What is the endgame now for 737 MAX planes? Every airline using them has had several weeks to totally reorganize to deal with these huge missing parts of their fleets.
Boeing keeps talking about fixing them and putting them back in the air, but I dunno. At this point, it should be agreed the fundamental design flaws are serious, and Boeing should have simply made a brand new plane, with much more modern controls and predictable maneuvering. Yes, pilots would have to be certified for these new plans, but that cost pails to the money lost from these grounded fleets.
I'd honestly like to see the 737 MAX taken out of service and Boeing simply ending this line. The old planes should be stripped for parts and as much recycled as possible. It's going to cost them a lot of money, and it should. Their mistakes lead to the deaths of two whole planeloads of passengers. Airbus, Bombardier and others will probably make a lot out of this disaster, and that's probably a good thing and will help competition in this small/narrow market.
The bugs will be addressed and they'll still fly. Airlines have no choice, there's a limited capacity in the world for airplane construction, several thousands of orders on the books for the 737 and 320 waiting to be filled. What can an airline do? They can cut back some orders but not all orders.
> I'd honestly like to see the 737 MAX taken out of service and Boeing simply ending this line.
I have an alternate history fantasy where instead of going with the MAX and then trying to kill the C-series as they did, they instead bought into the C-series. Swapping the cockpit for a Boeing cockpit design. Built the -500 stretch of the C-series, and then used the C-series to replace the 737 line in the <165 pax market. And moved ahead on the 797/NMA for which they'd have a shorter version covering the 200-270 pax market as a pure passenger mover as it's proposed.
I think the 737 MAX should be properly re-certified as a new airplane once the "fixes" are implemented. The whole idea that you can significantly alter an existing airplane by mounting larger engines more forward, add new automatic systems, and still pretend that it's the same airplane, is flawed.
There's no fundamental design flaw, the aircraft is sound. The problem came from using software systems to artificially make the plane behave like older designs to avoid entirely new training and certifications.
Even that would've been acceptable and similar systems are already in use in other planes but it was the inadequate info, redundancy, warnings and controls to disable the system that created the problem.
It's easily fixable but still a tragedy of greed and oversight that led to the situation in the first place.
Now imagine if Boeing had created a brand new design instead of the 737 MAX and it had some mysterious fatal flaw as well? Second System Syndrome is something every engineer should understand. There's just no good reason to suspect a brand new design would've been bug free or easier to debug than the 737 MAX.
The 787s or A320neos could start dropping out of the sky at any minute. Maybe their carbon fiber panels start disintegrating midair after some number of pressurization cycles. The 787s almost did drop out of the sky due to battery problems. Because of the complexity involved, the only hard proof of an aircraft's safety is many years of successful flying.
Other planes have had fatal flaws that took a lot more work to discover. The silver lining of the 737 MAX's MCAS problem seems to be that it is at least quite straightforward to fix, as far as aircraft bugs go.
IMHO Boeing should payout millions for each death they caused, fix the mistakes that caused them, reorient their culture towards safety first, and return the 737 MAX to service. If they work very hard and learn from this mistake there's no reason to think they can't regain the public's trust within a few years.
> Boeing keeps talking about fixing them and putting them back in the air, but I dunno.
More than that - they're continuing to manufacture them. There's quite a few of them stacked up at KPAE, just sitting there waiting for their software updates, all painted in customer livery. (They're not even manufactured at PAE; they're ferried there for storage.)
Airbus, Bombardier and others will probably make a lot out of this disaster
I don't think so. Traditionally manufacturers and airlines never argue about a security incident of the competition. I only know of one issue were this unwritten rule was not respected.[1]
It has been fascinating to watch layer after layer peel back around all of this.
Bad design decisions forced from chasing the bottom dollar, optional, critical safety features with the warning indicator and now these switches.
> Boeing declined to detail the specific functionality of the two switches
That's also interesting- I assume they are in CYA mode and wouldn't discuss anything that could be sensitive to the current investigations in any point. I wonder how hard the Seattle Times had to work to get manuals for the MAX.
