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I see in a sibling comment that you do not think the MCAS system on the MAX was well designed, and the reliance on a single AoA sensor was not a good decision.

I see in a sibling comment that you do not think the MCAS system on the MAX was well designed, and the reliance on a single AoA sensor was not a good decision. I agree. The aircraft should have never been declared airworthy. There should have been no need for an EAD in the first place. There is no excuse for putting a control system that flies the craft into the ground when there is a failure in a nonredundant sensor on a commercial aircraft. The high standards required for pilots, like Amelia Earhart, do not obviate the even higher standards for quality and safety from manufacturers.

WalterBright 1y ago
I suspect that Boeing didn't think it would be a problem because the runaway stab trim procedure is enough to stop it and recover. Who would have thought that trained pilots would not remember this procedure? It's supposed to be a "memory item", meaning consulting the checklist was not required. The stab trim cutoff switch is in a prominent position on the central console (not overhead or behind the crew). In the first Lion Air crash, the airplane dipped and recovered (via the thumb switches) 25 times over a period of 11 minutes. They never thought to turn off the stab trim system. It boggles the mind. Would you want to fly with a crew that didn't know what the switches on the console were for? Not me. Both Boeing and the crew are at fault. Some percentage also for whoever made the faulty sensor and the failure to see that it worked correctly after it was installed.
- genewitch 1y ago
  Do we also blame the drivers of the Toyotas that got stuck accelerators, because any driver should know to take the car out of gear or turn the key to the off position. Right? While the car is accelerating at or near WOT? I've been in a car when the throttle got stuck open, we crashed, I hit the windshield. It happened in about 5 seconds, and the driver spent most of those giving steering inputs to avoid hitting people and furiously working the break and kicking the gas pedal. It happened because enough engine mounts were broken or broke because of a hard throttle push. Also my dad died in a single seat plane crash because the engine died several times in flight, according to a witness interviewed by a local paper; there was no investigation at all so I'll never know what really happened. At least the company that made the plane changed their name!
  - WalterBright 1y ago
    I had the throttle stick on my car once. I immediately turned the ignition off. I was a teenager at the time (and my car was a POS). The brakes are much stronger than the engine (proof: you can brake in a much shorter distance than you can accelerate). On my current car, I have inadvertently hit the edge of the gas pedal while I stepped on the brake a couple times, as those pedals are too close together and I have wide feet. My reaction was to instantly move my foot. A number of those "surging" incidents are suspected of being the driver had their foot on the gas rather than the brake. Glad to hear you're all right after the crash. I nearly died in a car crash. Sorry to hear about your dad. It must be very frustrating to not know the cause. I thought all GA accidents were officially investigated.
    - genewitch 1y ago
      My car has a pushbutton "ignition switch" and i have not tried pushing it while travelling; however, my lexus also has floormat retention to stop the floormat from going onto the gas pedal. It wasn't "accidental" - there was a recall. The toyotas and lexus affected don't have a floating accelerator pedal, where it hangs from above and there's space underneath. The gas pedal is hinged on the floor, and swings free at the top. So you could shove something forward and it will push the gas pedal down. If memory serves there was an instance in southern california where the driver called 911 or some other recorded line (they died); but it may have just been a witness statement i remember.
  - quesera 1y ago
