BBC: 737 Max - Still Not Fixed

[SRMman]

Any comments on the BBC article today quoting ex-Boeing Ed Pierson's recent report about other problems at Renton having played a direct role in the crashes? His Report is the title of this post.

[Peter H]

Ah got it,
The BBC item is Boeing 737 Max cleared to fly again 'too early' https://www.bbc.co.uk/news/business-55751150
Which contains a link to Ed Pierson testifying before the U.S. Congress https://edpierson.com/
Which contains a link to 737 MAX - STILL NOT FIXED (pdf)https://img1.wsimg.com/blobby/go/ec12e28d-4844-4df3-a140-ca706a04c0f7/downloads/737%20MAX%20-%20Still%20Not%20Fixed.pdf?ver=1611532831723

[WillowRun 6-3]

It will be interesting (to this SLF/attorney, at least) to see whether the lawsuit against the FAA in Washington, D.C. federal district court, which seeks disclosure by FAA of substantially all the documents FAA has received from Boeing regarding the return to service of the 737 MAX aircraft, will try to add this recent report to its arguments. The lawsuit is filed under the FOIA, Freedom of Information Act.

It was filed by an affiliate of the Flyers' Rights advocacy group (Flyers Rights Education Fund, Inc). a little more than a year ago. Capt. Sullenberger is the most prominent of the group of expert consultants the advocacy group assembled. Both sides in the case have filed motions for summary rulings by the court and it appears the briefing on these motions was completed a few days before Christmas. (The judge's staff surely had a magnificent holiday break, neck-deep in legal papers.)

Pierson's report certainly appears to support the basic argument in the lawsuit, namely that the FAA decision process about the return to service cannot be evaluated properly unless and until substantially all the documents received from Boeing are disclosed to a suitably qualified public interest advocacy group (the Flyers Rights expert consultants).

[WHBM]

... the FAA decision process about the return to service cannot be evaluated properly unless and until substantially all the documents received from Boeing are disclosed to a suitably qualified public interest advocacy group (the Flyers Rights expert consultants).
Whyever should some self-appointed, self-publicist group, of what appear to be lawyers looking for an ambulance to chase, have any overriding position in this process ?

"Public interest advocacy group". Hah !

[WillowRun 6-3]

I'm just trying to be objective, in describing the group that way. But some facts might be interesting. The law firm involved is far from ambulance-chasing rungs - it is very politically connected up in Washington but that's a different point, isn't it? Also, the people assembled by the group, you can check out their credentials, they appear pretty highly qualified, maybe very highly qualified. Sullenberger certainly is.

And the lawyer who heads up the group sits on one of the FAA's main advisory committees. Other than these facts, I have no basis to say the group is on a stunt or not - though FAA in how it has conducted the litigation has taken it quite seriously.

[BRE]

Wow, the "Still not fixed" pdf is quite something. Very cogently argued and chilling.

[DaveReidUK]

The paper appears to revolve around AoA sensor reliability.

It doesn't seem to acknowledge anyhere that, while the sensor failure rate will never be zero, the redesigned MCAS is intended to mitigate the effect of AoA discrepany.

[Wakner]

In my reading of it, it seems as much to revolve around installation/construction issues (especially electrical systems) as it does around AoA sensor reliability - I am interested to know how abnormal is the incident rate (4%) that he refers to on pages 11/12 for new (or even not new) aircraft:

"Some aviation professionals might argue [...] This track record is unprecedented in modern day aircraft."

[BDAttitude]

There are some distinct questions/problems that are legitimate but thrown into a blender.
- Manufacturing problem with the Lion Air original AOA-Sensor and no known to the public measures derived from it.
- Unknown root cause of Ethopian AOA sensor failure (who tried to attribute it so a bird strike? I honestly can't remember.)
- Obvious E/E deficiencies on both new aircraft that could not be diagnosed and sorted out by local maintenance.
- The usual business of manufacturing problems, not only the MAX suffers from.

Maybe the more appropriate headline with regard to those problems would be Boeing - Still not fixed.

No, I don't think the MAX is fixed, but that is due to yet another balcony, another warning, another algorithm and tons of MEL items, Check list entries added to 60ies ramshackle base structure.

[vikingivesterled]

My reading of page 8 of the pdf is that the aoa sensor can fail at any time due to a magnet wire in it is placed between 2 different components that with variances in temperature expand and contract at different rates so cause fatigue in the wire until it eventually breaks. Except that when the heating for the sensor is on and it heats up to above 60 degrees the wire itself expands enough to make it connect again.
One would assume that this could happen to all aoa sensors produced before this was found in June 2019, and for a time after that until the production method was altered, if it was. There is something to be said for 3 aoa sensors from 3 different manufacturers on each plane.

[airsound]

Ed Pierson's own website (the paper's author) says this
Captain Sullenberger has read this paper and said that “it raises many important questions that must be answered.” Dr. Daniel Ossmann, a recognized expert in aerospace fault detection, has also reviewed the paper and “concluded that it illustrates an excellent compact summary of the events and raises concerns that should be thoughtfully addressed.”

Also, Wakner - when you quote Ed Pierson as sayingSome aviation professionals might argue [...] This track record is unprecedented in modern day aircraft, I think your connection of those two sentences is misleading. What that paragraph says in full isSome aviation professionals might argue these safety incidents are not statistically relevant and they are just “teething” problems from a new model airplane. They might say these incidents represent a tiny fraction of the thousands of Boeing planes that safely fly millions of miles around the world each day. Although impressive, these big numbers are misleading. It is true that before the pandemic, there were more than 10,000 Boeing airplanes in service around the world flying millions of miles each day. But when the 737 MAX was grounded in March 2019, there were only 371 MAX airplanes in service around the world. 15 safety incidents represent 4% of the entire MAX fleet (15/371=4%). Thus, 1 in 25 MAX airplanes had already experienced a safety incident within the first year of being in service, two of which happened to be fatal crashes. This track record is unprecedented in modern day aircraft.
So Ed P is actually stating his own view that the track record is unprecedented.

[BDAttitude]

vikingivesterled

The part is carry over from NG. So the general construction would have been sound. I understood the situation you describe was a manufacturing error.

[jmelson]

vikingivesterled

Resolvers have been used in aircraft systems for MANY years, and they are used specifically because they are VERY reliable. If two resolvers are used, then the failure of one can be worked around. They are capable of handling large temperature variations. There are likely hundreds of resolvers in a 737, in the engine controls, flight controls and other places. But, yes, of course, any device can fail at any time. Vane-type AOA sensors are really difficult, as they are prone tio damage in ground handling or bird strikes, water ingress and freezing and similar issues.

