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Boeing 737 MAX is stupidly designed

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Boeing 737 MAX is stupidly designed

Old 12-02-2019, 06:08 PM
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another question for pilots and aero engineers...

It seems from what I've heard/read about the 737 debacle being debated here that the trim system has more aerodynamic authority than the control column/stick.

Is it considered "normal" for trim to have more authority than stick?

It certainly seems counter intuitive to me (non pilot).

Why would you give a trim system more ability to pitch down into the ground than you would give the pilot ability to pull up ? surely in a condition of total trim failure the pilot should still be able to fly stick and throttle only and safely land?
Old 12-02-2019, 07:37 PM
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Originally Posted by mickt243 View Post
another question for pilots and aero engineers...

It seems from what I've heard/read about the 737 debacle being debated here that the trim system has more aerodynamic authority than the control column/stick.

Is it considered "normal" for trim to have more authority than stick?

It certainly seems counter intuitive to me (non pilot).

Why would you give a trim system more ability to pitch down into the ground than you would give the pilot ability to pull up ? surely in a condition of total trim failure the pilot should still be able to fly stick and throttle only and safely land?
I think you're reading that wrong, but what can happen (as in the Ethiopian Air event) is that when you're flying the plane near Vmax there are is too much aerodynamic loading on the control surfaces which can't be overcome by manual effort.
Old 12-02-2019, 09:23 PM
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Originally Posted by km1125 View Post
I think you're reading that wrong, but what can happen (as in the Ethiopian Air event) is that when you're flying the plane near Vmax there are is too much aerodynamic loading on the control surfaces which can't be overcome by manual effort.
I sureley could be reading things wrong....... BUT, if maximum down trim didnt give more "dive" than maximum up stick could counteract, wouldnt the pilots save their own skin by pulling up a bit more?
Old 12-02-2019, 10:21 PM
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Originally Posted by km1125 View Post
I think you're reading that wrong, but what can happen (as in the Ethiopian Air event) is that when you're flying the plane near Vmax there are is too much aerodynamic loading on the control surfaces which can't be overcome by manual effort.
mans when indicators say you are stalling, you are supposed to power down?
Old 12-02-2019, 10:24 PM
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Originally Posted by mickt243 View Post
another question for pilots and aero engineers...

It seems from what I've heard/read about the 737 debacle being debated here that the trim system has more aerodynamic authority than the control column/stick.

Is it considered "normal" for trim to have more authority than stick?

It certainly seems counter intuitive to me (non pilot).

Why would you give a trim system more ability to pitch down into the ground than you would give the pilot ability to pull up ? surely in a condition of total trim failure the pilot should still be able to fly stick and throttle only and safely land?
the authority originally designed into MCAS was .6 degrees...that was nowhere near what it would take to correct the faulty design of this plane and they upped it by 4x and kept that on the low.

They did did that for one reason...the design of the plane, as it stands, has major issues w/ the new/ larger engines. This is the crux of the matter (forget the single sensor) and something a few here just gloss over. This is the entire purpose of the thread topic. The design was rushed for the sake of $$$. It’s a bad design/plane.
Old 12-03-2019, 07:15 AM
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Originally Posted by schoolsout1 View Post
the authority originally designed into MCAS was .6 degrees...that was nowhere near what it would take to correct the faulty design of this plane and they upped it by 4x and kept that on the low.

They did did that for one reason...the design of the plane, as it stands, has major issues w/ the new/ larger engines. This is the crux of the matter (forget the single sensor) and something a few here just gloss over. This is the entire purpose of the thread topic. The design was rushed for the sake of $$$. It’s a bad design/plane.
Old 12-03-2019, 08:47 AM
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Originally Posted by schoolsout1 View Post
mans when indicators say you are stalling, you are supposed to power down?
Absolutely.

It'd be better to actually stall than continue to accelerate straight down to the ground. You have more time to figure out what's going wrong.

Stall indicators can be wrong, as they were in both the two planes that crashed.
Old 12-03-2019, 09:20 AM
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Originally Posted by km1125 View Post
Absolutely.

It'd be better to actually stall than continue to accelerate straight down to the ground. You have more time to figure out what's going wrong.

Stall indicators can be wrong, as they were in both the two planes that crashed.
Only if you're in a MAX, then maybe, maybe not...
What causes the indication is irrelevant. The stall indication, if believed to be incorrect could/would send the pilots to a different checklist. Unreliable airspeed.

Aussies did a study a few years back and determined 30% of stall indications were false.
Stall warnings in high capacity aircraft: The Australian context 2008 to 2012

The checklist will work at any altitude. 75% N1 isn't going to keep you at high cruising altitude, but as you mash down in to thicker air, you'll level off in the low to mid 20's. Plenty of altitude most placed on the planet. This checklist came front and center after the Air France airbus accident a few years ago.

