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How to Get People Flying on the 737 Max

blueone

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I believe it was due to the shift in the center of lift to the center of gravity. Maybe that was caused by the larger diameter engines.

By my admittedly superficial understanding, there is a center of gravity aspect to the overall aircraft design problem, but MCAS was apparently aimed at counteracting some abnormal (?) lift at high angles of attack (climb rate) caused by the engine positions that could affect the feel through an unassisted yolk (reducing "stick force" and confusing the pilot), causing the pilot to pull back the yolk more than necessary, and possibly putting the plane into a stall situation during the crucial climb-out phase. That's in the link I provided.

I have no expertise in this field at all, but I do remember the first time I tested a feature called lane-keeping assist in a new Mercedes I test drove. Perhaps I'm being a big baby about stuff like that, but when I purposely tried to drive over a double yellow line it was very disconcerting to have the vehicle's electronics take control of the steering wheel. I suppose I could get used to it, but it would take repeated practice. I can only imagine how some pilots felt having the yokes in a jetliner becoming unresponsive and the plane executing non-commanded actions without prior training.
 
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phoenixdogfan

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Commercial Scheduled Air Travel:

The Safest Way to Die.

( I've watched too many Smithsonian Channel's Air Disasters episodes)

---

Click here for a daily dose of incidents that don't make the front p
https://avherald.com/

Except for the 737 Max disasters, I'd be hard pressed to even name one air disaster on US domestic flights over the last 20 years. Air Travel is very, very safe.
 

tvrgeek

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It was not just a retrofit. Lengthened the cabin, new wings, new materials, and high efficiency lower noise engines. ( that yea, are larger diameter) Almost all new avionics. IMHO, it is a new airplane and should have gone through full certification, but as we know the FAA only looks out for the industry, so they let them self-certify a "modification" I believe that policy has been rolled back a little. I know no pilot who is a fan of the FAA.

Of course, it is your choice not to fly on one just as I have no intention of flying on anything. But in 10 years, you may find there are no alternatives for short to medium haul. It is very efficient and fuel is the #1 driving factor in airlines.
 

egellings

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Did not the plane have a switch that could turn MCAS off, but the pilots in planes that crashed were unaware of it?
 

blueone

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It was not just a retrofit. Lengthened the cabin, new wings, new materials, and high efficiency lower noise engines. ( that yea, are larger diameter) Almost all new avionics. IMHO, it is a new airplane and should have gone through full certification, but as we know the FAA only looks out for the industry, so they let them self-certify a "modification" I believe that policy has been rolled back a little. I know no pilot who is a fan of the FAA.

Of course, it is your choice not to fly on one just as I have no intention of flying on anything. But in 10 years, you may find there are no alternatives for short to medium haul. It is very efficient and fuel is the #1 driving factor in airlines.

Who said the Max was a retrofit? Because I joked that it reminded me of big block Chevette? Stuffing over-sized engines under the wings of aircraft platform not originally designed for them was just reminiscent of the Chevette. You're making me sorry I made that joking analogy.

The Max did go through a "full certification", as does every new model, even of an existing aircraft family. The problematic feature, MCAS, was intended to be so transparent that pilots didn't need dedicated training on its use.

https://www.seattletimes.com/seattl...-max-system-gained-power-and-lost-safeguards/

This is the most insightful quote from the article:

"As Boeing and the FAA advanced the 737 MAX toward production, they limited the scrutiny and testing of the MCAS design. Then they agreed not to inform pilots about MCAS in manuals, even though Boeing’s safety analysis expected pilots to be the primary backstop in the event the system went haywire."
 

orangejello

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Article in The Guardian today about a Max that returned to the airport 30 minutes after takeoff with one of the engines shut down on Dec 20. It landed safely but that does not help to inspire confidence either.
 

