Sep 19, 2017, 10:25 am
Last edit by: 24left
Jan 18 2021 TC issues Airworthiness Directive for the 737 MAX
Link to post https://www.flyertalk.com/forum/32976892-post4096.html
Cabin photos
Post 976 https://www.flyertalk.com/forum/29534462-post976.html
Post 1300 https://www.flyertalk.com/forum/29780203-post1300.html
Cabin Layout
Interior Specs can be found here https://www.aircanada.com/ca/en/aco/home/fly/onboard/fleet.html
- Window seats may feel narrower to come as the armrests are placed "into" the "curvature" of the cabin.
- Seats with no windows feel even more narrower as there is no space created by the curvature of window.
- All bulkhead seats have very limited legroom.
- Seats 15A, 16A, 16F, 17A and 17F have limited windows.
- Exit rows 19 and 20 have more legroom than regular preferred seats.
Routes
The 737 MAX is designated to replace the A320-series. Based on announcements and schedule updates, the following specific routes will be operated by the 737 MAX in future:
YYZ-LAX (periodic flights)
YYZ-SNN (new route)
YUL-DUB (new route)
YYZ/YUL-KEF (replacing Rouge A319)
YYT-LHR (replacing Mainline A319)
YHZ-LHR (replacing Mainline B767)
Hawaii Routes YVR/YYC (replacing Rouge B767)
Many domestic trunk routes (YYZ, YVR, YUL, YYC) now operated by 7M8, replacing A320 family
Link to post https://www.flyertalk.com/forum/32976892-post4096.html
Cabin photos
Post 976 https://www.flyertalk.com/forum/29534462-post976.html
Post 1300 https://www.flyertalk.com/forum/29780203-post1300.html
Cabin Layout
Interior Specs can be found here https://www.aircanada.com/ca/en/aco/home/fly/onboard/fleet.html
- Window seats may feel narrower to come as the armrests are placed "into" the "curvature" of the cabin.
- Seats with no windows feel even more narrower as there is no space created by the curvature of window.
- All bulkhead seats have very limited legroom.
- Seats 15A, 16A, 16F, 17A and 17F have limited windows.
- Exit rows 19 and 20 have more legroom than regular preferred seats.
Routes
The 737 MAX is designated to replace the A320-series. Based on announcements and schedule updates, the following specific routes will be operated by the 737 MAX in future:
YYZ-LAX (periodic flights)
YYZ-SNN (new route)
YUL-DUB (new route)
YYZ/YUL-KEF (replacing Rouge A319)
YYT-LHR (replacing Mainline A319)
YHZ-LHR (replacing Mainline B767)
Hawaii Routes YVR/YYC (replacing Rouge B767)
Many domestic trunk routes (YYZ, YVR, YUL, YYC) now operated by 7M8, replacing A320 family
Air Canada Selects Boeing 737 MAX to Renew Mainline Narrowbody Fleet
Apr 2, 2019, 6:58 am
#2296
Join Date: Apr 2000
Location: Mississauga Ontario
Posts: 4,105
@InTheAirGuy
can you please clarify which 500+ you are referring to?
MAX loss 346, which is 346 too many...
can you please clarify which 500+ you are referring to?
MAX loss 346, which is 346 too many...
Apr 2, 2019, 7:02 am
#2297
Join Date: Apr 2011
Location: YYC
Programs: AC 50k 1MM, Marriott LT Titanium Elite
Posts: 3,402
Oh wow, has this thread descended to the point of being little more than a cesspool of misinformation and poorly drawn conclusions based on misunderstandings of how the industry works and misguided attempts at trying to draw parallels to industries for which no parallels to aviation exist. 
Such a face-palm of a thread that just goes to show that most "enthusiasts, FFs, avgeeks, etc" have a hard time understanding the significant subtleties of the aviation world, how it is regulated and how aviation operates within those regulations.
That being said, there are a couple of buried nuggets of accurate information in this thread, but some of the conclusions drawn are inaccurate or incomplete.
There is no more of an inherent instability of the 737Max design than there is for the 737NG. The handling characteristics of the Max can be quite different than the handling characteristics of the NG under similar flight conditions.
The real crux of the issue is the desire (by the airlines) for the Max to have the same pilot type rating as the 737NG aircraft. This means that a pilot flying a 737NG would have the same feel is if they were flying a 737Max and vice versa. I guess an analog many could relate to would be making driving a motor-coach bus feel them same as driving a city-bus. This common type rating means that airlines do not have to maintain different pools of pilots which means greater operational flexibility and cheaper operation costs for airlines. The idea was a NG pilot could start the day in an NG, finish the day in a Max and not notice any difference.
