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Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

bbc.com

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Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#61

Post by jacquesm »

rwmj wrote: post #50
mrtksn wrote: post #41

Earlier quoted context omitted.

[flagged]

Pilots who don't know about systems that are not documented in the manual are dummies?

Given the number of studies on pilot workload and the many harsh lessons learned about how to put together a manual and a training program that has intended outcomes mrktsn is ignoring the realities of operating a vehicle where a second of delay can make a huge difference.

The most stark example was the ambiguity around 'take-off power' and 'take off power', and that is when the writers of the documentation and their management are not trying to pretend a new aircraft is the same as a complete redesign of an older one with which besides the name and the operational niche it has relatively little in common.

I always wondered why there were no whistleblowers before this led to accidents. Or were there?

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#62

Post by jacquesm »

autoexec wrote: post #12
rabidonrails wrote: post #9

Earlier quoted context omitted.

Well yes but Boeing also said it "would not result in a safety of flight condition." There's a lot of gray going on here.

A former air accident investigator who works as an aviation safety consultant said "It's extraordinary that Boeing concluded that a failure of this part would not have safety consequences," and said the report was "disturbing" Doesn't seem like gray to me. It seems a company who has a history of cutting corners and ignoring or downplaying safety problems did exactly that in this case too which resulted in the deaths…

I think every company operating Boeing aircraft should have reviewed their stance on Boeing directives in light of MCAS and the aftermath by now. If they did not that is a failure of sorts as well.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#63

Post by Dylan16807 »

jacquesm wrote: post #59
Dylan16807 wrote: post #47

Earlier quoted context omitted.

Maintenance crew are highly trained people that in strange situations can pause their work to figure out a fix and ask experts what to do. Very different from how a pilot has to handle strange situations. Being ready for anything in an airborne plane without a pause button is so much harder, impossibly hard, and not every air authority tries as hard to reach the impossible.

Stand outside an engine test cell for a while and tell me that maintenance crews don't deal with emergencies. I'll bet they do so more often than pilots, we just don't hear about it because there are no passengers at risk. Nobody is going to make a 'Sully' like movie about the maintenance mechanic that spotted an issue with a part under test before it led to one or more catastrophic failures. They're more likely to m…

I didn't say there aren't any emergencies, but the emergencies are not on the same level. And I said they're highly trained, you don't need to convince me of that. Nor do you need to convince me they're important. Those are entirely separate issues.

Also what fraction of engine test cell use is for engine maintenance? Is it a big amount?

But if that kind of test goes wrong the main outcomes are "hit stop" and "oh no it's too late". An emergency like that is not where much of their expertise is needed, their expertise is in other parts of their job.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#64

Post by hshdhdhj4444 »

nickff wrote: post #36
mrtksn wrote: post #33

Earlier quoted context omitted.

> blaming the presumably foreign maintenance crew The same happened with MCAS, the pro-Boeing argument was that if those were American pilots it would have been fine.

As a matter of fact, the same issue did occur to US-based-airlines, and the pilots did catch it. That does not however answer the question of whether they just got lucky, or were more skilled, though there are some indications that it may have been skill.

Can you share a link?

I’m pretty sure no American airline had the same situation that the airlines with the crash had because they paid extra for the redundant AOA sensor.

The MCAS issue was a major issue, but the ultimate fundamental flaw was Boeing not including a redundant sensor (which is the one that was malfunctioning in the crashes) in the base package as they should have.

The inexplicably considered redundancy in this part an optional extra, and as far as I’m aware there were no US airlines that hadn’t taken the optional extra package.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#65

Post by K0balt »

jacquesm wrote: post #61
rwmj wrote: post #50

Earlier quoted context omitted.

Pilots who don't know about systems that are not documented in the manual are dummies?

Given the number of studies on pilot workload and the many harsh lessons learned about how to put together a manual and a training program that has intended outcomes mrktsn is ignoring the realities of operating a vehicle where a second of delay can make a huge difference. The most stark example was the ambiguity around 'take-off power' and 'take off power', and that is when the writers of the documentation and their…

Ah, whistleblowers. Always and forever committing suicide. Turns out thinking you can stab the gorgon with no consequences is a form of mental illness.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#66

Post by fransje26 »

nickff wrote: post #36
mrtksn wrote: post #33

Earlier quoted context omitted.

> blaming the presumably foreign maintenance crew The same happened with MCAS, the pro-Boeing argument was that if those were American pilots it would have been fine.

As a matter of fact, the same issue did occur to US-based-airlines, and the pilots did catch it. That does not however answer the question of whether they just got lucky, or were more skilled, though there are some indications that it may have been skill.

> That does not however answer the question of whether they just got lucky, or were more skilled, though there are some indications that it may have been skill.

What a load of bullcrap. Full stop.

The crews of the two crashed 737Max were also well trained, skilled professionals.

