About the MCAS incidents in Boeing
Posted by IndividualIron1298@reddit | aviation | View on Reddit | 38 comments
Why is MCAS primarily blamed for the 2 notorious Boeing 737 MAX crashes?
To me it seems odd that a fault of an aircraft system is blamed for the crashes. For instance if a component like an engine, display, pitot tube, or other system failed and the plane crashed as a result of it, it seems in 9/10 scenarios it gets boiled down to pilot incompetence.
Given that when MCAS activates (and pitches down via trim) a loud noise can be heard from the Trim wheel as it begins to 'run away' often called Runaway trim, why would the basic assumption not be that the pilots were extremely incompetent to not have cut off the trim systems using the 'stab trim cut-off' that is taught to every Boeing pilot since the introduction of Automatic trimming systems in like the 1950s.
I don't see how this wouldn't have saved 500+ or however many lives across the both instances where nosedive crashes happened.
css555@reddit
Can't even get basic facts right, and you talk about MCAS and yaw? Ok
IndividualIron1298@reddit (OP)
So if I say the Sky is green and birds can fly that means birds cant fly because the first part of my statement isnt accurate. đź‘ŤExcellent reddit contrarian logic, dumbass
css555@reddit
Don't get hung up on a punctuation error. I just think it's very disrespectful to not even take five seconds to Google how many people died in those two crashes.
Let me try again: "Can't even get basic facts rights and talks about MCAS and yaw?"
exurl@reddit
someone put this on that internet explorer meme
memeboiandy@reddit
Bruh defenetly sounds like he just heard about those early max accidents 10 minutes ago and not 10 years ago like everyone else in the world.
If he isnt using internet explorer he has to be trolling
IndividualIron1298@reddit (OP)
Im a new boeing investor so I wanted to learn more about the facts of the matter.
I obviously knew about the Max crashes before today lmao. I spent my childhood years flight simming.
memeboiandy@reddit
Bullshit... you just came here arguing on Boeings defence to make yourself feel less bad about investing in them by blaming the pilots for things that were entirely out of their control
IndividualIron1298@reddit (OP)
Well we already established that Stab trim cutoff is definitely in pilots control and also has been taught to pilots since the introduction of the Boeing 707 in the 1950's.
So in reality the pilots were the decider of whether those people died or not.
But think what you want. I wouldn't come into here to find people I agree with would i, thats called an echo chamber or stroking your ego - so i'm glad there are people like yourself who fervently disagree.
BeardySi@reddit
I'm amazed nobody ever mentioned that before in all the scrutiny there's been of these cases. You clearly have a level of insight surpassing anyone else in the entire aviation industry.
Or
You haven't the first clue what you're talking about. It could be that either...
IndividualIron1298@reddit (OP)
It's all well and good saying that but I have very good comprehension of MCAS, its characteristics, how it manifests through stabiliser trim, I've flown in simulation level 737 and and the options that every pilot knows of that allow you to override any inputs in Trim, in fact you don't even have to override it you can theoretically just grab the trim wheel.
JPAV8R@reddit
That trim wheel is spinning incredibly fast
IndividualIron1298@reddit (OP)
that doesn't mean you cant immobilise it
The_Stockholm_Rhino@reddit
You're trolling, right?
IndividualIron1298@reddit (OP)
Nope just asking the question that nobody else ever asked.
PatricioDeLaRosa@reddit
Why? Because a business decision to alter a design in place for decades and not notify the operators of drastic changes in order to save money and not add costs to operating the product and training for it.
The previous design had not caused any crashes nor pilots whom had plenty of experience had no problems flying the previous design.
So don’t blame MCAS or the pilots, blame the corporation that allowed the changes by sacrificing safety for profit.
IndividualIron1298@reddit (OP)
You raise a fair point that they should have been informed, i cant disagree with that.
Its not altering a design though, its an entirely different aircraft, which in a sense makes your statement even more blaring that there was no information about this model specific feature.
I dont see how it can be for profit though. Boeing doesn't foot the bill for training, in fact they likely profit from training not only do they not procure it, but they are the ones who produce the documentation, and training companies have to License the documentation off boeing at a great cost.
memeboiandy@reddit
Boeing doesnt foot the bill for training, but if you can say "hey, if you upgrade to our newest model 737 and your pilots will only requier 5 hours of classroom instruction on model specific changes" that is a HUGE insentive for airlines to continue operating the 737 and also potentially upgrade their fleet early to reep better operating economics of a new aircraft which makes shit tones of money for boeing.