[chriscrepon88]

There's a super-detailed "brief" (hesitate to say so as a lawyer as it's 126 pages long) called MAX-Ungrounding-Notice-of-Appeal-12.3.2020.pdf on the Flyer's Rights dot org site if anyone's interested in reading it. This must have a docket number by now. Unless they're actually appealing the previous adjudication, which is likely what's going on. I don't see that the case called
Flyers Rights Education Fund, INC., D/B/A FLYERSRIGHTS.ORG, and Paul Hudson, Petitioners, v. Federal Aviation Administration, Et Al has much to do with the 737 MAX.
mo

[olster]

Sully did an amazing ditching on the Hudson. An extraordinary feat of aeronautical decision making with an incredible all surviving outcome. However the net result of that is the deification of Sully and the notion that every word he utters is somehow sacrosanct. The Hudson has given him a platform which no aviator could expect unless they inhaled a pair of Canadian geese with similar results. His views are relevant but probably not significantly more important than many other experienced aviators particularly the Boeing variety. The Max debacle was a stain on Boeing’s reputation which as the true horrible story emerges is going to take quite some overcoming. The loss of the 2 Max’s was utterly tragic. However, I have to believe that the now finished product will be as safe as it is possible to be. Boeing can not afford another disaster. Finally, anything the BBC produces these days will be distorted to fit an agenda coupled with technical inaccuracies. Just my view.

[airsound]

Olster, you believe thatthe now finished product will be as safe as it is possible to be.
and thatanything the BBC produces these days will be distorted to fit an agenda coupled with technical inaccuracies.
But the BBC was quoting from a well-argued paper from an insider who was ideally placed to observe Boeing manufacturing during the appropriate periods. And that paper suggests that there is much more that should be examined before anyone can conclude that the 737 Max is “as safe as it is possible to be”.

[olster]

Yes air sound I do believe that the Max will be safe. I don’t think Boeing could countenance another accident. I believe that Boeing engineers have produced solutions coupled with operational guidance which should of course have been in place at the start. Please believe that I am no defender of Boeing; the original service introduction was an absolute disgrace. You can look at the aftermath in two ways. A realisation that there is a moral responsibility to put it right. Plus an economical agenda. I believe that one has to have confidence in the aircraft now as further disasters are untenable.

[PAXboy]

In the early weeks and months after the grounding, we saw boeing doing all it could to rush the Max back into service. Are we all convinced?

For my part, I'll wait a few years before getting on one. YES it is a numbers game every time you board a car or aircraft. But there are several carriers and aircraft on my personal no fly list.

[Banana Joe]

. A realisation that there is a moral responsibility to put it right.
Moral responsibility? They blamed those poor pilots and they would still be blaming them if they could.

[olster]

Please read my post. I am not a defender of Boeing at all. I have personal experience of Boeing personnel attempting to blame the pilots. You can be assured those were robustly rebutted. The pilots were hapless scapegoats at the end of a very large slice of Swiss cheese. I also believe that the Max was a stretch too far for the 737 series. I have flown many variants from the -200 up to the -800 plus instructed / examined on most. If Boeing had asked me prior to developing the Max (a highly unlikely scenario) I would have said stop it here at the NG. I think that Boeing had lost its moral compass and they have a responsibility to show humility and contrition for the subsequent disasters.

[Wakner]

airsound10976027]Ed Pierson's own website (the paper's author) says this

Sorry - was not my intention to connect the two sentences, rather highlight this whole paragraph for reading.

[airsound]

Thank you for clarification, olster and Wakner

[Bend alot]

olster

Sully's CV is a bit more extensive than the Hudson in a BUS, and post that he was given the opportunity to fly the fatal MAX flights in the sim.

We can only assume he was given the same computer based differences training to supplement his original 737 type rating.

[568]

Wakner

Allegedly, those issues with some electrical connectors/connections were found during flight line tests after the MAX left the factory, which I assume were found by internal QA.

[Unregistered_]

So, reading that PDF, the MCAS anti stall system was actually doing what it was designed to do? You cant expect a computer program to work as designed with faulty inputs.
The faulty AoA sensors are the real culprits here?
(among other Boeing and Lion Air systemic failures as contributing factors)

[WillowRun 6-3]

chriscrepon88
The case filed in the U.S. Court of Appeals for the District of Columbia Circuit by the Flyers Rights group is docketed as 20-1486. It is an administrative law appeal of FAA's actions, specifically (1) the ungrounding order (I'm omitting the technical name for this order), and (2) the final AD. The underlying administrative rulings are filed, as published in the Federal Register in November. There are a number of procedural briefs and motions already in the appellate court (though without reading these, no further comment here).

The other current action by the Flyers Rights group, continuing in the federal District Court in D.C., is most definitely about the 737 MAX. It is a Freedom of Information Act lawsuit seeking disclosure by FAA of all documents relating to the ungrounding decision which, at the time the case was filed, was far from imminent. (There are cross-motions for summary judgment pending, last time I checked it out on Pacer.)

(And as SLF/attorney, I'm obliged to say, the foregoing attorney-talk is only for the purpose of clarification. Please return to the regularly conducted aviation subject matter thread.)

[SRM]

With all that said, I just returned a Max to service after 11 months in storage.
The aircraft performed well on the test flight returning without a write up.
Up until this stage I not encountered any abnormal electrical or avionics defects after the wiring mods.

[Flapsupbedsdown]

Bend alot

If Sully was given the same aoa/sirspeed unreliable faults at take off why was he not able to control the aircraft applying memory items for the condition, aircraft still with flaps in take off configuration?

[olster]

I am well aware that Sully is a highly experienced aviator and I completely endorse his incredible handling of the Hudson ditching. A great story mainly because everyone walked away. I am not one of them but certainly colleagues of my vintage can be a bit ahem, sniffy about the never ending Sully worship. Professional jealousy? Perhaps. However, Sully’s background while not particularly or radically different has given him a platform whereby the rest of aviation hangs on every word. He may or may not always be right. Personally I am glad I never had the misfortune to encounter corpulent Canadian geese @ 250 knots. So, to clear up any misunderstanding I have great admiration for the man but he shouldn’t be seen as the oracle without challenge either.

[Nige321]

olster

What agenda?
What technical innacuracies...?
Very quick to slag off the messenger with no evidence at all...

[DaveReidUK]

The BBC article is purely factual, reporting the stated concerns of Piersen, Sullenberger and others.

It even takes care to ensure that the judgement of the above re the lifting of the grounding, is described as "too early" (their quotes, not mine) to make it clear that the BBC itself has no view either way.

[SRMman]

Couldn't agree more with Nige321 and DaveReid, Olster's views about the BBC are just plain wrong.

[BRE]

Unregistered

One could argue that relying on a single sensor was the original sin. At the time, it was rationalized by the fact the system was slow and not very powerful, so any competent pilot would be able to reconize it and do the runaway trim routine. However, later on, it became much more powerful, which is when they really should have turned to at least two sensors.

