John Oliver did an episode on Boeing quality control just 5 days ago: https://www.youtube.com/watch?v=Q8oCilY4szc
Pilot of Boeing flight says he lost control after instrument failure
251–260 of 302 posts
Re: Pilot of Boeing flight says he lost control after instrument failure
#252Earlier quoted context omitted.
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
Ask the pilot ?
Re: Pilot of Boeing flight says he lost control after instrument failure
#253Aren’t turbulence / tailwinds / low pressure zone the only things that can cause a plane to suddenly lose lift and drop? I don’t think there’s any control input that can cause that, this story doesn’t seem to make sense.
Ice can do that too. And engine failure.
Re: Pilot of Boeing flight says he lost control after instrument failure
#254Earlier quoted context omitted.
Still, when two sensors disagree how do you determine which sensor is correct? Really 3+ are needed
Ask the pilot ?
Can't do that: the pilot can't be allowed to control, or even know about MCAS, because that would affect Boeing's ability to claim the plane is "just another" 737 and that the pilots don't need retraining. Giving the pilot the ability to control MCAS means the pilots all need retraining.
Re: Pilot of Boeing flight says he lost control after instrument failure
#255Earlier quoted context omitted.
Regarding that last part, you'd be surprised at how many people at the FAA/DOT also haven't come to this realization.
The last part doesn't always work the way you'd like it to - most aviation disasters these days have very definite things the pilots could have done to save themselves and everyone, which they failed to do.
Yep, and a regulator who thinks that the answer is millions of dollars in spending to build a system and hire admins. Understanding of self preservation could replace the same things with better training and empowerment of pilots to override unsafe decisions.
Re: Pilot of Boeing flight says he lost control after instrument failure
#256Earlier quoted context omitted.
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 th…
Close! AoA disagree hazard light was an optional feature. In the original implementation, the Flight computer in command, either the one on the pilot's side, or the one on the copilot's side (alternated on power up), were fed input from only the AoA sensor they shared a physical link with.
The optional feature was essentially networking the two ststems such that the data would be fed to the FCIC for warning light activation, so that pilot's could start running the right checklists.
Re: Pilot of Boeing flight says he lost control after instrument failure
#257Earlier quoted context omitted.
>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.
Mentour Pilot is for people interested in aviation. He does breakdowns/analyses of plane incidents—not just crashes. He's also a certified trainer on at least one type.
It's funny, I was also thinking about Mentour Pilot, both because of the whole discussion here, and because of the post upthread talking about clickbait. I love Mentour Pilot once I get into one of the videos, but looking at all the attention-grabbing (and clickbaity!) stills on his video list makes me have to force myself to remember that it's fine once the video starts.
Re: Pilot of Boeing flight says he lost control after instrument failure
#258Re: Pilot of Boeing flight says he lost control after instrument failure
#259If 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…
What is VAERS data?
Re: Pilot of Boeing flight says he lost control after instrument failure
#260Earlier quoted context omitted.
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.
All-new aircraft designs are only certified to fly after many years of rigorous analysis and testing. It was Boeing's desire to avoid the full expensive certification process, by claiming that the MAX was just a minor update to an existing design, which led to two catastrophic crashes in the space of a few months. On the other hand, no 787 or A380 has ever had a crash or incident that resulted in a passenger fatality…
> On the other hand, no 787 or A380 has ever had a crash or incident that resulted in a passenger fatality or hull loss.
There have been nearly 10x as many 737s built as 787s and A380s combined. Given the date of first flight (1967 vs. 2009 and 2203, respectively) it is safe to say they have been flown for significantly more than 10x the total flight hours. Probably at least 20x but I’m pulling that number out of thin air.
The data is certainly promising but it’s probably a little too soon to be too confident in relative safety comparisons. For one, we don’t have nearly as much data on those newer airframes as they age.