There's just one problem, it is physically impossible to make flying the Max "feel" like flying a NG, the larger diameter, further forward engines will make the handling characteristics (the feel) quite different than the NG. Enter MCAS, a good idea that probably should have never seen the light of day, an idea I have fundamental issues with (I'll explain) and issues with its implementation, which I'll also explain, as the two are not related. IMHO, the Max should not have been given the same type rating as the NG, but here we are.
MCAS - I have an issue with its purpose: It goes against the basic Boeing philosophy (Airbus & Boeing have differing philosophies related to control authority) which is that the pilot always has final control authority. MCAS is the opposite of this, and instead of proverbially saying "human this is happening, do something" it just takes an action and does not inform the pilot, which is more of an Airbus type of control philosophy.
MCAS - my issue with its implementation: All systems require a SFHA (System Function Hazard Analysis), Boeing has stated that the MCAS was rated hazardous, which means it is classified as a DAL-B (Design Assurance Level B) system, DAL-B systems have to meet a failure rate of 1e-7 per flight hour or less. I have personally performed more than a dozen SFHA's and supported a half dozen more, I can not for the life of me figure out how a DAL-B system can rely on a single sensor and would love to see what the other mitigating conditions Boeing listed for the MCAS SFHA that permitted its reliance on a single sensor.
Now the regulation piece that a lot of people seem to be jumping on, there is no "Fox in the hen house". It is an industry norm where the OEMs have their own specifically designated people perform some of the certification work, I performed that function myself as well for several aircraft systems. However, the FARs (regulations) still apply, and those OEM designated people need to follow and enforce the FARs, in fact, we are empowered to do so by law. In addition, the FAA (as well as EASA, CASA, TCCA, etc) are supposed to ask the OEMs to prove that their engineering and safety attestations are accurate, valid and in compliance with all applicable regulations.
So when it comes to MCAS, Boeing made some assertions, did the FAA challenge those assertions? That is really what I am waiting to see.
As for all the discussions regarding software engineering etc - oh man, just so much lack of understanding about how aviation software and systems are designed and tested. All I can say is read up on DO-178B/C and DO-1254 before any sort of intelligent discussion can be had on that topic. Suffice it to say, that until someone has worked on the design and testing of an aviation system, they will have no understating of just how complex, comprehensive the ordeal is and how every line of code can be traced back to a requirement that is tested against.
Now for the Air Canada spin on all of this. Air Canada did not have any 737 type rated pilots, so the training that AC pilots received for the Max is the complete several weeks long training that all new type rating pilots have to receive. In addition, it is the operator that defines and creates the pilot training programme, not the OEM. The OEM provides a room full of binders which comprises the owners manual, and it is up the operator to read the owners manual and create the pilot training programme, just as you receive an owners manual when you purchase a car. GM, Ford, Toyota, Honda, etc do not teach you how to drive/operate your car, same goes for aviation.
Such a face-palm of a thread that just goes to show that most "enthusiasts, FFs, avgeeks, etc" have a hard time understanding the significant subtleties of the aviation world, how it is regulated and how aviation operates within those regulations.
That being said, there are a couple of buried nuggets of accurate information in this thread, but some of the conclusions drawn are inaccurate or incomplete.
There is no more of an inherent instability of the 737Max design than there is for the 737NG. The handling characteristics of the Max can be quite different than the handling characteristics of the NG under similar flight conditions.
The real crux of the issue is the desire (by the airlines) for the Max to have the same pilot type rating as the 737NG aircraft. This means that a pilot flying a 737NG would have the same feel is if they were flying a 737Max and vice versa. I guess an analog many could relate to would be making driving a motor-coach bus feel them same as driving a city-bus. This common type rating means that airlines do not have to maintain different pools of pilots which means greater operational flexibility and cheaper operation costs for airlines. The idea was a NG pilot could start the day in an NG, finish the day in a Max and not notice any difference.
There's just one problem, it is physically impossible to make flying the Max "feel" like flying a NG, the larger diameter, further forward engines will make the handling characteristics (the feel) quite different than the NG. Enter MCAS, a good idea that probably should have never seen the light of day, an idea I have fundamental issues with (I'll explain) and issues with its implementation, which I'll also explain, as the two are not related. IMHO, the Max should not have been given the same type rating as the NG, but here we are.
MCAS - I have an issue with its purpose: It goes against the basic Boeing philosophy (Airbus & Boeing have differing philosophies related to control authority) which is that the pilot always has final control authority. MCAS is the opposite of this, and instead of proverbially saying "human this is happening, do something" it just takes an action and does not inform the pilot, which is more of an Airbus type of control philosophy.
