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Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

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Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#141

Post by ClumsyPilot »

kayfox wrote: post #132
JanSt wrote: post #106

Earlier quoted context omitted.

My understanding is that the pilots had only about 40 seconds time to solve the problem and were trained for one hour with an iPad (not on the MCAS, but the whole 737 Max). I'm not sure whether this is a question of pilots' standards in the US vs around the world.

The general idea was that pilots would correctly recognize large amounts of undesired and uncommanded trim being runaway trim and perform the checklist to resolve that issue that they are expected to know by memory, since there is a need to execute it fast, without paging through the Quick Reference Handbook. This is not a checklist that was introduced with the 737 MAX, but one that has existed since the introduction…

> 5. 5. The flight computer system and MCAS was implemented problematically, relying on one input because the expected control authority was very low, and then when that was not changed the system was not re-architected.

I like your approach: Pilot's failures caused the crash, and Boeing made an honest mistake. And you seem to think it would have been fine flying in the US. You do realise plane crashes and industrial accidents do happen in the US?

A safe system assumes they are operated by humans who are not infallible, and should not go up in flames from minor issues. Otherwise we must conclude Chernobyl reactor was a perfectly fine design.

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#142

Post by treis »

dahart wrote: post #99
treis wrote: post #84

Earlier quoted context omitted.

>Though I can’t help but wonder if this is a very subtle re-framing of the Max accidents to shift blame back towards pilots. Blame is a loaded word. Boeing assumed that pilots could be relied upon to recover from a MCAS induced runaway trim. Practice has shown that they can't. Whether Boeing or the pilots is at fault is, from a safety perspective, irrelevant. The bottom line is that an assumption was made, it was wro…

I appreciate the attempt to be diplomatic, and I agree that using average pilots is sensible. But, with respect, I could not disagree more with the rest of that. > Blame is a loaded word. Boeing’s response to the accidents was to blame the pilots, there is precedent for this word in this situation. https://www.cnn.com/2019/05/23/business/american-airlines-bo... > Boeing assumed that pilots could be relied upon No, Bo…

>Boeing’s response to the accidents was to blame the pilots, there is precedent for this word in this situation.

Your cite says Boeing said:

>The actions of the pilots played a role in the chain of events that caused the crashes

Which isn't blaming them and is factually correct in both crashes. The Lion Air pilots didn't disable electric trim and the Ethiopian air ones turned it back on. Those actions played a role in the crashes. Whether that makes the pilots responsible and at fault for the crash is a separate question.

>If you want to fix the problem, you must know what the problem is.

And, again, the problem (among other problems) was that the designer of the aircraft made assumptions about pilots that were incorrect.

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#143

Post by StreamBright »

treis wrote: post #84
dahart wrote: post #62

This seems like a good thing, they should be testing with people who don’t know the answers. Though I can’t help but wonder if this is a very subtle re-framing of the Max accidents to shift blame back towards pilots. This approach of a regulatory agency recommending “average pilot” testing makes both the agency and Boeing look good, and tends to downplay the fact that Boeing intentionally avoided training the pilots,…

>Though I can’t help but wonder if this is a very subtle re-framing of the Max accidents to shift blame back towards pilots. Blame is a loaded word. Boeing assumed that pilots could be relied upon to recover from a MCAS induced runaway trim. Practice has shown that they can't. Whether Boeing or the pilots is at fault is, from a safety perspective, irrelevant. The bottom line is that an assumption was made, it was wro…

You cannot really assume such thing in a situation like flying when the consequences of your assumption is loss of life potentially.

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#144

Post by kayfox »

ClumsyPilot wrote: post #141
kayfox wrote: post #132

Earlier quoted context omitted.

