposedly regulate all across most agencies.
[+] agumonkey|7 years ago|reply
I don't recall why but I think MH370 recorder was also sent to France. Probably to avoid conflict of interests ?
[+] Animats|7 years ago|reply
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|7 years ago|reply
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|7 years ago|reply
> 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-...

[+] js2|7 years ago|reply
''Eyewitness memory is reconstructive,'' said Dr. Honts, who is not associated with the safety board. ''The biggest mistake you can make is to think about a memory like it's a videotape; there's not a permanent record there.''

The problem, he said, is that witnesses instinctively try to match events with their past experiences: ''How many plane crashes have you witnessed in real life? Probably none. But in the movies? A lot. In the movies, there's always smoke and there's always fire.''

https://www.nytimes.com/2002/06/23/weekinreview/ideas-trends...

See also “Reliability of Eyewitness Reports to a Major Aviation Accident”:

https://commons.erau.edu/cgi/viewcontent.cgi?article=1040&co...

[+] stordoff|7 years ago|reply
Eyewitness accounts are _notoriously_ unreliable. Multiple witnesses saw something approaching TWA-800:

> Although there were considerable discrepancies between different accounts, most witnesses to the accident had seen a "streak of light" that was unanimously described as ascending, moving to a point where a large fireball appeared, with several witnesses reporting that the fireball split in two as it descended toward the water.

> 258 were characterized as "streak of light" witnesses ("an object moving in the sky... variously described [as] a point of light, fireworks, a flare, a shooting star, or something similar.") The NTSB Witness Group concluded that the streak of light reported by witnesses might have been the actual airplane during some stage of its flight before the fireball developed

> In addition, 18 witnesses reported seeing a streak of light that originated at the surface, or the horizon, which did not "appear to be consistent with the airplane's calculated flightpath and other known aspects of the accident sequence."

> [T]he NTSB noted that based on their experience in previous investigations "witness reports are often inconsistent with the known facts or with other witnesses' reports of the same events."

https://en.wikipedia.org/wiki/TWA_Flight_800

[+] InclinedPlane|7 years ago|reply
People said they saw a missile hit TWA-800 too. Eyewitness accounts are super unreliable.
[+] bittweeker|7 years ago|reply
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|7 years ago|reply
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|7 years ago|reply
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|7 years ago|reply
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

2. https://www.npr.org/2019/03/14/703298739/faa-acting-head-dan...

[+] ashnyc|7 years ago|reply
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|7 years ago|reply
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?

[+] sinuhe69|7 years ago|reply
Interesting question as this particular case is suspected to be political/economical involved already.
[+] drawkbox|7 years ago|reply
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...

[2] https://arstechnica.com/information-technology/2019/03/faa-a...

[+] xmly|7 years ago|reply
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...

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.

[+] rconti|7 years ago|reply
But the 767 was descending. It was SUPPOSED to be going down.

What I recall reading is that the nose was already down somewhat before changing pitch 4 degrees THEN pitching sharply down in direct response to pilot input.

ADS-B data is being TRANSMITTED. The plane is not responding to ADS.

[+] lysp|7 years ago|reply
The feet measurement was above sea-level not ground-level. The airport there is around 7600 feet. So in actual fact this plane was only sitting 500-1000 feet above ground.
[+] ravedave5|7 years ago|reply
I was going to suggest this is likely a common cruizing height, but no, it doesn't seem to be. That's an interesting correlation.