That the US-based crews decided to re-engage the auto-pilot, and with that action, by sheer luck, managed to bypass the fatal MCAS issues, shows you exactly what it was: sheer luck.

These pilots reacted to a system malfunction of a system they hardly knew existed (thanks to Boeing's lies), that changed the aircraft subsystems behaviour in fundamental, undocumented ways compared to the previous generation of 737s, and that they were therefore not trained to handle. So skill differences did not enter the equation, luck did.

The choice was between doing the manual procedures they were trained to do to try to regain control, and the hail mary approach of re-engaging the autopilot wtith the hope the problem went away. With no time to do both. The crashed crews chose option 1, the US crews option 2.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#67

Post by K0balt »

renewiltord wrote: post #52
nickff wrote: post #36

Earlier quoted context omitted.

As a matter of fact, the same issue did occur to US-based-airlines, and the pilots did catch it. That does not however answer the question of whether they just got lucky, or were more skilled, though there are some indications that it may have been skill.

Most likely just luck. These days US pilots can’t keep their planes separate from their helicopters so we're not exactly sending our best up there.

Mmmm…. Not saying us pilots are universally great, but I have definitely seen a significant regression from the mean in many foreign cohorts. I imagine it’s due to fundamental differences in the concept of training. It’s one of the things besides war that fear based societies seem to do better than shame based societies.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#68

Post by fransje26 »

hshdhdhj4444 wrote: post #64
nickff wrote: post #36

Earlier quoted context omitted.

As a matter of fact, the same issue did occur to US-based-airlines, and the pilots did catch it. That does not however answer the question of whether they just got lucky, or were more skilled, though there are some indications that it may have been skill.

Can you share a link? I’m pretty sure no American airline had the same situation that the airlines with the crash had because they paid extra for the redundant AOA sensor. The MCAS issue was a major issue, but the ultimate fundamental flaw was Boeing not including a redundant sensor (which is the one that was malfunctioning in the crashes) in the base package as they should have. The inexplicably considered redundanc…

> they paid extra for the redundant AOA sensor.

There was no redundancy AOA sensor option for MCAS.

All the planes were built with two AOA sensors, with the original MCAS implementation only using data from 1 sensor.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#69

Post by hshdhdhj4444 »

fransje26 wrote: post #68
hshdhdhj4444 wrote: post #64

Earlier quoted context omitted.

Can you share a link? I’m pretty sure no American airline had the same situation that the airlines with the crash had because they paid extra for the redundant AOA sensor. The MCAS issue was a major issue, but the ultimate fundamental flaw was Boeing not including a redundant sensor (which is the one that was malfunctioning in the crashes) in the base package as they should have. The inexplicably considered redundanc…

> they paid extra for the redundant AOA sensor. There was no redundancy AOA sensor option for MCAS. All the planes were built with two AOA sensors, with the original MCAS implementation only using data from 1 sensor.

Correct. And you could pay for the MCAS to use both sensors which all US airlines did.

Edit: I was misremembering. Both sensors were enabled on all planes and MCAS only used one at a time on all planes.

What was disabled, unless paid for, was software which displayed to the pilots that the 2 sensors were disagreeing, which would immediately have alerted them to what may have been wrong.

> According to Bjorn Fehrm, Aeronautical and Economic Analyst at Leeham News and Analysis, "A major contributor to the ultimate loss of JT610 is the missing AoA DISAGREE display on the pilots' displays."[109] > The software depended on the presence of the visual indicator software, a paid option that was not selected by most airlines.[110] For example, Air Canada, American Airlines and Westjet had purchased the disagree alert, while Air Canada and American Airlines also purchased, in addition, the AoA value indicator, and Lion Air had neither.[111][112] Boeing had determined that the defect was not critical to aircraft safety or operation, and an internal safety review board (SRB) corroborated Boeing's prior assessment and its initial plan to update the aircraft in 2020. Boeing did not disclose the defect to the FAA until November 2018, in the wake of the Lion Air crash.[113][114][115][116] Consequently, Southwest had informed pilots that its entire fleet of MAX 8 aircraft will receive the optional upgrades.[117][118] In March 2019, after the second accident of Ethiopian Airlines Flight 302, a Boeing representative told Inc. magazine, "Customers have been informed that AoA Disagree alert will become a standard feature on the 737 MAX. It can be retrofitted on previously delivered airplanes."[119]

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

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#70

Post by fransje26 »

ksaj wrote: post #27
mmooss wrote: post #19

Some are forgetting how risk in technology works: No technology is designed or operated without flaws; that's an absurd approach and impossible to implement. To reduce negative outcomes, we use risk management: assessing the likely lifetime cost of the flaw, and taking cost-effective measures to reduce the risk to an acceptable level. As a familiar example, redundant mass storage drives are much more cost-effective t…

They do mention that the DC10 (this plane's predecessor) was decommissioned for similar issues.

This article does not?

And the DC-10 was not decommissioned. It is, in fact, still in service.

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