MCAS - my issue with its implementation: All systems require a SFHA (System Function Hazard Analysis), Boeing has stated that the MCAS was rated hazardous, which means it is classified as a DAL-B (Design Assurance Level B) system, DAL-B systems have to meet a failure rate of 1e-7 per flight hour or less. I have personally performed more than a dozen SFHA's and supported a half dozen more, I can not for the life of me figure out how a DAL-B system can rely on a single sensor and would love to see what the other mitigating conditions Boeing listed for the MCAS SFHA that permitted its reliance on a single sensor.
Now the regulation piece that a lot of people seem to be jumping on, there is no "Fox in the hen house". It is an industry norm where the OEMs have their own specifically designated people perform some of the certification work, I performed that function myself as well for several aircraft systems. However, the FARs (regulations) still apply, and those OEM designated people need to follow and enforce the FARs, in fact, we are empowered to do so by law. In addition, the FAA (as well as EASA, CASA, TCCA, etc) are supposed to ask the OEMs to prove that their engineering and safety attestations are accurate, valid and in compliance with all applicable regulations.
So when it comes to MCAS, Boeing made some assertions, did the FAA challenge those assertions? That is really what I am waiting to see.
As for all the discussions regarding software engineering etc - oh man, just so much lack of understanding about how aviation software and systems are designed and tested. All I can say is read up on DO-178B/C and DO-1254 before any sort of intelligent discussion can be had on that topic. Suffice it to say, that until someone has worked on the design and testing of an aviation system, they will have no understating of just how complex, comprehensive the ordeal is and how every line of code can be traced back to a requirement that is tested against.
Now for the Air Canada spin on all of this. Air Canada did not have any 737 type rated pilots, so the training that AC pilots received for the Max is the complete several weeks long training that all new type rating pilots have to receive. In addition, it is the operator that defines and creates the pilot training programme, not the OEM. The OEM provides a room full of binders which comprises the owners manual, and it is up the operator to read the owners manual and create the pilot training programme, just as you receive an owners manual when you purchase a car. GM, Ford, Toyota, Honda, etc do not teach you how to drive/operate your car, same goes for aviation.
How confident that MCAS is the sole problem with the aircraft that led to the crashes? Not some other issue such as blowback or something unknown? I just ask because you believe in waiting for the reports (if I recall correctly and I may not) but seem to be focusing on just the one thing. Which hasn’t been definitely determined to be the primary cause of the fatalities yet. Or maybe that is just because you are only responding to other posts doing the same.
Apr 2, 2019, 7:24 am
#2298
Join Date: Jan 2017
Location: Halifax
Programs: AC SE100K, Marriott Lifetime Platinum Elite. NEXUS
Posts: 4,569
Oh wow, has this thread descended to the point of being little more than a cesspool of misinformation and poorly drawn conclusions based on misunderstandings of how the industry works and misguided attempts at trying to draw parallels to industries for which no parallels to aviation exist.
Such a face-palm of a thread that just goes to show that most "enthusiasts, FFs, avgeeks, etc" have a hard time understanding the significant subtleties of the aviation world, how it is regulated and how aviation operates within those regulations.
That being said, there are a couple of buried nuggets of accurate information in this thread, but some of the conclusions drawn are inaccurate or incomplete.
There is no more of an inherent instability of the 737Max design than there is for the 737NG. The handling characteristics of the Max can be quite different than the handling characteristics of the NG under similar flight conditions.
The real crux of the issue is the desire (by the airlines) for the Max to have the same pilot type rating as the 737NG aircraft. This means that a pilot flying a 737NG would have the same feel is if they were flying a 737Max and vice versa. I guess an analog many could relate to would be making driving a motor-coach bus feel them same as driving a city-bus. This common type rating means that airlines do not have to maintain different pools of pilots which means greater operational flexibility and cheaper operation costs for airlines. The idea was a NG pilot could start the day in an NG, finish the day in a Max and not notice any difference.
There's just one problem, it is physically impossible to make flying the Max "feel" like flying a NG, the larger diameter, further forward engines will make the handling characteristics (the feel) quite different than the NG. Enter MCAS, a good idea that probably should have never seen the light of day, an idea I have fundamental issues with (I'll explain) and issues with its implementation, which I'll also explain, as the two are not related. IMHO, the Max should not have been given the same type rating as the NG, but here we are.
MCAS - I have an issue with its purpose: It goes against the basic Boeing philosophy (Airbus & Boeing have differing philosophies related to control authority) which is that the pilot always has final control authority. MCAS is the opposite of this, and instead of proverbially saying "human this is happening, do something" it just takes an action and does not inform the pilot, which is more of an Airbus type of control philosophy.