jomark911

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I would like to clear some things out if you don't mind.
Center of gravity is one thing, center of lift is another. Center of pressure is also another.
These centres Do not coincide on an airplane , either empty or full of load. Center of lift changes dynamically along the flight, or even in a specific time of the flight. Depending on the dynamic equilibrium .
Now on MAX the problem is not the certification or whatever else was said here. Nor the larger engines or their position under the wing, nor their nacelles . Nor anything else.
All JET airplanes , specially the ones having the engines under the wings , tilted upwards or not tilted, extending forward or not, TEND to pitch up at the onset of power. This is inevitable.Even the 727 had that tendency to pitch up .
All 737's exhibit this tendency also. From the first -200 up to the MAX.
The problem is not that , but the human stupidity . They (boeing) tried to copy airbus , with the trillion mathematical acts performed by the three on board computers. They failed. They even failed notice the crews on how to disconnect MCAS, just two damn switches that already exist and used by the crew whenever a stabilizer runaway condition exists. It's on the QRH. Damn it.
As far as what the pilot does , when hand flying the plane , and getting confused on a relaxed or increased yoke pressure, he is only holding the pitch at the commanded pitch attitude by the flight director , seen in his adi. Not more not less degrees of pitch . Just what is needed to maintain a certain speed set at the mcdu with a given power setting , set at power management selector.
As far as the training and type rating licensing , MAX is a common type with all 737's . It is good for the airlines not to train and pay extra money for pilot's licenses and type ratings.
Common type rating is an old story conceived by AIRBUS. Back at 1980 or some when during that era.
Boeing had to follow .
My 2c.
 
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SoundAndMotion

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Air Travel is very, very safe.
I agree. I have a graphic showing the odds of dying from a list of causes, with airplane accident being the lowest listed (1 in 205,552; highest: heart disease 1 in 6). I use this and other facts/info to reassure my wife, who is a nervous flyer.
.... I'd be hard pressed to even name one air disaster on US domestic flights over the last 20 years.
Maybe you don’t look. I do, since it was a part of my previous job. Since air travel continues to get safer and safer, looking at the last 20 years makes sense. The next 20 will likely be even safer.
I’m not sure why you only considered US domestic flights, but ok.
And I’m not sure how you define air disaster, but if you mean US domestic civil flight/air accident where more died than survived (excluding 9/11 and pilot suicide), there have been 14 accidents with 530 dying since 2000.
 
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blueone

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I would like to clear some things out if you don't mind.
Center of gravity is one thing, center of lift is another. Center of pressure is also another.
These centres Do not coincide on an airplane , either empty or full of load. Center of lift changes dynamically along the flight, or even in a specific time of the flight. Depending on the dynamic equilibrium .
Now on MAX the problem is not the certification or whatever else was said here. Nor the larger engines or their position under the wing, nor their nacelles . Nor anything else.

I didn't know I was being so incorrect. However, in my defense I should note that you misinterpreted my inclusion of a photo of flattened-bottom nacelles on a 737-300 as depicting a problem with Max nacelles. My point was only that the 737 series had engine clearance challenges even before the Max series.

All JET airplanes , specially the ones having the engines under the wings , tilted upwards or not tilted, extending forward or not, TEND to pitch up at the onset of power. This is inevitable.Even the 727 had that tendency to pitch up .
All 737's exhibit this tendency also. From the first -200 up to the MAX.

So are you saying this quote:

"The LEAP engine nacelles are larger and had to be mounted slightly higher and further forward from the previous NG CFM56-7 engines to give the necessary ground clearance. This new location and larger size of nacelle cause the vortex flow off the nacelle body to produce lift at high AoA. As the nacelle is ahead of the C of G, this lift causes a slight pitch-up effect (ie a reducing stick force) which could lead the pilot to inadvertently pull the yoke further aft than intended bringing the aircraft closer towards the stall. This abnormal nose-up pitching is not allowable under 14CFR §25.203(a) "Stall characteristics". Several aerodynamic solutions were introduced such as revising the leading edge stall strip and modifying the leading edge vortilons but they were insufficient to pass regulation. MCAS was therefore introduced to give an automatic nose down stabilizer input during elevated AoA when flaps are up."

From this site:

http://www.b737.org.uk/mcas.htm

Is incorrect? If it is, then so are many other sites saying essentially the same thing. That would be an interesting insight.

The problem is not that , but the human stupidity . They (boeing) tried to copy airbus , with the trillion mathematical acts performed by the three on board computers. They failed. They even failed notice the crews on how to disconnect MCAS, just two damn switches that already exist and used by the crew whenever a stabilizer runaway condition exists. It's on the QRH. Damn it.
As far as what the pilot does , when hand flying the plane , and getting confused on a relaxed or increased yoke pressure, he is only holding the pitch at the commanded pitch attitude by the flight director , seen in his adi. Not more not less degrees of pitch . Just what is needed to maintain a certain speed set at the mcdu with a given power setting , set at power management selector.
As far as the training and type rating licensing , MAX is a common type with all 737's . It is good for the airlines not to train and pay extra money for pilot's licenses and type ratings.
Common type rating is an old story conceived by AIRBUS. Back at 1980 or some when during that era.
Boeing had to follow .
My 2c.

