Insane graph. As an layman, at first the data presented is overwhelming, but as you go line by line it is insane how it really tells you the story of what happened.
I assume the red AoA line is the functioning sensor since it shows the steep decline at the end? But then were they really at 75* up before that? Or were both AoA's pooched? Almost neither seems to tell the true story of the nose...
Insane graph. As an layman, at first the data presented is overwhelming, but as you go line by line it is insane how it really tells you the story of what happened.
I assume the red AoA line is the functioning sensor since it shows the steep decline at the end? But then were they really at 75* up before that? Or were both AoA's pooched? Almost neither seems to tell the true story of the nose...
I would think the red one would be faulty, as it shows the massive change near the start which looks to have activated MCAS. It stays steadily reading 75° most of the rest of the flight, which I think would be impossible.
The Following User Says Thank You to Fuzz For This Useful Post:
Starting to shine the light on the dangers of automation. It sure looks like Boeing didn't ask enough of the "well what if this happens?" type of questions.
On mobile, and I need to go back and read all the recent posts, but as a developer, this is what really stands out to me.
One would think that with a system like MCAS, there would be a LIMIT to how much nose down trim it can apply. At a certain point, you have to go, "uh, I'm almost full tilt here, you sure this sensor is right?"
Perhaps that speaks to the theory that the 737 MAX was developed too quickly.
I’m not sure why some of the sentiments in posts by Ryan Coke and others have stirred up such controversy in here. Nobody is blaming this accident on the pilots as this looks to be a fault that would be tough to surmount for any pilot, but it doesn’t detract from that statement to also infer that higher experience levels in the flight deck are likely to mitigate a larger number of bad outcomes. Human factors play a huge role in pretty much every aviation incident, so it’s fair game to take a look at elements like pilot experience in a situation such as this (and no, I realize that more experience doesn’t necessarily make for a “better pilot”).
It also isn’t controversial to observe that aviation standards do vary depending on your location on the earth. Nothing to do with racism, xenophobia, or a sense of superiority - just a fact. It’s also true that certain nations - not necessarily by any fault of their own - face shortages of pilots due either to lack of training infrastructure or an exploding middle class (and the growth in air travel that comes along with it), or both. If this in turn results in a net decrease of experience levels in the cockpit, you’re clearly looking at a potentially heightened risk factor. Bottom line, the more 200 hour butts you have in seats, the less likely crews will be able to identify and respond to problems that arise on the basis of any sort of prior experience.
I’m interested to hear what comes of this accident though. I’ve never heard anything negative with regards to Ethiopian and their safety record/practices, so all eyes are certainly on Boeing right now and the dudes in lab coats that are attempting to push out a software update to fix this mess.
__________________ Is your cat doing singing?
The Following 6 Users Say Thank You to Max Cow Disease For This Useful Post:
.@BoeingAirplanes to temporarily cut 737 production from 52 to 42 per month in the coming weeks "to accommodate the pause in MAX deliveries, allowing us to prioritize additional resources to focus on software certification and returning the MAX to flight."
.@BoeingAirplanes to temporarily cut 737 production from 52 to 42 per month in the coming weeks "to accommodate the pause in MAX deliveries, allowing us to prioritize additional resources to focus on software certification and returning the MAX to flight."
The wonderful world of aviation. 50 cent bolt at a hardware store. Same thing aviation certified? $10. I may be exaggerating but not by much most likely.
I work in the airline sector, specifically heli's and you're not wrong.. some #### you can buy that's literally $3 bucks gets quoted $20-30K. It's ####ed.
The Following User Says Thank You to skudr248 For This Useful Post:
Pardon my confusion on this, but what do the people building the planes have to do with the software certification process?
I was thinking that to, but it could be the verification process. I'd imagine every plane needs a full technical rundown before shipping. Perhaps the people doing the verification are also the ones who wrote the software fixes. So they could be the rate determining factor, or they have added a bunch of extra verification that takes longer to run that it does build planes.
Why would they not certify/verify the software as well as the hardware? It is part of "building" it.
This is the issue with automation of transportation and why i think we are way further away from self driving cars then some people seem to think. If you have ever seen a list of monthly patches for Windows or Linux servers you would never trust software again.
There is not only software malpractice but there also deliberate bad actors that lead to a very long list of Symantec fixes and anti virus code.
