"Good enough" is not good enough for a commercial aircraft.
Management and engineers have a long history of enmity across a lot of industries. Corporate takeovers make it worse. Look at what has happened to Jeep; all they kept was the reputation but in fact the new Jeeps are flaming pieces of crap. This mentality irritates me to no end, but it is the overwhelming norm nowadays.
Those are deep rabbit holes, but I suspect that the public will never be privy to the real dirty details.
Remember, Boeing deliberately set up a smokescreen to bamboozle the FAA into signing off on the aircraft. Don't hold your breath waiting for real accountability.
And yet, in the 21st century, there is an FAA inspector who did not miss the Studebaker engine on a B-17. Insisted it was the wrong engine. Offered to ground the plane pending an engine swap.
(The B-17 was developed for the Wright 1820 engine, but Wright could not make engines fast enough. Others were already making 1820s on license. Studebaker car production was stopped, Studie found enough boring machines to crank-out radials, and the Studie plant was bigger than all the rest. Studie-made 1820s are very well made and well-respected at the time. And yes, the B-17 had a variance to use the Studebaker. The B-17 owner had to show it to the FAA guy.)
One can just hope that the fixes are not accepted because of what Mr. Dickson 'saw on the flight this morning'.
Jan
Another iron in Boeing's fire is not going well:
Boeing Starliner commander Christopher Ferguson bows out of first crewed mission due to family commitments • The Register
The article is about a personnel change, but the background is that the Boeing Starliner spaceboat had "near-catastrophic problems on its flight in December 2019. ...the words "spacecraft loss" were heard .... agreed to fly the mission again once minor stuff, like a lack of end-to-end testing, had been addressed."
Boeing Starliner commander Christopher Ferguson bows out of first crewed mission due to family commitments • The Register
The article is about a personnel change, but the background is that the Boeing Starliner spaceboat had "near-catastrophic problems on its flight in December 2019. ...the words "spacecraft loss" were heard .... agreed to fly the mission again once minor stuff, like a lack of end-to-end testing, had been addressed."
U.S. allows Boeing to resume 737 MAX flights | CBC News
I agree with the EUASA for a third opinion, albeit "synthetic". It's not like the two physical sensors are entirely independent. I assume they are the same sensor type on either side of the same part of the plane and subject to the same causes of failure, like insects, ice, maintenance goofs. At least "synthetic" is based on extra, uncorrelated information.
I wonder why the FAA didn't wait for the synthetic sensor?
Hmm. Using 2 sensors is what Boeing should have been doing in the first place. How the hell the FAA let them get away with that...
I agree with the EUASA for a third opinion, albeit "synthetic". It's not like the two physical sensors are entirely independent. I assume they are the same sensor type on either side of the same part of the plane and subject to the same causes of failure, like insects, ice, maintenance goofs. At least "synthetic" is based on extra, uncorrelated information.
I wonder why the FAA didn't wait for the synthetic sensor?
I thought that the original problem was that with the system was monitoring the two sensors and when there would be a discrepancy between the two ( IE when one failed ).
See my original post #211 in this thread.
"default AOA sensor
737 Max AOA sensors have been problematic for many years, bug strikes can make them
read incorrectly, icing, etc. Relying on two and picking one randomly seems
to me to be a bit reckless without disconnecting or giving a warning when there are extremely different readings.
.
A former Collins Aerospace employee"
See my original post #211 in this thread.
"default AOA sensor
737 Max AOA sensors have been problematic for many years, bug strikes can make them
read incorrectly, icing, etc. Relying on two and picking one randomly seems
to me to be a bit reckless without disconnecting or giving a warning when there are extremely different readings.
.
A former Collins Aerospace employee"
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My understanding is that both sensors were used in normal flight but the new MCAS system only used input from one of them and ignored the other one. I assume they've changed it so MCAS uses both and won't operate if they disagree or something similar, but I don't know. The horror of the original system is that a single failure caused the MCAS to try to fly the plane into the ground. Successfully on two occasions.
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I don’t even do this kind of crap on my amplifier protection circuits and I’m just a goon with a soldering iron.
What where these guys thinking? The mind boggles.
My bet: someone wrote the code quickly super early in the implementation and the massive, massive, massive failure is no one went back and actually made sure this was checked/validated/etc correctly.
Summary of Final Rule
After careful consideration of the comments submitted and further review of the proposal, the FAA adopts this final rule. This final rule mandates corrective action that addresses an unsafe condition on the 737 MAX.
This unsafe condition is the potential for a single erroneously high AOA sensor input received by the flight control system to result in repeated airplane nose-down trim of the horizontal stabilizer, which, in combination with multiple flight deck effects, could affect the flight crew’s ability to accomplish continued safe flight and landing.
