The [Current Year] General Political/Salma Hayek discussion thread, part 4!!!

[KLB]

This could end up being worse than the Takata airbag fiasco.

 

[nonobaddog]

Boeing offered a "AOA Disagree" warning system as an option on the 737 Max planes. This makes a warning available to the pilot that the inputs for the AOA do not agree with each other. It was also offered on the predecessor 737 NA planes that did not have MCAS.

American Airlines, Southwest Airlines, Westjet(Canada), Silkair(Singapore) and Flydubai(Dubai) all had the 'AOA Disagree' system installed on their 737 Max planes.

American Airlines alone flies about 30,000 flights per year using the 737 Max planes. (no crashes)

 

[T.Lex]

Boeing offered a "AOA Disagree" warning system as an option on the 737 Max planes. This makes a warning available to the pilot that the inputs for the AOA do not agree with each other. It was also offered on the predecessor 737 NA planes that did not have MCAS.

American Airlines, Southwest Airlines, Westjet(Canada), Silkair(Singapore) and Flydubai(Dubai) all had the 'AOA Disagree' system installed on their 737 Max planes.

So Boeing offered an option that made it more likely the pilots would be unable to recognize when the plane's software was going to induce catastrophic pitch changes, and another option that made it more likely the pilots would be able recognize that problem.

Awesome.

 

[nonobaddog]

So Boeing offered an option that made it more likely the pilots would be unable to recognize when the plane's software was going to induce catastrophic pitch changes, and another option that made it more likely the pilots would be able recognize that problem.

Awesome.

Look at it anyway you like. The AOA readings for both sensors are always available for the pilot to read. The option just called attention to the case where they disagree with each other.

 

[T.Lex]

Look at it anyway you like. The AOA readings for both sensors are always available for the pilot to read. The option just called attention to the case where they disagree with each other.

The bad sensor is only part of the problem. The software doesn't know it is bad data, but makes flight control changes. Potentially significant ones. Even if the pilot can see the AOA is wrong, by comparing it with the visible world, he or she is now fighting the aircraft itself for control.

 

[nonobaddog]

The bad sensor is only part of the problem. The software doesn't know it is bad data, but makes flight control changes. Potentially significant ones. Even if the pilot can see the AOA is wrong, by comparing it with the visible world, he or she is now fighting the aircraft itself for control.

In that case the pilot should be trained to turn off MCAS - that is what I already said about the insufficient documentation and/or insufficient training. Could be Boeing's fault for a bad decision re documentation or the airline's fault in training levels or maintenance levels.

 

[T.Lex]

In that case the pilot should be trained to turn off MCAS - that is what I already said about the insufficient documentation and/or insufficient training. Could be Boeing's fault for a bad decision re documentation or the airline's fault in training levels or maintenance levels.

Some good information here:
https://www.theatlantic.com/notes/2...ecord-about-problems-with-the-737-max/584791/

The ASRS dataset is fascinating to search through. But, it is a .gov administered site. The query function was cutting edge in 1998.

 

[printcraft]

Airbus, Boeing's main competitor, is a consortium of contractors based in western europe. Coincidently many of those same countries rushed to ground the MAX8

Airbus has infiltrated the maintenance crews of the MAX8 and is having them install intentionally faulty components to cause the "errors".

 

[BugI02]

The bad sensor is only part of the problem. The software doesn't know it is bad data, but makes flight control changes. Potentially significant ones. Even if the pilot can see the AOA is wrong, by comparing it with the visible world, he or she is now fighting the aircraft itself for control.