[Semreh]

A man with one watch knows the time. A man with two is never sure.

In such a safety critical system, if you are using multiple sensors, you need an odd number so you can implement a voting system (and hope that there are no common-mode failures that afflict a majority of sensors, or at least engineer away the frequently occurring ones).

And, to be clear, MCAS, even when acting on incorrect information from the AoA sensors, never 'ran away' - it applied a one-shot adjustment which could easily be confused with normal running of STS. Unfortunately, adjusting trim with the pickle switches reset the MCAS trigger, allowing it to add another 'one-shot' adjustment, which if not fully recovered by the trim adjustment switches, added up with previous adjustments until the out-of-trim aerodynamic forces could not be overcome by use of the yoke. As history shows, this behaviour managed to fool several certified competent pilots who had not been fully informed of MCAS behaviour.

A continuous runaway is easy to recognise. An intermittent, slow piling up of small increments of unhelpful trim turns out not to have been obvious, especially in a busy work environment with falsely triggered alarms.

[Loose rivets]

I almost started this thread after reading the BBC 'paper' on my FireFox tab. I didn't because it was filled with a LOT of technical misinformation. In particular, they'd gone to the trouble of nose angle drawings but as was so often the case, got muddled with simple pitch and AoA measurements.

Many of the statements were entirely familiar to me. This is happening at a time when Boeing know they can't have another MCAS induced incident, and now they have an entirely new incident to start a lot of heads nodding. There are some striking similarities, but hopefully not a single causal factor that is the same.

We all know pretty much what happened. What we seem to let slip into dark corners of our memories is that the two vanes failed in disparate ways. To me, this spells a very high bad luck factor in the equation. The second crash might well have been avoided had there been time, or the inclination, to practice such an occurrence after the first crash. However, it's been mooted that the psychology at that moment was probably worsened - now having the awareness of some mystery system causing problems but nowhere near enough thought and training on how to handle it. i.e., the limited knowledge causing a greater feeling of disbelief and resultant stress.

There are many factors that take some of the share of blame, though such arguments become almost philosophic.

IIRC, The first vane had been sourced from FLA from a company that sells and or refurbishes parts. If this is true, a virtually new late-model Boeing had a critical part that was not only not new, but had been serviced (then) by an unknown. Service might mean nothing more than bench testing.

[DaveReidUK]

Loose rivets

"I almost started this thread after reading the BBC 'paper' on my FireFox tab. I didn't because it was filled with a LOT of technical misinformation. In particular, they'd gone to the trouble of nose angle drawings but as was so often the case, got muddled with simple pitch and AoA measurements."

That's grossly unfair to the BBC.

Firstly, the article simply reports on the judgment of some individuals whose views are widely accepted as relevant. I'd be interested to know which parts qualify as "technical misinformation".

Secondly, the infographic you object to has been kicking around for a couple of years. While it's an oversimplification in that it uses the term "angle" without explaining whether it's AoA or pitch attitude, that's perfectly reasonable given (a) the target audience and (b) the fact that the distinction is arguably irrelevant in the context of the MCAS failures.

[Semreh]

Hot 'n' High

On the contrary, my apologies. You are correct. The original incarnation of MCAS did trim again after 5 seconds if the triggering conditions continued to apply. Thank youfor the correction.

Details of MCAS here: 737 MAX - MCAS (http://www.b737.org.uk/mcas.htm)

Interesting to note FAA AD 2020-24-02 (https://www.faa.gov/foia/electronic_reading_room/boeing_reading_room/media/737_AD_2019-NM-035fr.pdf) issued 2020-11-18 changed the Runaway Stabilizer wording (page 105) to "If uncommanded stabilizer movement occurs continuously or in a manner not appropriate for flight conditions:" (My italics). The document's discussion of MCAS is worth reading.

[Hot 'n' High]

My pleasure Semreh! IIR, it took a while to figure out how it really worked right when all this started so I was more worried that I had lost the plot .... again! Thankfully, in this case, I remembered correctly it seems. And the rest of your Post #34 was spot on!

[hans brinker]

Semreh

AFAIK MCAS would apply up to 5ish degrees of AND trim if it sensed too high AOA. If the out of trim conditions were still there it would not apply trim again until one of several system reset triggers happened. One of those was the pilots using the trim thumb switches. If the pilots hadn’t used the trim after the first MCAS trim application MCAS would not have reactivated. Obviously, that doesn’t make MCAS okay, as we are all trained to fly with the aircraft in trim.

[Hot 'n' High]

Ah, cheers hans. My memory playing tricks here it seems. I just checked and found this - https://www.faa.gov/foia/electronic_reading_room/boeing_reading_room/media/737_RTS_Summary.pdf. Safety Item #2, page 7. Semreh, my apologies to you - it was my poor memory after all!

As an aside, I don't recall seeing the FAA doc at the link so may be of interest to others - unless it was only me who missed that too!! It seems quite comprehensive (at first glance) covering both tech and administrative issues (such as FAA oversight). Anyway, back under my stone before I confuse people even more.

[ivor toolbox]

The majority of aoa sensors I have twiddled have been dual channel, with the outputs split, 1 channel from one side goes to fdr, 1channel from each side to respective side systems, and the remaining channel is used for error detection . So there you have the odd number for computer voting system

[silverstrata]

Any comments on the BBC article today.


?
The bottom line here, is that the Max should never have been produced, as it is an ancient dog of an aircraft. But it was pushed down the line because S.outhwest and R.yan wanted a cheap aircraft with lineal commonality. But in truth a 21st century aircraft should never have:

a. Only one sensor controlling a safety system - because that is simply criminaI. Nobody except Boeing has had simplex systems in the last 70 years.

b. A MCAS system that is able to stab-trim fully forwards - when it is known that the stab-trim is more powerful than the elevator. Thus the system has sufficient authority to overpower the pilot, and fly the aircraft into the ground. And if this authority was so easily reduced in the revised Max, then why was this not specified for the original Max? Were there occasional conditions where the system needed full trim authority (for a high-speed stall perhaps), and they are not telling us about it?

c. A manual stab-trimmer that becomes mechanically locked if the pilots are pulling back on the control column - so that no manual re-trimming is possible. (The recommended roller-coaster recovery not being advisable at 2,000 ft, and never taught in the simulator.)

d. An anti-stall device (MCAS) that operates on the stab-trimmer, rather than the control column. Look, dear Boeing, the design and mechanics of an anti-stall device are well-known, ever since the Bae Trident got into trouble. The solution is to push the control column forward, because once the nose is lowered and speed increases, the pressure can be released instantly.
However, if you push forward on the stab-trim, you cannot easily pull out of the ensuing dive because you are still trimmed (fully) forward. (As several pilots have discovered, much to their dismay). So why did the FAA not recommend the complete scrapping of the MCAS system, and the installation of a stick-pusher? Cost? Time? Certification? Has the FAA skimped in their recommended MCAS fix?