MCAS - my issue with its implementation: All systems require a SFHA (System Function Hazard Analysis), Boeing has stated that the MCAS was rated hazardous, which means it is classified as a DAL-B (Design Assurance Level B) system, DAL-B systems have to meet a failure rate of 1e-7 per flight hour or less. I have personally performed more than a dozen SFHA's and supported a half dozen more, I can not for the life of me figure out how a DAL-B system can rely on a single sensor and would love to see what the other mitigating conditions Boeing listed for the MCAS SFHA that permitted its reliance on a single sensor.
Now the regulation piece that a lot of people seem to be jumping on, there is no "Fox in the hen house". It is an industry norm where the OEMs have their own specifically designated people perform some of the certification work, I performed that function myself as well for several aircraft systems. However, the FARs (regulations) still apply, and those OEM designated people need to follow and enforce the FARs, in fact, we are empowered to do so by law. In addition, the FAA (as well as EASA, CASA, TCCA, etc) are supposed to ask the OEMs to prove that their engineering and safety attestations are accurate, valid and in compliance with all applicable regulations.
So when it comes to MCAS, Boeing made some assertions, did the FAA challenge those assertions? That is really what I am waiting to see.
As for all the discussions regarding software engineering etc - oh man, just so much lack of understanding about how aviation software and systems are designed and tested. All I can say is read up on DO-178B/C and DO-1254 before any sort of intelligent discussion can be had on that topic. Suffice it to say, that until someone has worked on the design and testing of an aviation system, they will have no understating of just how complex, comprehensive the ordeal is and how every line of code can be traced back to a requirement that is tested against.
Now for the Air Canada spin on all of this. Air Canada did not have any 737 type rated pilots, so the training that AC pilots received for the Max is the complete several weeks long training that all new type rating pilots have to receive. In addition, it is the operator that defines and creates the pilot training programme, not the OEM. The OEM provides a room full of binders which comprises the owners manual, and it is up the operator to read the owners manual and create the pilot training programme, just as you receive an owners manual when you purchase a car. GM, Ford, Toyota, Honda, etc do not teach you how to drive/operate your car, same goes for aviation.
Such a face-palm of a thread that just goes to show that most "enthusiasts, FFs, avgeeks, etc" have a hard time understanding the significant subtleties of the aviation world, how it is regulated and how aviation operates within those regulations.
That being said, there are a couple of buried nuggets of accurate information in this thread, but some of the conclusions drawn are inaccurate or incomplete.
There is no more of an inherent instability of the 737Max design than there is for the 737NG. The handling characteristics of the Max can be quite different than the handling characteristics of the NG under similar flight conditions.
The real crux of the issue is the desire (by the airlines) for the Max to have the same pilot type rating as the 737NG aircraft. This means that a pilot flying a 737NG would have the same feel is if they were flying a 737Max and vice versa. I guess an analog many could relate to would be making driving a motor-coach bus feel them same as driving a city-bus. This common type rating means that airlines do not have to maintain different pools of pilots which means greater operational flexibility and cheaper operation costs for airlines. The idea was a NG pilot could start the day in an NG, finish the day in a Max and not notice any difference.
There's just one problem, it is physically impossible to make flying the Max "feel" like flying a NG, the larger diameter, further forward engines will make the handling characteristics (the feel) quite different than the NG. Enter MCAS, a good idea that probably should have never seen the light of day, an idea I have fundamental issues with (I'll explain) and issues with its implementation, which I'll also explain, as the two are not related. IMHO, the Max should not have been given the same type rating as the NG, but here we are.
MCAS - I have an issue with its purpose: It goes against the basic Boeing philosophy (Airbus & Boeing have differing philosophies related to control authority) which is that the pilot always has final control authority. MCAS is the opposite of this, and instead of proverbially saying "human this is happening, do something" it just takes an action and does not inform the pilot, which is more of an Airbus type of control philosophy.
MCAS - my issue with its implementation: All systems require a SFHA (System Function Hazard Analysis), Boeing has stated that the MCAS was rated hazardous, which means it is classified as a DAL-B (Design Assurance Level B) system, DAL-B systems have to meet a failure rate of 1e-7 per flight hour or less. I have personally performed more than a dozen SFHA's and supported a half dozen more, I can not for the life of me figure out how a DAL-B system can rely on a single sensor and would love to see what the other mitigating conditions Boeing listed for the MCAS SFHA that permitted its reliance on a single sensor.
Now the regulation piece that a lot of people seem to be jumping on, there is no "Fox in the hen house". It is an industry norm where the OEMs have their own specifically designated people perform some of the certification work, I performed that function myself as well for several aircraft systems. However, the FARs (regulations) still apply, and those OEM designated people need to follow and enforce the FARs, in fact, we are empowered to do so by law. In addition, the FAA (as well as EASA, CASA, TCCA, etc) are supposed to ask the OEMs to prove that their engineering and safety attestations are accurate, valid and in compliance with all applicable regulations.