I hope the loss of life is vindicated in the end.
I hope there are lessons learned from this but I fear our culture of quarterly profits and lack of real punishment for companies and their directors will result in nothing drastic happening.
Boeing declined to detail the specific functionality of the two switches
It seems like that's really the crux of the problem. They made changes that they didn't feel it was necessary to tell their customers about. Just another step along the "I know you bought this product from us, but it's still our product at the end of the day" timeline that we're stuck on.
Further, I'll bet that it transpires that no one entity inside Boeing is really to blame for this mess. The engineers in charge of the AOA indicator subsystem didn't know that someone else in the company was going to drive a safety-critical component from it. And that engineering group may not have realized that the AOA data they were getting came from only one of the two sensors. My guess is that Boeing not only hid this information from their customers, they hid it from themselves.
The problem will have to be addressed at the top, but I don't agree with those who say that blaming, firing, or jailing the CEO is going to be helpful. The culture that allowed this to happen will have grown organically over time.
1. The A320neo caught Boeing completely off-guard;
2. The threat of the likes of American Airlines (already a mixed Airbus/Boeing customer and the largest airline in the world) placing a large A320neo order for regional aircraft operations scared the bejesus out of Boeing management;
3. For airlines like Southwest that are pure 737, the prospect of adding a plane that didn't share a common type rating with their existing fleet would complicate their lives and make them vulnerable to a sales pitch from Airbus; and
4. The development cycle for a completely new body was too long for many customers as it would arrive several years after the A320neo.
I don't think any of this is in dispute so the constraints for Boeing were to design a more fuel-efficient plane that shared a common type rating with the 737. To get there:
- They added newer, more fuel efficient engines. These changed the flight characteristics so they had to be moved;
- These engines moving made the plane more vulnerable to a stall situation. To counter this, they added MCAS, which would point the nose down when the AoA sensor told it the nose was too high;
- Standard configuration had 2 AoA sensors but MCAS only ever read from one;
- There was a safer configuration as an optional extra purchase;
- Telling airlines and pilots about this and providing overrides risked the common type rating.
I don't believe any of this is in dispute. It is widely believed, but not yet proven, that the primary cause of both fatal crashes was a runaway MCAS that drove the planes into the ground. It's also believed that with proper training a pilot may have been able to counter this (as happened the day before the Lion Air crash with a pilot in the jump seat).
Now what I find interesting is the response people have to all this. Some claim this is a fundamental design flaw that puts a shadow over the plane. Others believe it will be corrected and everything will be fine.
I'm firmly in the first camp: the plane CLEARLY flies differently to a 737. An automatic system, with no triple redundancy, was required to correct the flight characteristics of the plane.
I'm no expert but it seems to me the plane is fundamentally flawed at this point.
> the plane CLEARLY flies differently to a 737[...]
There's no such thing as "a 737". A 737-600 is 31 meters long[1], and a 737-900ER is 42 meters. Both share the same type rating with the MAX[2], and have the same 36 meter wingspan.
That's going from a length:span ratio of 0.86:1 to 1.17:1, you think those sort of airframe changes don't make for a plane that flies differently?
Maybe the whole notion of a "common type rating" is foolish, and pilots should need to re-train from scratch for the smallest of changes. Change the paint job? New type!
There's a lot of "the engines moved!" discussion around the 737 MAX which seems to be ignorant of decades of significant airframe changes not impacting type, to little apparent ill effect until now.
> These engines moving made the plane more vulnerable to a stall situation.
I don't think this is correct. A lot is being made about the engine move with regard to aerodynamic behavior, but it doesn't seem at all outside of the bounds of what is considered standard. Pilots report that a similar 'light stick feel' at high AoA is already present in aircraft like the 757.
It's not that the aerodynamic change was worse or better, it's simply that it was a change at all. MCAS was there to satisfy the type rating. MCAS is not anti-stall.
