Hacker News Reader

Comment by Someone1234 | Hacker News Reader

I strongly suggest people skip this re-hosted article, and instead read the Reuters one here:

Title: Boeing software under scrutiny as Ethiopia prepares crash report

https://www.reuters.com/article/us-ethiopia-airplane-softwar...

I have numerous problems with Arstechnica's re-write, but suffice to say that nuance is lost and questionable conclusory statements added.

I will say in the case of BOTH articles, it sounds like we need to wait and see. Neither article has an answer for how auto-trim was re-actived, be it the pilots or something else. The answer to that question may have wide reaching implications.

View on HN

> Neither article has an answer for how auto-trim was re-actived, be it the pilots or something else. The answer to that question may have wide reaching implications.

I can imagine that being irrelevant in this case: Even if the pilots activated it, it doesn't mean they must have made any error, see my other comment here for the details.

In short, if the pilots turned the switch off, turning off much more than just the MCAS (as there's no switch "just turn MCAS off, keep the rest on"), but then the plane was already not possible to save (it was only 1000 ft above the ground!) and they turned the switch back on, hoping for obtaining more power/possibility to trim, and the faulty MCAS kicked in again (despite being the reason for the switch cutoff before) and even sped up the crash, then the pilots in fact did absolutely all that was possible to do.

And I can even imagine that the code which included the promised "fix" by Boeing until just a few days ago still had the built-in "obvious to implement by default" logic: "oh, I'm booting, now I can point the plane to the ground again because the sensors say so and I'm completely ignoring the fact that the pilots already turned me off shortly before" and that that was the reason the fix release is now delayed. But also note that that plane, the way it is constructed, certified and sold simply needs the MCAS and can't reliably fly without it, otherwise Boeing's fix would have been turning the feature off completely.

"...if the pilots turned the switch off, turning off much more than just the MCAS (as there's no switch "just turn MCAS off, keep the rest on"), but then the plane was already not possible to save (it was only 1000 ft above the ground!) and they turned the switch back on, hoping for obtaining more power/possibility to trim, and the faulty MCAS kicked in again (despite being the reason for the switch cutoff before) and even sped up the crash, then the pilots in fact did absolutely all that was possible to do..."

If this is indeed what is announced, I sincerely hope the responsible parties for making the decision to go through with MCAS in this way are paid well in jail time.

> If this is indeed what is announced, I sincerely hope the responsible parties for making the decision to go through with MCAS in this way are paid well in jail time.

I'm sorry, but your wording sounds like you're advocating taking revenge on engineers / managers for poor decisions made in good faith. That's barbaric, and I hope we as a society move beyond this sort of communal revenge. We'll all be psychologically better off if we encourage more healthy ways of seeking relief from tragedy.

Such a proposal would mean no more new airplane designs. Note that modern airliners are much safer than their predecessors.

An awful lot of mistakes are only "obvious" in hindsight; engineering is full of such.

> Such a proposal would mean

But who actually proposed what here?

Read the parent of my post.

I don't think there is a hindsight here. Boeing made false statements when certifying the plane.

> but your wording sounds like you're advocating taking revenge

No.

It's you, KMag, who is creating a straw man against SolaceQuantum.

SolaceQuantum's actual wording is using "paid well in jail time." Which means the expectancy of the involvement of the judicial system (courts, lawyers etc.) which could also eventually produce such a sentence (jail time).

And that is certainly not "advocating taking revenge."

SolaceQuantum also never mentions "engineers." It's again your straw man construction and a false claim.

It's already clear that in this case the "fox was guarding the hen house" (As reported in (1)): "The FAA, citing lack of funding and resources, has over the years delegated increasing authority to Boeing to take on more of the work of certifying the safety of its own airplanes." Note: FAA "is a governmental body of the United States with powers to regulate all aspects of civil aviation." Also note, just as an example: "The FAA has been cited as an example of regulatory capture, in which the airline industry openly dictates to its regulators its governing rules, arranging for not only beneficial regulation, but placing key people to head these regulators." (3)

1) https://www.seattletimes.com/business/boeing-aerospace/faile... )

Also (2):

2) https://www.seattletimes.com/business/boeing-aerospace/senat...

