Boeing 737Max

[old salt]

Articles with pics of the hardware attaching the door plugs.
https://theaircurrent.com/aviation-safe ... -assembly/

Note the plug is secured by 4 bolts (2 upper/2 lower) with castellated nuts w/cotter pins.
If the nuts work loose, the cotter pin prevents separation.
During inspections, United & Alaska have found loose hardware.
https://theaircurrent.com/feed/dispatch ... spections/

The failure mode which caused the plug to separate has not been reported.
This was a relatively new aircraft without a lot of cycles.
Interested to know if/how often the door plugs are inspected & removed, after initial factory installation.

Plug IN or Plug OUT. This is not new technology.
https://www.cnn.com/business/boeing-737-max/index.html

[cradleandshoot]

I didn't know where to post this but this thread should do. Northrup Grumman announced today they are losing over a billion dollars per copy over the low rate production B 21 bomber. This is confusing to me. I thought NG was in the business of making money?

[PizzaSnake]

Articles with pics of the hardware attaching the door plugs.
https://theaircurrent.com/aviation-safe ... -assembly/

Note the plug is secured by 4 bolts (2 upper/2 lower) with castellated nuts w/cotter pins.
If the nuts work loose, the cotter pin prevents separation.
During inspections, United & Alaska have found loose hardware.
https://theaircurrent.com/feed/dispatch ... spections/

The failure mode which caused the plug to separate has not been reported.
This was a relatively new aircraft without a lot of cycles.
Interested to know if/how often the door plugs are inspected & removed, after initial factory installation.

Plug IN or Plug OUT. This is not new technology.
https://www.cnn.com/business/boeing-737-max/index.html

The bolts don’t “hold” the plug in, they arrest its movement in a channel that allows the plug (or exit door) to slide up, clearing the real mechanism, the 12 points of contact (stop pads). Those don’t show signs of failure or disfigurement.

Most likely cause is failure to re-install, or correctly secure the four sheer bolts. The real issue is why the two quality assurance systems of Boeing and Spirit failed to require an inspection post “opening” of that component. Personally, I’d say, given the string of snafus at Boeing over the past twenty years, that their reputation for engineering excellence, to include manufacturing, is finished.

Trust is hard to win, almost impossible to regain.

[cradleandshoot]

Articles with pics of the hardware attaching the door plugs.
https://theaircurrent.com/aviation-safe ... -assembly/

Note the plug is secured by 4 bolts (2 upper/2 lower) with castellated nuts w/cotter pins.
If the nuts work loose, the cotter pin prevents separation.
During inspections, United & Alaska have found loose hardware.
https://theaircurrent.com/feed/dispatch ... spections/

The failure mode which caused the plug to separate has not been reported.
This was a relatively new aircraft without a lot of cycles.
Interested to know if/how often the door plugs are inspected & removed, after initial factory installation.

Plug IN or Plug OUT. This is not new technology.
https://www.cnn.com/business/boeing-737-max/index.html

The bolts don’t “hold” the plug in, they arrest its movement in a channel that allows the plug (or exit door) to slide up, clearing the real mechanism, the 12 points of contact (stop pads). Those don’t show signs of failure or disfigurement.

Most likely cause is failure to re-install, or correctly secure the four sheer bolts. The real issue is why the two quality assurance systems of Boeing and Spirit failed to require an inspection post “opening” of that component. Personally, I’d say, given the string of snafus at Boeing over the past twenty years, that their reputation for engineering excellence, to include manufacturing, is finished.

Trust is hard to win, almost impossible to regain.

Yeah, when the president of Boeing boldly claims they only manufacture safe aircraft it makes him look rather silly. Thanks for the detailed description. I would have thought this would have been on each and every safety check list involving a mechanical restraining device so vital to the safe operation of the aircraft. I'm glad I don't own stock in Boeing.

[old salt]

https://www.seattletimes.com/business/b ... max-9-jet/

Boeing, not Spirit, mis-installed piece that blew off Alaska MAX 9 jet, industry source says

Jan. 24, 2024 at 6:00 am Updated Jan. 24, 2024 at 6:04 am

By Dominic Gates, Seattle Times aerospace reporter

The fuselage panel that blew off an Alaska Airlines jet earlier this month was removed for repair then reinstalled improperly by Boeing mechanics on the Renton final assembly line, a person familiar with the details of the work told The Seattle Times.

If verified by the National Transportation Safety Board investigation, this would leave Boeing primarily at fault for the accident, rather than its supplier Spirit AeroSystems, which originally installed the panel into the 737 MAX 9 fuselage in Wichita, Kan.