The crucial mistake appears to be the extreme failure mode of the system; it is permitted to input high stabilizer trim angles without limit. Without any kind of restriction, the failure goes from annoying (pull up on flight stick + fiddle with stab control until you solve it) to the deadly crashes we've seen where pilots are in extremely tricky situations.
The fix could be as simple as making MCAS cutout in the case of an AoA disagree (no real hardware changes here) as well as limiting the input of extreme trim angles.
> There was a safer configuration as an optional extra purchase;
Forgive me if I'm missing something but these extra options are AoA cockpit indication and AoA discrepancy alert when two sensors disagree.
They don't alter software, MCAS would continue relying on just one sensor regardless of this indication. It's just an extra bit of information for pilot's decision making.
Sounds to me like another hack over the hack hardly adding much extra safety.
How hard would it be to add two more sensors to every plane? I'd imagine insanely expensive but this is clearly the ideal solution in addition to whatever patches they can do via software and existing hardware/controls in the whole plane.
One thing that appears concerning in the series of articles being written about the 737 Max incidents is that they suggest a culture at Boeing of speed/cost over safety.
Now we can assume that the Max won't re-enter service until this issue is completely solved (I'm sure regulators will be extra-scrupulous here and customers will want cast iron re-assurance).
However, is anyone going over all the other safety decisions and changes made to other Boeing models over the period of the Max development?
It seems unlikely that this was an isolated incident of rushing things for commercial benefit...
It strikes me how a seemingly insignificant decision at the time - to position fuselage slightly higher above the ground - gave Airbus a strategic advantage 50 years later. It forced the competitor into a services of unexplainable and reckless decisions that break basic principles of reliable engineering. Which in turn led to a very visible disastrous business consequences: Boeing had to silently reduce 737 MAX production despite having secured orders for over 5000 planes. A case to be studied in business schools.
Had Boeing built the 737 at the time Airbus built the A320 they would've had a taller undercarriage also. For example the narrow body 757 built around the time of the A320 does have this.
When the 737 was built back in the 60s it was intended to be a small regional jet, not the continent and ocean crossing aircraft it evolved into over the years since. It originally came with a retractable staircase for passengers to embark/alight the aircraft, and having a low fuselage also made it possible to hand load the luggage in a time before widespread belt loaders.
basic principles? i think that’s a bit far. the plane isn’t inherently unstable is it? i thought it’s just the black box of MCAS that is the problem and MCAS is there to avoid a lengthy type certification. it’s completely explainable.
and it wasn’t seemingly insignificant. it was for fuel efficiency. it was significant and they knew what they were doing.
I just wanted to note that Dominic Gates and the Seattle Times have been the gold standard for reporting on the 737 MAX. Really great work by them on reporting a technical subject so non-experts can understand.
Taking a forward view — I think FAA needs a way to defray the impact of operational costs by incentivizing the uptake of changes that produce safety improvements.
The ultimate economic reasoning for the 737 MAX was entirely to reduce operational cost: “give us a plane with better fuel efficiency that we don’t have to pay to train pilots for!”. This is actually a deeply broken incentive that, I think this case shows, should not exist. The plane delivered is objectively far worse than it _could be_ were it not for the need to reduce operational cost.
Ultimately — some large portion of that operational cost is induced as a result of the need to comply with safety regulations. That creates downward pressure on unecessary experimentation but also has created this very perverse incentive to design planes that are _deliberately_ not as safe as they could be given application of some approximation to “our best engineering knowledge”.
Pretty early on in the design process for the 737 MAX — there shouldve been a meeting with regulators. The regulators should’ve been presented with this option and the design and economic reasoning for it — and they should’ve also been presented with another option wherein there was a relaxing of the need to defuse operational costs. The regulators should be empowered to then say “don’t build this broken plane, build the safer plane and we will introduce tax credits sufficient to help offset the airlines retraining costs.”
So they removed a useful, granular functionality (switching off autopilot trim input while retaining electric-assisted manual trim) and made one switch simply a redundant backup, merging the previously separated functions without clear explanation.
