Amazing analysis of what's really going on with the Boeing 737 max technical issues..

Tom logic

Senior Villager
#1
Copied:
Some people are calling the 737MAX tragedies a software failure. Here's my response: It's not a software problem. It was an

* Economic problem that the 737 engines used too much fuel, so they decided to install more efficient engines with bigger fans and make the 737MAX.
This led to an

* Airframe problem. They wanted to use the 737 airframe for economic reasons, but needed more ground clearance with bigger engines.The 737 design can't be practically modified to have taller main landing gear. The solution was to mount them higher & more forward.
This led to an

* Aerodynamic problem. The airframe with the engines mounted differently did not have adequately stable handling at high AoA to be certifiable. Boeing decided to create the MCAS system to electronically correct for the aircraft's handling deficiencies.
During the course of developing the MCAS, there was a

* Systems engineering problem. Boeing wanted the simplest possible fix that fit their existing systems architecture, so that it required minimal engineering rework, and minimal new training for pilots and maintenance crews.
The easiest way to do this was to add some features to the existing Elevator Feel Shift system. Like the #EFS system, the #MCAS relies on non-redundant sensors to decide how much trim to add. Unlike the EFS system, MCAS can make huge nose down trim changes.
On both ill-fated flights, there was a:
* Sensor problem. The AoA vane on the 737MAX appears to not be very reliable and gave wildly wrong readings. On #LionAir, this was compounded by a
* Maintenance practices problem. The previous crew had experienced the same problem and didn't record the problem in the maintenance logbook. This was compounded by a:
* Pilot training problem. On LionAir, pilots were never even told about the MCAS, and by the time of the Ethiopian flight, there was an emergency AD issued, but no one had done sim training on this failure. This was compounded by an:
* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed.
All of this was compounded by a:

* Pilot expertise problem. If the pilots had correctly and quickly identified the problem and run the stab trim runaway checklist, they would not have crashed.
Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid.
I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved.
But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid.
 

Teddy_time

Village Elder
#2
Copied:
Some people are calling the 737MAX tragedies a software failure. Here's my response: It's not a software problem. It was an

* Economic problem that the 737 engines used too much fuel, so they decided to install more efficient engines with bigger fans and make the 737MAX.
This led to an

* Airframe problem. They wanted to use the 737 airframe for economic reasons, but needed more ground clearance with bigger engines.The 737 design can't be practically modified to have taller main landing gear. The solution was to mount them higher & more forward.
This led to an

* Aerodynamic problem. The airframe with the engines mounted differently did not have adequately stable handling at high AoA to be certifiable. Boeing decided to create the MCAS system to electronically correct for the aircraft's handling deficiencies.
During the course of developing the MCAS, there was a

* Systems engineering problem. Boeing wanted the simplest possible fix that fit their existing systems architecture, so that it required minimal engineering rework, and minimal new training for pilots and maintenance crews.
The easiest way to do this was to add some features to the existing Elevator Feel Shift system. Like the #EFS system, the #MCAS relies on non-redundant sensors to decide how much trim to add. Unlike the EFS system, MCAS can make huge nose down trim changes.
On both ill-fated flights, there was a:
* Sensor problem. The AoA vane on the 737MAX appears to not be very reliable and gave wildly wrong readings. On #LionAir, this was compounded by a
* Maintenance practices problem. The previous crew had experienced the same problem and didn't record the problem in the maintenance logbook. This was compounded by a:
* Pilot training problem. On LionAir, pilots were never even told about the MCAS, and by the time of the Ethiopian flight, there was an emergency AD issued, but no one had done sim training on this failure. This was compounded by an:
* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed.
All of this was compounded by a:

* Pilot expertise problem. If the pilots had correctly and quickly identified the problem and run the stab trim runaway checklist, they would not have crashed.
Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid.
I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved.
But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid.
Sweet analysis. Villager, youl soon be a Village Hero with this kind of posts
 
#3
Copied:
Some people are calling the 737MAX tragedies a software failure. Here's my response: It's not a software problem. It was an

* Economic problem that the 737 engines used too much fuel, so they decided to install more efficient engines with bigger fans and make the 737MAX.
This led to an

* Airframe problem. They wanted to use the 737 airframe for economic reasons, but needed more ground clearance with bigger engines.The 737 design can't be practically modified to have taller main landing gear. The solution was to mount them higher & more forward.
This led to an

* Aerodynamic problem. The airframe with the engines mounted differently did not have adequately stable handling at high AoA to be certifiable. Boeing decided to create the MCAS system to electronically correct for the aircraft's handling deficiencies.
During the course of developing the MCAS, there was a

* Systems engineering problem. Boeing wanted the simplest possible fix that fit their existing systems architecture, so that it required minimal engineering rework, and minimal new training for pilots and maintenance crews.
The easiest way to do this was to add some features to the existing Elevator Feel Shift system. Like the #EFS system, the #MCAS relies on non-redundant sensors to decide how much trim to add. Unlike the EFS system, MCAS can make huge nose down trim changes.
On both ill-fated flights, there was a:
* Sensor problem. The AoA vane on the 737MAX appears to not be very reliable and gave wildly wrong readings. On #LionAir, this was compounded by a
* Maintenance practices problem. The previous crew had experienced the same problem and didn't record the problem in the maintenance logbook. This was compounded by a:
* Pilot training problem. On LionAir, pilots were never even told about the MCAS, and by the time of the Ethiopian flight, there was an emergency AD issued, but no one had done sim training on this failure. This was compounded by an:
* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed.
All of this was compounded by a:

* Pilot expertise problem. If the pilots had correctly and quickly identified the problem and run the stab trim runaway checklist, they would not have crashed.
Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid.
I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved.
But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid.
How about they make all AoA's standard and not optional on the MAX?
 