That panel, a door plug used to seal a hole in the fuselage sometimes used to accommodate an emergency exit, blew out of Alaska Airlines Flight 1282 as it climbed out of Portland on Jan. 5. The hair-raising incident drew fresh and sharp criticism of Boeing’s quality control systems and safety culture, which has been under the microscope since two fatal 737 MAX crashes five years ago.

Last week, a different person — an anonymous whistleblower who appears to have access to Boeing’s manufacturing records of the work done assembling the specific Alaska Airlines jet that suffered the blowout — on an aviation website separately provided many additional details about how the door plug came to be removed and then mis-installed.

“The reason the door blew off is stated in black and white in Boeing’s own records,” the whistleblower wrote. “It is also very, very stupid and speaks volumes about the quality culture at certain portions of the business.”

The self-described Boeing insider said company records show four bolts that prevent the door plug from sliding up off the door frame stop pads that take the pressurization loads in flight, “were not installed when Boeing delivered the airplane.” the whistleblower stated. “Our own records reflect this.”

NTSB investigators already publicly raised the possibility that the bolts had not been installed.

UPDATE FAA blocks Boeing production push but clears way for MAX 9s to fly again
The account goes on to describe shocking lapses in Boeing’s quality control process in Renton.

The work of the mechanics on the door plug should have been formally inspected and signed off by a Boeing quality inspector.

It wasn’t, the whistleblower wrote, because of a process failure and the use of two separate systems to record what work was accomplished.

Boeing’s 737 production system is described as “a rambling, shambling, disaster waiting to happen.”

If that account of what happened is indeed fully documented in Boeing’s system it should be readily verified by the investigation.

The Seattle Times offered Boeing the opportunity to dispute the details in this story. Citing the ongoing investigation, Boeing declined to comment. Likewise, so did Spirit, the FAA, the Machinists union and the NTSB.

A convincing account
Passengers on Flight 1282 were traumatized when a door-sized section of the 737 MAX 9 fuselage exploded out 16,000 feet over Portland.

The door plug that blew out is a panel used to seal a fuselage cutout for an optional emergency exit door that is installed only by a few airlines with high-density seating. To a passenger seated at that location, it looks like just another cabin window.

The incident has proved a monumental setback for Boeing, drawing outrage and mockery across the world.

With large fleets of MAX 9 aircraft still grounded almost three weeks later, the chief executives of both Alaska and United on Tuesday sharply criticized Boeing.

“I’m more than frustrated and disappointed,” Alaska CEO Ben Minicucci told NBC News. “I am angry.”

It was clear soon after the incident that the plug must have been mis-installed.

When the cabin is pressurized, six small stop fittings on either side of the plug press against corresponding stop pads on the door frame.

[Kismet]

BIG trouble for Boeing and its CEO. Negligence is obvious. FAA is rightfully now all over them in Renton assembly facility.

Lucky the failure only occurred at 14,00 feet and not 30,000+.

Southwest Airlines removed MAX 7 from 2024 plans and United did the same with MAX 10.

[cradleandshoot]

Air Bus is looking like a solid investment. Boeing use to be a respected player in the aircraft industry. That ship has sailed.

[old salt]

Not a structural or design flaw. Negligent mechanical workmanship.

[PizzaSnake]

“If it’s Boeing, I’m not going.”

[old salt]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

[cradleandshoot]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

OS wouldn't Boeing have a record of what technician performed the work on the plane? I'm guessing the tech has to sign off on their work. I'm also guessing, given the importance of these plugs that a supervisor would also have to sign off. This is mind numbing negligence on the part of Boeing. It seems inevitable that some Boeing employees will lose their jobs over this.

[PizzaSnake]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

BS.

Boeing, because of the height of the 737 off the tarmac, kluged the fitting of the larger, more fuel-efficient engines, resulting in loss of aerodynamic stability -- the plane flew "up," not flat. So, in order to correct that engineering issue, they introduced the MCAS system to compensate. Then, in order to make the airframe easy to certify and cheap to adopt by the airlines -- no expensive re-training necessary, they hid the feature.

https://www.seattletimes.com/business/b ... missed-it/

But, my favorite part, they actually offer the plane with a single airspeed sensor. Now, if the MCAS detects certain conditions, to include incipient stall due to incorrect angle of attack or airspeed, it induces a nose-down condition.

https://www.seattletimes.com/business/b ... n-the-jet/

In the two cases of fatalities, on take off and initial ascent, the MCAS detected a "stall" due to faulty single airspeed sensor and induced a nose down condition, at full, or near, full throttle. Pilots didn't know what the plane was doing because they hadn't been trained on the "hidden" feature. They didn't stand a chance. Nose first into the ground at near full throttle.