A cynical man could be inclined to think that with this change, they casually removed a possibility of pilots/airlines realizing the existence of MCAS: "we have thrown off the right switch to unlink the autopilot from the trim motor and there is still something making automated stabilizer inputs, what could it be?"
> So they removed a useful, granular functionality ... without clear explanation
I’m as negative as the next person when it comes to the 737 Max, but this is just a bit to far. Read the rest of the article and you’ll understand a logical reason why this was done and how it was communicated.
>A cynical man could be inclined to think that with this change, they casually removed a possibility of pilots/airlines realizing the existence of MCAS: "we have thrown off the right switch to unlink the autopilot from the trim motor and there is still something making automated stabilizer inputs, what could it be?"
It's worse actually. They've taken a procedure, and are raising it on a pedestal as if to say "See, this is how a 737 flies! It's all right there! You can stop looking now!"
It's as if they don't want anyone to realize that this plane simply does not fly like a 737. Which is what has been getting shouted from the rooftops since the first disaster.
What I find wickedly ironic was it was exactly Boeing's insistence to "not inundate" flight pilot's with technical information, and give an accurate accounting of the vast differences in the minute details of the aircraft that created the problem.
Someone looked at the checklist item of "both stab trim switches to cutout", didn't look into what that actually meant, and changed the plane to fit the procedure. This change cost extra effort. Instead of using the same switches and wiring they were using before, they actually degraded the granularity of control of the plane to hide the differences.
I can't imagine the thought process at the time. Be nice to see what the documentation turns up.
Off topic, but oh man does that website embody everything that is wrong with display advertising. Left the site open for 6 minutes: 8000 requests, 100MB transferred and a memory footprint of 700MB for that tab and climbing. Absolute garbage.
Wait, what? Reading this is turns out that flipping both switches on the centre panel not only deactivates MCAS, but also deactivates the thumb switch on the control wheel that the pilots routinely use to change the elevator trim.
So, MCAS trims the plan to a dangerous attitude, then when pilots follow Boeing's SOP to disable, they lose the ability to re-trim the way they have done it a million times before? I can see valuable second being eaten up when pilots flick the thumb switch towards them and sit there wondering why the back pressure isn't easing up.
And the report also says that the manual trim adjustment wheel would be harder to move due to the load on the tail when the aircraft is in a nose (death) dive? This is already on top of the fact that the pilots have to hold around 60Kg back pressure on the control wheel while leaning forward to crank the manual trim wheel?
Yes, exactly. The MAX "stab trim cutout" simply disabled the trim motor altogether. Everything you describe appears to have happened in the Ethiopian flight report. A 737 pilot also tried to run the same flight in simulator and had his arms wrapped around the control column trying to hold level while the copilot failed to move the trim wheel.
I don't understand why there's not something that just allows the pilots to completely turn off all autopilot systems without also turning off hydraulic supports? It seems like if they turn off autopilot it makes the steering become not powered or something?
What changes should be made at the FAA (or international equivalents)? Clearly they weren't able to do their job of ensuring the aircraft were safe. They must share some of the responsibility, but how could we improve them?
> As various warnings went off in the cockpit, they never reached the conclusion to use the runaway stabilizer procedure.
We continue to put the microscope on Boeing but this is why there is a person in the cockpit: to oversee the planes automated systems. There were multiple failures, and while we pick apart Boeing, we have not done the same to the pilots.
> There were multiple failures, and while we pick apart Boeing, we have not done the same to the pilots.
At the time of the crash, it appears that the established procedures were insufficient. In particular, the MCAS failure creates a qualitatively different 'runaway stabilizer' than the previously-imagined failure mode of a stuck-on motor.
In turn, that seems to have created a situation where the pilots did accurately follow the runaway stabilizer checklist, but the trim was so far off neutral that they could not manually control it.
That's why the article here notes that the older-spec second switch, which deactivated just autopilot inputs into the electric trim system, could have helped. However, that is still far from a final answer, since the troubleshooting checklist would still need modification to try deactivating just auto-trim rather than both switches.