e. A master warning system that can be cancelled, so the warnings are extinguished and forgotten. Dimmed perhaps, but never extinguished. This must be the most stupid system ever invented for a commercial aircraft.

f. Important warnings, like low engine oil pressure, that simply don’t appear on the master warning system. It does not take too much in the way of distractions or inattention to miss the fact that the engine is about to seize.

g. Flight controls that cannot be separated if one side is jammed, because the two elevators are joined by a large torque tube. That would not be allowed on a modern aircraft.

h. Engine overheat and fire warning lights that are not in the pilot’s line of sight, with no repeater lights on the thrust levers. Back in 1960 the handles and lights were on the coaming, where they should be, but they were relegated to the center console to make way for the MCP. That was a retrograde fix that should never have been allowed, at least not without repeater lights on the thrust levers. But what do the FAA care, as long as profits are still being made?

i. Switches that are all identical, without even an attempt at colour coding. And the evidence for correct actioning is a light that goes bright and dim. Now between day and night, just what is bright and what is dim? Never in the history of aviation has there been such a stupid advisory/warning system.

j. Switches which are all down for on - unless they are on the forward and center instrument panels, where they are up for on. Note that the all-important electric trim cutoff switches are down for off - the complete opposite to the majority of switches on a 737. There is so much room for confusion here, you could drive a semi-trailer through it.

k. Paper checklists and emergency checklists. Now come on guys and gals, computer checklists were common back in the 80s, so why the hell are we still operating with bits of crumpled and torn paper?

l. Mainwheels that retract into the hydraulics and flight-controls bay, where shredded tyres can inflict severe damage on a multitude of systems. Some airlines placed cages in the wheel-bay to protect the systems, but they did make routine maintenance difficult. And the hydraulic release fuses were hardly an adequate solution to a failed 1960s design.

m. Center fuel pumps in the center tank, which can overheat and explode - and no auto-switching system was devised to prevent this. Has this been solved on the Max, because it was a butcher’s bin on the NG?

n. Passenger doors that have to be armed by grovelling on the floor. This is rather like having a starter-handle on a modern car.

o. Flight-deck windows that are smaller than an old-fashioned cruise-liner port-hole, because that was all they could make in 1950. Trouble is, we are in 2021 now.

I could go on, but that is sufficient for now.

[FlyingStone]

And if this authority was so easily reduced in the revised Max, then why was this not specified for the original Max? Were there occasional conditions where the system needed full trim authority (for a high-speed stall perhaps), and they are not telling us about it?

My bet would be that with the grounding, Boeing would focus on this sole issue much more than they did during the development of the aircraft.

c. A manual stab-trimmer that becomes mechanically locked if the pilots are pulling back on the control column - so that no manual re-trimming is possible.

Because in normal and large majority of abnormal situations there is no requirement for trimming in the opposite direction of control column, as this would just cause the out-of-trim condition, that could lead to aircraft being uncontrollable. There is an override switch available on the aft pedestal that disables this feature, if situation requires it.

d. An anti-stall device (MCAS) that operates on the stab-trimmer, rather than the control column. Look, dear Boeing, the design and mechanics of an anti-stall device are well-known, ever since the Bae Trident got into trouble. The solution is to push the control column forward, because once the nose is lowered and speed increases, the pressure can be released instantly.

MCAS is not an anti-stall device, it's a feature of the FCC to ensure stick force gradient remains positive at high AoA.

f. Important warnings, like low engine oil pressure, that simply don’t appear on the master warning system. It does not take too much in the way of distractions or inattention to miss the fact that the engine is about to seize.

That's true, but with low oil pressure caution (right next to N1 readings which hopefully we scan here and there), you'd also get a lower DU pop-up, which serves as another attention-getter.

h. Engine overheat and fire warning lights that are not in the pilot’s line of sight, with no repeater lights on the thrust levers.

Engine overheat generates a master caution, which is directly in front of each pilot, so is the fire warning light, which also has an audible warning as well. Later NGs and all MAX aircraft have modern thrust levers with fire warning lights incorporated in them, to aid identification of engine which is on fire.

. Paper checklists and emergency checklists. Now come on guys and gals, computer checklists were common back in the 80s, so why the hell are we still operating with bits of crumpled and torn paper?

Even the most modern aircraft still have fairly thick QRH, despite all the bells and whistles. Some operators do have approved electronic QRH solution for 737 though.

m. Center fuel pumps in the center tank, which can overheat and explode - and no auto-switching system was devised to prevent this. Has this been solved on the Max, because it was a butcher’s bin on the NG?

That's been fixed in 2004 or so with an auto shutoff if the pumps are left on. Nevertheless, you do have to switch them off when the tank is empty. Luckily, that's only once per (longer) flight, so hardly a big deal.

Sure, 737 is an old design, but it's still fit for purpose. I do hope the MAX is the last iteration, so Boeing can focus on building something state-of-the-art.

[infrequentflyer789]

Because in normal and large majority of abnormal situations there is no requirement for trimming in the opposite direction of control column, as this would just cause the out-of-trim condition, that could lead to aircraft being uncontrollable. There is an override switch available on the aft pedestal that disables this feature, if situation requires it.

That isn't what the post was referring to, it is referring to the manual trim being too weak to overcome aero forces (and therefore "locked" both ways) unless the pilot releases the control column (as per the later bit of the para regarding the rollercoaster). The trim wheel was made smaller, hence less powerful, on the NG.

[fergusd]

ivor toolbox

You could make billions with that idea . . . the number of people in the safety industry that think you need 3 actual sensors to ensure adequate safety and protection against sensor failure in safety critical systems . . . man . . . they are all barking up the wrong tree . . . all they need to do is fit two and pretend there are three . . . incredible . . . a proud british innovation . . . oven baked and world leading . . . well done ;-)

[Loose rivets]

DaveReidUK replied:

Loose rivets

"I almost started this thread after reading the BBC 'paper' on my FireFox tab. I didn't because it was filled with a LOT of technical misinformation. In particular, they'd gone to the trouble of nose angle drawings but as was so often the case, got muddled with simple pitch and AoA measurements."

That's grossly unfair to the BBC.

Hardly. A slight prod perhaps. In my view, well deserved.

Secondly, the infographic you object to has been kicking around for a couple of years. While it's an oversimplification in that it uses the term "angle" without explaining whether it's AoA or pitch attitude,

Perhaps if it's been kicking around that long it's high time someone prodded them. Not to explain that it's AoA or pitch attitude seems to be missing a major point. But, the nice but inappropriate drawings. . . . that's perfectly reasonable given (a) the target audience and . . .

