ams6110

I do think the complacency issue might be a component here. Humans tend to quickly accept recent history as "normal" and over time forget the lessons learned by past disasters.

"Those who don't remember history are doomed to repeat it"

It's been a couple of decades I think, maybe more, since an engineering screwup affected a passenger airliner like this. You could argue that the 787 LiIon battery thermal runaway thing was a red flag. That also resulted in an FAA grounding, but that was fairly easily remedied and nobody died.

Read the narrative in the report. Why do you suppose that after they got the same initial signs of trouble that the Lion Air flight had (stick shaker on left side, disagreement in airspeed values, etc. immediately after takeoff) that the captain tried to engage autopilot and instructed the first officer to retract flaps and inform controllers they were proceeding to climb to FL 320 (32,000 ft). Why not instead turn back and land and hand the aircraft over to maintenance?

From the report:

At 05:38:44, shortly after liftoff, the left and right recorded AOA values deviated. Left AOA decreased to 11.1° then increased to 35.7° while value of right AOA indicated 14.94°. Then after, the left AOA value reached 74.5° in ¾ seconds while the right AOA reached a maximum value of 15.3°. At this time, the left stick shaker activated and remained active until near the end of the recording. Also, the airspeed, altitude and flight director pitch bar values from the left side noted deviating from the corresponding right side values. The left side values were lower than the right side values until near the end of the recording.

...

At 05:39:06, the Captain advised the First-Officer to contact radar and First Officer reported SHALA 2A departure crossing 8400 ft and climbing FL 320.

...

At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt.

At 05:39:45, Captain requested flaps up and First-Officer acknowledged. One second later, flap handle moved from 5 to 0 degrees and flaps retraction began.

Bear in mind stick shaker and divergent instrument readings all this time.

Why not just return and land, leave the flaps configuration alone (which would have inhibited MCAS), especially since this is exactly how the Lion Air flight started.

I know this is easy to critique from the comfort of my chair, and the pilots are not here to defend themselves, but some things in this narrative just don't make sense.

The pilots didn't actually do that. They did not use electric stabilizer trim to "neutralize control column pitch forces before moving the STAB TRIM CUTOUT switches to CUTOUT" in fact the trim had been run markedly down by MCAS by the time they switched off the electric trim.

Classic illustration of why conversations between geeky technology people and "normal" people usually and in awkward silence after about two minutes.

I see this playing out in a couple of possible ways. One is that it ends up like the DC-10. Public confidence is lost, even though the problem is fixed. The aircraft end up going into freighter service.

The other is that they make a convincing case that the problem is resolved. I don't know if that's possible given today's default hate for big corporations, we'll see. They've done it before with the 737 and the rudder problem it had in the 1990s or so. That problem led to a few fatal crashes, but I'm not sure it ever got the attention that this story is getting. The news cycle was different then.

I would absolutely fly on one once the problem is corrected.

You're correct that the AD and runaway trim procedure does not instruct them to extend flaps. What I was addressing was the statement upthread that "Flaps out supposedly would have kept MCAS off but the pilots weren't expected to know that."

If I'm a 737 MAX pilot, after the Lion Air crash I'm learning absolutely everything I can about MCAS. And from information Boeing provided I would learn that it operates with autopilot off, flaps up, at high indicated AoA.

You mention unreliable airspeed, that was actually their first problem. Flaps were extended at that point, as according to the narrative they were not retracted until after the AoA disagree, stick shaker, and airspeed disagree. In fact it almost reads like they were intending to continue the flight, engage autopilot, and climb to 32,000 ft with the stick shaker going the whole time. That seems very odd to me.

At the very least it seems that some specific "differences training" on MCAS should have been included. I don't know at what point the differences are enough to require a new type designation.

Pilots should have known that MCAS is inactive with flaps extended, per information from Boeing.

Yes, pilots selecting "up" on the trim switch should stop and override MCAS. But it also "resets" MCAS so that it will pitch down again on its next cycle. So you'd have to be constantly correcting it, or switch the electric trim off entirely (i.e. treat it as runaway trim).

Post Lion Air, they should have known that.

Interesting, that when they turned the electric trim back on, they only momentarily blipped the switches to trim up, and the stabilizer did move. Then five seconds later MCAS pitched down again and it was over.