The core of the discussion precisely revolves around Boeing wilfully making it more difficult for the person in the cockpit to oversee the planes' automated systems.
That's because this is HN. Playing the blame game is what we get to do. The NTSB will analyze all factors and if the pilots had any contribution to the crashes that will be noted. This is why aviation has become so safe. If the investigators just looked for blame like we do, planes wouldn't be nearly as safe as they are today.
If a hazard or potential failure mode can be eliminated in the design of a system, it's better to do that than to rely on every single operator to mitigate it individually.
The pilots are dead, how do you propose fixing their failures? Or do you mean we should also focus the standard checklists and procedures? Are we not doing that also? I think the article sufficiently tried to cover those as well.
Read up on the extensive reporting on both accidents. They never reached that conclusion because it was absolutely unexpected, as a result of Boeing’s stealth changes to the aircraft.
There was an article recently where they put very experienced pilots in a simulator under the same conditions and they all failed.
[+] [-] djsumdog|6 years ago|reply
Boeing keeps talking about fixing them and putting them back in the air, but I dunno. At this point, it should be agreed the fundamental design flaws are serious, and Boeing should have simply made a brand new plane, with much more modern controls and predictable maneuvering. Yes, pilots would have to be certified for these new plans, but that cost pails to the money lost from these grounded fleets.
I'd honestly like to see the 737 MAX taken out of service and Boeing simply ending this line. The old planes should be stripped for parts and as much recycled as possible. It's going to cost them a lot of money, and it should. Their mistakes lead to the deaths of two whole planeloads of passengers. Airbus, Bombardier and others will probably make a lot out of this disaster, and that's probably a good thing and will help competition in this small/narrow market.
[+] [-] erentz|6 years ago|reply
The bugs will be addressed and they'll still fly. Airlines have no choice, there's a limited capacity in the world for airplane construction, several thousands of orders on the books for the 737 and 320 waiting to be filled. What can an airline do? They can cut back some orders but not all orders.
> I'd honestly like to see the 737 MAX taken out of service and Boeing simply ending this line.
I have an alternate history fantasy where instead of going with the MAX and then trying to kill the C-series as they did, they instead bought into the C-series. Swapping the cockpit for a Boeing cockpit design. Built the -500 stretch of the C-series, and then used the C-series to replace the 737 line in the <165 pax market. And moved ahead on the 797/NMA for which they'd have a shorter version covering the 200-270 pax market as a pure passenger mover as it's proposed.
[+] [-] jwr|6 years ago|reply
[+] [-] manigandham|6 years ago|reply
Even that would've been acceptable and similar systems are already in use in other planes but it was the inadequate info, redundancy, warnings and controls to disable the system that created the problem.
It's easily fixable but still a tragedy of greed and oversight that led to the situation in the first place.
[+] [-] staunch|6 years ago|reply
The 787s or A320neos could start dropping out of the sky at any minute. Maybe their carbon fiber panels start disintegrating midair after some number of pressurization cycles. The 787s almost did drop out of the sky due to battery problems. Because of the complexity involved, the only hard proof of an aircraft's safety is many years of successful flying.
Other planes have had fatal flaws that took a lot more work to discover. The silver lining of the 737 MAX's MCAS problem seems to be that it is at least quite straightforward to fix, as far as aircraft bugs go.
IMHO Boeing should payout millions for each death they caused, fix the mistakes that caused them, reorient their culture towards safety first, and return the 737 MAX to service. If they work very hard and learn from this mistake there's no reason to think they can't regain the public's trust within a few years.
[+] [-] massysett|6 years ago|reply
[+] [-] Aeolun|6 years ago|reply
Airlines need their airplanes, and if boeing would recompense them for the lost planes they’d be instantly out of business.
Conversely, the carriers cannot just write off a significant part of their fleet and buy new ones, which wouldn’t show up for years anyway.
[+] [-] btgeekboy|6 years ago|reply
More than that - they're continuing to manufacture them. There's quite a few of them stacked up at KPAE, just sitting there waiting for their software updates, all painted in customer livery. (They're not even manufactured at PAE; they're ferried there for storage.)
