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Pilot of Boeing flight says he lost control after instrument failure

cnn.com

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Re: Pilot of Boeing flight says he lost control after instrument failure

#241

Post by Log_out_ »

tptacek wrote: post #81
notRobot wrote: post #80

Earlier quoted context omitted.

This is worthy of reporting. 50+ people were injured, one is in severe condition.

Flight control incidents that cause injuries are not hard to find on avherald. I guess I'm not saying it isn't worth reporting. Before the Boeing Narrative set in, these kinds of stories did get reported! But now they're tied into this long-running Boeing arc, and it's frustrating because there isn't enough in the story to know what's really going on.

Perfectly good diesel engines and the carbon dioxide they saved with these cars. Madness, pure madness. Should have just ignored the scandal to protect the local car industry..

Re: Pilot of Boeing flight says he lost control after instrument failure

#242

Post by uuddlrlrbaba »

Reason077 wrote: post #218
breadwinner wrote: post #185

Earlier quoted context omitted.

> They are complex machines, but they typically have so many redundancies But Boeing reduced redundancies, presumably to cut costs. The 737 MAX planes that crashed only had one AoA sensor. Where else did they cut costs? Where else did they reduce redundancies? The public trust has been lost. Boeing needs to design a new plane from scratch, this time let engineers design the plane without interference from accountants…

The 737 MAX, like all 737s, always had two AoA sensors. The problem was that Boeing engineers wrote software for the 737 MAX which could make critical flight control inputs based on the data from one sensor only. And didn't really tell pilots about it. The fix, amongst other mitigations, was to have the MCAS software cross-check inputs from both AoA sensors.

Still, when two sensors disagree how do you determine which sensor is correct? Really 3+ are needed

Re: Pilot of Boeing flight says he lost control after instrument failure

#243

Post by Log_out_ »

whatshisface wrote: post #155
Scoundreller wrote: post #154

Earlier quoted context omitted.

> it's like a nationalized company that just happens to be nominally owned by investors So like Embraer, Airbus, Bombardier and probably others?

Yes, that's right. The free market has no horses in this race, it's a comparison of the relative corruption of different governments and societies. Our military-industrial complex, of which Boeing is an important member, is one of the most corrupt institutions in the world.

Empires tend to produce these outcomes. Usually there are also mega projects going nowhere.

https://en.m.wikipedia.org/wiki/Cape_to_Cairo_Railway

Re: Pilot of Boeing flight says he lost control after instrument failure

#244

Post by dotancohen »

Reason077 wrote: post #218
breadwinner wrote: post #185

Earlier quoted context omitted.

> They are complex machines, but they typically have so many redundancies But Boeing reduced redundancies, presumably to cut costs. The 737 MAX planes that crashed only had one AoA sensor. Where else did they cut costs? Where else did they reduce redundancies? The public trust has been lost. Boeing needs to design a new plane from scratch, this time let engineers design the plane without interference from accountants…

The 737 MAX, like all 737s, always had two AoA sensors. The problem was that Boeing engineers wrote software for the 737 MAX which could make critical flight control inputs based on the data from one sensor only. And didn't really tell pilots about it. The fix, amongst other mitigations, was to have the MCAS software cross-check inputs from both AoA sensors.

The airplane could have a dozen AoA sensors, but if the software is ignoring 11 of them then there is only one actual AoA sensor for purpose of discussion. Even if the sensors are used for other aspects, such as pilot instrumentation.

And yes, I understand perfectly well that this invalidates the idea that the second sensor was "eliminated" to save cost - but if I remember correctly there was a paid option to have the MCAS consider both sensors. So there was a financial aspect to the decision. Someone please correct me if I'm wrong.

Re: Pilot of Boeing flight says he lost control after instrument failure

#245

Post by paulmd »

anigbrowl wrote: post #190
tptacek wrote: post #76

If you watch The Aviation Herald, this kind of reporting feels a little like trying to write news stories off VAERS data. Crazy shit is happening more or less all the time in planes; the idea isn't that nothing ever goes wrong, but that layered controls prevent injuries or hull losses. It's not that there necessarily isn't a thru-line to these stories. And I read "Flying Blind" like everyone else and share the popula…

50 injuries on a commercial flight is very unusual. The story is about half description of the incident and half background info on Boeing's ongoing woes. It doesn't seem reasonable to expect an engineering explainer on a breaking news story. There are experts somewhere that can put events like this into context, but they're not cited and the story isn't written around that kind of analysis, so we're left to supply i…

787 is known to have computer bugs that are tied to system uptime too.

https://www.theregister.com/AMP/2020/04/02/boeing_787_power_...

Like obviously that is not the failure mode in this scenario… but it’s the same aircraft type. It’s totally believable imo that they just bumped into some other bug/timeout/overflow, especially on the 787 of all aircraft.