I think the questioningly intelligent target audience might be lifted to a new level if the BBC could regain some of its old standards. They do after all have Pulitzer prizewinning articles to refer to. But then you say,

(b) the fact that the distinction is arguably irrelevant in the context of the MCAS failures.

Well, if it's irrelevant, they put a huge amount of effort into getting it not really correct.;)

Whirligigs or what have you. I think the fisherman's reel is possibly the best way of explaining to the layman the unloading of the H-Stabilizer cable run. Hauling on the luckless fish is interrupted by sharply lowering the rod and reeling in the line while slack. It's easy to imagine this being needed numerous times. A reminder about the Toronto 707 might well focus the reader's minds about historic difficulties.

[hans brinker]

The majority of aoa sensors I have twiddled have been dual channel, with the outputs split, 1 channel from one side goes to fdr, 1channel from each side to respective side systems, and the remaining channel is used for error detection . So there you have the odd number for computer voting system

I just sit up front, and don’t design things, but I see a two glaring problems with that “solution”.
If the vane breaks in the AOA with the error detection channel you now have two wrongs outvoting one right. And the FDR will not tell the investigators the reason for the crash, because it only has the information from the unaffected AOA.
You need three independent AOAs, and all three should be connected to the FDR.

[BDAttitude]

Towards that channel argument:
1.) Hans Brinker is right. If you pick two channels from one sensor and one channel of another sensor for voting you are distorting your probability of occurence of certain fault modes to a degree where you cannot make any useful statments of the failure rate of the entire system.
2.) AFAIK the two channels are processed by one air data unit and are used for diagnosing electrical faults. That's what they are good and useful for. Hooking them up to different FCUs will either deprive you of that integrity check or things get an awful lot complicated, see 1)

[Dave Therhino]

The MCAS function itself is not critical; its failure to function is likely classified as major because the result of its failure to function is simply a non-compliant column force gradient. It's malfunction was catastrophic, and still is potentially catastrophic. It is acceptable for loss of a valid AOA signal to cause the system to become inactive, as long as it does not malfunction. As such, two independent AOA sensors and signals can be an acceptable system architecture if any significant disagreement of the two AOA values causes the MCAS function to be deactivated, and no foreseeable common cause failures can cause identical errors in the two AOA sources. A voting system of three signals is not necessary when loss an accurate signal is not critical.

[SRMman]

I've received this by PM (the last line explains why), which takes us back to the original Pierson report. It is clearly relevant, but it's not my composition and will therefore not respond to any questions about it.

"Sorry for the length, but to understand Ed Pierson's report one needs the parts he left out.

He mixes two separate issues.

The first issue: A resolver is a variable transformer that measures the alignment of the magnetic field generated by a reference/excitation winding coil using the sense winding coils. If either the reference coil or the sense coils are interrupted, for example by a break, then the resolver can no longer function correctly. https://en.wikipedia.org/wiki/Resolver_(electrical) There is a fourth winding that causes the current in the reference winding; it can be treated the same as part of the reference winding for discussion purposes.

To emphasize, there are two sense coils. One provides the sine of the rotation angle multiplied by the magnetic field and other constants, the other is at a right angle to the first and provides the cosine of the rotation angle. It effectively "resolves" the mechanical angular motion into these two electrical components. By comparing the magnitude of the two signals one can get the ratio and therefore the tangent and then develop the arc-tangent to get the angle.

The reason for looking at the ratio is that losses in the system will be proportional to the signal strength. However, this means if one of the sense coils develops a high-resistance, such as from a broken wire barely making contact or a corroded connector, the angle reported will not represent the actual angle. In the Lion Air report I believe the maintainers had previously sprayed some cleaner on some connectors, which did not help, before replacing it with the miscalibrated unit.

If a wire breaks completely, that can be detected during test. If the reference winding is broken no current will flow and both sine and cosine components will be zero. If the sine or cosine winding is broken then turning the vane will show one output changing and the other remaining at zero output.

Where that leads to in the Lion Air case is that a broken wire in one of the sense windings was apparently being pulled apart by the surrounding epoxy when the epoxy was cold, causing a total failure that was reported by the system.

When the AoA assembly was cold electricity could not be conducted across the gap. As the assembly heated the epoxy expanded and brought the broken ends together. This would initially allow microscopic contact, resulting in an unstable conductivity making the ratio with the other winding appear to vary even if/when the vane was not being moved. Finally, at a sufficiently increased temperature, the two ends of the wire would be forced together to conduct sufficiently to give a stable and correct reading.

The heat that was being applied to the assembly during the Lion Air bench test appeared to be from the anti-ice heater in the AoA vane.

The second issue: The AoA vane has a heater. This is a resistive element that converts electrical power into thermal energy. The system can detect if there is current flowing through that heater and if that current is zero when voltage is applied the system does the Power = Current * Voltage-drop calculation and determines that with zero current there is zero electrical power and therefore the unit cannot produce heat. There is apparently an integral regulator to limit the maximum temperature and prevent melting the AoA vane. This failure is part of the anti-icing failure system to report.

Where Pierson fails is when he claims the heater that affected the failed winding at Lion Air has anything to do with the heater error that was reported after the AoA vane was apparently torn from the aircraft in Ethiopia.

What is certain is that the Ethiopian plane did not have a history of gradually increasingly unreliable AoA readings; in fact the AoA reading was accurate until after take-off, at least to the extent it was reading as expected and agreed with the second AoA sensor. Had there been a wire break in the resolver it would not have become the exact value that dropping against the high AoA stop, which happens when the counterweight no longer had a weight balance from the AoA vane. However that is exactly what is expected were the AoA vane torn off by a bird strike. In addition, losing that vane would also lose electrical continuity through the heater, causing the anti-icing failure warning, which is what the Ethiopian data showed.

When Ed Pierson writes: "Why did the sensor signal go unstable when heater power was removed during testing of the “removed AOA Sensor” from the Lion Air airplane?" he is mistakenly linking the effect of heat from a heater that is not part of the resolver and is trying to build on that false assumption. Had the resolver been put into a toaster-oven and no power applied to the anti-ice heater the resolver would have acted the same. I doubt that he would then blame toaster ovens as being part of a conspiracy. It went unstable because the epoxy slowly cooling gradually reduced the force with which the wires were held together, gradually increasing the resistance until a gap formed.

Note that the 60C temperature was a moving target. At some point it worked at 20C, then at 30C, 40C, and 50C. The damage done by forcing the broken wires into end-to-end contact will accumulate to where it will eventually never function. I have personally seen a mechanical system fail the same way - differential thermal expansion causing cumulative damage and a sliding window on the ability to function until it no longer could.