Follow-up testing of these conditions in flight simulators by Boeing test pilots who were aware of the MCAS system resulted in crash conditions. So spare me the sanctimonious, thinly veiled racism about the foreign pilots. I bet you a buck you couldn't handle those conditions in a simulator either.

So, two things: being cheap and deciding to kluge a competitor to the Airbus retrofitted fuel efficient airframe resulted in a software solution to basic aerodynamic problems, and allowing sale of platforms with single point of failures -- airspeed sensor, were both management decisions, not engineering.

Boeing has lost its way. These debacles, together with the disaster of the Boeing Starliner, signal the likely passing of an icon. The only thing keeping them going is a lack of competition.

https://www.seattletimes.com/seattle-ne ... afeguards/

[old salt]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

BS.

Boeing, because of the height of the 737 off the tarmac, kluged the fitting of the larger, more fuel-efficient engines, resulting in loss of aerodynamic stability -- the plane flew "up," not flat. So, in order to correct that engineering issue, they introduced the MCAS system to compensate. Then, in order to make the airframe easy to certify and cheap to adopt by the airlines -- no expensive re-training necessary, they hid the feature.

https://www.seattletimes.com/business/b ... missed-it/

But, my favorite part, they actually offer the plane with a single airspeed sensor. Now, if the MCAS detects certain conditions, to include incipient stall due to incorrect angle of attack or airspeed, it induces a nose-down condition.

https://www.seattletimes.com/business/b ... n-the-jet/

In the two cases of fatalities, on take off and initial ascent, the MCAS detected a "stall" due to faulty single airspeed sensor and induced a nose down condition, at full, or near, full throttle. Pilots didn't know what the plane was doing because they hadn't been trained on the "hidden" feature. They didn't stand a chance. Nose first into the ground at near full throttle.

Follow-up testing of these conditions in flight simulators by Boeing test pilots who were aware of the MCAS system resulted in crash conditions. So spare me the sanctimonious, thinly veiled racism about the foreign pilots. I bet you a buck you couldn't handle those conditions in a simulator either.

So, two things: being cheap and deciding to kluge a competitor to the Airbus retrofitted fuel efficient airframe resulted in a software solution to basic aerodynamic problems, and allowing sale of platforms with single point of failures -- airspeed sensor, were both management decisions, not engineering.

Boeing has lost its way. These debacles, together with the disaster of the Boeing Starliner, signal the likely passing of an icon. The only thing keeping them going is a lack of competition.

https://www.seattletimes.com/seattle-ne ... afeguards/

You are correct in quoting "Pilots didn't know what the plane was doing because they hadn't been trained on the 'hidden' feature". If they had been trained on the system, they could have maintained controlled flight & not crashed. The split sensor glitch would have been fixed in the normal course of events for a new series aircraft.

All fly-by-wire aircraft have software written to compensate for varying design aerodynamics. Boeing dumbed down their systems & differences training so current 737 pilots would not need to obtain a new type certificate to operate the MAX.

You chose to inject race instead of a training flaw. Boeing's training for all pilots on the MAX was at fault for not adequately explaining the system & not including this failure mode into the differences training.

[old salt]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

BS.

Boeing, because of the height of the 737 off the tarmac, kluged the fitting of the larger, more fuel-efficient engines, resulting in loss of aerodynamic stability -- the plane flew "up," not flat. So, in order to correct that engineering issue, they introduced the MCAS system to compensate. Then, in order to make the airframe easy to certify and cheap to adopt by the airlines -- no expensive re-training necessary, they hid the feature.

https://www.seattletimes.com/business/b ... missed-it/

But, my favorite part, they actually offer the plane with a single airspeed sensor. Now, if the MCAS detects certain conditions, to include incipient stall due to incorrect angle of attack or airspeed, it induces a nose-down condition.

https://www.seattletimes.com/business/b ... n-the-jet/

In the two cases of fatalities, on take off and initial ascent, the MCAS detected a "stall" due to faulty single airspeed sensor and induced a nose down condition, at full, or near, full throttle. Pilots didn't know what the plane was doing because they hadn't been trained on the "hidden" feature. They didn't stand a chance. Nose first into the ground at near full throttle.