I thought the Ethiopian Max that crashed had the MCAS cutoff switches engaged, yet it still crashed. These are old links I saved last year, but they still work. Are you saying they're incorrect, or that somehow I misinterpreted them?

https://leehamnews.com/2019/04/03/et302-used-the-cut-out-switches-to-stop-mcas/

https://visualapproach.io/et302-even-without-answers-the-data-tells-a-story/

You sound a bit like a commercial pilot. Are you?
 
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jomark911

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On the last of all these statements.
The switches that turn MCAS off are the stabilizer trim cut out switches. They are not separates for mcas . If those are off, stabilizer trim is not working either manually or through the auto pilot. So they could not be in the off position for take off.

I am a Airline pilot.
 

jomark911

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I didn't know I was being so incorrect. However, in my defense I should note that you misinterpreted my inclusion of a photos of flattened-bottom nacelles on a 737-300 as depicting a problem with Max nacelles. My point was only that the 737 series had engine clearance challenges even before the Max series.
QUOTE
Also , regarding the above , 737's 3,4,5,6,7,8,9 ,max, all have the flattened low end nacelles for FOD avoidance reasons.
Just not to suck any foreign objects that might be free in the taxiways or runways.
This is the reason . Not anything else.
 

Chrispy

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While I dislike commercial flying and probably won't fly again, as I have no need or desire to, if somehow something came up and it was necessary I wouldn't discriminate against this recertified aircraft....but I doubt that's going to happen.
 

TSB

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I would like to clear some things out if you don't mind.
Center of gravity is one thing, center of lift is another. Center of pressure is also another.
These centres Do not coincide on an airplane , either empty or full of load. Center of lift changes dynamically along the flight, or even in a specific time of the flight. Depending on the dynamic equilibrium .
Now on MAX the problem is not the certification or whatever else was said here. Nor the larger engines or their position under the wing, nor their nacelles . Nor anything else.
All JET airplanes , specially the ones having the engines under the wings , tilted upwards or not tilted, extending forward or not, TEND to pitch up at the onset of power. This is inevitable.Even the 727 had that tendency to pitch up .
All 737's exhibit this tendency also. From the first -200 up to the MAX.
The problem is not that , but the human stupidity . They (boeing) tried to copy airbus , with the trillion mathematical acts performed by the three on board computers. They failed. They even failed notice the crews on how to disconnect MCAS, just two damn switches that already exist and used by the crew whenever a stabilizer runaway condition exists. It's on the QRH. Damn it.
As far as what the pilot does , when hand flying the plane , and getting confused on a relaxed or increased yoke pressure, he is only holding the pitch at the commanded pitch attitude by the flight director , seen in his adi. Not more not less degrees of pitch . Just what is needed to maintain a certain speed set at the mcdu with a given power setting , set at power management selector.
As far as the training and type rating licensing , MAX is a common type with all 737's . It is good for the airlines not to train and pay extra money for pilot's licenses and type ratings.
Common type rating is an old story conceived by AIRBUS. Back at 1980 or some when during that era.
Boeing had to follow .
My 2c.
With all due respect, this doesn't fit generally accepted expert opinion on the case, and seems like a rather desperate attempt to blaim Airbus.

Airbus introduced the 320neo (320 with larger engines = higher bypass, more fuel efficient) with same type rating as the old 320. This is attractive to airlines because pilots don't need to get new certification for the new plane and you can use all your 320 rated pilots right away. Smart move airbus.

Boeing could not do the same because the 737 is lower than the 320, not leaving enough space to fit a bigger engine. They fixed this by placing the engine in a weird position, creating torque that could lead to a new pitch up behaviour. They fixed this in the MCAS by applying an opposite nose down, but they didn't want to tell pilots about this new behaviour because it would mean not sharing type rating with previous 737. The sales department did not like that idea. If they had told the pilots, the fix would be fine. But they didn't.

Thus pilots were confused when confronted with this new nose down behaviour due to failed angle of attack sensors.

Boeing knew what they were doing but they were desperate not to lose market share to Airbus. People died because of it.
 

orangejello

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With all due respect, this doesn't fit generally accepted expert opinion on the case, and seems like a rather desperate attempt to blaim Airbus.