Old 12-03-2019, 09:24 AM
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Originally Posted by schoolsout1 View Post
the authority originally designed into MCAS was .6 degrees...that was nowhere near what it would take to correct the faulty design of this plane and they upped it by 4x and kept that on the low.

They did did that for one reason...the design of the plane, as it stands, has major issues w/ the new/ larger engines. This is the crux of the matter (forget the single sensor) and something a few here just gloss over. This is the entire purpose of the thread topic. The design was rushed for the sake of $$$. It’s a bad design/plane.
The authority of a shorted wire is essentially infinity, until the trim hits a limit switch or a mechanical limit. It also won't stop or pause every five seconds and re-evaluate (like MCAS does), giving the pilots more time to analyze or respond.

However, Boeing has a simple set of two switches, easily available to either pilot, to control either an MCAS or a shorted wire that is resulting in an uncommanded trim or "runaway trim" situation and it can be done in single-digit seconds. This is well before MCAS could run the trim to full stop.

And they DID NOT do it because of a design problem with the plane, they did it to fit the plane under the same FAA requirements for the same TYPE rating. Perhaps that's not even a necessary requirement in terms of safety (I haven't seen anybody explore that yet, but it's a possibility).
Old 12-03-2019, 05:32 PM
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Originally Posted by km1125 View Post
The authority of a shorted wire is essentially infinity, until the trim hits a limit switch or a mechanical limit. It also won't stop or pause every five seconds and re-evaluate (like MCAS does), giving the pilots more time to analyze or respond.

However, Boeing has a simple set of two switches, easily available to either pilot, to control either an MCAS or a shorted wire that is resulting in an uncommanded trim or "runaway trim" situation and it can be done in single-digit seconds. This is well before MCAS could run the trim to full stop.

And they DID NOT do it because of a design problem with the plane, they did it to fit the plane under the same FAA requirements for the same TYPE rating. Perhaps that's not even a necessary requirement in terms of safety (I haven't seen anybody explore that yet, but it's a possibility).
Learjets come in all different flavors with different engines, wings, etc and back when I flew them my LR-JET type rating covered something to the effect of 8 or 9 different models. Not once has that had anything bearing in an NTSB investigation that I know of and a Learjet can bite you a lot of different ways if you’re not careful.

I flew the Max within a year or so of learning to fly 737’s in general, it was a seemless transition even coming from a -300.

I find it to be a bit of a stretch to blame and aircraft specifically for the result of two accidents in which pilot error was the major factor in both. People need to put the blame where it is due, there’s enough to spread around, but the airplane shouldn’t be the target like it is here. Especially when the thread starts out with “I’m not a pilot or an engineer, but I ride on a lot of airplanes....”




Old 12-03-2019, 07:01 PM
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Originally Posted by km1125 View Post
The authority of a shorted wire is essentially infinity, until the trim hits a limit switch or a mechanical limit. It also won't stop or pause every five seconds and re-evaluate (like MCAS does), giving the pilots more time to analyze or respond.
thats the bit I was referring to - not MCAS. Is it normal to, and why would you build a trim system that at full deflection seems to have more aerodynamic authority than the elevators?

Surely a shorted trim system wire commanding "dive" should not be able to over ride the pilots control column commanding "climb"?
Old 12-07-2019, 07:26 AM
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I'll leave this here....

https://thehill.com/policy/transport...ling-defective

Old 12-11-2019, 07:06 AM
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https://www.wsj.com/articles/interna...es-11576069202
The November 2018 internal Federal Aviation Administration analysis, expected to be released during a House committee hearing Wednesday, reveals that without agency intervention, the MAX could have averaged one fatal crash about every two or three years, according to industry officials and regulators. That amounts to a substantially greater safety risk than either Boeing Co. or the agency indicated publicly at the time.
Old 12-15-2019, 07:32 PM
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https://www.wsj.com/articles/boeing-...DhhzK5eZXUEr7A

Boeing may cut or halt 737 MAX production.
Old 12-15-2019, 08:28 PM
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Originally Posted by Classic25 View Post
https://www.wsj.com/articles/boeing-...DhhzK5eZXUEr7A

Boeing may cut or halt 737 MAX production.
impossible. They have yet to consult the THT braintrust
Old 12-16-2019, 08:47 AM
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The 737 Max is in deeper trouble than Boeing thought, and its stock is sinking

https://www.cnn.com/2019/12/16/busin...ion/index.html

Again, it begs the question, will the Boeing 737 Max ever be certified to fly again? And if it does not, it seems likely that Boeing will become bankrupt which will have a significant impact on the US economy since it is a Dow component.

Hopefully Boeing will return to integrity and solve this problem which clearly has uncovered some questionable business practices in the favor of dollars over safety.
Old 12-16-2019, 09:34 AM
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Originally Posted by Kendall View Post

The 737 Max is in deeper trouble than Boeing thought, and its stock is sinking

https://www.cnn.com/2019/12/16/busin...ion/index.html

Again, it begs the question, will the Boeing 737 Max ever be certified to fly again? And if it does not, it seems likely that Boeing will become bankrupt which will have a significant impact on the US economy since it is a Dow component.