Follow-up testing of these conditions in flight simulators by Boeing test pilots who were aware of the MCAS system resulted in crash conditions. So spare me the sanctimonious, thinly veiled racism about the foreign pilots. I bet you a buck you couldn't handle those conditions in a simulator either.

So, two things: being cheap and deciding to kluge a competitor to the Airbus retrofitted fuel efficient airframe resulted in a software solution to basic aerodynamic problems, and allowing sale of platforms with single point of failures -- airspeed sensor, were both management decisions, not engineering.

Boeing has lost its way. These debacles, together with the disaster of the Boeing Starliner, signal the likely passing of an icon. The only thing keeping them going is a lack of competition.

https://www.seattletimes.com/seattle-ne ... afeguards/

You are correct in quoting "Pilots didn't know what the plane was doing because they hadn't been trained on the 'hidden' feature". If they had been trained on the system, they could have maintained controlled flight & not crashed. The split sensor glitch would have been fixed in the normal course of events for a new series aircraft.
United alerted their pilots on how to respond. https://skift.com/2018/11/13/united-air ... air-crash/.

All fly-by-wire aircraft have software written to compensate for varying design aerodynamics. Boeing dumbed down their systems & differences training so current 737 pilots would not need to obtain a new type certificate to operate the MAX.

You chose to inject race instead of a training flaw. Boeing's training for all pilots on the MAX was at fault for not adequately explaining the system & not including this failure mode in the differences training.

[old salt]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

OS wouldn't Boeing have a record of what technician performed the work on the plane? I'm guessing the tech has to sign off on their work. I'm also guessing, given the importance of these plugs that a supervisor would also have to sign off. This is mind numbing negligence on the part of Boeing. It seems inevitable that some Boeing employees will lose their jobs over this.

Yes. The FAA & NTSB should be able to identify everyone involved.

[Farfromgeneva]

It’s safe to say Boeing has not continued to earn its independence as a business (in the court a living thing). They have too much to be a zero unless there’s unknown fraud there as well. But they will be owned by some strategic for pennies on
The dollar and it will happen within 3yrs.

[old salt]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

BS.

Boeing, because of the height of the 737 off the tarmac, kluged the fitting of the larger, more fuel-efficient engines, resulting in loss of aerodynamic stability -- the plane flew "up," not flat. So, in order to correct that engineering issue, they introduced the MCAS system to compensate. Then, in order to make the airframe easy to certify and cheap to adopt by the airlines -- no expensive re-training necessary, they hid the feature.

https://www.seattletimes.com/business/b ... missed-it/

But, my favorite part, they actually offer the plane with a single airspeed sensor. Now, if the MCAS detects certain conditions, to include incipient stall due to incorrect angle of attack or airspeed, it induces a nose-down condition.

https://www.seattletimes.com/business/b ... n-the-jet/

In the two cases of fatalities, on take off and initial ascent, the MCAS detected a "stall" due to faulty single airspeed sensor and induced a nose down condition, at full, or near, full throttle. Pilots didn't know what the plane was doing because they hadn't been trained on the "hidden" feature. They didn't stand a chance. Nose first into the ground at near full throttle.

Follow-up testing of these conditions in flight simulators by Boeing test pilots who were aware of the MCAS system resulted in crash conditions. So spare me the sanctimonious, thinly veiled racism about the foreign pilots. I bet you a buck you couldn't handle those conditions in a simulator either.

So, two things: being cheap and deciding to kluge a competitor to the Airbus retrofitted fuel efficient airframe resulted in a software solution to basic aerodynamic problems, and allowing sale of platforms with single point of failures -- airspeed sensor, were both management decisions, not engineering.

Boeing has lost its way. These debacles, together with the disaster of the Boeing Starliner, signal the likely passing of an icon. The only thing keeping them going is a lack of competition.

https://www.seattletimes.com/seattle-ne ... afeguards/

You are correct in quoting "Pilots didn't know what the plane was doing because they hadn't been trained on the 'hidden' feature". If they had been trained on the system, they could have maintained controlled flight & not crashed. The split sensor glitch would have been fixed in the normal course of events for a new series aircraft.
United alerted their pilots on how to respond. https://skift.com/2018/11/13/united-air ... air-crash/.

All fly-by-wire aircraft have software written to compensate for varying design aerodynamics. Boeing dumbed down their systems & differences training so current 737 pilots would not need to obtain a new type certificate to operate the MAX.