You really need to do some research on pilot/autopilot mode confusion and how long it's been a thing. Aviation Week did IMO the definitive articles on it in two consecutive issues in 1994 I believe

Just as an example, there is an airbus case where an A320 is turned to intercept the ILS at Narita (IIRC) high and hot. The pilot selects 'Flaps 3' but is in a slight overspeed condition for that setting. The FMS begins trimming the horizontal stabilizer for nose up to slow the aircraft into the allowable speed range for the selected flap setting, It does not ask for permission or pilot input or enunciate what it is doing. Meanwhile, the flight crew is concerned about getting down to an altitude where they can capture the ILS signal and complete the approach, the pilot reacts to the airplane not responding to nose down input in the way he expected by increasing the amount of nose down commanded. The process repeats with the a/c FMS taking action to achieve its purpose and the pilot inputting greater amounts of control actuation to achieve his desired results. The pilot eventually concludes they have unreported windshear and he cannot make the approach so he initiates a go-around. By this point the horizontal is trimmed to almost full nose up; when the engine power comes on the a/c pitches up strongly, enters stall buffet and is recovered and repeats this cycle once more before the crew fully recovers it. There is no crash, but had they been lower to start with there likely would have been.

There is software aloft doing what it thinks best all the time, especially in full fly by wire aircraft.

 

[BugI02]

Some good information here:
https://www.theatlantic.com/notes/2...ecord-about-problems-with-the-737-max/584791/

The ASRS dataset is fascinating to search through. But, it is a .gov administered site. The query function was cutting edge in 1998.

From your cite:

In all airplanes I know of, the recovery is—including the 737 MAX—to shut off the system using buttons on the control wheel then a switch, or sometimes circuit breaker to make a positive disconnect.


Though the pitch system in the MAX is somewhat new, the pilot actions after a failure are exactly the same as would be for a runaway trim in any 737 built since the 1960s. As pilots we really don’t need to know why the trim is running away, but we must know, and practice, how to disable it.

 

[nonobaddog]

Airbus uses AOA sensors and controlling software similar to MCAS. They have also had AOA sensor problems and crashes.


Shem Malmquist, a Boeing 777 captain and a visiting professor at the Florida Institute of Technology, said "Most commercial pilots today know how to respond to a malfunctioning sensor."

Apparently some don't too.

 

[T.Lex]

Airbus uses AOA sensors and controlling software similar to MCAS. They have also had AOA sensor problems and crashes.

I'm familiar with the issue of having 2 of the 3 sensors give the "wrong" but consistent data to the flight control computer, but that was awhile ago. Is there something more recent? More for curiosity than anything else, has there been something recently in this area?

If we're allocating blame, then the over-reliance on digital devices is part of the modern human condition. We're more likely to believe the GPS and let it take us into the desert.

 

[nonobaddog]

Even the Wright Brothers had a crude AOA sensor on their plane.

 

[T.Lex]

Even the Wright Brothers had a crude AOA sensor on their plane.

??? Of course. The issue isn't whether planes have them.

Heck, phones have them now.

 

[nonobaddog]

??? Of course. The issue isn't whether planes have them.

Heck, phones have them now.

The point is AOA sensors have been around a long, long time. All sensors have been failing for a long, long time. A pilot is supposed to know how to fly a plane. If there is software control he should know how to shut it off and override it.

Now that self driving cars are happening - I would not be driving one if I didn't know how to take manual control and override it when it tried to take a dive in the ocean. I would expect the same of a commercial pilot - only more so.

 

[ghitch75]

Even the Wright Brothers had a crude AOA sensor on their plane.

there ass.....

 

[nonobaddog]

there ass.....

No, they didn't bring any democrats on the flights.

 

[DoggyDaddy]

there ass.....

Where ass?

 

[actaeon277]

I work on instrumentation and control systems.
Instrument failure has always been a problem for humans, and even more of a problem for automation systems.
This is nothing new.

So, to fix things, you make them more complicated.
But more complicated means you are introducing even more failure points.

 

[KLB]

I'm familiar with the issue of having 2 of the 3 sensors give the "wrong" but consistent data to the flight control computer, but that was awhile ago. Is there something more recent? More for curiosity than anything else, has there been something recently in this area?

If we're allocating blame, then the over-reliance on digital devices is part of the modern human condition. We're more likely to believe the GPS and let it take us into the desert.

Or onto a closed highway and off of a bridge that was demolished.