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How Boeing, FAA certified the suspect 737 MAX flight control system

seattletimes.com

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Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#71

Post by MockObject »

wnevets wrote: post #66
MockObject wrote: post #64

Earlier quoted context omitted.

But an inherent bug of government regulation is that it's always vulnerable to lobbying like you cited. So it's still a failure of regulation, except one that is permanent and unsurprising.

Are you arguing that it was a failure of the government regulation by allowing the self regulation that caused the mess?

Yes.

If a suspect nicely asks a police officer not to arrest them, and the officer complies, that's a failure of policing.

The only difference here is that the vulnerability of regulatory bodies to asking nicely is so well-recognized that it has a fancy name ("Regulatory Capture"), and is backed by loads of published research, and quite frankly is probably the reason that the business class even submits to this sort of regulation at all.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#72

Post by michaelcampbell »

linuxftw wrote: post #51
GuB-42 wrote: post #49

Earlier quoted context omitted.

AFAIK, the FAA, like many regulating bodies take everything at face value, making sure they are not getting lied to isn't their jobs. An audit usually goes like: "I see that you mentioned a change in document X, show me the corresponding test report", "who is responsible for that part?", "does document Y match document X, as required by norm Z?". They will never check that you actually did the tests, or that the anal…

> AFAIK, the FAA, like many regulating bodies take everything at face value, making sure they are not getting lied to isn't their jobs. I don't think this is accurate whatsoever. USDA has inspections all the time, they don't just check a report you file with them and go "Oh yeah, they know what they're doing over there." Similar with other industries. If a regulatory body doesn't validate the tests of a manufacturer,…

> > AFAIK, the FAA, like many regulating bodies take everything at face value, making sure they are not getting lied to isn't their jobs.

> I don't think this is accurate whatsoever.

Which part, that the FAA encourages delegation to Boeing? This is established, AFAIK.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#73

Post by wnevets »

MockObject wrote: post #71
wnevets wrote: post #66

Earlier quoted context omitted.

Are you arguing that it was a failure of the government regulation by allowing the self regulation that caused the mess?

Yes. If a suspect nicely asks a police officer not to arrest them, and the officer complies, that's a failure of policing. The only difference here is that the vulnerability of regulatory bodies to asking nicely is so well-recognized that it has a fancy name ("Regulatory Capture"), and is backed by loads of published research, and quite frankly is probably the reason that the business class even submits to this sort…

The industry didn't lobby the FAA to allow more self regulation, the POTUS demanded it.

A more accurate analogy would be the police chief ordering the officer not to arrest the judge's son for drunk driving.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#74

Post by tzakrajs »

ajross wrote: post #65
tafda wrote: post #62

Earlier quoted context omitted.

Not true. https://www.seattletimes.com/business/boeing-aerospace/faile... Quote: The discrepancy over this number is magnified by another element in the System Safety Analysis: The limit of the system’s authority to move the tail applies each time MCAS is triggered. And it can be triggered multiple times, as it was on the Lion Air flight. One current FAA safety engineer said that every time the pilots on the Lion Air…

Yes true.[1] You're misunderstanding that quote. It's talking about "authority" in the sense of software's authorization to move the trim tab, not the aerodynamic authority of the tailplane. The 737 has a 60 year old, very conventional elevator with a trim tab. The tab changes the resting angle of the overall elevator, and thus the "center point" of tailplane force on the airframe. Being out of trim means that the ai…

Your footnote is really appreciated. I think there is a lot of trauma in this world and coping is a daily struggle for many of us. My hat is off to you.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#75

Post by speakeron »

ajross wrote: post #65
tafda wrote: post #62

Earlier quoted context omitted.

Not true. https://www.seattletimes.com/business/boeing-aerospace/faile... Quote: The discrepancy over this number is magnified by another element in the System Safety Analysis: The limit of the system’s authority to move the tail applies each time MCAS is triggered. And it can be triggered multiple times, as it was on the Lion Air flight. One current FAA safety engineer said that every time the pilots on the Lion Air…

Yes true.[1] You're misunderstanding that quote. It's talking about "authority" in the sense of software's authorization to move the trim tab, not the aerodynamic authority of the tailplane. The 737 has a 60 year old, very conventional elevator with a trim tab. The tab changes the resting angle of the overall elevator, and thus the "center point" of tailplane force on the airframe. Being out of trim means that the ai…

The 737 isn't trimmed with a trim tab; the whole stabilizer is moved (rotated) by a jackscrew driven by an electric motor.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#76

Post by zkms »

ajross wrote: post #65
tafda wrote: post #62

Earlier quoted context omitted.

