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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

#211

Post by mrguyorama »

thejazzman wrote: post #163
weaksauce wrote: post #162

Earlier quoted context omitted.

I think it's worth reporting on because this particular issue is known to everyone... you need to cycle the power on the planes every 3 days or else the reset themselves. it's crazy that a modern plane needs to have that happen but it does. the most likely situation is that the plane didn't get shutdown and happened to occur at a level flying situation and the pilots probably freaked out and overflew the plane which…

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 reset at least once every other day? They "reboot" the engines damn near once a flight! Most pilots have experience and training on shutting down a plane for say overnight and then starting it from cold and dark the next day.

It's an odd idea to us software developers but the computer isn't the primary function of the plane, and doesn't need to serve customers 24/7. 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?

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

#212

Post by BWStearns »

nsguy wrote: post #147
BWStearns wrote: post #116

Earlier quoted context omitted.

Not a control issue but there was a Hawaiian flight that had 36 injuries from turbulence. Edit to add: it would be unsurprising if turbulence was the cause here and the passenger quoted had their facts wrong. https://www.cnn.com/2022/12/18/us/hawaiian-airlines-injuries...

An airplane doesn't suddenly drop out of the sky because its controls stops responding. So I agree that on the face of it it's either turbulence or some sort of aggressive manoeuvre, either initiated by the pilots accidentally or somehow initiated by the airplanes control systems, not simply "stopped responding to controls".

Yeah, I just started typing out a scenario where instruments blipping might do it and it started getting implausible several clauses in.

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

#213

Post by nradov »

bbor wrote: post #74
mym1990 wrote: post #42

Earlier quoted context omitted.

How do you suppose a half a trillion dollar market is not a "huge industry"? I am definitely aware of the cultural issues at Boeing, but boiling it down to "sometimes things are simple" is just a lot of ignorance on your part.

I just meant that there are only two companies in the industry at all - the industry being “commercial passenger flight”, or what they seem to call “airliners” (?): Still, in the large commercial aircraft market, there are just two major players: the U.S.-based Boeing (BA) and the Airbus Group (EADSY), formerly known as the European Aeronautic Defense and Space Company (EADS). I totally understand your pushback again…

That depends on how you define the market. Boeing and Airbus are the only two manufacturers of large civil airliners on the worldwide market. But there is a second tier including Bombardier, Embraer, Comac, Mitsubishi, and UAC which either manufacture smaller (regional) airliners or have more limited sales options.

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

#214

Post by breadwinner »

schlauerfox wrote: post #205
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…

This is VERY bad engineering practice, you throw away knowns for unknowns. A blue sky design isn't a fix. Especially if your corporate culture has the wrong leadership. First year engineers take engineering economics for a reason. Money is always an object.

Is there never a case where it is cheaper + better to start over? I think sometimes there is. The design of 737 MAX was flawed from the get-go. They made the engines bigger because bigger engines run hotter and burn less fuel. Ordinarily this would require the fuselage to be raised as well, so that the bigger engine can fit under the wing. Instead they changed the position of the engine. Instead of being hung under the wing, as in earlier models, the engines have been moved forward and upward, potentially leading to an aerodynamic stall under certain circumstances. Instead of going back to the drawing board and getting the airframe hardware right, Boeing relied on something called the ‘Maneuvering Characteristics Augmentation System,’ or MCAS. [1]

It's just poor design. If software fails, then any plane should be designed to have a neutral center of gravity in order to give the crew the greatest amount of time to recover from the loss.

[1] https://spectrum.ieee.org/how-the-boeing-737-max-disaster-lo...

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

#215

Post by cesarb »

breadwinner wrote: post #185
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:…

> 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 planes that crashed only had one AoA sensor.

IIRC, it had two, but each of the computers only used the sensor on its side; which was OK for the original (pre-MAX) design because of they way these sensors were originally used by it.

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

#216

Post by BasilPH »

wkat4242 wrote: post #2

This sounds more worrying now. When I heard it originally it sounded like a mountain wave. Those are extremely powerful natural downdrafts (or up!) and common in South New Zealand.. They've crashed flights before: https://en.m.wikipedia.org/wiki/BOAC_Flight_911 though that was at mount Fuji in Japan. But if the plane did this by itself.. wow. The 787 is fly by wire. Worrying. And very bad timing for Boeing.

Fascinating article. Some interesting anecdotes:

> The victims even included several survivors of the Canadian Pacific Air Lines Flight 402 crash. (Note: A plane that crashed the day prior, with only 8 out of 72 people on board surviving)

> Several booked passengers cancelled their tickets at the last moment to see a ninja demonstration. These passengers, Albert R. Broccoli, Harry Saltzman, Ken Adam, Lewis Gilbert, and Freddie Young, were in Japan scouting locations for the fifth James Bond film, You Only Live Twice (1967).

Coincidences like this are of course bound to happen with large enough numbers of people traveling, but I still find this interesting.

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

#217

Post by burnte »

schlauerfox wrote: post #205
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…

This is VERY bad engineering practice, you throw away knowns for unknowns. A blue sky design isn't a fix. Especially if your corporate culture has the wrong leadership. First year engineers take engineering economics for a reason. Money is always an object.

Yes. A place design that's 70 years old has had THOUSANDS of bugs fixed. I'd rather fly on a new 737 than an "all new 797 or A390".

Side note: I know there isn't a 797 or A390 yet, that was the intent of the statement, a future unknown plane.

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

#218

Post by Reason077 »

breadwinner wrote: post #185
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:…

> 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.

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

#219

Post by sooheon »

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…

You want a news story to be an engineering postmortem instead?

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

#220

Post by Arn_Thor »

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.

Ok, so you don’t like the titles. Do you have any problems with the actual content—the thing that matters?
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