Could the airmen do anything to save the Boeing 737 Max

[PeterBushMan]

1) Can they stop the computer to fly the aircraft, ant they just fly the aircraft by a living person?

 

2) Can they turn off MCAS, that rubbish device forced the aircraft flies head to the ground?

 

3) Can they just  stop try to pull back the control stick, they just stop to fight with the machine, the computer may fix its own mistake, anyway the chance should be very little.

[Sensei]

On 7/1/2024 at 6:15 AM, PeterBushMan said:

2) Can they turn off MCAS, that rubbish device forced the aircraft flies head to the ground?

It is not a "rubbish device." It is used to keep an aircraft in flight in rare situations with overweight, oversized and over-powered engines. Which malfunctions under rare conditions in which pilots must take control of the entire aircraft. But they were not taught about the existence of this device, so they could not react properly at the crucial moment, so people died.

They had just a few seconds to figure out what is happening, and act accordingly.

On 7/1/2024 at 6:15 AM, PeterBushMan said:

3) Can they just  stop try to pull back the control stick, they just stop to fight with the machine, the computer may fix its own mistake, anyway the chance should be very little.

The autopilot takes data from sensors. Just like a human. If the sensor malfunctions, and the weather is bad, such as nighttime, with no external light sources such as stars, sun, city lights, the understanding of the situation (position, altitude, aircraft rotation) is disrupted, both for the human and the computer. Hence the disasters.

On 7/1/2024 at 6:15 AM, PeterBushMan said:

3) Can they just  stop try to pull back the control stick,

Pulling back the stick when you don't have lift is a recipe for disaster. You need the correct data from sensors or daylight to know if you have no lift force. Many disasters have happened simply because pilots thought "pulling back the stick" was a good idea in their situation. Understanding the situation is most important. Therefore, sensor redundancy to be able to determine which sensor is malfunctioning. One sensor may be malfunctioning, two sensors give different results, one gives bad results and the other gives good results, which one is correct? Three sensors, one is defective, two are unlikely to.. at the same time (unless they share the same wires/computers, etc.).

[ImplicitDemands]

I don't think we really understand some of the technology we have in our possession. And we get mistakes like this. 

[Phi for All]

20 minutes ago, ImplicitDemands said:

I don't think we really understand some of the technology we have in our possession. And we get mistakes like this. 

At some point, the cost of the disasters should outweigh the cost of the training that's being neglected. For some reason, in the last few decades, training employees correctly has become a bad practice. Too many employers don't want to spend the resources up front because the employee MIGHT leave for a better job after training.

[MigL]

The 737 MAX is a third generation 737.
The 1st generation used low bypass engines, but the new fuel efficient high bypass engines of the MAX require much more space under the wing than is available.
Boeing solution necessitated a very short engine pylon, such that the engines are not underslung, but almost level with the wing surface.
This generates the very dangerous situation of 'pitch up', which can cause wing stall, and the plane just drops out of the sky because of no lift.

To remedy the situation Boeing came up with the MCAS system, which forces the nose of the aircraft down when it detects this pitch up moment through twin pitot tubes.
This system overrides the control stick inputs from the pilot.

What happened in the 737 MAX incidents is faulty data from the pitot tubes activated the system, and the pilots could not pull the nose up and avoid crashing into the ground.
There is a switch to turn off the MCAS system but none of the pilots were trained in this.

I'm not sure what Boeing has done to remedy the situation after the 737 MAX grounding and investigation.
Either the system has been modified, orbetter pilot training has been introduced.

More and more planes are being designed to be unstable in flight, to take advantage of the efficiencies of better aerodynamics, and only the flight computers make them controllable. I remember an interview with one of the designers of the flight control system of the  Eurofighter Typhoon where he states that flying the plane manually would be like'holding a bike backwards, by the handlebars, while sitting on the hood of a car moving at 100 m/hr, and trying to keep it going straight'.