So when it comes to MCAS, Boeing made some assertions, did the FAA challenge those assertions? That is really what I am waiting to see.
As for all the discussions regarding software engineering etc - oh man, just so much lack of understanding about how aviation software and systems are designed and tested. All I can say is read up on DO-178B/C and DO-1254 before any sort of intelligent discussion can be had on that topic. Suffice it to say, that until someone has worked on the design and testing of an aviation system, they will have no understating of just how complex, comprehensive the ordeal is and how every line of code can be traced back to a requirement that is tested against.
Now for the Air Canada spin on all of this. Air Canada did not have any 737 type rated pilots, so the training that AC pilots received for the Max is the complete several weeks long training that all new type rating pilots have to receive. In addition, it is the operator that defines and creates the pilot training programme, not the OEM. The OEM provides a room full of binders which comprises the owners manual, and it is up the operator to read the owners manual and create the pilot training programme, just as you receive an owners manual when you purchase a car. GM, Ford, Toyota, Honda, etc do not teach you how to drive/operate your car, same goes for aviation.
1: Instability and difference in control vs the NG: There is an inherent instability & difference in feel of the airframe & engines. That is undeniable, as the MCAS exists to overcome that instability and difference in feel. If some working MCAS would be good enough to mitigate this difference is good enough is a complex engineering question, which I'm not qualified to answer with available statistics, but the MCAS doesn't work, and it takes zero qualifications to notice two aircraft losses and a massive death count.
2: Shared Type Certification: A business decision with engineering solutions to allow for. The goal here is to save everyone money, PAX included, by not requiring retraining (of not just pilots, also maintenance, ground crew, and on and on), not requiring a full re-certification process, etc, etc. Again, I'n not qualified to judge exactly which plank of oak turns the Design of Theseus into something else, but since we have reports of pilots not only from 3rd world airlines, but 'MURCAN mainline carriers reporting their 15 minute iPad training session skipped over (1), and aircraft have crashed because of it, it doesn't take an expert to see that they moved at least one rivet too many.
3: MCAS & Boeing philosophy: agreed, and this further implicates (1) and (2), especially the training part. I've stated before that, e.g. an AC pilot transitioning from an Airbus, even if they the same zero training in MCAS that everyone else did, could intuitively have a better chance at recovery. Boeing pilots never need to override the computer, which makes the omission of that need even more egregious.
4: Software Engineering: Yes, there is an incredibly complicated and strict framework for writing flight control software. I'm not blaming any particular software developer for a buggy line of code - there is this incredibly complicated and strict framework to test, review, test and test again that that line of code both implements a design goal and does so without failure. But note the two aircraft smashed into the ground, either that framework failed or wasn't followed.
5. System Engineering as a whole: None of the components exist in a vacuum. The engines are fine, the airframe is fine, the seats are fine, the pilots are fine, the software is fine, the training material is fine. The FAA delegated their responsibility to the OEM to certify designs and implementations as safe. The entirety of the system has failed. Four pilots with appropriate experience and training have put two aircraft into the ground. Their trainers had no knowlage of MCAS to teach them. They had no configuration-managed to MAX specs simulators to train in. No one was in a rush for MAX grade simulators, anyway, because the MAX is allegedly the same as the NG to fly. The MCAS did as it was designed, the each line of code was perfect; it took data from a sensor and overrode the pilots commands.
The MCAS should not have fought with the pilots
The MCAS should have read multiple sensor readings
Something should have warned the pilots of a computer override
Something should have warned the pilots of mismatched readings
The pilots should have been trained specifically on the possibility of computer override, and how to dis-engage it
The trainers should have had that training material
The pilots should have had a MAX CM'd simulator
There should have been documentation to produce a MAX CM simulator
The OEM should have documented it
The OEM in house certification team should not have certified the system
The regulators meta certification team should do more spot checking to catch problems
A software fix will not fix any of the other problems in the chain.
The aircraft is not "fine", and the process that allowed it to fly is not "fine".
Apr 2, 2019, 7:34 am
#2299
Join Date: Apr 2015
Location: YVR
Programs: UA Premier Platinum
Posts: 3,759
For a properly trained pilot - the aircraft are just fine.
As for the 346 dead people - well, aviation is not 100% risk free, and people will always die, given the number of people that fly everyday and the number that will fly over the life span of the aircraft program, the 346 dead can not even be called a statistical rounding error. Cold, I know, but that is the approach to safety - nothing but cold hard numbers. There is no place for emotion when performing safety work - it is all about the numbers.