In fairness these types of reports can also “prime” people to favor certain explanations. It doesn’t mean it is a software bug, or related in any way to the previous ones. But as a software engineer… yeah that really does sound like some kind of overflow or hang, followed by a lockup, followed by a watchdog timeout and reboot. Good thing it’s not booting off spinning rust there. “Please wait while windows checks your file system for errors” is not what I’d want to see as I’m falling out of the sky :V

It obviously has to be something very edgy otherwise it would have been caught already. Uptime is a good theory imo. But that’s pure unfounded speculation.

On the other hand, not good news for Boeing given the other situation. Yes, it’s unrelated and a totally different aircraft type, and small bugs are routine in newer types. But people don’t have confidence in Boeing to engineer and manufacture well anymore - when people know deep down in their heart of hearts it’s another big Boeing bug you have a mindshare problem. It’s like smeltdown etc. Even if it affects everyone it certainly reminds them of intel the most.

Re: Pilot of Boeing flight says he lost control after instrument failure

#246

Post by Retric »

breadwinner wrote: post #230
Retric wrote: post #229

Earlier quoted context omitted.

You can definitely treat it as a design flaw and fix it without impacting most systems. Designers need to make radical changes before cockpit windows would need to be updated. That specific example may not seem like much but there’s a lot of safety critical engineering that goes into such things and yet design flaws where still uncovered.

Sure you can bring over the "good parts" of the old plane, but if this design flaw is fixed then it is essentially a new plane. They will no longer be able to pretend it is the same as the old 737s (and that's what got them into trouble).

When you say “parts” it’s really complex systems. The 737 family of aircraft has gone through many revisions over 50+ years at this point.

The original 737-100 was 61,994 lbs empty and the 737-900ER was more than 50% heavier at 98,495 before they started calling them MAX. The 900ER was in many ways a radically different aircraft but got there through a long list of incremental changes leveraging the past.

That’s not to say new designs can’t be quite safe. The much newer A320 family are some of the safest aircraft flying with only 38 hull losses and 1505 fatalities, but do not mistake good design for inevitability.

Re: Pilot of Boeing flight says he lost control after instrument failure

#247

Post by Havoc »

maybelsyrup wrote: post #84

Anyone have the tail number for the airplane involved? Is it CC-BGG? Wondering if there's any way to tell if this is one of the 787s built in South Carolina or in Washington state.

You can probably fish it off flight radar. If you have an adsb broadcaster they’ll give you a free pro subscription

Re: Pilot of Boeing flight says he lost control after instrument failure

#248

Post by dotancohen »

trompetenaccoun wrote: post #204
dynisor wrote: post #126

Earlier quoted context omitted.

74gear[1] on YouTube is a 747 Captain. It's a great aviation channel in general if anyone is interested in that stuff. He had mentioned two things that really illustrated to me your point a while back: A) Stuff breaks on planes. All the time. They are complex machines, but they typically have so many redundancies that unless there is a completely catastrophic failure, they are still perfectly safe to fly. An example:…

>It's a great aviation channel in general if anyone is interested in that stuff. It's an aviation channel for people who aren't into aviation. Lot's of clickbait + obvious optimization of titles and topics to appeal to the masses. The Mr Beast of pilots.

Sounds just up my alley. I know nothing about airplanes yet find them fascinating.

Re: Pilot of Boeing flight says he lost control after instrument failure

#249

Post by dotancohen »

bombcar wrote: post #170
nsguy wrote: post #144

Earlier quoted context omitted.

IIRC there were other Airbus incidents and concerns. It's been so long I don't recall the details but I remember being worried about flying Airbus.

Airbus has had any number of incidents (here's one: https://safetyfirst.airbus.com/landing-with-nosewheels-at-90... ) - and for awhile their approach to autopilots was widely argued back and forth (Airbus wouldn't let you put the plane outside of the envelope, basically), and there's some disagreement on how competing sticks should be handled.

I love when I can read something and identify the guy who's been interested in the topic for decades.

Re: Pilot of Boeing flight says he lost control after instrument failure

#250

Post by dotancohen »

mrguyorama wrote: post #211
thejazzman wrote: post #163

Earlier quoted context omitted.

Unless you're a pilot I'm not sure why anyone would expect that to be common knowledge. And it's insane such a system would ever be authorized IMO. That sounds like a hack to fix a memory leak or similarly some bug they can't figure out

>Unless you're a pilot I'm not sure why anyone would expect that to be common knowledge. It should sure as hell be common knowledge to the pilots of the plane. I would have expected something like this to be on a checklist somewhere though: "Step 74, check uptime in Flight Computer, pull breaker if too high" Why would it be insane for a computer controller of what is essentially industrial machinery be designed to be…

  > If the computer is 100% reliable only for 18 hours, and the plane cannot fly for longer than 12 hours in the first place, is that a problem?
It is a problem if it requires a human to remember to do the procedure, especially if it is not done on every flight. Putting it on the checklist, but making it optional per situation, is asking for someone to make a mistake.

The reset should happen on every flight, if forgetting it on the wrong flight could potentially lead to an incident.

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