3) https://en.wikipedia.org/wiki/Federal_Aviation_Administratio...

All that is certainly not about the "engineers." And the Senate Committee already investigates.

> Which means the expectancy of the involvement of the judicial system

Mob vengeance intermediated by the state is still mob vengeance.

> SolaceQuantum also never mentions "engineers."

The decision makers certainly included management and engineers, and the OP was ambiguous about which decision makers should be punished. I think my statement is just as true if amended to just read "management".

> It's already clear that in this case the "fox was guarding the hen house"

A conflict of interest is not proof that one is making decisions in bad faith. We should certainly strive to eliminate conflicts of interest.

On the other hand, to jump to the conclusion that decision makers are likely deserving of prison time shows a lack of perspective and empathy. I'm sure a lot of people at Boeing will carry a lot of guilt with them for the rest of their lives over this.

Maybe there were decisions made in bad faith, but I think we have far far too little information (and too much hindsight bias in the balance) at this point to determine if those making poor decisions were making them in bad faith, even if there was a clear conflict of interest.

It's comforting to believe that most tragedies are the result of evil people making decisions in bad faith, and that most tragedies can be avoided by identifying and punishing these evil people. The real world is seldom so black-and-white, and I strongly oppose our society's common knee-jerk reaction to quickly reach for imprisonment as the solution to the latest tragedy. By all means, punish people who make conscious decisions to harm their fellow humans, but many tragedies don't fit this simple narrative.

How exactly would this classify as mob vengeance?

Negligence in critical safety infrastructure is bad faith.

The OP said that if it's true that disabling MCAS made it impossible to trim the plane without losing too much altitude, that they hope those responsible for the decision to "go through with" (deploy?) MCAS are jailed.

The poor design of the system is directly stated as the reason the OP hopes people are imprisoned.

I'm al for an investigation. Publicly calling for jail time so prematurely, in a case that would surely be highly publicized and politicized, makes it even harder to conduct an impartial investigation and trial.

When the public puts pressure on the courts to hand down a predetermined verdict and punishement and they are successful in their efforts to bias the process, that is mob vengeance.

> punish people who make conscious decisions to harm their fellow humans, but many tragedies don't fit this simple narrative.

Causing death of 350 people due to "intended" ("it's good for our business") negligence is enough to deserve an evaluation of the decisions made and the evaluation if the punishment is warranted (including the "jail time"). Especially the Boeing's top executives behavior after the first crash can't be defended, given everything we already know.

I'm all for an investigation. I'm very much against public calls for jail time before we've been able to properly investigate the actions and intentions of the parties involved. The OP's stated justification for jail time is "[purely technical description of system functioning] ... if this is true, I sincerely hope [people are jailed]".

My basic point is that when ther's a tragedy, there's a knee-jerk reaction to punish people regardless of mens rea. Putting pressure on courts for predetermined outcomes, particularly without regard to intent of the accused, is the slightly civilized version of getting out the torches and pitchforks.

Deterrence requires interrupting the ill-intentioned thought process. If there are no ill intentions, then jail time has no deterrent effect. We may feel better if someone is punished, but if the public's feelings are the only positive outcome of punishing someone, then punishing them is barbaric. (Note that restitution is separate from punishment. Restitution, if possible, is still called for if there's no ill intent.)

No, not barbaric, that's the liability attached to all normal activities.

"Knew or should have known" is the standard. Boeing management knew or should have known that selling an essential safety system relying on a single sensor is categorically unsafe.

All blame to management unless the programmers knowingly miscoded the software.

This other HN submission has some interesting hypotheticals on why the system might have been reactivated multiple times:

https://news.ycombinator.com/item?id=19565056

This analysis sounds very plausible (all emphasis marks mine):

https://leehamnews.com/2019/04/03/et302-used-the-cut-out-swi...