As for the 346 dead people - well, aviation is not 100% risk free, and people will always die, given the number of people that fly everyday and the number that will fly over the life span of the aircraft program, the 346 dead can not even be called a statistical rounding error. Cold, I know, but that is the approach to safety - nothing but cold hard numbers. There is no place for emotion when performing safety work - it is all about the numbers.
Apr 2, 2019, 7:59 am
#2301
Join Date: Jan 2017
Location: Halifax
Programs: AC SE100K, Marriott Lifetime Platinum Elite. NEXUS
Posts: 4,569
Also:
Apr 2, 2019, 10:10 am
#2302
Suspended
Join Date: Nov 2007
Location: YVR
Programs: Air Canada Super Elite 2+ Million Miles
Posts: 2,478
@RangerNS
something like MTBF far better measure, and provides statistical comparison across platforms...which also means loss of even one hull in low volume production lines could have far greater impact on overall safety concerns given sufficient period of time for observations.
e.g. +1,400 A330 delivered with Air France 447 loss indicatively attributable to design and pilot response...
with nearly 400 MAX in operation with two hull loses arising POTENTIALLY from design and pilot response, your right failure rate statistically much higher right now.
but 10 years from now, assuming MAX problem resolved so related events do NOT occur again, then we are comparing +5,000 MAX in operation vs +1,800 A330.
If nothing changes given the 3 case events, and assuming MCAS fault permanently corrected, the MAX will have a significantly higher safety record...
something like MTBF far better measure, and provides statistical comparison across platforms...which also means loss of even one hull in low volume production lines could have far greater impact on overall safety concerns given sufficient period of time for observations.
e.g. +1,400 A330 delivered with Air France 447 loss indicatively attributable to design and pilot response...
with nearly 400 MAX in operation with two hull loses arising POTENTIALLY from design and pilot response, your right failure rate statistically much higher right now.
but 10 years from now, assuming MAX problem resolved so related events do NOT occur again, then we are comparing +5,000 MAX in operation vs +1,800 A330.
If nothing changes given the 3 case events, and assuming MCAS fault permanently corrected, the MAX will have a significantly higher safety record...
Last edited by tcook052; Apr 2, 2019 at 10:29 am Reason: off topic
Apr 2, 2019, 10:50 am
#2303
Join Date: Dec 2011
Location: YYZ
Programs: AC SEMM / HH Diamond
Posts: 3,167
An assumption which, prior to the MCAS problems arising, would have been eminently easy to make for a new Boeing plane .... but given that the MCAS issue slipped through, then my confidence that there are no other latent design flaws in the MAX has diminished somewhat of late.
Keep in mind that the MCAS was a terrible software implementation .... but the root issue of the two crashes appears to have been that the AOA sensor failed (and then the MCAS reacted badly to it). Sure, it's a poor design to rely on only one sensor in the first place, but why are two brand new planes both having a failed sensor in the first place? A sensor that was replaced at least once for the Indonesian plane, so it's unlikely to be the actual sensor ... so is there a latent problem with the wiring or system that receives the sensor data? I dunno, but if true then that's two pretty fundamental issues with the MAX .... are you really confident that those are the only two problems that the plane has?
I'm not.
Apr 2, 2019, 11:01 am
#2304
Join Date: Feb 2009
Location: YYC
Programs: BA bronze, Aeroplan peon
Posts: 4,746
I think it's fair to say that a lot of regulators will be taking a much closer look at the aircraft and it's certification process before it's allowed back into the sky worldwide.
Apr 2, 2019, 11:06 am
#2305
Join Date: Sep 2011
Location: Ideally YOW, but probably not
Programs: AC SE*MM
Posts: 1,827
@jaysona is right, this thread is a cesspool, which I try to avoid but somehow keep getting sucked in to.
You (and others) keep on calling the MAX "unstable". The use of this word is either ignorant or misinformation or both. The plane is not "unstable" any more than any other plane that has auto-trim characteristics, which is to say every modern airliner in commercial service. Every time you fly commercially, even when the plane is being hand flown (i.e. not on autopilot) automatic systems trim the aircraft. That doesn't make them "unstable" by any definition of that word that is used in aviation. So stop with the crap.
From what we know, and I'll emphasize this heavily since we don't have the conclusions fro Lion Air or ET, there were serious issues with the design of MCAS in failure modes. The Boeing changes purport to fix the top issues on your list. Regulatory oversight changes clearly need to made too, and Boeing clearly made numerous major errors around process and training. 346 people are dead, which is horrible, but like other aviation disasters the entire industry will learn from this. The 737 MAX will get fixed. Boeing will learn lessons. Regulatory agencies will learn lessons. We will get better. This has happened hundreds of times over the history of aviation and it will happen again here.