You chose to inject race instead of a training flaw. Boeing's training for all pilots on the MAX was at fault for not adequately explaining the system & not including this failure mode in the differences training.

Here's what I was looking for :
https://www.npr.org/2019/03/13/70293689 ... wasnt-alon
Several U.S. pilots who reported having trouble controlling Boeing 737 Max planes early in their flights used NASA's Aviation Safety Reporting System to flag issues they encountered.

"In two cases, pilots flying in the U.S. late last year had their planes pitch down unexpectedly after departures. Both times, the crew disengaged the autopilot and were able to keep flying safely," NPR's Russell Lewis reports. "In a third report, a pilot complained that the Boeing 737 MAX's flight manual was inadequate and 'almost criminally insufficient.' "

On Tuesday, the Allied Pilots Association, which represents American Airlines' 15,000 pilots, issued a statement saying the union "remains confident in the Boeing 737 Max and in our members' ability to safely fly it." The group said its pilots "have the necessary training and experience to troubleshoot problems and take decisive actions on the flight deck to protect our passengers and crew."

Several US pilots experienced the same nose down pitch command after takeoff that caused the 2 crashes. They responded the way airline pilots are trained to respond when experiencing an unanticipated hardover control command -- they disengaged the autopilot. Even on the most rudimentary 3 axis autopilots, pilots train in simulators for runaway nose down trim. It becomes an automatic human response to disengage the autopilot, hand fly the aircraft, regain stable flight conditions & manually retrim the aircraft before reengaging the auto pilot. In the 2 crashes, the pilots apparently did not recognize the hardover soon enough to disconnect the autopilot & manually fly the aircraft.

The software has been changed to eliminate the cause for the uncommanded nose down pitch.
https://www.seattletimes.com/business/b ... 20activate.
After months of intense scrutiny, even some of the harshest critics of the 737 MAX’s flight-control system believe Boeing’s software fix will prevent a recurrence of the scenarios that killed 346 people in the crashes in Indonesia and Ethiopia.

Boeing has redesigned the MAX’s new automated Maneuvering Characteristics Augmentation System (MCAS) that relentlessly pushed down the noses of the two aircraft on both crash flights. Though serious questions linger about the overall safety culture at Boeing that waved through MCAS’s original development and certification, U.S. airline pilots are almost ready to fly the updated jet.

“The hazard is designed out of it,” Capt. John DeLeeuw, chairman of the safety committee of the Allied Pilots Association (APA), the union for American Airlines pilots, declared to colleagues a week after trying the flight-control fix in a Boeing simulator in Miami in late September.

Boeing’s fix for MCAS entails three changes to the system design:

It will take input from the jet’s two angle of attack sensors instead of just one.
If they disagree by more than a nominal amount, the system assumes a false signal and will not activate.

If both angle of attack sensors somehow get stuck at the same wrong high value — perhaps if they got frozen in the wrong position — again MCAS won’t activate because the upgrade is designed to do so only when the angle moves suddenly from below the threshold to a new high value.

If both sensors together register a sudden movement to a high angle of attack, the system will activate once only — not repeatedly, as in the accident flights.
The capability of the system to move the horizontal stabilizer so as to pitch the jet nose-down will be limited. The pilot will always be able to counter it by pulling back on the control column.

In addition, Boeing has revised the overall architecture of the MAX’s flight-control computer system, so that on every flight the MAX takes separate inputs from the jet’s two flight-control computers, rather than just one as previously.

These two computers, each processing air data readings from the various sensors on both sides of the airplane, will cross-check and compare values. Again, if they disagree, automated systems including MCAS will be shut down.

This change should catch any computer error as opposed to a sensor fault.

To get the flying public equally comfortable with the MAX, Boeing needs also to counter a recurring theme on social media: the idea that software shouldn’t have been needed in the first place and that the plane’s large engines throw its aerodynamic balance out of whack and make it “inherently unstable.”

Boeing says MCAS is needed not for stability but only to make the MAX feel the same to a pilot as the previous 737 model. The airplane will fly safely with or without MCAS, Boeing insists.

To prove that, Boeing has flown near-stall maneuvers in flight tests this summer with MCAS turned off. Safety regulators plan to do the same during upcoming recertification flights.

[PizzaSnake]

PR disaster. Nobody's going to believe Boeing, but FAA, DoT & the affected airlines could be doing much more to reassure the public.

The MAX 9 is a good airplane. The first accidents were due to pilot training. The door plug was due to shoddy maintenance.

Self-inflicted damage by Boeing.