    I do not work in aero or auto, but I have a much higher expectation of training and retention of a commercial airline pilot than I do of a random Toyota driver. I had a stuck accelerator on an old Ford F-150. The throttle inside the carb got stuck. I was lucky to have the Toyota case in my memory, so I just shifted into neutral. It was an automatic, which I think is another factor -- the more direct control you remove from the driver, the less intuitive it becomes to compensate for a single system failure. Obviously a standard transmission driver would just hit the clutch. (And I've had a similar failure on an unfamiliar motorcycle that just came out of storage. Pulling the clutch bail was the instinctive response, after manually untwisting the throttle did not work. I learned my lesson about old vehicles eventually. Trust nothing, verify everything.) Very sorry to hear about your dad!
- throwaway5752 1y ago
  1. The Maneuvering Characteristics Augmentation System (MCAS) system existed because the plane was unstable at high angles of attack. 2. The 737 MAX was unstable because Boeing wanted to milk the 737 airframe further than it should have been for financial reasons and oversized engines were mounted forward on the wings. 3. Since the plane was unstable in this way, it would pitch up when climbing. MCAS would detect this through the angle of attack (AoA sensors) and automatically engage, forcing the nose down. 4. When the single, nonredundant AoA sensor failed, MCAS would misinterpret this and try to continuously force the nose down in normal operations. Or more plainly, it would fly the plane into the ground for no reason. 5. This happened at least 3 times. In two cases, it caused crashes, killing everyone - almost 350 men, women, and children - aboard. 6. Boeing strenuously blamed the crew in the first crash, and did not ground the planes. 7. Boeing did not ground the 737 MAXes after the second crash, either. The FAA only grounded the aircraft after much of the rest of the world already had. As you noted previously, MCAS existed to make the 737 MAX fly like prior versions of the plane. Boeing, in fact, lobbied for this outcome so it would not affect certification or require separate pilot training, which would have cost time and money. So while MCAS was documented, pilots were not required to be trained on the system, because of Boeings efforts. One cannot put a "don't crash the plane button" on a plane, even if it is well documented. It is particularly disgraceful if the "don't crash the plane" button only exists because the plane's manufacturer added the button to increase their own profits. I have to admit, you have made me lose my composure here a bit. I thought anyone this knowledgable about flying would not blame pilot error in the 737 MAX crashes. The plane was grounded for almost 2 years, this was arguably the greatest scandal in the production and regulation of commercial aircraft in history. Boeing paid $20 billion in fines and restitution, and pled guilty to criminal charges. For the benefit of anyone else curious about this, good starting points are https://en.wikipedia.org/wiki/Boeing_737_MAX_groundings https://en.wikipedia.org/wiki/Boeing_737_MAX_groundings "hours after the approval for MCAS's redesign was granted, Boeing sought, and the FAA approved, the removal of references to MCAS from Boeing's flight crew operations manual (FCOM)" "Boeing wanted the FAA to certify the airplane as another version of the long-established 737; this would limit the need for additional training of pilots, a major cost saving for airline customers. During flight tests, however, Boeing discovered that the position and larger size of the engines tended to push up the airplane nose during certain maneuvers. To counter that tendency and ensure fleet commonality with the 737 family, Boeing added MCAS so the MAX would handle similar to earlier 737 versions." "The MAX was exempted from certain newer safety requirements, saving Boeing billions of dollars in development costs." https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_groundings https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_groundi... https://www.amazon.com/Flying-Blind-Tragedy-Fall-Boeing/dp/0385546491 https://www.amazon.com/Flying-Blind-Tragedy-Fall-Boeing/dp/0...