Where he really runs off the rails is "a factory environment under duress with a shortage of electricians" because the factory electricians do not manufacture resolvers, electrical technicians at the supplier do. There is nothing at all having to do with the factory environment that affected either crash involved AoA sensor. Honestly if it takes a Scanning Electron Microscope to see a defect and seeing that only after destructive disassembly, that's beyond what a typical Boeing assembler can detect on the factory floor.

I expect that the Blacksburg information will be used to guide remove and inspect/replace with new resolvers based on which technician or which process was being followed per which serial numbers, alongside a design review to ensure it cannot recur.

I can agree with his righteous indignation over how a factory is run and how procedures are developed, but they have no bearing on the two crashes.

I'm on the banned-from-posting list, so it may be that direct messages to me get bounced. That's a choice by the moderators and I respect it. It's their platform and up to them what to make public."
MechEngr is offline

[DaveReidUK]

Loose rivets

"I think the fisherman's reel is possibly the best way of explaining to the layman the unloading of the H-Stabilizer cable run. Hauling on the luckless fish is interrupted by sharply lowering the rod and reeling in the line while slack."

Hmmm. And you were complaining about the BBC oversimplifying things ?

[Loose rivets]

I'm not a fisherman, but I've seen horrendously expensive reels totally stalled while reeling in. 'Dropping' the rod instantly took the load off and allowed the reel to continue cranking. I don't think it's a too bad analogy.


The Pierson report. That's interesting. I spent my first working years fault-finding systems. What jumps out of the read above is the stability of such a fault. Assessing conductivity of a moving break at atomic level I think would take a lot of very creative imagination.

I have personally seen a mechanical system fail the same way - differential thermal expansion causing cumulative damage and a sliding window on the ability to function until it no longer could.

That sounds more like the real world, but then, I've been surprised before. Electronics started with the Cat's Whisker, and the currents involved possibly altered the junction after a period of time.

A partially conducting junction happening due to varied compression - more than a few times - makes the old credulity warning light come on.

[chriscrepon88]

Hi all, and Willow, I don't think you mentioned this in your reply to me the other day, but for anyone here who doesn't know, the Washington DC Circuit Court (of Appeals) denied the 126-page emergency motion. To quote an article on law360 published on January 14, 2021 at 6:02 PM EST:

The D.C. Circuit on Thursday declined the Federal Aviation Administration's approval to return Boeing's 737 Max jets to service after a 20-month flight ban and two deadly crashes overseas as it considers claims the FAA hasn't been transparent about its safety review.

A three-judge panel of the D.C. Circuit issued a brief order denying an emergency motion to stay the FAA's November decision lifting the 737 Max flight ban. Flyers Rights Education Fund Inc. and individual air travelers petitioned the appeals court in December claiming the jets shouldn't be allowed to fly again until the FAA discloses critical information on the...

That's all that's available for free without paying or getting a free trial to read the article, but as Willow said in his post, all of this is available on PACER dot gov - for either 5 or 10 cents per page. Perhaps a more experienced user here could eventually post a PDF of the full order. ~Chris

[WillowRun 6-3]

SLF & attorney as a poster status can sometimes lead to, well, awkward posture with regard to deciding what to say.... but I guess I opened the door.

Reading this will lead the reader into legal stuff. The post is necessary (or I think it is, at least) because information about pending court cases which is somewhat misleading or mistaken has crept into the thread. Having been chastised previously for riffing on legal stuff on a pilots' message community (and having deserved it), ... hence this lead-in apology first.

There is litigation in the federal appellate court for the District of Columbia Circuit involving the 737 MAX return to service. The appellate case is a direct outgrowth of the Freedom of Information Act lawsuit still pending in federal district court in D.C. (the trial court) - the case filed by the Flyers Rights group seeking disclosure by FAA of all the documents relating to decision-making about returning the aircraft to service. That case was filed little bit more than a year ago. It got bogged down in a dispute over whether FAA was correct to withhold "proprietary information" submitted by Boeing (the FOIA statute allows this but there are judgment calls and balancing factors being litigated still).

But while the district court case droned on (yeah yeah, I know FOIA review and disclosure takes time, more than 4 seconds of reaction time no doubt), FAA went ahead and returned the aircraft to service in the U.S. It needs to be understood, that is by anyone wanting to understand this litigation because it could and likely will affect the course of future events involving FAA reform as well as lawsuits brought against Boeing....to be understood that the entire purpose of the Flyers Rights FOIA lawsuit was to get the documents from FAA and to conduct an independent review in the public interest -- that's not my characterization let alone endorsement, it's just what they claim in their lawsuit.

So the appellate case is about getting the federal appellate court (where one of the judges also is the President's nominee for Attorney General of the United States, just a little interesting fact) to review the FAA's decision, and to reverse it. But that process - briefing the issues, any procedural motions first, getting the court to resolve the case - takes time.

So the Flyers Rights group also filed a motion asking the appellate court to "stay" the FAA's decision, on an emergency basis. In other words, even though the court has not had much of a chance to "get ahold" of the issues in the case let alone decide them, let alone decide those issues in favor of reversing the FAA's decision, the motion for a "stay" asks the court to undo the return to service while this appeal is pending. (In proper litigation terminology, a motion for stay pending court review.)

The Court of Appeals did, however, deny the motion for a "stay". But the main appeal is still ongoing. There are procedural motions already on file, including one by FAA to dismiss the appeal (on certain formalistic grounds). And there is this very, very relevant item in one of the briefs:
"In its Opposition, the FAA indicates that (if its motion to dismiss is denied) the agency will include in the administrative record the withheld proprietary data on which FAA relied, and make it available to the Court under seal and to Petitioners under an appropriate protective order. That is a very positive step that will indeed permit meaningful review by this Court." (Flyers Rights brief -- if you must know, it's the Reply Brief in Support of Emergency Motion for Stay Pending Review and Opposition to Cross-Motion to Dismiss - but the bold-type for emphasis is mine).

In other words, there is progress, of a sort, as a result of all the litigation and legal maneuvering. If the Appellate Court lets the Flyers Rights appeal go forward, then FAA evidently has told the Court it will provide the documents still being argued over in the district court, for limited review by the court and by Flyers Rights, under a Protective Order of Confidentiality. I seem to recall some poster with a callsign supposedly honoring some airport where the Arsenal of Democracy - and Henry Ford - build bombers in the 1940s saying something about a Protective Order of Confidentiality being a reasonable solution to the FOIA case, about six dozen lawyer jokes ago.

I'd quote and post the summary of the reasoning Flyers Rights cites for its Emergency Stay motion, but the Court's already denied it, and so to close a post already too long, here is all that the Court said in issuing that denial:
"Upon consideration of the emergency motion for stay, the response thereto, and the reply, it is ORDERED that the motion for stay be denied. Petitioners have not satisfied the stringent requirements for a stay pending court review. See Nken v. Holder, 556 U.S. 418, 434 (2009); D.C. Circuit Handbook of Practice and Internal Procedures 33 (2020)."