Last edited by Flamenspiel; 04-05-2019 at 05:08 PM.
Pardon my confusion on this, but what do the people building the planes have to do with the software certification process?
They don’t. But it doesn’t make financial sense to keep building aircraft if you cannot delivery them to your customers (and get paid). Trimming production reduces labor costs, those dollars can be reallocated to fixing the issue. I read this as more of a financial move more than anything.
They don’t. But it doesn’t make financial sense to keep building aircraft if you cannot delivery them to your customers (and get paid). Trimming production reduces labor costs, those dollars can be reallocated to fixing the issue. I read this as more of a financial move more than anything.
I don't think its financial in terms of needing the money to fund the fix. The fix is cheap and Boeing is a monstrous entity with plenty of revenue still coming in, and that doesn't even touch on their massive cash reserves (USD 8B+), debt availability, etc. Plus the fact they were paying these people already so not like it is actually costing them much more than some additional OT and related development costs. A drop in the bucket of their costs.
I don't think its financial in terms of needing the money to fund the fix. The fix is cheap and Boeing is a monstrous entity with plenty of revenue still coming in, and that doesn't even touch on their massive cash reserves (USD 8B+), debt availability, etc. Plus the fact they were paying these people already so not like it is actually costing them much more than some additional OT and related development costs. A drop in the bucket of their costs.
Not sure which employees you are referring to here. The assembly line workers putting the aircraft together are hourly employees so reducing production will directly reduce costs to Boeing. But yes, otherwise much of the cost to fix is relatively cheap for Boeing to fix.
I wonder if Boeing is testing these flights with defective AOA sensors onboard as part of the test, or just testing these in normal conditions. I can't imagine many pilots wanting to test in similar real-life conditions as the 2 crashes.
There is also a lot of unanswered questions from the Ethiopian flight despite the preliminary report. Out of all this however I am surprised at how little scrutiny the AOA sensor maker has seen, considering malfunctioning sensors were the center of at least 3 plane crashes.
Angle-of-attack sensors have been flagged as having problems more than 50 times on U.S. commercial airplanes over the past five years, although no accidents have occurred over millions of miles flown, according to reports made to the Federal Aviation Administration’s Service Difficulty Reporting database. That makes it a relatively unusual problem, aviation experts said — but also one with magnified importance because of its prominent role in flight software.
Quote:
Placing too much trust in the sensors can cause trouble. One of the most serious crashes tied to angle-of-attack sensors occurred in 2008, when XL Airways Germany Flight 888T hit the Mediterranean Sea, killing seven people. French authorities blamed water-soaked angle-of-attack sensors on the Airbus 320, saying they generated inaccurate readings and set up a chain of events that resulted in a stall.
According to investigators, the downed airplane’s sensors were made by Rosemount, the same company that made the sensors on the Lion Air crash. At the time, Rosemount was also called Goodrich, the company that owned the aerospace manufacturer at the time.
Near disaster could have also happened on an A320, that uses similar anti-stall software and got impacted when 2 of 3 AoA sensors were faulty.
Quote:
One important difference between the Lufthansa incident and the two 737 MAX crashes, aviation experts said, was where they occurred.
The Lufthansa plane was soaring at 31,000 feet when it launched into a steep dive. It dropped 4,000 feet in less than a minute before the pilots wrestled back control.
Additional simulator training to be required once the grounding is lifted. Presumably applies to all airlines that fly the Max series to/from/over Canadian airspace.
Not sure if this was posted already. Interesting article about from IEEE.
How the Boeing 737 Max Disaster Looks to a Software Developer
Quote:
I believe the relative ease—not to mention the lack of tangible cost—of software updates has created a cultural laziness within the software engineering community. Moreover, because more and more of the hardware that we create is monitored and controlled by software, that cultural laziness is now creeping into hardware engineering—like building airliners. Less thought is now given to getting a design correct and simple up front because it’s so easy to fix what you didn’t get right later.
Every time a software update gets pushed to my Tesla, to the Garmin flight computers in my Cessna, to my Nest thermostat, and to the TVs in my house, I’m reminded that none of those things were complete when they left the factory—because their builders realized they didn’t have to be complete. The job could be done at any time in the future with a software update.
Additional simulator training to be required once the grounding is lifted. Presumably applies to all airlines that fly the Max series to/from/over Canadian airspace.