That being said, I have flown in a 737 MAX, and would do so again; it is still safer than riding in a bus.

 

3 minutes ago, Phi for All said:

training employees correctly has become a bad practice

But we train would be terrorists well enough to hit buildings.

[Phi for All]

32 minutes ago, MigL said:

But we train would be terrorists well enough to hit buildings.

Terrorists are usually state funded. Prophets over profits.

[swansont]

58 minutes ago, Phi for All said:

At some point, the cost of the disasters should outweigh the cost of the training that's being neglected. For some reason, in the last few decades, training employees correctly has become a bad practice. Too many employers don't want to spend the resources up front because the employee MIGHT leave for a better job after training.

I think various things with Boeing have pointed out that a lack of independent oversight is not a wise path to take regarding safety. We see it in other industries but the damage there is not quite as spectacular (e.g. banking failures ruin lives, too, but not quite as dramatically)

[ImplicitDemands]

3 hours ago, Phi for All said:

At some point, the cost of the disasters should outweigh the cost of the training that's being neglected. For some reason, in the last few decades, training employees correctly has become a bad practice. Too many employers don't want to spend the resources up front because the employee MIGHT leave for a better job after training.

No I'm saying the technology itself is reverse engineered and misunderstood. There's no-one to train anyone if no-one really knows computers. 

2 hours ago, Phi for All said:

Terrorists are usually state funded. Prophets over profits.

I've heard it was a computer program, not a terrorist group. "Zeitgeist addendum" was where I heard that. 

Edited July 1 by ImplicitDemands

[exchemist]

3 hours ago, MigL said:

The 737 MAX is a third generation 737.
The 1st generation used low bypass engines, but the new fuel efficient high bypass engines of the MAX require much more space under the wing than is available.
Boeing solution necessitated a very short engine pylon, such that the engines are not underslung, but almost level with the wing surface.
This generates the very dangerous situation of 'pitch up', which can cause wing stall, and the plane just drops out of the sky because of no lift.

To remedy the situation Boeing came up with the MCAS system, which forces the nose of the aircraft down when it detects this pitch up moment through twin pitot tubes.
This system overrides the control stick inputs from the pilot.

What happened in the 737 MAX incidents is faulty data from the pitot tubes activated the system, and the pilots could not pull the nose up and avoid crashing into the ground.
There is a switch to turn off the MCAS system but none of the pilots were trained in this.

I'm not sure what Boeing has done to remedy the situation after the 737 MAX grounding and investigation.
Either the system has been modified, orbetter pilot training has been introduced.

More and more planes are being designed to be unstable in flight, to take advantage of the efficiencies of better aerodynamics, and only the flight computers make them controllable. I remember an interview with one of the designers of the flight control system of the  Eurofighter Typhoon where he states that flying the plane manually would be like'holding a bike backwards, by the handlebars, while sitting on the hood of a car moving at 100 m/hr, and trying to keep it going straight'.

That being said, I have flown in a 737 MAX, and would do so again; it is still safer than riding in a bus.

 

But we train would be terrorists well enough to hit buildings.

How does this work? I'd have thought that the longer the engine pylon, i.e. the further below the centre of gravity (or rather, drag, I suppose) of the plane, the bigger would be the upward pitching turning effect, when the engines throttle up. So surely a shorter pylon, bringing the line of engine thrust closer to the centre of drag, would reduce this, wouldn't it?  

[MigL]

1 hour ago, exchemist said:

I'd have thought that the longer the engine pylon, i.e. the further below the centre of gravity

The pitch up is not a result of the thrust vector rotating the aircraft about its CoG, rather it is due to the aerodynamic interaction of the engine nacelle being too close to the active wing surfaces. If you ever see a photo of a second generation 737, you'll notice the underside of the fan cowling on the engine nacelle is 'flattened' so as to enable ground clearance. On the third generation, with an even larger bypass turbofan and cowling, that wasn't possible, so Boeing raised the nacelles such that the engine pylon is almost non-existent, and affects airflow on the wing to a much greater degree.
At least from what I've read after the incidents.

