> It isn’t like they are making decisions with the intent of compromising safety.

That really is actually exactly what they did and are doing. When you don’t do tests because you are confident something will pass, that doesn’t change that you aren’t testing, and you are compromising quality on the basis of productivity. Here Boeing decided to go against the safe practice because that would have classified the plane as a different plane and incurred huge costs, but it would have increased safety and likely avoided the accidents.

They did compromise safety, they did so thinking that it wouldn’t matter because the overall safety would be good enough for no one to notice, but that gamble failed and others paid their lives to cover the bet.

On the other hand, making X behave like Y, where Y is something pilots are very used to, is safer.

MD-11 and now MAX raise questions on the execution of that. Pilots have to understand the how and why the different thing can fly like the old thing so that when something goes wrong and that invariant is inevitably violated, they aren't caught off guard.

Since the advent of powered flight controls, they've been shaped to give desired handling characteristics. For example, in the 70's control forces were lightened considerably to accommodate female pilots, though many were concerned this would lead to overcontrolling the airplane by the male pilots.

Human factors design is nowhere near easy or settled science, not in iphone design nor in flight controls design.

>Human factors design is nowhere near easy or settled science, not in iphone design nor in flight controls design.

Given.

The issue I keep coming back to is the flawed regard for human factors in MCAS. They paid enough attention to squeak by the artificial feel, but then completely ignored the fact that a pilot can't react or stay ahead of something on a plane that no one tells them even exists. Then when it became evident it might be a problem, they back pedaled, putting as much blame on the operators as they could.

They thought about it. They decided "Nah, they don't need to know." At some point the tech pilot even expressed concerns over the system, yet was still pressured to keep it out of the manual...why?

No one in good faith has anything to gain from that system's implementation details seeing the light of day. Unless of course, there was some other motivation, like avoiding the costs of compliance at some point.

Boeing relied on the pilot noticing runaway stabilizer and doing what they're trained to do on runaway stabilizer - turn off the trim motors.

The first of the 3 sets of pilots did this, and landed without incident.

The next set overrode MCAS successfully 25 times, inexplicably did not turn off the trim, did not override it the last time, and crashed.

The last set successfully countered MCAS twice, then turned off the trim. They did not follow the directions on Boeing's Flight Crew Operations Manual Bulletin: "Uncommanded Nose-Down Stabilizer Trim Due to Erroneous Angle Of Attack During Manual Flight Only", which the FAA turned into a mandatory emergency airworthiness directive.

-- Aviation Week, Aug 19, 2019

>The first of the 3 sets of pilots did this, and landed without incident.

Extra pilot in cockpit. Not a CRM situation that's a given.

>The next set overrode MCAS successfully 25 times, inexplicably did not turn off the trim, did not override it the last time, and crashed.

They didn't know why the trim was kicking in in the first place, and the senior pilot was the one countering the trim. He handed it off to the junior pilot to sift through the manual, which ironically, would have been futile anyway as MCAS was dropped from the manual. The behavior did not present as a classic stabilizer runaway. Other pilots interviewed also pointed this out including in the Australian 60 minutes expose on the 737 MAX if I recall correctly, so I'm not sure that the same definition you're fond of is universally shared amongst pilots. Bad priming is also a human factor that is catastrophically lacking among other things not being taken into account.

Furthermore, if pilots were really held to account for knowing the hardware they're operating, they should have known the nature of the trim switch change between the 737 NG and MAX, and the consequences thereof; that wasn't included.

>The last set successfully countered MCAS twice, then turned off the trim. They did not follow the directions on Boeing's Flight Crew Operations Manual Bulletin: "Uncommanded Nose-Down Stabilizer Trim Due to Erroneous Angle Of Attack During Manual Flight Only", which the FAA turned into a mandatory emergency airworthiness directive.

They did follow it actually, but also notice the Note toward the end (see the appendix in the Ethiopian preliminary report. The line reads)

>Note: Initially higher control forces may be needed to overcome any stabilizer nose down trim already applied. Electric stabilizer trim can be used to neutralize control column pitch before moving the STAB TRIM CUTOUT switches to CUTOUT.

Now. There is something to be said for "Gee, did they read it", but considering the bloody thing includes a disclaimer that the AFM supersedes the bulletin due to not being approved by the FAA, the note being presented outside the main content of the directive, and the notification beeping issued in November, I don't have high hopes for the real effectiveness of the bulletin at clearly communicating the severity of the problem, something which simulator time would have made plain and obvious.

Then again, that's just me.

> They didn't know why the trim was kicking in in the first place

Unknown cause is symptomatic of runaway trim.

> The behavior did not present as a classic stabilizer runaway

How is runaway trim different from classic runaway trim? The trim was mysteriously turning on and trying to drive the nose into the ground. If that isn't runaway trim, I have no idea what runaway trim is.

BTW, I worked for 3 years on the Boeing 757 stabilizer trim gearbox. I know what runaway trim is. The cutoff switches are there as the last resort to stopping it, and they're prominently and conveniently on the center console for darn good reason.

