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737-Max 8 safety concerns

Old Jul 20, 2019, 7:49 pm

737-Max 8 safety concerns

Old Apr 8, 2019, 11:40 pm
  #196  
 
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Originally Posted by MSPeconomist
He might be the lone 737 pilot here too. I suspect that pilots rarely blame other pilots unless the other pilot deserves the blame.
ALPA does have a history of supporting self-serving ideas like inexperience caused the Colgan crash, thus the 1500 hour rule in the US. Pointing the blame at a young captain (29 years old) and brand new FO (c.200 hours) is in line with that view - although ab initio programmes put pilots safely into cockpits in the ROW with that experience (and into the USAF/ USN cockpits in the US) Actually, a properly structured ab inititio training programme, with strict entry and wash out criteria, such as BA/ LH/ USAF run, will likely produce better pilots than self financing pilots working their wy up an unstructured process of trying to build hours whereever they can - where as long as they can pay for hours, no-one will wash them out.

There's the romantic view that flying bugsmashers around for a few hundred hours on a wide range of aircraft allows people to 'see the elephant' and do 'real flying' before they get into a real plane - but I am not sure of any real evidence that that is better than an airline internal apprentice system
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Old Apr 9, 2019, 12:07 am
  #197  
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Originally Posted by peasant
... As to the 'blame the pilots' - they were certified & trained as per Boeing/ ICAO standards, and in both cases, sure, someone absolutely on the ball, and aware of all the issues, making the right decisions could have saved the aircraft. But Sully failed as well from that POV (pilots in the simulator could land his aircraft safely back, rather than ditching) ...
on the first 20 or so simulator runs, the pilots knew what to expect, and therefore began the emergency procedures immediately ... Capt Sullenberger and the First Officer reminded the investigators that they had had to react to the bird impact, interpret the instrument indications, and determine a course of action before beginning the emergency procedures ... that 30-40 seconds made the difference between a return to LGA (or a safe landing at another airport) and ditching

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Old Apr 20, 2019, 8:32 pm
  #198  
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I work in IT myself and find this article very interesting:

How the Boeing 737 Max Disaster Looks to a Software Developer - IEEE Spectrum
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Old Apr 21, 2019, 8:59 pm
  #199  
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This part of the article published in IEEE Spectrum's site (not their official view) is pretty much my viewpoint

Finally, the software relied on systems known for their propensity to fail (angle-of-attack indicators) and did not appear to include even rudimentary provisions to cross-check the outputs of the angle-of-attack sensor against other sensors, or even the other angle-of-attack sensor. Big strike No. 3.

...

Another difference is between the autopilots in my system and that in the 737 Max. All of the CAN businterconnected components constantly do the kind of instrument cross-check that human pilots do and that, apparently, the MCAS system in the 737 Max does not.
(bolding mine)

MCAS software design violates the fundamental principles of quality automated monitoring/response software.

If there were two separate flight computers each with access to (in theory) identical sensor data, then a basic principle says that MCAS should NOT be permitted to take any action without agreement between both computers. Boeing didn't include that basic precaution.

That's why I think Boeing bears the primary responsibility for 350+ people being dead.
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Old Apr 25, 2019, 3:34 pm
  #200  
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Originally Posted by Plato90s
That's why I think Boeing bears the primary responsibility for 350+ people being dead.
Exactly! Boeing had responsibility for 350 people who being killed. That's big problem.
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Old Apr 28, 2019, 1:51 pm
  #201  
 
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https://www.businessinsider.com/boei...ussions-2019-4

Southwest Airlines and the Federal Aviation Administration (FAA) officials who monitor the carrier were unaware that a standard safety feature, designed to warn pilots about malfunctioning sensors, on Boeing 737 Max jets was turned off when Southwest began flying the model in 2017, reported Andy Pastzor of the Wall Street Journal.

In earlier 737 models, the safety feature alerted pilots when a sensor called the "angle-of-attack vane" incorrectly conveyed the pitch of the plane's nose, according to Pastzor. In the Max, it functions as such while also signaling when the Maneuvering Characteristics Augmentation System (MCAS) — a new automated system linked to both October's Lion Air crash and March's Ethiopian Airlines crash — could misfire; but these alerts were only enabled if carriers purchased additional safety features, Pastzor wrote.
Twice there were discussions within the FAA about grounding the WN fleet and requiring additional MAX training, in connection with this feature.
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Old Apr 29, 2019, 12:06 pm
  #202  
 
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I have not read the whole thread but this article should be of interest:

https://spectrum.ieee.org/aerospace/...ware-developer
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Old Apr 30, 2019, 2:10 am
  #203  
 
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Boeing Co. on Monday said certain safety alerts on its 737 MAX jets didn’t operate as airlines would have anticipated because of a previously undisclosed error on its part.
https://www.wsj.com/articles/boeing-...rs-11556592646
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Old May 1, 2019, 6:23 am
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Boeing relied on single sensor for 737 Max that had been flagged 216 times to FAA

In addition to not including inputs from two AOA sensors in its original design, Boeing did not flight test AOA sensor malfunctions and how MCAS software would respond, according to several sources.