Hopefully Boeing will return to integrity and solve this problem which clearly has uncovered some questionable business practices in the favor of dollars over safety.
Do you even read the crap you post?? Right in the article you posted, it says "No one suggests that the company is facing any threat to its survival. Boeing's balance sheet is still strong, and even critics acknowledge that it will be flush with cash once it can start delivering the hundreds of 737 Max jets it has continued to build since March."

It's good that Boeing is curtailing production for now, and they probably should have at the earliest signs that they were going to have a parking problem putting these airframes somewhere while the FAA goes though its motions. Keep in mind: The FAA has NO OBLIGATION to be efficient in what they do, nor do they offer ANY guarantees that what they will end up with will be any better -at all- that what Boeing would have come up with as a solution. Boeing should be working with their airline partners, the pilots and engineers to come up with solutions to address the issues. The FAA is oversight and regulation and those regulations don't necessarily make anything really safer by themselves. The FAA has NO OBLIGATION to execute the reviews in an expeditious manner. Perhaps they should have some pressure - not to cut corners, but to make sure they are being expeditious, as there will be thousands of folks whose paychecks will now be "on hold" until they finish. Anyone who has dealt with the government in any capacity from your local permit reviewer to the EPA realizes that your priorities don't really dictate their resources or their calendar.
Old 12-16-2019, 10:07 AM
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Originally Posted by km1125 View Post
Do you even read the crap you post?? Right in the article you posted, it says "No one suggests that the company is facing any threat to its survival. Boeing's balance sheet is still strong, and even critics acknowledge that it will be flush with cash once it can start delivering the hundreds of 737 Max jets it has continued to build since March."

It's good that Boeing is curtailing production for now, and they probably should have at the earliest signs that they were going to have a parking problem putting these airframes somewhere while the FAA goes though its motions. Keep in mind: The FAA has NO OBLIGATION to be efficient in what they do, nor do they offer ANY guarantees that what they will end up with will be any better -at all- that what Boeing would have come up with as a solution. Boeing should be working with their airline partners, the pilots and engineers to come up with solutions to address the issues. The FAA is oversight and regulation and those regulations don't necessarily make anything really safer by themselves. The FAA has NO OBLIGATION to execute the reviews in an expeditious manner. Perhaps they should have some pressure - not to cut corners, but to make sure they are being expeditious, as there will be thousands of folks whose paychecks will now be "on hold" until they finish. Anyone who has dealt with the government in any capacity from your local permit reviewer to the EPA realizes that your priorities don't really dictate their resources or their calendar.

To be honest, they would never say anything like that, but I have a feeling if the 737 Max becomes an issue where it will never be certified to fly as it is designed, it won't be easy for Boeing. Remember, they have continued to build them (and, I really think part of that decision is to extort the US Gov't to bail them out should that become necessary, but that's just a hunch). That said, I don't see the US Gov't letting them fail in any shape, form or fashion because they are "too big to fail."
Old 12-16-2019, 11:06 AM
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Originally Posted by km1125 View Post
Do you even read the crap you post?? Right in the article you posted, it says "No one suggests that the company is facing any threat to its survival. Boeing's balance sheet is still strong, and even critics acknowledge that it will be flush with cash once it can start delivering the hundreds of 737 Max jets it has continued to build since March."

It's good that Boeing is curtailing production for now, and they probably should have at the earliest signs that they were going to have a parking problem putting these airframes somewhere while the FAA goes though its motions. Keep in mind: The FAA has NO OBLIGATION to be efficient in what they do, nor do they offer ANY guarantees that what they will end up with will be any better -at all- that what Boeing would have come up with as a solution. Boeing should be working with their airline partners, the pilots and engineers to come up with solutions to address the issues. The FAA is oversight and regulation and those regulations don't necessarily make anything really safer by themselves. The FAA has NO OBLIGATION to execute the reviews in an expeditious manner. Perhaps they should have some pressure - not to cut corners, but to make sure they are being expeditious, as there will be thousands of folks whose paychecks will now be "on hold" until they finish. Anyone who has dealt with the government in any capacity from your local permit reviewer to the EPA realizes that your priorities don't really dictate their resources or their calendar.
Wait a minute. Aren't you someone who essentially said there is not an issue with this plane and that the issue was poorly trained foreign pilots who are at fault not Boeing and that they would be back flying soon. Now it's the FAA who is at fault for dragging its feet.

Seriously, how much Boeing stock do you own? Perhaps you can cover your losses by shorting the stock.
Old 12-16-2019, 11:52 AM
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Boeing has a great product design team. Unfortunately it's the executive suite that has lost its way. They're no longer competitive in the narrow body airliner market. Bean counters won with going all in on the old tech 737.

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