> if pilots were really held to account for knowing the hardware they're operating

The point being, even if they knew what MCAS was, the corrective action is the exact same thing as in the instructions provided by Boeing, before and after the Lion Air crash.

> They did follow it actually

I'm glad you read it, but read it again. They did not follow it.

> clearly communicating the severity of the problem

Considering that it was an emergency mandatory notification, and the LA pilots had already crashed, I don't know how to harder communicate the severity. I'm not a pilot, but if I was a MAX pilot, I'd certainly not want to die the same way the LA pilots did, and I'd pay attention to an AD explaining how not to die.

But I do agree that evidently pilots needed more training to understand what to do about runaway trim, which they need to understand regardless of whether MCAS is causing the runaway trim or some other problem. There's a reason the runaway trim procedure is something that is a memory item, meaning pilots are supposed to know what to do about it without needing to consult the checklist. Training in this is clearly insufficient.

There's a level of engineering judgement involved here though.

If product A has passed testing and I made minor changes and made a product B if I can avoid running the whole battery of tests as if product B is brand new and not derivative then I totally will and Aerospace and Automotive operate like this all the time in every country in the world it's not poor practice.

Boeing executive decision makers don't. They never fly commercial, they have private jets.

Interesting side note, Boeing does make private jets - the Boeing Business Jet family[0].

But Boeing executives doesn't fly on these, since they're too large for even CEOs. Boeing executives fly on one of the three Boeing owned Bombardier Challenger 650s [1][2][3].

[0] https://en.wikipedia.org/wiki/Boeing_Business_Jet

[1] https://www.planelogger.com/Aircraft/Registration/N541BA/908...

[2] https://www.planelogger.com/Aircraft/Registration/N543BA/908...

[3] https://www.planelogger.com/Aircraft/Registration/N544BA/884...

Former CEO James McNerney used to fly in the BBJ all the time. Sometimes he was the only passenger.

General aviation (private jets included) has a higher fatality rate than commercial aviation [1]. Even after backing out amateur general aviation, it is still more dangerous [2], though not egregiously so like personal planes, and helicopters make a sizeable chunk of fatality rate that is lumped into the same category as private jets.

But it is still poor optics to rarely dog food your own products.

[1] https://qz.com/work/1169517/executives-are-dying-in-private-...

[2] https://fivethirtyeight.com/features/corporate-jets-commerci...

I think there are a few other factors to take into account, such as private jets flying faster on average, no layovers, etc. Looking only at flight hours doesn't really show the risk for an individual (e.g. an exec choosing between commercial flights and private flights). My guess is that the average exec is about as likely to die from one vs the other since the exec would spend more time flying in the commercial jet.

So it's really not a fair comparison and I wouldn't be surprised if they're functionally equivalent after taking into account all major variables.

Including BBJs, which are 737s. Note there's a BBJ MAX.

My comment is being misread — I said they don’t make decisions with the intent to compromise safety. I am not defending the decisions, but they aren’t actively trying to make unsafe planes in order to save money. It isn’t like they are doing what some car makers did where they judged the expense of a recall as cheaper than the litigation from deaths.

I read your comment and interpreted it as a misalignment of incentives in the context of informed decisions about risk.

The second part is key to me. Inadequate system safety analysis seemed to give them the green light in decisions to save money (or make more money with safety critical 'options'). It's not like they knew MCAS would have an out-sized chance of downing a plane. My guess is they didn't know what they didn't know and it led them to have overconfidence in their ability to properly gauge business/safety trade-offs

i have quite the video for you (timestamped, but the whole thing is worth watching): https://youtu.be/rvkEpstd9os?t=2499

That documentary is very naive. This is a good review: https://www.forbes.com/sites/airchive/2014/09/10/review-al-j...

this is weak industry pr. the fact is that boeing did not have safety issues before finance took over, and that opening a non-union shop for the purpose of labor fungibility is going to result in less experienced workers with a lower stake on average. it doesn't even bother mentioning what i linked, which is that 2/3 of the informally surveyed employees lack confidence in the final product to the point that they wouldn't want their families to fly on the planes.

Seems like a totally unbiased source. /s

I mean, do you really not understand how that sort of thing is done? They ask 100 people and then edit it down to the 5 most extreme responses.

While that's a reasonable suspicion to have, the reporting in this case is accurate.

I'm from Charleston, where the plant is located, & I have several friends that work at Boeing in assembly and quality inspection. What you see in the video is exactly the same sentiment I've heard for years.

While I always remain skeptical, they said that they asked 15 and 10/15 wouldn't fly on it.

Boeing employees don't go anywhere right now.

I love seeing these false statements on HN, where most users have no idea what the aerospace industry is like.

The Boeing people that I work with are not allowed to travel.

Some still do. I suspect you only know a very small percentage of the total number of employees.

Not allowed to? How does that work? Boeing thinks they control what people do on their vacation time?

They are American, they don't get significant vacation time.

I was really writing about work travel though.

Ah, I see. Yes, that Boeing can legitimately control.