See, not all legalese goes on interminably.

[crazyaviator]

"Boeing had lost its moral compass" Can a human make a more succinct answer to this evolution of foolishness and the only 2 decisions that mankind must make ? I am saddened

[GlobalNav]

@WR6-3
“In its Opposition, the FAA indicates that (if its motion to dismiss is denied) the agency will include in the administrative record the withheld proprietary data on which FAA relied, and make it available to the Court under seal and to Petitioners under an appropriate protective order. That is a very positive step that will indeed permit meaningful review by this Court."

I understand it’s satisfying to make some apparent progress, but if the proprietary data is available under seal, then who can see it that has the technical expertise to grasp its significance? It would need to assessed in the context of the design, testing and certification work.

[WillowRun 6-3]

GlobalNav, thanks for the question . . . . probably the best answer is to say that incremental progress counts too.

To start, the group assembled by Flyers Rights includes people who have - or at least to a non-engineer, non-pilot, appear to have - pretty strong credentials. This is not saying any of them (Capt. Sully included) belong hoisted up on top of a pedestal of authoritativeness. But compared to, say, the average inquisitor in a Congressional hearing? Or to attorneys on any and all sides of the litigation directly related to the crashes?

By itself, the fact of review by the FR group might not convince an objective observer (even one striving for logic and rationality) that any progress toward fuller disclosure will result. But.... FAA had dug in pretty strongly in the district court on its statutory basis for withholding proprietary information it received from Boeing. I haven't devoted time needed to read the cross-motions for summary judgment on the confidentiality issue filed in the district court late last year. (As an aside, "cross-motions" just means both parties in the lawsuit filed this type of motion, each one claiming that the undisputed factual record leads inexorably and necessarily to a ruling in its favor now, summarily.) Maybe FAA gave some ground in that briefing though I would doubt it. But it did make a concession in the appellate case.

So with the credentialed group reviewing the docs, and the Court reviewing them also, and in light of this being a change from FAA's position in the trial court, I could understand a ruling by the Court of Appeals which, shall we say, encourages the district court action to yield certain results. Among other things, the need for Boeing confidentiality to be sacrificed in this one very unique and very serious situation can be said to override all the factors usually cited to support upholding nondisclosure of proprietary information. To unfairly modify a familiar phrase, the unprecedented aftermath of completely senseless crashes calls for unprecedented but one-time overriding of confidentiality. Or if this is too controversial, at least it is the correct argument to assess.

This isn't a prediction that if the appellate court denies the motion to dismiss and FAA follows through on the limited, under seal, disclosure, that necessarily more public disclosure will result. But the facts of the procedural posture of these cases do suggest to this SLF/att'y that such a result seems to be brewing, and don't we all think it's high time, way past high time, for Boeing to wake up and smell the coffee.

[Charlie_Fox]

EU approves Boeing 737 Max return to service

The European Union Aviation Safety Agency (EASA) has certified (https://bxlconnect.us8.list-manage.com/track/click?u=378ef9a46905a09ce9c9a14ed&id=ba8e75f863&e=1a87f383f6) that the redesign of the Boeing 737 MAX aircraft has met the conditions for a return to service in Europe. However, its actual return may take some time as the EASA mandated a package of software upgrades, electrical wiring rework, maintenance checks, operations manual updates and crew training which will allow the plane to fly safely in European skies. Aircraft operators will schedule these mandated actions under the oversight of Member States’ national aviation authorities. Moreover, subsequent travel restrictions across Europe due to the COVID-19 pandemic will certainly have an influence on the pace of the aircraft’s return to normal commercial operations. The plane has been grounded worldwide since March 2019 following two crashes in October 2018 and March 2019, which together claimed 346 lives. The main cause for the loss of control of the Lion Air Flight 610 and the Ethiopian Airlines Flight 302 was traced to software known as the MCAS (Maneuvering Characteristics Augmentation System), which automatically pushed the airplanes nose down repeatedly due to a sensor fault.

[WillowRun 6-3]

Wall Street Journal today (Feb. 9 2021) - headline & sub-head:
"Boeing Board Draws Fire on CEO - Shareholders in suit say directors failed to challenge Muilenburg on postcrash media plan"
[by-line in WSJ, Andy Pasztor, Andrew Tangel]

One would guess, with some confidence, this is a shareholder derivative action. Your friendly neighborhood SLF/attorney has not (so far) found a way to access the court filings of the Delaware state court in which the case is pending. Regardless, some comments here may be worth the time to read them.

The lawsuit was originally filed with some or perhaps nearly all quotations and related information from Boeing internal documents blacked out ("redacted"). But the WSJ filed some sort of petition or request to the court for release of more information, and indeed the court granted the publication's request. In the news article today (all of the information about the case in this post is derived from the article) there is an interesting quotation from a court official. Here it is, as in the article:Morgan Zurn, vice chancellor of the Delaware state court, said in her Feb. 1 order that Boeing’s internal “communications are at the very heart of this board oversight case.” Saying that little had been revealed about how Boeing’s board responded to the MAX crashes, she added: “The public interest favors disclosure.”As noted in previous posts about the 737 MAX legal matters, a strong case can be articulated for the same logic applying to documents submitted to FAA for its review and decision about lifting the grounding order.

More broadly, the article paints what can only be a head-shaking-causal-factor with regard to Boeing's activities (to apply a completely bloodless word) in the time period between the two crashes, and in the early aftermath of the second. Some of the internal communications are, or would be, comical - if not for the tragic loss of life. Case in point: an internal communication excoriating the Wall Street Journal over reporting, early on, about how the MCAS system was not in the FCOMs, not disclosed to pilots. Comical, if not horrifying first.

In this SLF/atty's career time I've given a few presentations to boards, and I could see starting a presentation slide deck with a plain, simple .... or possibly simplistic .... attention-focusing title. But this paragraph, by which the article concludes, leaves me speechless ... ... ... for now anyway:In April 2019, vice presidents in charge of engineering and safety for the commercial aircraft unit provided their first report directly to the board, according to the suit: “The presentation opened with a primer titled: ‘What is Certification?’”

[GlobalNav]

I wonder if Boeing would be kind enough to deliver that presentation to the FAA. The evolution of the certification process over the last two or three decades makes the current process hardly recognizable from the earlier one. The loss of checks and balances, independent technical oversight and increase of managerial resistance has rendered the current process relatively toothless. One can only hope that legislative action will begin to reverse this trend.