Airbus introduced the 320neo (320 with larger engines = higher bypass, more fuel efficient) with same type rating as the old 320. This is attractive to airlines because pilots don't need to get new certification for the new plane and you can use all your 320 rated pilots right away. Smart move airbus.

Boeing could not do the same because the 737 is lower than the 320, not leaving enough space to fit a bigger engine. They fixed this by placing the engine in a weird position, creating torque that could lead to a new pitch up behaviour. They fixed this in the MCAS by applying an opposite nose down, but they didn't want to tell pilots about this new behaviour because it would mean not sharing type rating with previous 737. The sales department did not like that idea. If they had told the pilots, the fix would be fine. But they didn't.

Thus pilots were confused when confronted with this new nose down behaviour due to failed angle of attack sensors.

Boeing knew what they were doing but they were desperate not to lose market share to Airbus. People died because of it.
From what I have read about this I think your summation is spot on. And I don’t think it is anymore complicated than this. Boeing made decision that cost people their lives in order to save money and stay competitive.
 

jomark911

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@Timon VDB , obviously you are not an aviation professional.
Nobody accused airbus on the common type ratings. All plane manufacturers are the same , years now.
As far as low height and high height airplanes , it is completely irrelevant what you say.
airbus A320, A321 , A330 , AND A340 they are common type airplanes with only a differences school and a couple of simulator sessions required to get the rating in a pilots license.
Pilots don't get confused so easily as you think . They know and follow specific routines and procedures when they hand fly the airplanes.
Everything you write is completely wrong.
 

blueone

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@Timon VDB , obviously you are not an aviation professional.
Nobody accused airbus on the common type ratings. All plane manufacturers are the same , years now.
As far as low height and high height airplanes , it is completely irrelevant what you say.
airbus A320, A321 , A330 , AND A340 they are common type airplanes with only a differences school and a couple of simulator sessions required to get the rating in a pilots license.
Pilots don't get confused so easily as you think . They know and follow specific routines and procedures when they hand fly the airplanes.
Everything you write is completely wrong.

You are very assertive and accusatory, but to be honest your assertions don't persuade. You haven't provided any evidence beyond your opinions that what I've read in various publications over the last two years or concluded about their information is incorrect.
 

jomark911

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While trying to clear some things out as an airline pilot you find my opinions what?
Assertive? hell yeah. It's what I do the last 30 years.
I've given an insight knowledge and you find it assertive and accusatory.
Well ok , this is your opinion also .
BUT Airplanes don't fly by opinions . They've being flown by procedures and techniques unknown to you or anybody else that is not a airline pilot.
I really don't give a f---k of what some articles or publications may say , just to sell some papers , and supposedly brief people of what is going wrong with the aviation business.
 

SoundAndMotion

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While trying to clear some things out as an airline pilot you find my opinions what?
Assertive? hell yeah. It's what I do the last 30 years.
You may well happen to be the nicest, most knowledgeable and competent pilot I've ever encountered, but your posts here don't reflect that. As an ATP, you certainly could offer some insights and correct some misconceptions, but instead you offer opinions and attempt to back them up with appeals to your own authority. ...usually a sign of weakness, in my experience.
BUT Airplanes don't fly by opinions .
That's right, including yours.
They've being flown by procedures and techniques unknown to you or anybody else that is not a airline pilot.
Hmmm... is there a secret ATP society where you learn them, but promise not to divulge them? Stuff that's not in the manufacturer's FCOM or FCTM? Where I worked for a few years, we had the NG Flight Crew Training Manuals and the Flight Crew Operating Manuals direct from Boeing, even though none of us had ATPLs (but 4 of us had PPLs). Are you saying there are procedures and techniques that are not in those? I'm impressed by your society's ability to keep it all secret.
I really don't give a f---k of what ...[snip]... may say ,
I hope you have multiple personalities, and this is not the one you take into the cockpit. Otherwise, your appeals to self-authority and disregard for differing views would be a huge CRM red flag, and I feel sorry for any first officer stuck with you (assuming you're a captain).

(For non-pilots: ATP-airline transport pilot, ATPL-ATP license, PPL-private pilot license, CRM-crew resource management, a hot, newish (< 40 years) area in aviation safety that basically finds teamwork safer than a hierarchy in the cockpit)
 
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