[+] [-] mandeepj|6 years ago|reply
They did not think - it'd ever happen. The shortcuts were taken for bringing 737 max quick to market.
[+] [-] dboreham|6 years ago|reply
[+] [-] CaptainZapp|6 years ago|reply
I don't think so. Traditionally manufacturers and airlines never argue about a security incident of the competition. I only know of one issue were this unwritten rule was not respected.[1]
[1] https://en.wikipedia.org/wiki/Trump_Shuttle
[+] [-] skybrian|6 years ago|reply
(Not to mention that these planes have never crashed in most countries, even with an admittedly serious bug.)
[+] [-] jeremyjh|6 years ago|reply
[+] [-] leetrout|6 years ago|reply
Bad design decisions forced from chasing the bottom dollar, optional, critical safety features with the warning indicator and now these switches.
> Boeing declined to detail the specific functionality of the two switches
That's also interesting- I assume they are in CYA mode and wouldn't discuss anything that could be sensitive to the current investigations in any point. I wonder how hard the Seattle Times had to work to get manuals for the MAX.
I hope the loss of life is vindicated in the end.
I hope there are lessons learned from this but I fear our culture of quarterly profits and lack of real punishment for companies and their directors will result in nothing drastic happening.
[+] [-] MaxBarraclough|6 years ago|reply
[+] [-] CamperBob2|6 years ago|reply
It seems like that's really the crux of the problem. They made changes that they didn't feel it was necessary to tell their customers about. Just another step along the "I know you bought this product from us, but it's still our product at the end of the day" timeline that we're stuck on.
Further, I'll bet that it transpires that no one entity inside Boeing is really to blame for this mess. The engineers in charge of the AOA indicator subsystem didn't know that someone else in the company was going to drive a safety-critical component from it. And that engineering group may not have realized that the AOA data they were getting came from only one of the two sensors. My guess is that Boeing not only hid this information from their customers, they hid it from themselves.
The problem will have to be addressed at the top, but I don't agree with those who say that blaming, firing, or jailing the CEO is going to be helpful. The culture that allowed this to happen will have grown organically over time.
[+] [-] Farradfahren|6 years ago|reply
[deleted]
[+] [-] cletus|6 years ago|reply
1. The A320neo caught Boeing completely off-guard;
2. The threat of the likes of American Airlines (already a mixed Airbus/Boeing customer and the largest airline in the world) placing a large A320neo order for regional aircraft operations scared the bejesus out of Boeing management;
3. For airlines like Southwest that are pure 737, the prospect of adding a plane that didn't share a common type rating with their existing fleet would complicate their lives and make them vulnerable to a sales pitch from Airbus; and
4. The development cycle for a completely new body was too long for many customers as it would arrive several years after the A320neo.
I don't think any of this is in dispute so the constraints for Boeing were to design a more fuel-efficient plane that shared a common type rating with the 737. To get there:
- They added newer, more fuel efficient engines. These changed the flight characteristics so they had to be moved;
- These engines moving made the plane more vulnerable to a stall situation. To counter this, they added MCAS, which would point the nose down when the AoA sensor told it the nose was too high;
- Standard configuration had 2 AoA sensors but MCAS only ever read from one;
- There was a safer configuration as an optional extra purchase;
- Telling airlines and pilots about this and providing overrides risked the common type rating.
I don't believe any of this is in dispute. It is widely believed, but not yet proven, that the primary cause of both fatal crashes was a runaway MCAS that drove the planes into the ground. It's also believed that with proper training a pilot may have been able to counter this (as happened the day before the Lion Air crash with a pilot in the jump seat).
Now what I find interesting is the response people have to all this. Some claim this is a fundamental design flaw that puts a shadow over the plane. Others believe it will be corrected and everything will be fine.
I'm firmly in the first camp: the plane CLEARLY flies differently to a 737. An automatic system, with no triple redundancy, was required to correct the flight characteristics of the plane.
I'm no expert but it seems to me the plane is fundamentally flawed at this point.
