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How the Boeing 737 Max Disaster Looks to a Software Developer
Design shortcuts meant to make a new plane seem like an old, familiar one are to blame (spectrum.ieee.org) Más...Sort type: [Top] [Newest]
And your point is? MOST of the issue with the MAX8/9 is the stupidity that went into A: designing a jet that would be known to create additional uplift/easier to stall then B: installing utterly STUPID software into it that RELIES on only 1 sensor. Redundancy, Redundancy, Redundancy! AND THEN HAVING the utter audacity to turn off and "optionize" the system that would warn of AoA disagreement..look at your 737NG...AoA disagreement lights THAT WORK!
Yes a software developer THAT MAKES SENSE..I couldn't care less if he only flew gliders, he has basic working knowledge of aerodynamic lift AND proper software coding!
Yes a software developer THAT MAKES SENSE..I couldn't care less if he only flew gliders, he has basic working knowledge of aerodynamic lift AND proper software coding!
There you are! What took so long? I was starting to worry.
I'm not saying anything other than maybe the iee guy is wrong and the max is actually not "inherently unstable" like he claims it is. And if he is wrong, it's not unreasonable to wonder if he might be wrong about something else. The alternative is to assume he's perfect except for just that one thing.
If it turns out the airplane is not inherently unstable, you can still hate Boeing you know.
Anyway, your last sentence is my point. You'll accept any experience, training, or education as authoritative as long as it aligns with your position, and you'll dismiss them just as easily when they don't (or change the subject, attack the messenger, type IN ALL CAPS, click the down arrow, or whatever). You said it yourself, you could care less....like being incapable of changing your mind is a good thing. It's not good, it's irrational. As a coder you should know that. It's also confirmation bias at it's best.
I'm not saying anything other than maybe the iee guy is wrong and the max is actually not "inherently unstable" like he claims it is. And if he is wrong, it's not unreasonable to wonder if he might be wrong about something else. The alternative is to assume he's perfect except for just that one thing.
If it turns out the airplane is not inherently unstable, you can still hate Boeing you know.
Anyway, your last sentence is my point. You'll accept any experience, training, or education as authoritative as long as it aligns with your position, and you'll dismiss them just as easily when they don't (or change the subject, attack the messenger, type IN ALL CAPS, click the down arrow, or whatever). You said it yourself, you could care less....like being incapable of changing your mind is a good thing. It's not good, it's irrational. As a coder you should know that. It's also confirmation bias at it's best.
It is pointless to even try any conversation with you. A pilot must understand the basic fundamentals of lift of an aircraft and what can cause additional lift and when you do and do not want it. I am quite capable of changing my mind when something seems out of the ordinary, but you keep dwelling on the fact how he's only a Cessna 172 pilot (So he knows the fundamentals of aircraft lift), and a software coder. He knows lift and he knows proper software coding, and the caps were there to try and drive a point home. Obviously that failed and you still wish to argue which I am done with.
P.S.If the aircraft wasn't "inherently unstable", why did Boeing add the MCAS?
P.S.If the aircraft wasn't "inherently unstable", why did Boeing add the MCAS?
OK rw, I'll take a crack at it. You ask, "If the aircraft wasn't 'inherently unstable', why did Boeing add the MCAS?" JMart's link explains it below, but it rambles a bit. So let me start with the simplest true statement of that 'why', then add some explanatory thoughts. >Boeing added MCAS to the 737Max Series flight control systems to allow them to 'feel' more like legacy 737 airframes in all flight regimes.< "Inherently instability" was not the issue. The phrase "pitch stability" is engineer-speak referring to rates of change, in the rate of change, in the pitch attitude of the aircraft. Two aircraft can easily be well matched in overall stability, and yet "feel" completely different due to small differences in pitch stability in various flight regimes. Boeing seems to assert MCAS was written to better match the feel of a 737Max to a 737-400.
Did that help?
Did that help?
You can try and place that thot with someone else "to make it feel like a 737-400". The MAX is not equal to stability of a 737-400. even with the addition of MCAS. But thanks for adding 2 cents
Show me the graphs hotshot. You are blaming the hardware for a software issue that collided with a couple of dumbshit marketing decisions. Yes, the airframe issues "could have been avoided" but do you really expect Boeing to promote the 717 to be their primer short-to-medium range type?
He isn't blaming the hardware for the software issue. The hardware issue is easily apparent; he's blaming THE USE OF SOFTWARE TO RESOLVE THE HARDWARE PROBLEM. That's been the problem the entire time The use of compensating for the design flaw with software is like trying to use a bandaid or gauze on the 5th chamber of your heart to stop it from being used, despite the fact being that you have a 5th chamber in your heart when we are supposed to only have four.
On the B38M and B39M, the engines are too big, so they were moved, but that combined with the location of the landing gear can contribute to a sharper AoA. design problem there. MCAS is the bandaid, where a redesign of the fuselage of the B38M and B39M are the solution.
Also, note how the MAX 10 gets a pass here, because of the longer/larger fuselage, allotting for the repositioning of the landing gear and engines.
On the B38M and B39M, the engines are too big, so they were moved, but that combined with the location of the landing gear can contribute to a sharper AoA. design problem there. MCAS is the bandaid, where a redesign of the fuselage of the B38M and B39M are the solution.
Also, note how the MAX 10 gets a pass here, because of the longer/larger fuselage, allotting for the repositioning of the landing gear and engines.
Shh Brad...somehow, I dont think some folks realize how much influence an engine nacell, or its location, has on lift/
See Above
I am blaming hardware that does not fly properly without software patches, hotshot. If this was just "software that collided with dumbshit marketing decisions" WTH is Boeing going all out, to the tune of over $1 billion and counting?
