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Boeing Unveils 737 Max Software Fixes (cnbc.com)
hcs_$reboot shares a report from CNBC: Boeing previewed its software fix, cockpit alerts and additional pilot training for its 737 Max planes on Wednesday, saying the changes improve the safety of the aircraft which has been involved in two deadly crashes since October. By the end of this week, Boeing plans to send the software updates and plan for enhanced pilot training to the FAA for certification approval. After the FAA approves the fix, Boeing said it will send the software update to customers.
Among the notable changes to the MAX flight controls:
- The plane's Maneuvering Characteristics Augmentation System, or MCAS, automated flight control system, will now receive data from both "angle of attack" sensors, instead of just one.
- If those disagree by more than 5.5 degrees, the MCAS system will be disabled and will not push the nose of the plane lower.
- Boeing will be adding an indicator to the flight control display so pilots are aware of when the angle of attack sensors disagree.
- There will also be enhanced training required for all 737 pilots so they are more fully aware of how the MCAS system works and how to disable it if they encounter an issue.
As someone that has worked in both functional safety and off-highway vehicles.
How the fuck did this ever make it into production. Why is a 'second sensor' an upsell?
When given the option to completely update the cockpit to the latest and greatest with digital displays.
They chose to replicate the old mechanical dials so the pilots couldn't be retrained.
The entire thing from start to finish was rushed. Mechanical design comes first. There is no 'try and develop software in parallel'. A clean software design depends on a good mechanical design.
The plane should have been a white board redesign, it should have been balanced such that a pilot could fly it stable with no avionics. This isn't a jet fighter.
But it was rushed because Europe invested in R&D and beat them to economy routes. How much money did Boeing C-suites make before 2011? During the 2009 crash there was a hiring spree by some companies because the market was flooded with cheap, good engineers that just got laid off. Companies invested in talent. Did Boeing?
People died because... Boeing sat on R&D from post WWII while making a ton of money so when Airbus released a good plane they scrambled to retrofit an old design by putting huge engines on an airframe causing it to pitch up but to appease its clients it added software to mimic the old plane behavior and tested it themselves and told the FAA they promise they did it right.
More or less.
Reality the only safe choice now, DO NOT BUY US AIRCRAFT
A whole set of EU pitot tubes would never ice over above a tropical storm, any more than an EU rudder would snap off in wake turbulence, would they now?
Just your industry standard screwup. A better design is expensive, more testing is expensive, any delay is expensive. To the product managers will push and push and push for you to ship the product. The plan was not designed from scratch, it's an incremental modification of the 737 line and this feature was essentially a patch that was less expensive than a redesign.
The MAX 8 will be one of the safest planes in the sky after this design review is done and the software gets updated.
A plane where the engines have to much power and push the nose so far up that the plane can stall: does not sound safe to me.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
So by disabling the MCAS you can't go full throttle without manually adjusting trim. That's not exactly ideal.
I've heard elsewhere that the purpose of the MCAS was also to make the Max fly like previous 737 and thus reduce retraining. With MCAS disabled, the pilot is flying a plane he is not trained for.
I'm not sure if I'm comfortable with this solution. Instead of a crash you get a high risk situation which sure is better but far from good.
The airplane in the LION air crash was 2 months old (delivered new mid-August, crashed in October). They had no time to do poor maintenance.
The depressing (or incriminating?) part here is that the fix didn't require any hardware modifications, as I would have expected. I assumed that there was some cost/weight issue to having the MCAS have access to the left and right sensors. But nope, it could have compared both.
If it can be fixed with a software fix, then it could have been done right from the start without any extra hardware costs of production.
Very damning.
I get so tired of the reports calling clear software/algorithm bugs "computer glitches."
It's akin to blaming every pilot error situation on the plane.
Just as with hardware design flaws, software design flaws should have repercussions for the manufacturer, and not written off as "oh, one of those computer glitches!" If your computers are glitchy, don't put them on my plane, thanks.
Love many, trust a few, do harm to none.
The more redundant devices you use, the more likely that there is a failure of at least one, which is not good, because now you have to decide what' going on. And if the failure modes are not different enough, it may be common that when one fails, many fail. You could be no better off with more and, depending on the math of the specifics, you might be actually worse off with more.