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Old 09-16-2020, 06:52 AM   #1  
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Default Boeing 737 MAX Investigation

Final Committee Report Materials

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Old 10-12-2020, 02:57 AM   #2  
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Default Sully Says MAX Needs More Fixes

https://www.avweb.com/aviation-news/...ds-more-fixes/

Flight 1549 Capt. Chesley Sullenberger says he’ll fly on the recertified Boeing 737 MAX but he wants to see improvements to the aircraft and its ancestors for flaws laid bare in the investigation of the MAX flight control system. “People are going to fly on it and I will probably be one of them,” he told the Seattle Times. “I’m going to keep on pushing for future improvements to this airplane even if it flies in the meantime,” he said.


The FAA is likely weeks away from clearing the MAX for revenue service after Boeing spent the last year rewriting a major portion of the flight control software to change the way the Maneuvering Characteristics Augmentation System (MCAS) behaves. Bad data from single-source angle of attack indicators on a Lion Air MAX and an Ethiopian Airlines MAX started a catastrophic chain of events that led to both aircraft entering high-speed dives that killed a total of 346 people in late 2018 and early 2019. Sullenberger says the MCAS fix is fine but the process of achieving it showed the MAX and its predecessor, the NG series, need upgrades in other systems.

Part of the MCAS revision was making it require agreement from both angle of attack indicators. Sullenberger agrees with the European Aviation Safety Agency (EASA) that there should be a third AOA and not necessarily a conventional aerodynamic type. Boeing 787s have a digital AOA that calculates attitude based on various sensor inputs and it acts as a check on the other two so pilots know which of those is acting up. Boeing considered adding the digital AOA to the MAX but it was rejected because of the cost.

Sullenberger also says something must be done about the cacophony of alarms and flashing lights that assault pilots when something goes wrong with the MAX. He said the noise and resulting confusion in the Lion Air and Ethiopian cockpits likely played a role in the outcome as they tried to isolate the source of the problems. “It was clear to me how the accident crews could have run out of time and altitude,” he said. He said he also agrees with Transport Canada that there should be a switch to turn off the stick shaker when pilots are sure it was triggered erroneously. With the flaws now revealed, Sullenberger says the FAA and Boeing have a duty to address them and not just leave it at the MCAS fix. “I’m not going to say, ‘We’re done, good enough, move on,'” said Sullenberger.
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Old 10-12-2020, 07:15 PM   #3  
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For something as critical as MCAS, I never could figure out why it was not mandatory to have both AOA sensors installed and both in agreement, called 2oo2 voting. If instruments don’t agree, kick it to the pilots to fly the plane. Give them the sensor disagreements and let skilled, experienced humans make the decision. Seems too obvious to me. Maybe Monday morning quarterbacking, but...
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Old 10-12-2020, 09:33 PM   #4  
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Quote:
Originally Posted by takingmessages View Post
https://www.avweb.com/aviation-news/...ds-more-fixes/

Flight 1549 Capt. Chesley Sullenberger says he’ll fly on the recertified Boeing 737 MAX but he wants to see improvements to the aircraft and its ancestors for flaws laid bare in the investigation of the MAX flight control system. “People are going to fly on it and I will probably be one of them,” he told the Seattle Times. “I’m going to keep on pushing for future improvements to this airplane even if it flies in the meantime,” he said.


The FAA is likely weeks away from clearing the MAX for revenue service after Boeing spent the last year rewriting a major portion of the flight control software to change the way the Maneuvering Characteristics Augmentation System (MCAS) behaves. Bad data from single-source angle of attack indicators on a Lion Air MAX and an Ethiopian Airlines MAX started a catastrophic chain of events that led to both aircraft entering high-speed dives that killed a total of 346 people in late 2018 and early 2019. Sullenberger says the MCAS fix is fine but the process of achieving it showed the MAX and its predecessor, the NG series, need upgrades in other systems.

Part of the MCAS revision was making it require agreement from both angle of attack indicators. Sullenberger agrees with the European Aviation Safety Agency (EASA) that there should be a third AOA and not necessarily a conventional aerodynamic type. Boeing 787s have a digital AOA that calculates attitude based on various sensor inputs and it acts as a check on the other two so pilots know which of those is acting up. Boeing considered adding the digital AOA to the MAX but it was rejected because of the cost.

Sullenberger also says something must be done about the cacophony of alarms and flashing lights that assault pilots when something goes wrong with the MAX. He said the noise and resulting confusion in the Lion Air and Ethiopian cockpits likely played a role in the outcome as they tried to isolate the source of the problems. “It was clear to me how the accident crews could have run out of time and altitude,” he said. He said he also agrees with Transport Canada that there should be a switch to turn off the stick shaker when pilots are sure it was triggered erroneously. With the flaws now revealed, Sullenberger says the FAA and Boeing have a duty to address them and not just leave it at the MCAS fix. “I’m not going to say, ‘We’re done, good enough, move on,'” said Sullenberger.
There was a fascinating article I read last year about using an artificial airspeed indicator to provide a backup, similar to the artificial AOA. It found that the margin of error estimating airspeed from GPS/FMS speed after having input the winds-aloft data was very small, I don't remember if it was 5%, but 5-10% and generally enough to safely fly the airplane in any condition. This was more directed towards the air-france accident and a few others, where people thought they were stalling when they started getting erroneous airspeed readings, but same general idea. The real interesting part was the error was not nearly as big as one might think.
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Old 10-13-2020, 07:58 AM   #5  
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From what I read in the report, The OEM floated the idea of synthetic airspeed for the Max but realized quickly that due to “new & novel” language in Part 25 Cert rules, this would delay the cert and jeopardize their plan of “minimal training differences (Level B) between NG and Max.