"the high speeds observed in ET302’s FlightRadar24 trace (Figure 1) were logical. It’s a consequence of following the Emergency checklist for “IAS disagree” (IAS is Indicated Airspeed, i.e. the dynamic air pressure experienced by the aircraft) after takeoff.

The combination of the preceding checklist followed by an MCAS Trim Runaway checklist could create a situation where manual trimming after a Trim Cut-Out would be difficult to impossible and would require non-checklist actions."

"At a miss-trimmed Stabilator, you either have to re-engage Electric trim or off-load the Stabilator jackscrew by stick forward, creating a nose-down bunt maneuver, followed by trim.

Stick forward to trim was not an option for ET302, they were at 1,000ft above ground. According to The Wall Street Journal, the ET302 crew re-engaged electrical trim to save the situation, to get the nose up. It was their only chance. But too late. The aggressive MCAS kicked in and worsened the situation before they could counter it."

The Airport elevation of Addis Ababa airport is 7625 feet AMSL. The highest point of the flight recorded by the flightradar24 is 8600 ft AMSL which gives the plane's altitude of around only 1000 ft at highest! The speeds relative to the ground recorded near the end were 380 kt, i.e. 640 ft/s. Obviously every second mattered, and at the above speeds, the plane was only a few seconds from crash away when the MCAS was pointing the nose down.

Weird, I guessed at something like that in a related article submitted earlier:

https://news.ycombinator.com/item?id=19560596

Not quite the same -- the issue wouldn't be that they didn't crank enough, but that cranking was physically impossible due to the aerodynamic load on the stabilizer created by being at high speed with the elevator and stabilizer airflow opposing each other. You'd have to release the elevator in order to regain control of the stabilizer, and you can't do that without losing altitude that you don't have to give.

I remember reading precisely this scenario theorized here on HN a few weeks ago: https://news.ycombinator.com/item?id=19383756

Leeham worked with MentourPilot, a training captain for Ryanair, on this article. There was a video included, but it's since been taken down. If you've seen any of Mentour's videos they are fantastic and he is typically quite good about remaining objective and avoiding wild speculation.

> The combination of the preceding checklist followed by an MCAS Trim Runaway checklist could create a situation where manual trimming after a Trim Cut-Out would be difficult to impossible and would require non-checklist actions."

This is a talk by Professor Nancy Leveson that describes exactly this type of problem. Dangerous interactions between systems. I posted this before when a lot of people were engaging in low grade racism by blaming the Indonesian and Ethiopian pilots competence and training. Seems very topical at this point tho.

https://www.youtube.com/watch?v=WBktiCyPLo4

I presume this is the same Nancy Leveson who wrote Safeware?

If I could push one book on all engineers (and not just programmers as it goes over entire systems failures), let it be this, I recommend it to everyone.

https://www.amazon.co.uk/Safeware-System-Safety-Computers-19...

I'll watch that link ASAP - thanks @Gibbon1!

> The highest point of the flight recorded by the flightradar24 is 8600 ft AMSL which gives the plane's altitude of around only 1000 ft at highest!

Not to be pedantic, but altitude is the distance measured from MSL, height is measured from the ground. So their altitude was 8600ft, their height was ~1000ft.

Thank you very much for the link.

If true, and more and more seems to point into this direction, we can pretty much lay the arguments of the "badly educated and overworked third world pilots who are too dumb to work a checklist" to rest.

I always found that reasoning rather bigoted and jingoistic.

It seems more that Boeing was selling a death trap certified by their cronies at the FAA.

What galls me most is the fact that they didn't ground that atrocity after the Lion Air crash, but used their energies to throw customers and pilots under the bus and developed a checklist, which, as it turns out, is actually counterproductive and does nothing to fix the inherent design problems of the plane. If anything, it serves the exact opposite.

The second crash is mass murder for commercial reasons, period. If not legally then at the very minimum morally.

Thanks! We've updated the link from https://arstechnica.com/information-technology/2019/04/ethio....

Reply on news.ycombinator.com