1: Instability and difference in control vs the NG: There is an inherent instability & difference in feel of the airframe & engines. That is undeniable, as the MCAS exists to overcome that instability and difference in feel. If some working MCAS would be good enough to mitigate this difference is good enough is a complex engineering question, which I'm not qualified to answer with available statistics, but the MCAS doesn't work, and it takes zero qualifications to notice two aircraft losses and a massive death count.
The MCAS should not have fought with the pilots
The MCAS should have read multiple sensor readings
Something should have warned the pilots of a computer override
Something should have warned the pilots of mismatched readings
The pilots should have been trained specifically on the possibility of computer override, and how to dis-engage it
The trainers should have had that training material
The pilots should have had a MAX CM'd simulator
There should have been documentation to produce a MAX CM simulator
The OEM should have documented it
The OEM in house certification team should not have certified the system
The regulators meta certification team should do more spot checking to catch problems
A software fix will not fix any of the other problems in the chain.
The aircraft is not "fine", and the process that allowed it to fly is not "fine".
The MCAS should have read multiple sensor readings
Something should have warned the pilots of a computer override
Something should have warned the pilots of mismatched readings
The pilots should have been trained specifically on the possibility of computer override, and how to dis-engage it
The trainers should have had that training material
The pilots should have had a MAX CM'd simulator
There should have been documentation to produce a MAX CM simulator
The OEM should have documented it
The OEM in house certification team should not have certified the system
The regulators meta certification team should do more spot checking to catch problems
A software fix will not fix any of the other problems in the chain.
The aircraft is not "fine", and the process that allowed it to fly is not "fine".
Apr 2, 2019, 11:29 am
#2306
Join Date: Jan 2017
Location: Halifax
Programs: AC SE100K, Marriott Lifetime Platinum Elite. NEXUS
Posts: 4,569
You (and others) keep on calling the MAX "unstable". The use of this word is either ignorant or misinformation or both. The plane is not "unstable" any more than any other plane that has auto-trim characteristics, which is to say every modern airliner in commercial service. Every time you fly commercially, even when the plane is being hand flown (i.e. not on autopilot) automatic systems trim the aircraft. That doesn't make them "unstable" by any definition of that word that is used in aviation. So stop with the crap.
Two MAX have crashed because its unstable and the automatic system to provide stability failed.
There are engineering, software, industry, regulatory standards. Either those standards were not met, or those standards are not strict enough.
Apr 2, 2019, 11:58 am
#2307
Join Date: Feb 2009
Location: YYC
Programs: BA bronze, Aeroplan peon
Posts: 4,746
You (and others) keep on calling the MAX "unstable". The use of this word is either ignorant or misinformation or both. The plane is not "unstable" any more than any other plane that has auto-trim characteristics, which is to say every modern airliner in commercial service. Every time you fly commercially, even when the plane is being hand flown (i.e. not on autopilot) automatic systems trim the aircraft. That doesn't make them "unstable" by any definition of that word that is used in aviation. So stop with the crap.
Apr 2, 2019, 12:11 pm
#2308
Join Date: Dec 2014
Location: YVR
Programs: Bottom feeder Star Gold
Posts: 2,652
Originally Posted by jaysona
For a properly trained pilot - the aircraft are just fine.
...
The OEM provides a room full of binders which comprises the owners manual, and it is up the operator to read the owners manual and create the pilot training programme, just as you receive an owners manual when you purchase a car. GM, Ford, Toyota, Honda, etc do not teach you how to drive/operate your car, same goes for aviation.
...
As for the manuals, the 737 Max manual already had a mention of the MCAS - albeit a brief mention - in the original manual, and Boeing issued an update to all operators on November 6, 2018 to emphasize the procedures provided in the runaway stabilizer non-normal checklist (NNC).
...
The OEM provides a room full of binders which comprises the owners manual, and it is up the operator to read the owners manual and create the pilot training programme, just as you receive an owners manual when you purchase a car. GM, Ford, Toyota, Honda, etc do not teach you how to drive/operate your car, same goes for aviation.
...
As for the manuals, the 737 Max manual already had a mention of the MCAS - albeit a brief mention - in the original manual, and Boeing issued an update to all operators on November 6, 2018 to emphasize the procedures provided in the runaway stabilizer non-normal checklist (NNC).
The "mention of the MCAS" in the original Boeing manuals with literally just that: a mention. It was listed - not even defined - in the glossary as MCAS - Maneuvering Characteristics Augmentation System. So whiskey tango foxtrot is that exactly? No definition, no explanation, no procedures to explain why it's there, what it does, when it does so, and how to correct the system if it goes sideways, or more accurately, straight down. No wonder the US (and likely other countries as well) 737 Max pilots were so livid and stated Boeing betrayed their trust.