As proposed in the NPRM, the corrective actions mandated by this AD include a revision of the airplane’s flight control laws (software). The new flight control laws now require inputs from both AOA sensors in order to activate MCAS. They also compare the inputs from the two sensors, and if those inputs differ significantly (greater than 5.5 degrees for a specified period of time), will disable the Speed Trim System (STS), which includes MCAS, for the remainder of the flight and provide a corresponding indication of that deactivation on the flight deck.
The new flight control laws now permit only one activation of MCAS per sensed high-AOA event, and limit the magnitude of any MCAS command to move the horizontal stabilizer such that the resulting position of the stabilizer will preserve the flight crew’s ability to control the airplane’s pitch by using only the control column. This means the pilot will have sufficient control authority without the need to make electric or manual stabilizer trim inputs.
The new flight control laws also include FCC integrity monitoring of each FCC’s performance and cross-FCC monitoring, which detects and stops erroneous FCC-generated stabilizer trim commands (including MCAS)
Jan (with thanks to Ian Hegglun).
FCC = Flight Control Computer;
AOA = Angle of Attack.
After careful consideration of the comments submitted and further review of the proposal, the FAA adopts this final rule. This final rule mandates corrective action that addresses an unsafe condition on the 737 MAX.
This unsafe condition is the potential for a single erroneously high AOA sensor input received by the flight control system to result in repeated airplane nose-down trim of the horizontal stabilizer, which, in combination with multiple flight deck effects, could affect the flight crew’s ability to accomplish continued safe flight and landing.
As proposed in the NPRM, the corrective actions mandated by this AD include a revision of the airplane’s flight control laws (software). The new flight control laws now require inputs from both AOA sensors in order to activate MCAS. They also compare the inputs from the two sensors, and if those inputs differ significantly (greater than 5.5 degrees for a specified period of time), will disable the Speed Trim System (STS), which includes MCAS, for the remainder of the flight and provide a corresponding indication of that deactivation on the flight deck.
The new flight control laws now permit only one activation of MCAS per sensed high-AOA event, and limit the magnitude of any MCAS command to move the horizontal stabilizer such that the resulting position of the stabilizer will preserve the flight crew’s ability to control the airplane’s pitch by using only the control column. This means the pilot will have sufficient control authority without the need to make electric or manual stabilizer trim inputs.
The new flight control laws also include FCC integrity monitoring of each FCC’s performance and cross-FCC monitoring, which detects and stops erroneous FCC-generated stabilizer trim commands (including MCAS)
Jan (with thanks to Ian Hegglun).
FCC = Flight Control Computer;
AOA = Angle of Attack.
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I am surprised no one has mentioned this -
Boeing's 737 Max debacle could be the most expensive corporate blunder ever - CNN
Airlines who don't need planes because of the Covid debacle can cancel them without penalty because of the 737 debacle.
Hard to think of a worse combination for B.
By the time any demand returns the Chinese 737 competitor will practically certainly be certified.
Best wishes
David
Boeing's 737 Max debacle could be the most expensive corporate blunder ever - CNN
Airlines who don't need planes because of the Covid debacle can cancel them without penalty because of the 737 debacle.
Hard to think of a worse combination for B.
By the time any demand returns the Chinese 737 competitor will practically certainly be certified.
Best wishes
David
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Here’s a BBC story about it
'Boeing played Russian roulette with people’s lives'
I would like to think with all the attention this plane has got over the last 18 months, that it is now safe, but only time will tell. I also hope the FAA is all over the aircraft industry in general on safety.
My preferred approach is a ‘hostile regulatory regime’. Step out of line, and you get hammered with fines etc. Ditto here in Europe.
I had some wiring done in my house by a certified electrician about 5 yrs ago. He told of a case here where an electrician had mis-wired a mains plug that had resulted in the death of a woman. When they investigated, the authorities were able to prove that he had not tested the job ie he wired it up and just left. He got 8 yrs in jail for that. Dennis Muilenberg got a $14 million payout ad IIRC, kept his $60 million stock options.
'Boeing played Russian roulette with people’s lives'
I would like to think with all the attention this plane has got over the last 18 months, that it is now safe, but only time will tell. I also hope the FAA is all over the aircraft industry in general on safety.
My preferred approach is a ‘hostile regulatory regime’. Step out of line, and you get hammered with fines etc. Ditto here in Europe.
I had some wiring done in my house by a certified electrician about 5 yrs ago. He told of a case here where an electrician had mis-wired a mains plug that had resulted in the death of a woman. When they investigated, the authorities were able to prove that he had not tested the job ie he wired it up and just left. He got 8 yrs in jail for that. Dennis Muilenberg got a $14 million payout ad IIRC, kept his $60 million stock options.
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