Tom1200 said:
In reply to wearymicrobe :
I am aware of that but it speaks to the level of arrogance I see in software rollouts and or updates all the time.
Things are done by people who think they are smarter and or no better than the people using the equipment and or software that don't turn out so well.
When they start to unravel those people refuse to believe the issue is actually an issue.......until it blows up multiple times.
My concern is that we see this with our cars as the nannies become more and more intrusive.
DUIs and inattentive driving are the two most common cases of fatal accidents.
Regarding sticking with your software - see the British Post Office Horizon fiasco. Search that and bring a semi load of popcorn. It's the story that keeps on giving.
Berck
HalfDork
7/10/24 12:42 p.m.
Tom1200 said:
In reply to BenB :
Boeing basically came up with a system that was never needed. The pilots with some very basic training could do what MCAS does.
I think you misunderstand a bit, here. The problem isn't that pilots couldn't learn to handle it, it's that the uncorrected behavior is terrible. The last thing you want is a natural pitch-up tendency as an aircraft approaches a stall--this is real bad and there was nothing wrong with the decision to add MCAS. As a former airline pilot, I'll take MCAS over a plane that naturally pitches itself deeper into a stall any day, even if I've been "trained" to deal with it. The same tendency in T-tail jets is why they all have stick pushers that push the control column forward at high AoA with a force strong enough to rip the yoke right out of your hands.
Also, the FAA would never have certified the plane without MCAS.
The decision to not tell pilots wasn't great, but also wasn't that big a deal. The pilots who let MCAS kill them would almost certainly have let MCAS kill them even if they knew about it. The MCAS failure presents as a runaway trim situation. The same scenario also could have presented itself without MCAS and those pilots that died still would have died. The solution was the same as every other runaway trim in the 737--disengage the electric trim and trim manually. Remember that one of the accident airplanes completed an entire flight with the same failure mode and the pilots (mostly) handled it fine, thanks to a jumpseater who told them what to do.
The decisions to allow only 2 AoA sensors, however, is unconscionable. Keep in mind that this was a cost-saving option and most US carriers opted for the 3rd sensor, while the accident budget operators did not.
Driven5
PowerDork
7/10/24 1:39 p.m.
In reply to Berck :
I've read that while MAX without MCAS experiences stronger pitch-up than NG approaching flaps-up stall, it seems like they're actually not entirely dissimilar in this regard and that actual differences felt by pilots may not actually be as bad as some of the measurements otherwise indicated.
Here's an article link, the pertinent area is most of the way down, if you want to pick at it from a more experienced perspective: https://theaircurrent.com/aircraft-development/mcas-may-not-have-been-needed-on-the-737-max-at-all/
Tom1200
PowerDork
7/10/24 1:47 p.m.
In reply to Berck :
I appreciate the input very much.
I totally agree not having two sensors.......that was just outrageous.
The Boeing case is classic compounding bad decisions...........which brings me back to auto nannies; I can see someone repeating this given the financial pressures many of these decisions are made under.
Berck said:
The decisions to allow only 2 AoA sensors, however, is unconscionable. Keep in mind that this was a cost-saving option and most US carriers opted for the 3rd sensor, while the accident budget operators did not.
And I'm sure those sensors cost millions of dollars.
American was the only MAX operator who opted for the second AoA sensor, at the insistance of the APA...literally every other operator was single AoA.
MCAS was less about *need* for safety of flight than it was about Part 25 certification requirements to maintain type certification.
In the end, doing somma that pilot sh!t wins over all. Knowing & correctly performing memory items is vital, but knowing about a system that can change pitch all by itself is pretty critical too.
jmabarone said:
Berck said:
The decisions to allow only 2 AoA sensors, however, is unconscionable. Keep in mind that this was a cost-saving option and most US carriers opted for the 3rd sensor, while the accident budget operators did not.
And I'm sure those sensors cost millions of dollars.
This is an uniformed comment. The 737, 757, 767, 747 and 777 all only have two AOA's. The same AOA's that are on the max in the same configuration. Millions and millions of safe flight hours.
airbus considers aoa's safety critical (they use three) same with embraer with their four smart probes(smart probes do speed/aoa/pitch roll/ altitude). Boeing does not( or at least did not pre max) there were other procedures developed so that a pilot could develop attitude.
the main issue was with the lack of training for the pilots. Pilots didn't know what was going on and therefore could not correct.
Berck
HalfDork
7/10/24 4:03 p.m.
Ack, you're right, it looks like it only ever had 2 AoA. I was certain I read that a third was optional (for better dispatch rates) early on in the investigation, but I don't see evidence of that now.
"the main issue was with the lack of training for the pilots. Pilots didn't know what was going on and therefore could not correct." -- hard disagree here. It was obvious it was a runaway trim situation and, at least in the US, the pilots would have had a runaway trim in the sim and should have been able to deal with one in real life.