WalterBright 1y ago

I suspect that Boeing didn't think it would be a problem because the runaway stab trim procedure is enough to stop it and recover. Who would have thought that trained pilots would not remember this procedure? It's supposed to be a "memory item", meaning consulting the checklist was not required. The stab trim cutoff switch is in a prominent position on the central console (not overhead or behind the crew). In the first Lion Air crash, the airplane dipped and recovered (via the thumb switches) 25 times over a period of 11 minutes. They never thought to turn off the stab trim system. It boggles the mind. Would you want to fly with a crew that didn't know what the switches on the console were for? Not me. Both Boeing and the crew are at fault. Some percentage also for whoever made the faulty sensor and the failure to see that it worked correctly after it was installed.

genewitch 1y ago
Do we also blame the drivers of the Toyotas that got stuck accelerators, because any driver should know to take the car out of gear or turn the key to the off position. Right? While the car is accelerating at or near WOT? I've been in a car when the throttle got stuck open, we crashed, I hit the windshield. It happened in about 5 seconds, and the driver spent most of those giving steering inputs to avoid hitting people and furiously working the break and kicking the gas pedal. It happened because enough engine mounts were broken or broke because of a hard throttle push. Also my dad died in a single seat plane crash because the engine died several times in flight, according to a witness interviewed by a local paper; there was no investigation at all so I'll never know what really happened. At least the company that made the plane changed their name!
- WalterBright 1y ago
  I had the throttle stick on my car once. I immediately turned the ignition off. I was a teenager at the time (and my car was a POS). The brakes are much stronger than the engine (proof: you can brake in a much shorter distance than you can accelerate). On my current car, I have inadvertently hit the edge of the gas pedal while I stepped on the brake a couple times, as those pedals are too close together and I have wide feet. My reaction was to instantly move my foot. A number of those "surging" incidents are suspected of being the driver had their foot on the gas rather than the brake. Glad to hear you're all right after the crash. I nearly died in a car crash. Sorry to hear about your dad. It must be very frustrating to not know the cause. I thought all GA accidents were officially investigated.
  - genewitch 1y ago
    My car has a pushbutton "ignition switch" and i have not tried pushing it while travelling; however, my lexus also has floormat retention to stop the floormat from going onto the gas pedal. It wasn't "accidental" - there was a recall. The toyotas and lexus affected don't have a floating accelerator pedal, where it hangs from above and there's space underneath. The gas pedal is hinged on the floor, and swings free at the top. So you could shove something forward and it will push the gas pedal down. If memory serves there was an instance in southern california where the driver called 911 or some other recorded line (they died); but it may have just been a witness statement i remember.
- quesera 1y ago
  I do not work in aero or auto, but I have a much higher expectation of training and retention of a commercial airline pilot than I do of a random Toyota driver. I had a stuck accelerator on an old Ford F-150. The throttle inside the carb got stuck. I was lucky to have the Toyota case in my memory, so I just shifted into neutral. It was an automatic, which I think is another factor -- the more direct control you remove from the driver, the less intuitive it becomes to compensate for a single system failure. Obviously a standard transmission driver would just hit the clutch. (And I've had a similar failure on an unfamiliar motorcycle that just came out of storage. Pulling the clutch bail was the instinctive response, after manually untwisting the throttle did not work. I learned my lesson about old vehicles eventually. Trust nothing, verify everything.) Very sorry to hear about your dad!
throwaway5752 1y ago
1. The Maneuvering Characteristics Augmentation System (MCAS) system existed because the plane was unstable at high angles of attack. 2. The 737 MAX was unstable because Boeing wanted to milk the 737 airframe further than it should have been for financial reasons and oversized engines were mounted forward on the wings. 3. Since the plane was unstable in this way, it would pitch up when climbing. MCAS would detect this through the angle of attack (AoA sensors) and automatically engage, forcing the nose down. 4. When the single, nonredundant AoA sensor failed, MCAS would misinterpret this and try to continuously force the nose down in normal operations. Or more plainly, it would fly the plane into the ground for no reason. 5. This happened at least 3 times. In two cases, it caused crashes, killing everyone - almost 350 men, women, and children - aboard. 6. Boeing strenuously blamed the crew in the first crash, and did not ground the planes. 7. Boeing did not ground the 737 MAXes after the second crash, either. The FAA only grounded the aircraft after much of the rest of the world already had. As you noted previously, MCAS existed to make the 737 MAX fly like prior versions of the plane. Boeing, in fact, lobbied for this outcome so it would not affect certification or require separate pilot training, which would have cost time and money. So while MCAS was documented, pilots were not required to be trained on the system, because of Boeings efforts. One cannot put a "don't crash the plane button" on a plane, even if it is well documented. It is particularly disgraceful if the "don't crash the plane" button only exists because the plane's manufacturer added the button to increase their own profits. I have to admit, you have made me lose my composure here a bit. I thought anyone this knowledgable about flying would not blame pilot error in the 737 MAX crashes. The plane was grounded for almost 2 years, this was arguably the greatest scandal in the production and regulation of commercial aircraft in history. Boeing paid $20 billion in fines and restitution, and pled guilty to criminal charges. For the benefit of anyone else curious about this, good starting points are https://en.wikipedia.org/wiki/Boeing_737_MAX_groundings https://en.wikipedia.org/wiki/Boeing_737_MAX_groundings "hours after the approval for MCAS's redesign was granted, Boeing sought, and the FAA approved, the removal of references to MCAS from Boeing's flight crew operations manual (FCOM)" "Boeing wanted the FAA to certify the airplane as another version of the long-established 737; this would limit the need for additional training of pilots, a major cost saving for airline customers. During flight tests, however, Boeing discovered that the position and larger size of the engines tended to push up the airplane nose during certain maneuvers. To counter that tendency and ensure fleet commonality with the 737 family, Boeing added MCAS so the MAX would handle similar to earlier 737 versions." "The MAX was exempted from certain newer safety requirements, saving Boeing billions of dollars in development costs." https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_groundings https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_groundi... https://www.amazon.com/Flying-Blind-Tragedy-Fall-Boeing/dp/0385546491 https://www.amazon.com/Flying-Blind-Tragedy-Fall-Boeing/dp/0...