The general idea was that pilots would correctly recognize large amounts of undesired and uncommanded trim being runaway trim and perform the checklist to resolve that issue that they are expected to know by memory, since there is a need to execute it fast, without paging through the Quick Reference Handbook. This is not a checklist that was introduced with the 737 MAX, but one that has existed since the introduction…

> 5. 5. The flight computer system and MCAS was implemented problematically, relying on one input because the expected control authority was very low, and then when that was not changed the system was not re-architected. I like your approach: Pilot's failures caused the crash, and Boeing made an honest mistake. And you seem to think it would have been fine flying in the US. You do realise plane crashes and industrial…

So... I said the design was bad and your saying I'm not harsh enough in that?

Are we trying to solve engineering problems by getting emotional about them or something?

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#145

Post by treis »

elbrian wrote: post #98
treis wrote: post #84

Earlier quoted context omitted.

>Though I can’t help but wonder if this is a very subtle re-framing of the Max accidents to shift blame back towards pilots. Blame is a loaded word. Boeing assumed that pilots could be relied upon to recover from a MCAS induced runaway trim. Practice has shown that they can't. Whether Boeing or the pilots is at fault is, from a safety perspective, irrelevant. The bottom line is that an assumption was made, it was wro…

> Boeing assumed that pilots could be relied upon to recover from a MCAS induced runaway trim. Practice has shown that they can't. Whether Boeing or the pilots is at fault is, from a safety perspective, irrelevant. From a practical perspective, however, Boeing making universal assumptions about pilot capabilities in life-or-death situations, utilizing new equipment that they were not trained on, is anything but irrel…

Their logic was that pilots are trained to deal with runaway trim, a MCAS failure is runaway trim, ergo pilots are trained to deal with a MCAS failure. Obviously that logic turned out to be faulty but it's not like Boeing made some outlandish leap here.

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#146

Post by eyo2019 »

jacobush wrote: post #94
rowanG077 wrote: post #81

Actually they must use the worst pilots. If they use average pilots that means 50% of the pilots might be out of their depth flying that plane. What kind of insanity is this?

Depends on the distribution

You're technically correct, but for the metric "human pilot skill" I think the median and average probably align fairly well.

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#147

Post by kayfox »

pdonis wrote: post #127
kayfox wrote: post #115

Earlier quoted context omitted.

Most of those reports involved the autopilot or were while flaps were extended, which disables MCAS. The ones that did not were complaining about not being informed about MCAS and not about it actuating. There were even incidents reported as being MCAS that did not involve stabilizer trim or a 737 MAX.

Reports like the one where the plane started descending when autopilot was engaged are still relevant because they indicate issues with the angle of attack sensor, which is also what MCAS relies on.

AoA sensors are notoriously unreliable and Boeing should not have depended on just one.

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#149

Post by mark-r »

ebg13 wrote: post #21

Uh oh. What are they going to do when they discover that there aren't any average pilots? https://www.thestar.com/news/insight/2016/01/16/when-us-air-... (HN discussion: https://news.ycombinator.com/item?id=11230287 ) https://www.theatlantic.com/business/archive/2016/02/the-inv... (HN discussion: https://news.ycombinator.com/item?id=11155889 )

A friend of mine was once told to make his product idiot-proof. He said "sure, as soon as you give me the spec for the standard idiot."

Re: Plane Tests Must Use Average Pilots, NTSB Says After 737 Max Crashes

#150

Post by erikpukinskis »

treis wrote: post #145
elbrian wrote: post #98

Earlier quoted context omitted.

> Boeing assumed that pilots could be relied upon to recover from a MCAS induced runaway trim. Practice has shown that they can't. Whether Boeing or the pilots is at fault is, from a safety perspective, irrelevant. From a practical perspective, however, Boeing making universal assumptions about pilot capabilities in life-or-death situations, utilizing new equipment that they were not trained on, is anything but irrel…

Their logic was that pilots are trained to deal with runaway trim, a MCAS failure is runaway trim, ergo pilots are trained to deal with a MCAS failure. Obviously that logic turned out to be faulty but it's not like Boeing made some outlandish leap here.

Do you really think that’s an appropriate level of analysis for the manufacturer of a brand new MCAS? “Any failure of this new thing we’re shipping is just a trim failure, pilots can handle it”?
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