Tom logic

Senior Villager
#4
How about they make all AoA's standard and not optional on the MAX?
Villager I think you mean make MCAS a standard feature,,,but it still baffles me why Boeing did not require the MCAS feature as a standard safety feature on the Boeing 737 Max 8, but rather allowed it to be an optional add-on
 

Tom logic

Senior Villager
#6
How about they make all AoA's standard and not optional on the MAX?
Is it really so hard to connect the secrecy about MCAS and why it was needed in the first place? The lawyers will have a ball of the decade with this issue: the defendant created a secret software,moreso made the software dependent on a single sensor, and made it difficult to switch the software off.
The networked Western pilots learned how to compensate for the faulty design, but non-networked foreign pilots never got in on the flying tricks needed for this new plane because it was never been in their training. Also, the critical sensor may not be available on an airport in Ethiopia or Indonesia or .....
 

M2Random

Village Elder
#8
Copied:
Some people are calling the 737MAX tragedies a software failure. Here's my response: It's not a software problem. It was an

* Economic problem that the 737 engines used too much fuel, so they decided to install more efficient engines with bigger fans and make the 737MAX.
This led to an

* Airframe problem. They wanted to use the 737 airframe for economic reasons, but needed more ground clearance with bigger engines.The 737 design can't be practically modified to have taller main landing gear. The solution was to mount them higher & more forward.
This led to an

* Aerodynamic problem. The airframe with the engines mounted differently did not have adequately stable handling at high AoA to be certifiable. Boeing decided to create the MCAS system to electronically correct for the aircraft's handling deficiencies.
During the course of developing the MCAS, there was a

* Systems engineering problem. Boeing wanted the simplest possible fix that fit their existing systems architecture, so that it required minimal engineering rework, and minimal new training for pilots and maintenance crews.
The easiest way to do this was to add some features to the existing Elevator Feel Shift system. Like the #EFS system, the #MCAS relies on non-redundant sensors to decide how much trim to add. Unlike the EFS system, MCAS can make huge nose down trim changes.
On both ill-fated flights, there was a:
* Sensor problem. The AoA vane on the 737MAX appears to not be very reliable and gave wildly wrong readings. On #LionAir, this was compounded by a
* Maintenance practices problem. The previous crew had experienced the same problem and didn't record the problem in the maintenance logbook. This was compounded by a:
* Pilot training problem. On LionAir, pilots were never even told about the MCAS, and by the time of the Ethiopian flight, there was an emergency AD issued, but no one had done sim training on this failure. This was compounded by an:
* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed.
All of this was compounded by a:

* Pilot expertise problem. If the pilots had correctly and quickly identified the problem and run the stab trim runaway checklist, they would not have crashed.
Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid.
I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved.
But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid.
Your analysis is very good. Assuming that I understand 30% of what you just typed. You seem like a technical guy. If you could summarize your findings in 5 bullet points and use non-technical language then maybe you would put your point across better.
 
#11
Surely the 5000 orders for this engineering disaster cannot be sustained. I predict mass cancellations. Nobody wants to buy a manyanga without brakes.
I think in the industry, such setbacks are expected. Boeing and airbus planes have had such manufacturing defects in the past but we always end up with incrementally safer planes. Check out the Aircrash Investigation series on youtube. Alot of the crashes were caused by manufacturers defects which were consequently corrected
 

Nattydread

Village Sponsor
#12
I think in the industry, such setbacks are expected. Boeing and airbus planes have had such manufacturing defects in the past but we always end up with incrementally safer planes. Check out the Aircrash Investigation series on youtube. Alot of the crashes were caused by manufacturers defects which were consequently corrected
The 737 MAX is a unicum, with greed completely eclipsing safety.
 

Tom logic

Senior Villager
#14
I think in the industry, such setbacks are expected. Boeing and airbus planes have had such manufacturing defects in the past but we always end up with incrementally safer planes. Check out the Aircrash Investigation series on youtube. Alot of the crashes were caused by manufacturers defects which were consequently corrected
I agree there're setbacks bt at this era we shouldn't be experiencing such,,,as for the Ethiopian crash,Boeing knew about the system believed responsible for the catastrophe and sold the fix as an "optional package"why not make it standard and inform the pilots?
 

Tom logic

Senior Villager
#15
Your analysis is very good. Assuming that I understand 30% of what you just typed. You seem like a technical guy. If you could summarize your findings in 5 bullet points and use non-technical language then maybe you would put your point across better.
Random,I hope this will help
• Switch to more fuel efficient engines
• However, they are bigger, need to be placed further forward
• Changes aerodynamics, degrades flight stability
• Software hack cheaper than real fix
• But software relies on an unreliable sensor w/o redundancy
→Sensor fails #737MAX
 
#19
There is no solution because the aircraft has a fatal flaw. engines mounted in the wrong position causing flight instability. all other hacks involving installing warnings are insufficient. even the american pilots are just using hacks. the proper solution is to modify the aircraft accordingly.
 

hinzan

Senior Villager
#20
Villager I think you mean make MCAS a standard feature,,,but it still baffles me why Boeing did not require the MCAS feature as a standard safety feature on the Boeing 737 Max 8, but rather allowed it to be an optional add-on
that's already a billion dollar loophole that they will pay dearly for, plus any other regulatory requirements they might have jumped along the way in improving then correcting and re-correcting the aircraft.
 
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