If instead, Boeing made a whole new plane in the same size and operating class as the 737 and told airlines "hey we got this sick new plane that will save you 3% on your fuel bill, but requiers you to type certify your pilots on a whole new aircraft" than smaller airlines may be more likely to put off air craft replacement, and larger airlines then will start to consider alternatives from Airbus or Embrair depending on the size if they have to do the hundress/thousands of hours per pilot of type certifying on a new aircraft anyway. Than, instead of Boeing making a ton of money on a minor revision of an aircraft youd sell thousands of, you could end up sinking billions into designing a new aircraft that customers dont want and drive major airlines who would buy hundreds of new 737s to buy A320neos instead.
Aircraft manufactorers want to spend the least possible to update existing aircraft to make them competative in the market, and airlines want aircraft that they can introduce with minimal disruption to their flight operations/logistics. The 737 MAX was designed by Boeing to make them the most money for the least investment possible, and to apease the airlines who wanted new 737 airframes with larger more fuel effecient engines. It is an irrefutable fact that every decision involving the Max's development was about money for every party involved
PatricioDeLaRosa@reddit
All decisions were made for profit. Redesigning an old plane instead of creating a new aircraft, to hiding operational changes (MCAS) in a way to reduce cost to airlines as it would have incurred them additional training costs, reducing safety redundancies such as single AOA sensors and deeming them as an option was a for profit business choice.
All this due to their poor choice in forward thinking and being complacent while their competitors caught them with their pants down as Airbus had new designs, new engine options and more efficient designs.
So yes as much as you want to see it differently, this was a poorly executed profit generating decision on behalf of Boeing which continues to hurt them and will continue for decades.
FlyingDog14@reddit
It’s not at all an entirely new aircraft. The 737 NG and especially the Max is like taking a car from the 70s and putting a new engine and radio in it and all the quirks that would come with doing so.
Boeing decided some of the “behind the scenes” modifications to the 737 Max weren’t important to operators so they never bothered to inform them, again reducing the apparent training required for the transition to the Max. The plane already has a few auto trim functions that pilots were used to seeing, so Boeing brushed the new computer logic under the rug because pilots couldn’t control it
As far as Boeing profit, it’s all about aircraft sales. Not necessarily paying to train pilots. The Max was a very hasty update to try to keep sales especially for American Airlines and to some extent Southwest after Airbus announced the 320 NEO. There was a short deadline to make to try to get some sales to keep competitive against the NEO and they knew it. If they couldn’t come up with a product, they were going to lose A LOT of sales to airbus. It could have been very dangerous to the future of the 737 program.
I’m not an Airbus pilot so I can’t speak to the differences of the NEO compared to other options, but I can’t imagine the pilots need much extra training to fly the NEO. Boeing wanted the same thing to make the sale more convincing. If you can tell an airline they can keep guys flying the line and not have to take away a weeks worth of their time flying and making the company money, instead of spending money to send them to differences training, that’s pretty appealing. Sending pilots a brief guide of updates to their ipad is literally millions of dollars cheaper than sending pilots in for classroom and simulator training. On a large scale, the costs of buying and operating an A320 vs a 737 fleet are close enough, the type really doesn’t matter. So then it’s all about what other sorts of deals manufacturers can make for airlines. Bulk discounts, future support, etc. come up with something appealing to the airlines = airplane sales = money for Boeing. That’s really the bottom line.
MikeHoncho2568@reddit
The issue is that Boeing didn’t tell the pilots about MCAS even existing or how it operated so they had no way of knowing how to correct the issue. I believe the pilots in the Ethiopian airlines flight figured out what the issue was but MCAS kept fighting them until the plane went down.
XYooper906@reddit
IIRC, in the Ethiopian crash, the pilots did, in fact, disable the stab trim with the cutout switches. This initially stopped the runaway trim. They were barely able to counteract the nose down trim with the elevators. They were also unable to manually turn the stab trim wheel. Somehow, they decided to re-arm the stab trim. Since the MCAS was still receiving an errant signal, it again started driving the stab trim towards the nose down direction, past the point where the elevators could counteract the stabs.
IndividualIron1298@reddit (OP)
Nonetheless this doesn't dispute the fact that the Trim would have been running away and audibly so, cutting off stabiliser trim would have meant that MCAS had no means to yaw down.
But i definitely get the valid point that a pilot should be aware of any systems that can override their control
Rilex1@reddit
You seem like you’re interested in this subject but lack the knowledge. I suggest you watch Frontline’s “Boeing’s Fatal Flaw”.
hr2pilot@reddit
Hit the nail on the head.
PandaNoTrash@reddit
Actually during the second accident the pilots did know about MCAS and actually correctly diagnosed the problem and cut the trim systems as you describe. BUT aerodynamic forces on the horizontal stabilizer made it impossible to correct the position because humans were incapable of moving the manual trim wheel. So the plane nose dived into the ground with the pilots knowing exactly what was happening.
I've argued in this forum before that the manual trim problem should have been looked at ages ago, and a better solution devised that gives the pilot more leverage. I think this is an underappreciated aspect of this accident that is still a potential issue.