Boeing stock went up 1.78 % today.

BS.

Boeing, because of the height of the 737 off the tarmac, kluged the fitting of the larger, more fuel-efficient engines, resulting in loss of aerodynamic stability -- the plane flew "up," not flat. So, in order to correct that engineering issue, they introduced the MCAS system to compensate. Then, in order to make the airframe easy to certify and cheap to adopt by the airlines -- no expensive re-training necessary, they hid the feature.

https://www.seattletimes.com/business/b ... missed-it/

But, my favorite part, they actually offer the plane with a single airspeed sensor. Now, if the MCAS detects certain conditions, to include incipient stall due to incorrect angle of attack or airspeed, it induces a nose-down condition.

https://www.seattletimes.com/business/b ... n-the-jet/

In the two cases of fatalities, on take off and initial ascent, the MCAS detected a "stall" due to faulty single airspeed sensor and induced a nose down condition, at full, or near, full throttle. Pilots didn't know what the plane was doing because they hadn't been trained on the "hidden" feature. They didn't stand a chance. Nose first into the ground at near full throttle.

Follow-up testing of these conditions in flight simulators by Boeing test pilots who were aware of the MCAS system resulted in crash conditions. So spare me the sanctimonious, thinly veiled racism about the foreign pilots. I bet you a buck you couldn't handle those conditions in a simulator either.

So, two things: being cheap and deciding to kluge a competitor to the Airbus retrofitted fuel efficient airframe resulted in a software solution to basic aerodynamic problems, and allowing sale of platforms with single point of failures -- airspeed sensor, were both management decisions, not engineering.

Boeing has lost its way. These debacles, together with the disaster of the Boeing Starliner, signal the likely passing of an icon. The only thing keeping them going is a lack of competition.

https://www.seattletimes.com/seattle-ne ... afeguards/

You are correct in quoting "Pilots didn't know what the plane was doing because they hadn't been trained on the 'hidden' feature". If they had been trained on the system, they could have maintained controlled flight & not crashed. The split sensor glitch would have been fixed in the normal course of events for a new series aircraft.
United alerted their pilots on how to respond. https://skift.com/2018/11/13/united-air ... air-crash/.

All fly-by-wire aircraft have software written to compensate for varying design aerodynamics. Boeing dumbed down their systems & differences training so current 737 pilots would not need to obtain a new type certificate to operate the MAX.

You chose to inject race instead of a training flaw. Boeing's training for all pilots on the MAX was at fault for not adequately explaining the system & not including this failure mode in the differences training.

Here's what I was looking for :
https://www.npr.org/2019/03/13/70293689 ... wasnt-alon
Several U.S. pilots who reported having trouble controlling Boeing 737 Max planes early in their flights used NASA's Aviation Safety Reporting System to flag issues they encountered.

"In two cases, pilots flying in the U.S. late last year had their planes pitch down unexpectedly after departures. Both times, the crew disengaged the autopilot and were able to keep flying safely," NPR's Russell Lewis reports. "In a third report, a pilot complained that the Boeing 737 MAX's flight manual was inadequate and 'almost criminally insufficient.' "

On Tuesday, the Allied Pilots Association, which represents American Airlines' 15,000 pilots, issued a statement saying the union "remains confident in the Boeing 737 Max and in our members' ability to safely fly it." The group said its pilots "have the necessary training and experience to troubleshoot problems and take decisive actions on the flight deck to protect our passengers and crew."

Several US pilots experienced the same nose down pitch command after takeoff that caused the 2 crashes. They responded the way airline pilots are trained to respond when experiencing an unanticipated hardover control command -- they disengaged the autopilot. Even on the most rudimentary 3 axis autopilots, pilots train in simulators for runaway nose down trim. It becomes an automatic human response to disengage the autopilot, hand fly the aircraft, regain stable flight conditions & manually retrim the aircraft before reengaging the auto pilot. In the 2 crashes, the pilots apparently did not recognize the hardover soon enough to disconnect the autopilot & manually fly the aircraft.

The software has been changed to eliminate the cause for the uncommanded nose down pitch.
https://www.seattletimes.com/business/b ... 20activate.
After months of intense scrutiny, even some of the harshest critics of the 737 MAX’s flight-control system believe Boeing’s software fix will prevent a recurrence of the scenarios that killed 346 people in the crashes in Indonesia and Ethiopia.