[+] [-] avar|6 years ago|reply
That's going from a length:span ratio of 0.86:1 to 1.17:1, you think those sort of airframe changes don't make for a plane that flies differently?
Maybe the whole notion of a "common type rating" is foolish, and pilots should need to re-train from scratch for the smallest of changes. Change the paint job? New type!
There's a lot of "the engines moved!" discussion around the 737 MAX which seems to be ignorant of decades of significant airframe changes not impacting type, to little apparent ill effect until now.
1. https://en.wikipedia.org/wiki/Boeing_737_Next_Generation#Spe...
2. https://en.wikipedia.org/wiki/Boeing_737_MAX#Specifications
[+] [-] Obi_Juan_Kenobi|6 years ago|reply
I don't think this is correct. A lot is being made about the engine move with regard to aerodynamic behavior, but it doesn't seem at all outside of the bounds of what is considered standard. Pilots report that a similar 'light stick feel' at high AoA is already present in aircraft like the 757.
It's not that the aerodynamic change was worse or better, it's simply that it was a change at all. MCAS was there to satisfy the type rating. MCAS is not anti-stall.
The crucial mistake appears to be the extreme failure mode of the system; it is permitted to input high stabilizer trim angles without limit. Without any kind of restriction, the failure goes from annoying (pull up on flight stick + fiddle with stab control until you solve it) to the deadly crashes we've seen where pilots are in extremely tricky situations.
The fix could be as simple as making MCAS cutout in the case of an AoA disagree (no real hardware changes here) as well as limiting the input of extreme trim angles.
[+] [-] mcsoft|6 years ago|reply
Forgive me if I'm missing something but these extra options are AoA cockpit indication and AoA discrepancy alert when two sensors disagree.
They don't alter software, MCAS would continue relying on just one sensor regardless of this indication. It's just an extra bit of information for pilot's decision making.
Sounds to me like another hack over the hack hardly adding much extra safety.
[+] [-] dmix|6 years ago|reply
[+] [-] rtempaccount1|6 years ago|reply
Now we can assume that the Max won't re-enter service until this issue is completely solved (I'm sure regulators will be extra-scrupulous here and customers will want cast iron re-assurance).
However, is anyone going over all the other safety decisions and changes made to other Boeing models over the period of the Max development?
It seems unlikely that this was an isolated incident of rushing things for commercial benefit...
[+] [-] mcsoft|6 years ago|reply
[+] [-] erentz|6 years ago|reply
When the 737 was built back in the 60s it was intended to be a small regional jet, not the continent and ocean crossing aircraft it evolved into over the years since. It originally came with a retractable staircase for passengers to embark/alight the aircraft, and having a low fuselage also made it possible to hand load the luggage in a time before widespread belt loaders.
[+] [-] anticensor|6 years ago|reply
[+] [-] techslave|6 years ago|reply
and it wasn’t seemingly insignificant. it was for fuel efficiency. it was significant and they knew what they were doing.
[+] [-] trimbo|6 years ago|reply
[+] [-] breatheoften|6 years ago|reply
The ultimate economic reasoning for the 737 MAX was entirely to reduce operational cost: “give us a plane with better fuel efficiency that we don’t have to pay to train pilots for!”. This is actually a deeply broken incentive that, I think this case shows, should not exist. The plane delivered is objectively far worse than it _could be_ were it not for the need to reduce operational cost.
Ultimately — some large portion of that operational cost is induced as a result of the need to comply with safety regulations. That creates downward pressure on unecessary experimentation but also has created this very perverse incentive to design planes that are _deliberately_ not as safe as they could be given application of some approximation to “our best engineering knowledge”.
Pretty early on in the design process for the 737 MAX — there shouldve been a meeting with regulators. The regulators should’ve been presented with this option and the design and economic reasoning for it — and they should’ve also been presented with another option wherein there was a relaxing of the need to defuse operational costs. The regulators should be empowered to then say “don’t build this broken plane, build the safer plane and we will introduce tax credits sufficient to help offset the airlines retraining costs.”