A former Boeing pilot who tested the 737 Max, who requested anonymity due to fears of negative repercussions, told CNN "I don't think we appreciated the ramifications of a... failure of an AOA probe."

Another source familiar with the 737 MAX testing said the failure of an AOA sensor was not flight tested, but rather "analyzed in the design and certification" of the aircraft, and it was determined trained pilots would have been able to handle the failure.

A second former Boeing test pilot was surprised to learn that the company had relied on a single sensor, as opposed to a redundant system, to perform such a vital function in the first place. "I would be very curious to know what their logic was on that...and what drove them to think that was a suitable solution," said the pilot, who also spoke on the condition of anonymity.
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Old May 1, 2019, 9:39 pm
  #205  
 
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Originally Posted by serfty
I work in IT myself and find this article very interesting:

How the Boeing 737 Max Disaster Looks to a Software Developer - IEEE Spectrum
Originally Posted by FlyingUnderTheRadar
I have not read the whole thread but this article should be of interest:

https://spectrum.ieee.org/aerospace/...ware-developer
So apparently flying a 757 simulator and being a private pilot makes one an airplane design expert.
The piece is full of misleading comments and some downright errors. The guy's credibility is blown with such idiotic comments as implying the airplane is "dynamically unstable"; that AOA and pitch are the same thing; etc. etc. Plus implying that the DER concept is some recent innovation based upon bad intentions (it's been around since the 1940's, and I don't think FAA EVER had "armies of engineers").

True, there appear to be serious shortcomings and downright failures at Boeing in how MCAS was designed, implemented, and in the related risk assessments. But opinion pieces like this by so-called "experts" don't help the cause in investigating and fixing such failures.

Here's a link to an article that corrects many of the IEEE "article's" errors:
https://abnormaldistribution.org/ind...liner-crashes/
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Old May 2, 2019, 6:33 am
  #206  
 
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Looks like the first of what will likely be several Congressional hearings is happening in a couple of weeks:

https://www.reuters.com/article/us-e...-idUSKCN1S74MO

The U.S. House Transportation and Infrastructure Committee will hold a May 15 hearing on the grounded Boeing 737 MAX and the Federal Aviation Administrations (FAA) aircraft certification program, three people briefed on the matter said on Wednesday.
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Old May 2, 2019, 8:24 am
  #207  
 
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Originally Posted by Maxwell Smart
Here's a link to an article that corrects many of the IEEE "article's" errors:
https://abnormaldistribution.org/ind...liner-crashes/
Good article. Thanks for the link!
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Old May 2, 2019, 2:50 pm
  #208  
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Originally Posted by Maxwell Smart
...

True, there appear to be serious shortcomings and downright failures at Boeing in how MCAS was designed, implemented, and in the related risk assessments. But opinion pieces like this by so-called "experts" don't help the cause in investigating and fixing such failures.

Here's a link to an article that corrects many of the IEEE "article's" errors:
https://abnormaldistribution.org/ind...liner-crashes/
The issue is not any general instability inherent with the way the aircraft was designed.

However, within the normal flight envelope there were occasionally certain situations occurring that would have the aircraft handle in variance with the behavior with other 737 models in the same situations.

If pilots were specifically trained on how to handle the MAX8 in those situation (with simulator time, lists etc.) then there would be less likely to be an issue.

But by doing that, it almost certainly would have required a new type certificate for pilots.

The manufacturer wished to avoid this since for revenue/expediency reasons.

To avoid this, they came up with software to make the plane emulate how, say, a 737NG would handle in those situations and it would function in such a manner so that aircrew would be oblivious to its operation.

And then, they basically did not tell the pilots about it.

Down the track, it appears the software has flaws that had it crash two aircraft.

Yes, the IEEE article has levels of hyperbowl, but the rebuttal posted does not change the above.
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Old May 3, 2019, 3:11 am
  #209  
 
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The key error seems to be in Boeing's definition of its real corporate values:
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Old May 3, 2019, 4:03 pm
  #210  
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Much of this is already known but it does place many relevant facts together:

The many human errors that brought down the Boeing 737 Max - The Verge
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Last edited by serfty; May 3, 2019 at 4:09 pm
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