And what, or better still why, would you be bringing up the old 717?
And what, or better still why, would you be bringing up the old 717?
What I was trying to say when I got excessively succinct (apparently)...
{forgive the cut&paste for ease of reference only} You said, "stupidity that went into A: designing a jet that would be known to create additional uplift/easier to stall then B: installing utterly STUPID software into it that RELIES on only 1 sensor. Redundancy, Redundancy, Redundancy! AND THEN HAVING the utter audacity to turn off and "optionize" the system that would warn of AoA disagreement..look at your 737NG...AoA disagreement lights THAT WORK!"
>>> So point A is weak, so oversimplified as to potentially confuse the uninitiated and demand discount from the expert. Also a bit naive, I suspect you would be shocked how many post-WW-II aircraft have designed in "handling quirks". Some of them more severe than the 737Max. Some, so severe as to cause the withdrawal of the aircraft from service. But my main objection to point A is that insisting that the 737Max is "unstable" (common usage of the term, like maybe "been known to wobble a bit") is just not true. I insist overall the whole 737 lineup has consistent enough airframe stability, end to end, that the part95 certification of 737Max does not seem unreasonable (don't get excited, I am not dismissing the procedural controversy, I am just saying I believe a competent team could have accomplished that without the debacle Boeing is currently bathing in.) Worst insisting on an overblown hardware issue weakens your argument by shifting focus from the bone-headed management decisions.
Moreover, while I might reword your point B, I like most commenters on this thread heartily agree. I (and I assume we) also find it's key points quite unsettling. I would argue however that MCAS does not "rely on only one sensor" it is simply capable of not crashing (software sense) when it finds itself missing that input. MCAS "knows" about redundant AOA sensors and how to use them and set off alarms when they disagree. It was a "dumbshit marketing decision" that made the second sensor an "option"... Your point exactly. If it were up to me I would make a third AOA sensor on a deiced stalk out front of the wing somewhere standard. But I'm just a software geek that likes lots of inputs.
Boeing took control of the DC-9<>MD-xx<>717 intellectual property in the early nineties. As a short to medium range platform, it was the standard. For decades the aft fuselage mounted twin-engined T-tail has dominated the class, with too many imitators to count. The 737 has, in contrast, been a hodge-podge quickie design to optimize schedules and minimize construction costs. From its beginning as a hacked up 707 with a scaled-down wing, sporting shortie landing gear for easy baggage loading, and adequate engines mounted with no strut it has trailed a snowstorm of fixes and advisories. Had Boeing not suffered from the all too common NIH (not invented here) syndrome, it might (should) have begun upgrading the 717 platform with modern engines, enhanced super-critical wing and fatter fuselage to create a Real class killer. {As opposed to a passenger killer.}
That is why I would bring up the old 717.
{forgive the cut&paste for ease of reference only} You said, "stupidity that went into A: designing a jet that would be known to create additional uplift/easier to stall then B: installing utterly STUPID software into it that RELIES on only 1 sensor. Redundancy, Redundancy, Redundancy! AND THEN HAVING the utter audacity to turn off and "optionize" the system that would warn of AoA disagreement..look at your 737NG...AoA disagreement lights THAT WORK!"
>>> So point A is weak, so oversimplified as to potentially confuse the uninitiated and demand discount from the expert. Also a bit naive, I suspect you would be shocked how many post-WW-II aircraft have designed in "handling quirks". Some of them more severe than the 737Max. Some, so severe as to cause the withdrawal of the aircraft from service. But my main objection to point A is that insisting that the 737Max is "unstable" (common usage of the term, like maybe "been known to wobble a bit") is just not true. I insist overall the whole 737 lineup has consistent enough airframe stability, end to end, that the part95 certification of 737Max does not seem unreasonable (don't get excited, I am not dismissing the procedural controversy, I am just saying I believe a competent team could have accomplished that without the debacle Boeing is currently bathing in.) Worst insisting on an overblown hardware issue weakens your argument by shifting focus from the bone-headed management decisions.
Moreover, while I might reword your point B, I like most commenters on this thread heartily agree. I (and I assume we) also find it's key points quite unsettling. I would argue however that MCAS does not "rely on only one sensor" it is simply capable of not crashing (software sense) when it finds itself missing that input. MCAS "knows" about redundant AOA sensors and how to use them and set off alarms when they disagree. It was a "dumbshit marketing decision" that made the second sensor an "option"... Your point exactly. If it were up to me I would make a third AOA sensor on a deiced stalk out front of the wing somewhere standard. But I'm just a software geek that likes lots of inputs.
Boeing took control of the DC-9<>MD-xx<>717 intellectual property in the early nineties. As a short to medium range platform, it was the standard. For decades the aft fuselage mounted twin-engined T-tail has dominated the class, with too many imitators to count. The 737 has, in contrast, been a hodge-podge quickie design to optimize schedules and minimize construction costs. From its beginning as a hacked up 707 with a scaled-down wing, sporting shortie landing gear for easy baggage loading, and adequate engines mounted with no strut it has trailed a snowstorm of fixes and advisories. Had Boeing not suffered from the all too common NIH (not invented here) syndrome, it might (should) have begun upgrading the 717 platform with modern engines, enhanced super-critical wing and fatter fuselage to create a Real class killer. {As opposed to a passenger killer.}
That is why I would bring up the old 717.
vs.
Software developer 172 pilot
https://youtu.be/KB4lCbT5oX8?t=626
Keep hitting that down arrow if it makes you feel better.