[+] [-] JorgeGT|6 years ago|reply
A cynical man could be inclined to think that with this change, they casually removed a possibility of pilots/airlines realizing the existence of MCAS: "we have thrown off the right switch to unlink the autopilot from the trim motor and there is still something making automated stabilizer inputs, what could it be?"
[+] [-] jsjohnst|6 years ago|reply
I’m as negative as the next person when it comes to the 737 Max, but this is just a bit to far. Read the rest of the article and you’ll understand a logical reason why this was done and how it was communicated.
[+] [-] SilasX|6 years ago|reply
https://news.ycombinator.com/item?id=19888261
[+] [-] salawat|6 years ago|reply
It's worse actually. They've taken a procedure, and are raising it on a pedestal as if to say "See, this is how a 737 flies! It's all right there! You can stop looking now!"
It's as if they don't want anyone to realize that this plane simply does not fly like a 737. Which is what has been getting shouted from the rooftops since the first disaster.
What I find wickedly ironic was it was exactly Boeing's insistence to "not inundate" flight pilot's with technical information, and give an accurate accounting of the vast differences in the minute details of the aircraft that created the problem.
Someone looked at the checklist item of "both stab trim switches to cutout", didn't look into what that actually meant, and changed the plane to fit the procedure. This change cost extra effort. Instead of using the same switches and wiring they were using before, they actually degraded the granularity of control of the plane to hide the differences.
I can't imagine the thought process at the time. Be nice to see what the documentation turns up.
[+] [-] oldmantaiter|6 years ago|reply
[+] [-] chimpburger|6 years ago|reply
It loads much better in Lynx with a tiny fraction of the resources.
[+] [-] quickthrower2|6 years ago|reply
[+] [-] cyberferret|6 years ago|reply
So, MCAS trims the plan to a dangerous attitude, then when pilots follow Boeing's SOP to disable, they lose the ability to re-trim the way they have done it a million times before? I can see valuable second being eaten up when pilots flick the thumb switch towards them and sit there wondering why the back pressure isn't easing up.
And the report also says that the manual trim adjustment wheel would be harder to move due to the load on the tail when the aircraft is in a nose (death) dive? This is already on top of the fact that the pilots have to hold around 60Kg back pressure on the control wheel while leaning forward to crank the manual trim wheel?
Recipe for absolute disaster.
[+] [-] cjbprime|6 years ago|reply
[+] [-] mannykannot|6 years ago|reply
...and without that commonality, the FAA might have required additional training?
[+] [-] salawat|6 years ago|reply
[+] [-] sabujp|6 years ago|reply
[+] [-] Jabbles|6 years ago|reply
[+] [-] jordache|6 years ago|reply
Regulations needs to ensure every little detail about these planes are articulated to the end-user.
[+] [-] exabrial|6 years ago|reply
We continue to put the microscope on Boeing but this is why there is a person in the cockpit: to oversee the planes automated systems. There were multiple failures, and while we pick apart Boeing, we have not done the same to the pilots.
[+] [-] Majromax|6 years ago|reply
At the time of the crash, it appears that the established procedures were insufficient. In particular, the MCAS failure creates a qualitatively different 'runaway stabilizer' than the previously-imagined failure mode of a stuck-on motor.
In turn, that seems to have created a situation where the pilots did accurately follow the runaway stabilizer checklist, but the trim was so far off neutral that they could not manually control it.
That's why the article here notes that the older-spec second switch, which deactivated just autopilot inputs into the electric trim system, could have helped. However, that is still far from a final answer, since the troubleshooting checklist would still need modification to try deactivating just auto-trim rather than both switches.
[+] [-] AnthonBerg|6 years ago|reply
[+] [-] rootusrootus|6 years ago|reply
[+] [-] eigenvector|6 years ago|reply
[+] [-] proto-n|6 years ago|reply
[+] [-] ricardobeat|6 years ago|reply
There was an article recently where they put very experienced pilots in a simulator under the same conditions and they all failed.