Not true. https://www.seattletimes.com/business/boeing-aerospace/faile... Quote: The discrepancy over this number is magnified by another element in the System Safety Analysis: The limit of the system’s authority to move the tail applies each time MCAS is triggered. And it can be triggered multiple times, as it was on the Lion Air flight. One current FAA safety engineer said that every time the pilots on the Lion Air…

Yes true.[1] You're misunderstanding that quote. It's talking about "authority" in the sense of software's authorization to move the trim tab, not the aerodynamic authority of the tailplane. The 737 has a 60 year old, very conventional elevator with a trim tab. The tab changes the resting angle of the overall elevator, and thus the "center point" of tailplane force on the airframe. Being out of trim means that the ai…

> You're misunderstanding that quote. It's talking about "authority" in the sense of software's authorization to move the trim tab, not the aerodynamic authority of the tailplane.

> The 737 has a 60 year old, very conventional elevator with a trim tab. The tab changes the resting angle of the overall elevator, and thus the "center point" of tailplane force on the airframe. Being out of trim means that the aircraft might naturally want to pitch up or down, and forces the pilot to apply to force to the stick (which moves the elevator, not the trim tab!) to correct it.

I don't think so. The 737 has a trimmable horizontal stabilizer. Stab trim moves (and MCAS moves) the big and leading-edge airfoil and not a trailing-edge tab on a trailing-edge elevator control surface: https://my.mixtape.moe/tkyyzt.png

See https://www.satcom.guru/2018/11/stabilizer-trim.html (where i took this image from) for further details.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#77

Post by 0xffff2 »

kevin_thibedeau wrote: post #21

I wonder who at Boeing pushed to redesign the landing gear. At this point it would have been the cheaper option.

Redesigning the landing gear means redesigning the wing. I'm not an aerospace engineer, but I do work at an aerospace organization. I've been told my multiple AE's that redesigning the wing is basically the same amount of work as designing a new plane from scratch. In light of that, I'm still not sure we're there yet in terms of purely monetary costs.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#78

Post by MockObject »

wnevets wrote: post #73
MockObject wrote: post #71

Earlier quoted context omitted.

Yes. If a suspect nicely asks a police officer not to arrest them, and the officer complies, that's a failure of policing. The only difference here is that the vulnerability of regulatory bodies to asking nicely is so well-recognized that it has a fancy name ("Regulatory Capture"), and is backed by loads of published research, and quite frankly is probably the reason that the business class even submits to this sort…

The industry didn't lobby the FAA to allow more self regulation, the POTUS demanded it. A more accurate analogy would be the police chief ordering the officer not to arrest the judge's son for drunk driving.

Yes, your analogy is fine.

If the police chief was asked on a golf course not to arrest someone, but instead do "self policing", and he complied, it's still a failure in policing, and not any failure of whatever "self policing" is supposed to be.

Maybe we need a regulation solution that doesn't involve handing over ultimate authority half the time to a party that is consistently on record as opposing regulation?

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#79

Post by dang »

linuxftw wrote: post #28

This article seems to be second-hand reporting some of the information originally broken here [1]. There's a lot of damning information, not only for Boeing, but also a lot of negligence at the FAA for pushing engineers to 'delegate' reviews of certain components back to Boeing themselves. [1] https://www.seattletimes.com/business/boeing-aerospace/faile...

Ok, we've changed the URL to that article from https://qz.com/1574878/pilots-trained-for-boeing-737-max-wit... in keeping with the guidelines' call for original sources. Thanks!

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#80

Post by linuxftw »

michaelcampbell wrote: post #72
linuxftw wrote: post #51

Earlier quoted context omitted.

> AFAIK, the FAA, like many regulating bodies take everything at face value, making sure they are not getting lied to isn't their jobs. I don't think this is accurate whatsoever. USDA has inspections all the time, they don't just check a report you file with them and go "Oh yeah, they know what they're doing over there." Similar with other industries. If a regulatory body doesn't validate the tests of a manufacturer,…

> > AFAIK, the FAA, like many regulating bodies take everything at face value, making sure they are not getting lied to isn't their jobs. > I don't think this is accurate whatsoever. Which part, that the FAA encourages delegation to Boeing? This is established, AFAIK.

Regulatory agencies taking things at face value.
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