IndividualIron1298@reddit (OP)
That's a fair assessment and I thank you for your input and not just saying im uneducated like other comments,
There should be options available to a pilot where Trim can be controlled in a fast manner, like what's available in most GA aircraft. Even though it's rare than a commercial jet will need to trim out of a nosedive it should be an option.
S1075@reddit
You're being called uneducated because you're making grand statements about what the pilots should have done, and about what "really" happened, and what Boeing "should" do without yourself being a pilot, engineer, or any actual expert in this field..
JPAV8R@reddit
You’re not accounting for startle effect and how that can really impact now quickly you can assess the situation.
The issue was also further complicated by the multiple warnings that the aircraft’s speed altitude and and instruments were unreliable.
These pilots were faced with an aircraft that was giving them several conflicting warnings, and all the while, as they are trying to process this the aircraft is intermittently, pushing the trim further and further nose down.
Furthermore, Boeing decided to give MCAS authority to pitch the plane aggressively nose down based on a single sensor which is a known failure point. It is not like AOA sensors have never failed in the past.
Not to mention that nobody was aware of this system or what its failure would look like.
The whole thing was a recipe for disaster initiated by Boeing. It showed an incredible lack of imagination by the engineers who designed this.
Lastly, calling the pilots extremely incompetent is a ridiculous statement.
IndividualIron1298@reddit (OP)
I didn't call them incompetent, I was raising the question of whether they can be considered that, of course in a discussion-provoking way. Thanks for explaining.
JPAV8R@reddit
That’s fair you didn’t. My apologies, as a pilot I guess I was reading too much into that.
Let me go a step further to why it’s an issue with Boeing. Part of the design of the plane is to consider human factors and to make your aircraft capable of allowing the pilots the time they need to react.
In aviation safety we sometimes refer to this a a “time event” or a “no-time event” an engine failure is a “time event” in that you have time to run a checklist and make a safe landing. Something like a wind shear encounter is a “no-time” event. This requires an almost immediate reaction.
Good design means most if not all of your aircraft systems failures are “time events.” An example of a bad design could include the 767 thrust reverser system that crashed Lauda Air 004. The pilots had something like 6 seconds to correct a deployed thrust reverser before the aircraft was unrecoverable. That’s not enough time. Therefore the thrust reverser system was modified.
According to Boeing and other aviation experts the average time it would take for a pilot to take corrective action against the MCAS trim runways was around 10 seconds or less if they wanted to prevent an accident.
That’s a “no-time” event. Factor in several aural and annunciated warnings. Seeing something you’ve never seen or had been trained for and you’ve got Boeing having designed and trained pilots in a way that set them up to fail.
Lauda air was 1991 and 6 seconds to react was deemed not long enough back then and it’s not long enough now.
RonPossible@reddit
The Ethiopian flight did shut off the MCAS. Boeing redesigned the switchs so that shutting it off also helpfully shut off the trim adjust wheel on the controls. And didn't bother to tell anyone that. By the time they shut it off, the trim was full down and they couldn't fix it in time with the manual control.
Also, the trim controls would momentarily override the MCAS. So the pilots were able to control the trim, which meant it didn't appear to be a runaway condition.
IndividualIron1298@reddit (OP)
Thanks for explaining. To me it sounds like Boeing should have options to control the trim at a faster pace - like how the system computer can do it during takeoffs or landings - so pilots can manually trim out of a dive if its necessary.
HonoraryCanadian@reddit
Just because a pilot is expected to correctly solve an issue doesn't mean it's acceptable for that issue to be an unnecessary system with a single point failure that will overwhelm the pilots with distractions while it tries to rapidly put them in a situation that is nearly unrecoverable.Â
That two crews died, one of which would have fresh awareness of the issue, should be proof enough that a trim runaway during a L AOA failure is extremely difficult to handle without practice.
ccifra@reddit
Watch the Air Disasters episode on those crashes. It is pretty informative about everything that caused the crashes.
CapStar362@reddit
Mentour Pilot covered this extremely well as well - he is a 737 pilot himself https://www.youtube.com/@MentourPilot
CapStar362@reddit
Mentour Pilot on youtube also covered this extremely well, as he is a B737 pilot himself
https://www.youtube.com/@MentourPilothttps://www.youtube.com/@MentourPilothttps://www.youtube.com/@MentourPilothttps://www.youtube.com/@MentourPilothttps://www.youtube.com/@MentourPilot
tenderlychilly@reddit
Also the “Downfall” documentary on Netflix, has some really good info in there as well.
CapStar362@reddit
as Mike Honcho stated, the pilots did not even know about MCAS or how to work around it, and it physically fought them and their inputs.
Even after the MCAS incidents, Boeing continued to fight the Regulatory changes to train pilots on MCAS, and add EICAS instrumentation cues that MCAS is active and controlling the aircraft.