Berck
HalfDork
7/10/24 4:11 p.m.
Fueled by Caffeine said:
airbus considers aoa's safety critical (they use three) same with embraer with their four smart probes(smart probes do speed/aoa/pitch roll/ altitude). Boeing does not( or at least did not pre max) there were other procedures developed so that a pilot could develop attitude.
Also going to disagree here. AoA is not about attitude, it's about AoA. These are unrelated--you can exceed critical AoA in any attitude. AoA sensors are safety critical on any airliner. There are too many systems that rely on them--not just stall prevention, but things like wind shear detection and escape guidance, and continuous ignition to prevent flameout are also triggered by AoA sensors.
BenB
HalfDork
7/10/24 4:12 p.m.
I recently read a very good article that went into great detail about the development of the Max series and the training and maintenance practices of the two crash airlines. "Pencil whipping" maintenance logs was commonplace at Lion Air. They train low time pilots to be button pushers, so when something out of the ordinary happened, people died. One thing that really stood out to me was Lion Air would pack a bunch of trainees in the back of the simulator, they'd watch over the shoulders of a couple of guys as they'd demonstrate a procedure, then everyone would get signed off as having completed that block of training. I saved the link on my currently dead computer, but I'll see if I can find it again online.
jmabarone said:
wearymicrobe said:
Too be clear Boeing was following the demands of the airliners who did not want a single hour of retraining to be required for the retrofits. To mush cost.
Not to turn this into a "well, I heard..." kind of thread, but I thought Boeing made this variant to avoid going through a whole FAA certification again. In a nutshell, they wanted to change just enough to meet the airlines' requests but not enough to warrant a completely new design and requisite certification.
I do not know the full inside baseball on this one but that sounds about correct.
People wonder why I spend so much time reading our actual contracts and setting SAT/FAT documents up. Its because boilerplate contracts that were used in the past are often not specific enough. I used to ask for things in the contracts that were completely one-sided and in my favor years ago and the good companies caught them. The ones that did almost always under delivered.
This is why I absolutely avoid working on things that are public facing. Want me to design something for a scientist who knows exactly what they want and they have a full list of CSF. DONE. Want something custom that will have a SOP that has to be followed. No problem. I totally get not the whole not understanding why your push had issues and most of the time IMO it comes back to the operators not reading the documentation or if you did a really good job on the UI some sort of black swan event that nobody could predict or wrote a test for.
Those black swan events require cycles and time. Its almost impossible to simulate or test all of that at the product level with what ever team you have. There are software tools that can help but never understimate a untrained and determined user.
Berck
HalfDork
7/10/24 4:19 p.m.
In reply to BenB :
Probably thinking about this one: https://www.nytimes.com/2019/09/18/magazine/boeing-737-max-crashes.html
I think it's overly harsh on the foreign pilots and gives a little too much credit to domestic ones, but it's on the right track.
In reply to Berck :
Sorry not a pilot. Poor phrasing. But Boeing does or did not consider an AOA to be safety critical. Just a guy who was named in both of the eth and lion air lawsuits. I've been out of that space since Covid.
Berck
HalfDork
7/10/24 4:30 p.m.
Boeing absolutely didn't want to go through the full certification process again, but the bigger consideration is that the airlines didn't want to send their pilots to get a new type rating. Consider Southwest airlines: one of the ways that they've managed to be profitable all these years is that, since they launched in 1967, they've only really ever operated the 737. Any pilot, flight attendant or mechanic can operate any aircraft in Southwest's fleet. This is a huge advantage. If Boeing stopped making the 737 in favor of a clean sheet design, Southwest would lose this advantage. Furthermore, once they've got to split their pilot group by type, they might as well start shopping Airbus. A clean sheet design just wasn't a viable business option for Boeing.
It's possible that some differences training (like Bombardier required for the CRJ-700/900 on top of the CRJ-200 type rating) would have been in order here, but I continue to maintain that the pilots who died by MCAS would be just as dead if they knew about MCAS. It doesn't matter whether a runaway trim situation was caused by a computer doing a thing they didn't know about (at a time they wouldn't have expected it to be doing it) or some loose wiring. The problem is the same, the solution is the same.
The 737 was designed before jetways were such a common thing and so it has tiny landing gear that keep the plane close to the ground for easier boarding. The turbojet engines that the original 737 was equipped with fit under the wing just fine. The trouble is that newer engines keep getting fatter and fatter because higher bypass ratio turbofans are more fuel efficient. They don't fit under the wing, and it's been a series of increasing kludges to make it fit.
In reply to Berck :
This is a fair assemement.
Mr_Asa
MegaDork
7/10/24 4:59 p.m.
jmabarone said:
wearymicrobe said:
Too be clear Boeing was following the demands of the airliners who did not want a single hour of retraining to be required for the retrofits. To mush cost.