The November 6/18 manual update you mentioned only came after the Lion Air accident (a week later than when would have been helpful), and I'm sure was the first large-scale inkling that Boeing had an 'uh-oh' moment.
Apr 2, 2019, 12:54 pm
#2309
Join Date: Feb 2004
Location: USA
Programs: AC SE100K, F9 100k, NK Gold, UA *S, Hyatt Glob, Bonvoy Titanium
Posts: 5,195
MCAS as it was implemented would be akin to buying a car that forces the steering wheel into a hard turn at highway speeds if a single wheel/sensor/camera is blocked or malfunctions. The car has multiple sensors that could have been averaged but JUST THE FAULTY ONE was used.
A near certain crash with seconds to respond. Steer the other direction? NOPE--It also locks the steering column so that the driver cannot adjust it back.
Blame the owner for not reading his new car manual? NOPE-someone removed all instruction/diagrams/warnings (but accidentally left the abbreviation listed in the index page, meaning they purposefully removed all other data but forgot one part of covering the tracks).
Boeing blaming the pilot would be like the car manufactuer in this example blaming the driver for not knowing they just needed to open the fuse panel, find and pull out fuse #26 to disable the sensor. Oh, and at the rate the car was turning into a tree they had *seven seconds* to do so before instant death.
Many criminally wrong assumptions were made by the software folks, regulatory folks, and training folks.
This reminds me a few years ago when GM had cheapened a clip inside ignition systems without revising a part #. Weight of other keys on a key ring was enough to weaken this and pull the ignition out of the 'run' position. GM eventually internally knew this and dedided it was not a risk to human life. Then it proved fatal multiple times causing head-on impact. The collisions would have been survivable had the airbags deployed. Everyone involved (NHTSA, GM design engineers, etc) had assumed the airbag system was still armed/operating when the ignition was moved from the 'run' to the 'on/acc' position. Until it was proven that it wasn't. oops.
A near certain crash with seconds to respond. Steer the other direction? NOPE--It also locks the steering column so that the driver cannot adjust it back.
Blame the owner for not reading his new car manual? NOPE-someone removed all instruction/diagrams/warnings (but accidentally left the abbreviation listed in the index page, meaning they purposefully removed all other data but forgot one part of covering the tracks).
Boeing blaming the pilot would be like the car manufactuer in this example blaming the driver for not knowing they just needed to open the fuse panel, find and pull out fuse #26 to disable the sensor. Oh, and at the rate the car was turning into a tree they had *seven seconds* to do so before instant death.
Many criminally wrong assumptions were made by the software folks, regulatory folks, and training folks.
This reminds me a few years ago when GM had cheapened a clip inside ignition systems without revising a part #. Weight of other keys on a key ring was enough to weaken this and pull the ignition out of the 'run' position. GM eventually internally knew this and dedided it was not a risk to human life. Then it proved fatal multiple times causing head-on impact. The collisions would have been survivable had the airbags deployed. Everyone involved (NHTSA, GM design engineers, etc) had assumed the airbag system was still armed/operating when the ignition was moved from the 'run' to the 'on/acc' position. Until it was proven that it wasn't. oops.
Apr 2, 2019, 1:13 pm
#2310
Join Date: Apr 2015
Location: YVR
Programs: UA Premier Platinum
Posts: 3,759
It's well known that space travel is extremely risky and that astronauts take on considerably higher risk to life than would ever be acceptable in commercial aviation.
Yet the Challenger space shuttle incident is considered an instructive moment in history of engineering design not only because lives were lost, but because the flaw that caused the loss of life was known in advance and glossed over with inadequate mitigation. In other words, it was not part-and-parcel of the admittedly dangerous business of space travel, but a simple act of negligence not much different from one that might occur in the design of an automobile, building or other consumer product.
The number of planes that have not crashed is irrelevant. It is true that modern aviation cannot exist without some level of risk to passengers. But the level of risk Boeing and the FAA created by putting a poorly designed, non-failure tolerant, untested system in the position to single-handedly crash a commercial airliner with no time for the pilot to react is NOT something we need to tolerate, nor should we.
Yet the Challenger space shuttle incident is considered an instructive moment in history of engineering design not only because lives were lost, but because the flaw that caused the loss of life was known in advance and glossed over with inadequate mitigation. In other words, it was not part-and-parcel of the admittedly dangerous business of space travel, but a simple act of negligence not much different from one that might occur in the design of an automobile, building or other consumer product.
The number of planes that have not crashed is irrelevant. It is true that modern aviation cannot exist without some level of risk to passengers. But the level of risk Boeing and the FAA created by putting a poorly designed, non-failure tolerant, untested system in the position to single-handedly crash a commercial airliner with no time for the pilot to react is NOT something we need to tolerate, nor should we.