Wonder why didn't they trim up more when they turned the electric trim back on. On the surface it appears that was their last chance to salvage the situation.

tl; dr: the false positive rate is too high.

This story is disingenuous. For people with "simple" tax situations (no itemized deductions, etc) the forms are already very simple.

The scenario they paint with chasing down form after form simply does not happen for most people. For most people it's one page.

But the idea that your taxes can be pre-computed by the IRS is fantasy beyond that, unless the tax code is significantly changed.

Sure they know your W2 income and some other standard stuff. How do they know your self-employment or business income? How much you gave to charity? How do they know what unreimbursed expenses you had? How do they know how many kids you have? How do they know your marital status?

I guess most of that could be addressed by just eliminating all deductions and allowances but even at that there are a lot of things they simply cannot possibly know until you, the taxpayer, tell them.

Running with a minimalist shoe helps protect your knees. You learn to strike with your middle foot rather than flat-footed or heel first. The shock is absorbed by the muscles and tendons in your calf rather than by your knees.

I still don't get it. CGI scripts would run with reduced privileges. The CVE description says "code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute arbitrary code with the privileges of the parent process (usually root) by manipulating the scoreboard"

What is the scoreboard?

Giving everyone $10K/year would just inflate prices until $10K was the zero baseline for income.

If you look at communities where large portions of the population have their basic medical care, food, and housing all provided or paid for by the government, you don't see hotbeds of creative and entrepreneurial activity. You see cesspools of drugs and crime.

I'd phrase it as "massive taxation reduces the reward of doing business" and therefore, assuming equivalent risk, some number of potential entrepreneurs (and their investors) will decide it's not worth it.

Yes that is how human nature evolved. Competition for scarce resources so you and your offspring can survive. This extends to supporting society to the extent it helps your personal survival.

Exactly. Those are time killing activities to keep from staring out the window and losing your mind. Which is also a big problem for the elderly and unemployed.

You're presumably doing something productive for somebody who's willing to pay you $100K for it. Or do you work for the government?

Honestly I think about 5% of people will be motivated by that sentiment.

Maybe, if you extend that to free software in general. It's interesting to think about.

TFA is from an OpenBSD-oriented blog, and they tend to avoid gnu software if there is another way.

Companies that develop aircraft control software do. I read your comment as implying that they don't.

The software that runs safety-critical flight controls is actually developed nothing like typical ecommerce or social media. It is designed and developed to an engineering standard. You can review DO-178C requirements[1].

Not all software has the same consequences for failure. The highest level is when failure is catastrophic, i.e. "Failure may cause deaths, usually with loss of the airplane." This requires the highest "Level A" assurance level.

Presumably MCAS was not originally evaluated as needing to meet the highest level. If it were, the single AoA input would have immediately disqualified the design right off the bat.

There's some speculation that the delays on the "fix" are because if they have to redevelop the software at a "Level A" standard that means basically a complete reimplementation with full tracability of requirements from design to source code through compilation to executable, with independent verification. That won't happen in a few weeks.

[1] https://en.wikipedia.org/wiki/DO-178C

Agreed. Hard not to speculate though. I personally find this stuff fascinating from a technical and human factors perspective -- the deaths are tragic of course.

No, the working theory I've heard is that the hand-crank trim wheels may have been overwhelmed by the air load on the stabilizer given its "nose down" configuration, probable full "nose up" pull on the elevators, and the very high speed they were flying. Speculation is they may have turned the electric trim back on to use the manual trim switches to trim up. By that time possibly too late or even the electric trim was overwhelmed by the load, and of course this would have brought MCAS back into play also.

Turbine engines in theory can run on almost any flammable liquid. However in practice they would need substantial re-engineering. Also ethanol is less energy-dense than kerosene/jet fuel.

Combinatorial complextity. It's impossible to foresee every possible combination of failures. There are checklists for the ones that can be foreseen (and these have often been written in the blood of those who discovered them) and maybe in theory most of those could be automated. But they cannot be exhaustive. So when all else fails, you rely on human intelligence guided by experience and training as the last line of defense. It doesn't always work, but until we have an AI that performs better, it's the best option we have.