[exchemist]

44 minutes ago, MigL said:

The pitch up is not a result of the thrust vector rotating the aircraft about its CoG, rather it is due to the aerodynamic interaction of the engine nacelle being too close to the active wing surfaces. If you ever see a photo of a second generation 737, you'll notice the underside of the fan cowling on the engine nacelle is 'flattened' so as to enable ground clearance. On the third generation, with an even larger bypass turbofan and cowling, that wasn't possible, so Boeing raised the nacelles such that the engine pylon is almost non-existent, and affects airflow on the wing to a much greater degree.
At least from what I've read after the incidents.

Thanks, very clear explanation.

[ImplicitDemands]

Person problem, or technical problem? I don't think anyone in this thread has the expertise to answer that. 

[exchemist]

59 minutes ago, ImplicitDemands said:

Person problem, or technical problem? I don't think anyone in this thread has the expertise to answer that. 

All we need do is read the press to understand what happened. It was extensively reported. @Sensei's post, the 2nd in this thread, summarises it. Essentially it was a failure by the manufacturer to disclose information about an automated system that had been fitted. In effect, flight crew were -deliberately - not fully informed about the systems employed on the aircraft they were flying. This was done to avoid the cost and inconvenience of further training, but meant that when there was a malfunction in this "hidden" system, the crew were not equipped to take the right decisions.  

An appalling result of the way Boeing had come to prioritise financial performance over safety. This cultural failure has also been extensively reported in the press (at least in the Financial Times, which I read) and has quite rightly led to a change of top personnel at the company. It also revealed an unduly close relationship between Boeing and the US regulator for aircraft safety, a state of affairs known as "regulatory capture". There have been many examples of such "capture", across various industries around the world, and it practically always ends in disaster. Business people often resent what they see as bureaucratic "box-ticking" by inspection and supervisory regimes, and lobby politicians to slacken the oversight. It goes fine....until it doesn't, and then it's pointy finger time.  

Edited July 1 by exchemist

[ImplicitDemands]

6 hours ago, exchemist said:

There have been many examples of such "capture", across various industries around the world, and it practically always ends in disaster. Business people often resent what they see as bureaucratic "box-ticking" by inspection and supervisory regimes, and lobby politicians to slacken the oversight. It goes fine....until it doesn't, and then it's pointy finger time.  

You use the word "malfunction". Can we prove that someone, like the manufacturer, or the inspector, or those in charge of training the pilots, didn't do there job?

Malfunctions are common in computer programs. I was originally in software CS before I switched to an electronic and mechanical major and the reason was most computer programs are limited to their hardware, and even the hardware depends upon the engineering makeup so I figured I could try and understand how code becomes a whole mechanical/robotic movement among everything else. I have some ideas on this, a universal blueprint that can be used for any app, robotic command, or input you can think of. 

[exchemist]

1 hour ago, ImplicitDemands said:

You use the word "malfunction". Can we prove that someone, like the manufacturer, or the inspector, or those in charge of training the pilots, didn't do there job?

Malfunctions are common in computer programs. I was originally in software CS before I switched to an electronic and mechanical major and the reason was most computer programs are limited to their hardware, and even the hardware depends upon the engineering makeup so I figured I could try and understand how code becomes a whole mechanical/robotic movement among everything else. I have some ideas on this, a universal blueprint that can be used for any app, robotic command, or input you can think of. 

The MCAS malfunction  is not the main point in this case, though steps were taken after the crashes to make a malfunction less likely. The main issue  of culpability is as I explained to you in my previous post.

[Eise]

15 hours ago, ImplicitDemands said:

Person problem, or technical problem? I don't think anyone in this thread has the expertise to answer that. 

Person, definitely: the management of Boeing.