Not to turn this into a "well, I heard..." kind of thread, but I thought Boeing made this variant to avoid going through a whole FAA certification again. In a nutshell, they wanted to change just enough to meet the airlines' requests but not enough to warrant a completely new design and requisite certification.
From outside looking in, I kinda wonder if those at the top went this route because they knew they wouldn't meet certification or withstand that scrutiny
kb58
UltraDork
7/10/24 5:14 p.m.
In reply to Mr_Asa :
I believe it was being able to avoid certifying a "brand new" aircraft, instead saying that it was a modified version of a previous certified aircraft, so that requirement - and the associated time - was saved.
Here are comments on it from an airline pilot, and yes, we're veering off-topic but people seem interested:
Berck
HalfDork
7/10/24 5:21 p.m.
Driven5 said:
In reply to Berck :
I've read that while MAX without MCAS experiences stronger pitch-up than NG approaching flaps-up stall, it seems like they're actually not entirely dissimilar in this regard and that actual differences felt by pilots may not actually be as bad as some of the measurements otherwise indicated.
Here's an article link, the pertinent area is most of the way down, if you want to pick at it from a more experienced perspective: https://theaircurrent.com/aircraft-development/mcas-may-not-have-been-needed-on-the-737-max-at-all/
I hadn't seen this before--this is interesting. It's clear that the NG was already bad in this area, but those Boeing emails indicate the test pilots didn't like it either. I assume the FAA would have been making certification decisions based on graphs of stick force vs AoA, an area that Boeing knew was already weak on the NG and only makes sense that it'd get worse with larger engines further forward. That stick force vs load factor graph is a thing the FAA was definitely going to look at, regardless of what pilots thought it felt like.
Driven5
PowerDork
7/10/24 5:44 p.m.
In reply to Mr_Asa :
Imagine you're the long-standing #1 maker of a product and are currently deciding how to proceed with an aging model that is your #1 source of income. To capitalize on significant technological advancements, you could update it or you could redesign it. The timeline to do so is 5+ years for the former and 10+ years for the latter. Your only (growing) competitor, offers a fundamentally newer product design, although it's still currently considered less capable. Your competitor announces that they'll be updating to take advantage of the same technological advancements you're considering, which will greatly improve their product capability and surpass your own. One of your biggest, and exclusively yours, customers calls to let you know that they're ready to place a massive order that will go to your competitors updated product (opening the door to more of the same in the future) if they have to wait on a redesign from you. Do you tell them to pound sand and just let your competitor get a major new foothold against you in your most critical market?
In reply to Driven5 :
This is a good analogy. Iirc. Customers flat out told Boeing they wouldn't order the new aircraft if it required simulator time.
BenB
HalfDork
7/10/24 6:24 p.m.
In reply to Berck :
That probably is the one. I had found a non-paywall version of it somewhere.
Rons said:
Tom1200 said:
In reply to wearymicrobe :
I am aware of that but it speaks to the level of arrogance I see in software rollouts and or updates all the time.
Things are done by people who think they are smarter and or no better than the people using the equipment and or software that don't turn out so well.
When they start to unravel those people refuse to believe the issue is actually an issue.......until it blows up multiple times.
My concern is that we see this with our cars as the nannies become more and more intrusive.
DUIs and inattentive driving are the two most common cases of fatal accidents.
Regarding sticking with your software - see the British Post Office Horizon fiasco. Search that and bring a semi load of popcorn. It's the story that keeps on giving.
I only learned about THAT from the Plainly Difficult video on the fiasco.
If you like colossal berkeleyups explained in a common manner, exploring all the ways it berkeleyed up, Plainly Difficult is a good series to watch on YouTube.
Driven5
PowerDork
7/10/24 6:46 p.m.
In reply to Fueled by Caffeine :
"The Copy and Paste Penalty" section in the article I linked may actually have been the main source of the oft-mentioned customer demands.
Tom1200
PowerDork
7/10/24 9:01 p.m.
Fueled by Caffeine said:
In reply to Driven5 :
This is a good analogy. Iirc. Customers flat out told Boeing they wouldn't order the new aircraft if it required simulator time.
And this is what makes me think a car maker could do this sort of boondoggle.
This falls under the classic "we don't have time or money to do it right but we have time to do it over"
Before I went to the public sector I worked as a buyer in manufacturing........I could tell endless tales of shortsighted decisions come in back to bite the company.
Driven5
PowerDork
7/10/24 9:43 p.m.
In reply to Tom1200 :
As far as I can tell "How to make shortsighted decisions that will come back to bite the company" is one of the core classes in business and finance curriculum. I think it's the prerequisite for "How to use shortsighted decisions to climb the corporate ladder and personally prosper" and "How to avoid blame for the repercussions of your shortsighted decisions."