The ADIRUs provide HDG/Groundspeed display to the ISDU on the overhead. Not stated in the NNC for Unreliable Airspeed explicitly, but this could be useful information if the pilots know where to find it and how it is determined.
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Old 10-13-2020, 08:22 AM   #6  
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Quote:
Originally Posted by PerfInit View Post
From what I read in the report, The OEM floated the idea of synthetic airspeed for the Max but realized quickly that due to “new & novel” language in Part 25 Cert rules, this would delay the cert and jeopardize their plan of “minimal training differences (Level B) between NG and Max.
Lessons learned the hard way drive stringent regulation and oversight bureaucracy in aviation... the flip side of that is that it naturally slows technical progress. The only reason we're getting new alternatives to our ASEL motors designed in the 1940's is because of leaded gas and environmental pressure.

Quote:
Originally Posted by PerfInit View Post
The ADIRUs provide HDG/Groundspeed display to the ISDU on the overhead. Not stated in the NNC for Unreliable Airspeed explicitly, but this could be useful information if the pilots know where to find it and how it is determined.
Could be useful for triage on instrument disagreements... if you have the presence of mind to use it in the heat of battle. I'd hate to have to fly the plane by reference to the overhead panel though. Unless you had a jumpseater who could call out the parameters for you.
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Old 10-13-2020, 02:30 PM   #7  
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Hornet runs dual probes and a third INS-derived AOA. If a probe mismatch occurs, you get a warning, and can manually select the good probe by comparing them to the INS-derived AOA (which is pretty tight).

I’m sure the software is very different, but the logic is already there...in another Boeing product, nonetheless.......
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Old 12-18-2020, 05:28 PM   #8  
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Oops. Again.

Boeing alleged to have "coached" test pilots in re-cert efforts...


https://www.reuters.com/article/us-b...KBN28S314?il=0
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Old 12-18-2020, 09:55 PM   #9  
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Quote:
Originally Posted by rickair7777 View Post
Oops. Again.

Boeing alleged to have "coached" test pilots in re-cert efforts...


https://www.reuters.com/article/us-b...KBN28S314?il=0
Thank you for saying "alleged", page 7 of the report.

Quote:
The Committee’s investigation (Meaning a bunch of Senators on a Committee)
discovered that at least one official FAA recertification
test event was improperly influenced by Boeing. At least one FAA Aircraft Certification Test
Pilot appears to have been complicit in this testing. Slow and incomplete responses to document
requests and incomplete interviews have hindered progress on this specific topic. Some of the
delays are due to conflict with ongoing criminal investigations. Therefore, it is impossible to
determine how much of the systemic training, oversight, and management intervention problems
detailed in this report may have contributed to the certification of the 737 MAX
. (Translation: We have no idea, but we are going to say it anyway)

Page 44 of the Report.

Quote:
The whistleblower’s ad hoc testing was encouraged by the Aircraft Evaluation Group
(AEG) officials, due to previous testing related to pilot reaction times to an MCAS induced
runaway stabilizer in July 2019. According to the whistleblower and at least one other FAA
official, the test was conducted utilizing one FAA Aircraft Certification Office (ACO) test pilot
and one AEG test pilot who also participated on the 737 MAX Flight Standardization Board
(FSB). The AEG pilot was only included in the test after a second ACO test pilot became
unavailable. The whistleblower alleges Boeing officials were present for the testing and
encouraged the test pilots to “remember, get right on that pickle switch” immediately prior to the
exercise, which they acknowledged. “Pickle switch” refers to the stabilizer trim control
switches
, which adjust the horizontal stabilizer via electrical controls, enabling the pilot to
quickly counter the MCAS action. According to the whistleblower, the FAA ACO test pilot
reacted in approximately four seconds in accordance with the assumed reaction time. The AEG
pilot reacted in approximately sixteen seconds, or four times longer than the accepted assumption
of four seconds.
Who calls the Stab Trim switches "The pickle switch?"


Senate investigators fault FAA over Boeing jet, safety (msn.com)

Quote:
In a statement, the FAA said the report “contains a number of unsubstantiated allegations" and defended its review of the Max, calling it thorough and deliberate.
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Old 12-19-2020, 05:59 PM   #10  
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People need to go to jail for this.
On both sides, Boeing and the FAA.
So now it’s safe?
Like it was last time?

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