Boeing has redesigned the MAX’s new automated Maneuvering Characteristics Augmentation System (MCAS) that relentlessly pushed down the noses of the two aircraft on both crash flights. Though serious questions linger about the overall safety culture at Boeing that waved through MCAS’s original development and certification, U.S. airline pilots are almost ready to fly the updated jet.

“The hazard is designed out of it,” Capt. John DeLeeuw, chairman of the safety committee of the Allied Pilots Association (APA), the union for American Airlines pilots, declared to colleagues a week after trying the flight-control fix in a Boeing simulator in Miami in late September.

Boeing’s fix for MCAS entails three changes to the system design:

It will take input from the jet’s two angle of attack sensors instead of just one.
If they disagree by more than a nominal amount, the system assumes a false signal and will not activate.

If both angle of attack sensors somehow get stuck at the same wrong high value — perhaps if they got frozen in the wrong position — again MCAS won’t activate because the upgrade is designed to do so only when the angle moves suddenly from below the threshold to a new high value.

If both sensors together register a sudden movement to a high angle of attack, the system will activate once only — not repeatedly, as in the accident flights.
The capability of the system to move the horizontal stabilizer so as to pitch the jet nose-down will be limited. The pilot will always be able to counter it by pulling back on the control column.

In addition, Boeing has revised the overall architecture of the MAX’s flight-control computer system, so that on every flight the MAX takes separate inputs from the jet’s two flight-control computers, rather than just one as previously.

These two computers, each processing air data readings from the various sensors on both sides of the airplane, will cross-check and compare values. Again, if they disagree, automated systems including MCAS will be shut down.

This change should catch any computer error as opposed to a sensor fault.

To get the flying public equally comfortable with the MAX, Boeing needs also to counter a recurring theme on social media: the idea that software shouldn’t have been needed in the first place and that the plane’s large engines throw its aerodynamic balance out of whack and make it “inherently unstable.”

Boeing says MCAS is needed not for stability but only to make the MAX feel the same to a pilot as the previous 737 model. The airplane will fly safely with or without MCAS, Boeing insists.

To prove that, Boeing has flown near-stall maneuvers in flight tests this summer with MCAS turned off. Safety regulators plan to do the same during upcoming recertification flights.

So, after the death of 346 people, they choose to do the "right thing" and fix their crappy software? Two single points of failure: air speed sensors and flight control modules not constantly verifying and "checking" the other? Who the hlel thought that was good software practice?

They couldn't, or wouldn't do the right thing and "blank sheet" the proposed platform to compete with the retro-fitted Airbus. So instead they tried a "software" solution. And they did a really, really poor job on that given the requirements that it not require re-training of the pilots, and that it could, and did, introduce scenarios like the recurring invocation of the nose down condition. All of the corrective actions they subsequently introduced should have been found and implemented during development. Maybe, just maybe, the executive wunderkind shouldn't have laid off all of those senior software engineers, hmm?

"It remains the mystery at the heart of Boeing Co.’s 737 Max crisis: how a company renowned for meticulous design made seemingly basic software mistakes leading to a pair of deadly crashes. Longtime Boeing engineers say the effort was complicated by a push to outsource work to lower-paid contractors.

The Max softwareーplagued by issues that could keep the planes grounded months longer after U.S. regulators this week revealed a new flawーwas developed at a time Boeing was laying off experienced engineers and pressing suppliers to cut costs.

Increasingly, the iconic American planemaker and its subcontractors have relied on temporary workers making as little as $9 an hour to develop and test software, often from countries lacking a deep background in aerospaceーnotably India."

https://www.industryweek.com/supply-cha ... -engineers

But they were in such a rush to meet management "targets," and get the product to market, 346 people died. But hey, those 346 people weren't real people, were they?

I find that completely unacceptable and feel strongly that many involved from Boeing and the FAA should have been charged and tried for 346 counts of manslaughter. At a minimum, they should have been removed from the aeronautics industry, permanently, counting themselves lucky not to be incarcerated for life.

[old salt]

So, after the death of 346 people, they choose to do the "right thing" and fix their crappy software? Two single points of failure: air speed sensors and flight control modules not constantly verifying and "checking" the other? Who the hlel thought that was good software practice?

They couldn't, or wouldn't do the right thing and "blank sheet" the proposed platform to compete with the retro-fitted Airbus. So instead they tried a "software" solution. And they did a really, really poor job on that given the requirements that it not require re-training of the pilots, and that it could, and did, introduce scenarios like the recurring invocation of the nose down condition. All of the corrective actions they subsequently introduced should have been found and implemented during development. Maybe, just maybe, the executive wunderkind shouldn't have laid off all of those senior software engineers, hmm?

"It remains the mystery at the heart of Boeing Co.’s 737 Max crisis: how a company renowned for meticulous design made seemingly basic software mistakes leading to a pair of deadly crashes. Longtime Boeing engineers say the effort was complicated by a push to outsource work to lower-paid contractors.

The Max softwareーplagued by issues that could keep the planes grounded months longer after U.S. regulators this week revealed a new flawーwas developed at a time Boeing was laying off experienced engineers and pressing suppliers to cut costs.

Increasingly, the iconic American planemaker and its subcontractors have relied on temporary workers making as little as $9 an hour to develop and test software, often from countries lacking a deep background in aerospaceーnotably India."

https://www.industryweek.com/supply-cha ... -engineers

But they were in such a rush to meet management "targets," and get the product to market, 346 people died. But hey, those 346 people weren't real people, were they?

I find that completely unacceptable and feel strongly that many involved from Boeing and the FAA should have been charged and tried for 346 counts of manslaughter. At a minimum, they should have been removed from the aeronautics industry, permanently, counting themselves lucky not to be incarcerated for life.

Using software to standardize the flying qualities across the 737 fleet is a sound concept which enhances safety if done correctly.
Boeing did a good job making the F-18 E/F Super Hornet fly like the original F-18 A/B/C/D Hornet, which were, in fact, different airplanes.
The F-18 also had a rigorous system safety process to catch "sneak circuit" faults like those in the 737 Max MCAS. We still lost a F-18 in flight test using a manual adaptation to yield a more "natural" control feedback for the F-18's used by the Blue Angels.
Boeing did not do it as well with the 737 Max family succession as they did with the F-18's.
The FAA was not as capable in checking Boeing's work on the 737 Max as the Naval Air Test Center was in certifying the original F-18 & it's follow on models, ...in my biased opinion.

[Typical Lax Dad]

So, after the death of 346 people, they choose to do the "right thing" and fix their crappy software? Two single points of failure: air speed sensors and flight control modules not constantly verifying and "checking" the other? Who the hlel thought that was good software practice?

They couldn't, or wouldn't do the right thing and "blank sheet" the proposed platform to compete with the retro-fitted Airbus. So instead they tried a "software" solution. And they did a really, really poor job on that given the requirements that it not require re-training of the pilots, and that it could, and did, introduce scenarios like the recurring invocation of the nose down condition. All of the corrective actions they subsequently introduced should have been found and implemented during development. Maybe, just maybe, the executive wunderkind shouldn't have laid off all of those senior software engineers, hmm?

"It remains the mystery at the heart of Boeing Co.’s 737 Max crisis: how a company renowned for meticulous design made seemingly basic software mistakes leading to a pair of deadly crashes. Longtime Boeing engineers say the effort was complicated by a push to outsource work to lower-paid contractors.

The Max softwareーplagued by issues that could keep the planes grounded months longer after U.S. regulators this week revealed a new flawーwas developed at a time Boeing was laying off experienced engineers and pressing suppliers to cut costs.

Increasingly, the iconic American planemaker and its subcontractors have relied on temporary workers making as little as $9 an hour to develop and test software, often from countries lacking a deep background in aerospaceーnotably India."

https://www.industryweek.com/supply-cha ... -engineers

But they were in such a rush to meet management "targets," and get the product to market, 346 people died. But hey, those 346 people weren't real people, were they?

I find that completely unacceptable and feel strongly that many involved from Boeing and the FAA should have been charged and tried for 346 counts of manslaughter. At a minimum, they should have been removed from the aeronautics industry, permanently, counting themselves lucky not to be incarcerated for life.

Using software to standardize the flying qualities across the 737 fleet is a sound concept which enhances safety if done correctly.
Boeing did a good job making the F-18 E/F Super Hornet fly like the original F-18 A/B/C/D Hornet, which were, in fact, different airplanes.
The F-18 also had a rigorous system safety process to catch "sneak circuit" faults like those in the 737 Max MCAS. We still lost a F-18 in flight test using a manual adaptation to yield a more "natural" control feedback for the F-18's used by the Blue Angels.
Boeing did not do it as well with the 737 Max family succession as they did with the F-18's.
The FAA was not as capable in checking Boeing's work on the 737 Max as the Naval Air Test Center was in certifying the original F-18 & it's follow on models, ...in my biased opinion.

Boeing checked their own work. A client is heavily involved with the 737 Max program.