[Equivocal]

One can only hope that legislative action will begin to reverse this trend.Whilst I can't comment on the US arrangements, the weakness in the European environment is not a lack of legislation or rules - in fact, EUR is awash with aviation rules - but commonly a lack of understanding of those rules by both regulators and industry people alike, and, in a small number of cases, a complete understanding of the rules but a lack of desire to comply with those rules. Those who seek to avoid compliance do so for a variety of reasons, some because they think they know better than the rules, some for an easy life - or a mixture of the two - and some simply because they do not know what they are dealing with. An over-generalisation, perhaps, but unfortunately I've seen it up close and personal, and I can quite understand how the latest generation of the 737 ended up in the mess that it is and also the premise of the BBC piece that prompted this thread.

[WillowRun 6-3]

GlobalNav, somewhere - perhaps a staff of one of the pertinent Congressional committees, or in the civil service cadres of Dept of Transportation (including now the new hot-shot wunderkinds brought along with the new Secretary), or amongst the many attorneys working in the several active lawsuits against Boeing - there "should" be someone who knows the status. That is, the status of what documents which have come to light from various investigations and reporting, and what documents have been produced by Boeing or other discovery respondents in the various suits.

I know that in some types of cases with multiple lawsuits by different parties, there can be useful coordination so that discovery document production is shared across the cases. Whether this is happening here, I don't know and shouldn't speculate.

As I have posted before the FAA reform legislation passed at the end of the most recent Congress did envision an overhaul of several aspects of how FAA does business. Not wanting to devote time to mastering the details and intricacies of the legislation itself - which would tend to cause posts here to be even more off-piloting track and annoying - I can't say much more. But again, as is true with the documents slowly emerging from the Boeing shadows, presumably some bright staff member or attorney someplace is quarterbacking this whole drama.

I can't leave the post without saying, some of the stuff quoted in the WSJ article today has a high cringe factor. I mean, it's so unlawyerly to say I'm mad as h*ll and I'm not going to take it anymore. One gets the sense that the proverbial windows of opportunity available to cause meaningful reform or restructuring to take place already were limited in both scope and availability, and the situation will get only more stark as time lapses on by.

[tdracer]

I'm going to give a contrary take - the problem is that the regulatory burden has soared to the point that everyone is looking for shortcuts, or you'll never get certified no matter how good the product.
The first flight of the 747 prototype was this day in 1969. Even though it was a revolutionary aircraft in size, propulsion, and avionics - and encountered numerous issues in flight test (flutter and engine surges to name two), it was certified and in-service before the end of 1969. That would have taken twice as long (at least) with todays regulations and processes - with a corresponding increase in costs.
In 1988, Boeing certified the 747-400. It had massive issues with avionics, EIS was months late, but the cert hurdles were - by today's standards - quite low. When I was working the 767-2C/KC-46 - we were using the same PW4000 engines that had been certified for the 767 and the 747-400 in 1988. So I sourced up the cert plan they'd used for the engine control system back then. Now, this cert plan covered the PW4000, the CF6-80C2 FADEC, and the RB211-524G/H engine control systems, for both the 767 and the 747-400. A total of six engine/airframe combinations (more if you count minor models of the 767 and various engine ratings). It was 30 pages long. My cert plan for the 767-2C engine control system - a derivative system for a single engine type on a single airframe - using the same hardware, with modified software and additional HIRF/Lightning/EMI hardening - was over 100 pages long. Then, over two years after that Cert Plan had been reviewed and accepted by the FAA - at the point where I thought I was just about done - the FAA suddenly decided it was insufficient - they needed additional man-years of documentation and analysis (far above and beyond what had been done originally - for a system with over 100 million flight hours of very safe in-service experience) that even the FAA admitted wasn't going to add anything to the system safety but would allow them to check some boxes. There have been something like 100 amendments to the FARS in the last 30 years (compared to about 40 in the previous 30 years). Yes, a few addressed shortcomings or updated the regulations to reflect current technology (e.g. FBW, FADEC, and carbon composite structures). But the vast majority have been bureaucratic make-work that increased the regulatory burden with zero contribution to safety.
The problem isn't a lack of regulatory oversight. The problem is that the regulators are not looking at the right things. It's a classic case of missing the forest because they are too busy looking at a tree.

[BDAttitude]

There have been something like 100 amendments to the FARS in the last 30 years (compared to about 40 in the previous 30 years). Yes, a few addressed shortcomings or updated the regulations to reflect current technology (e.g. FBW, FADEC, and carbon composite structures). But the vast majority have been bureaucratic make-work that increased the regulatory burden with zero contribution to safety.
The problem isn't a lack of regulatory oversight. The problem is that the regulators are not looking at the right things.
Complexity of systems has exploded since then. Gauges, switches and knobs are no longer handeled by humans but by algorithms and control loops that are strongly dependent on each other, introducing failure modes that - if not cought in design and certification - will cause loss of life because the effects cannot be expected to be diagnosed and fixed by human operators timely.
The 737Max is a prime example of what happens if this is not done with due dilligence and care by both the design bureau and the regulator.
Of course this increased complexity adds significant amount of effort equally to design and validation. Regulation is only second line of defence but must keep pace with this increased complexity and sometimes fails to do so - by advancing slower than technology and containing loopholes.
It is therefore vital, that organisations provide the ressources neccessary to cope with increased complexity and that individuals in these organisations do not take the bait of compensating work load by cutting corners.
Both did not happen within the regulator and the designer. Add some Forkners (people that are not governed by engineering ethics but by career considerations and slavish obedience of unrealistic objectives by superiors) and you have a Max.

[WillowRun 6-3]

Seattle Times (website) reporting that Inspector General of Dep't of Transportation is issuing another report pertaining to the 737 MAX debacle, on Thursday (Feb. 25). Evidently this is the final report of the IG, completing the process that earlier led to an initial report (discussed on the forum on one of the MAX threads, IIRC).

Quoting the first five paragraphs from the website (by-line of Dominic Gates):

The final report by the Inspector General of the U.S. Department of Transportation highlights failures that led the FAA to miss the flaws in the MAX’s new flight control system during certification of the jet in 2015 and 2016.

The Seattle Times obtained a copy ahead of the report’s official release.

“Much work remains to address weaknesses in FAA’s certification guidance and processes,” the report concludes. “FAA has not yet taken sufficient steps to ensure it best targets its … oversight to the highest-risk areas.”

The report makes 14 specific recommendations to address those weaknesses, changes it says are “vital to restore confidence in FAA’s certification process and ensure the highest level of safety in future certification efforts of major passenger aircraft.”

The FAA received a copy of the report in December and has already agreed to implement all the recommendations on a set timeline

In possibly related news, on Feb. 19 the incoming Chairwoman of the Senate Committee on Commerce, Science and Transportation (Sen. Maria Cantwell, D.-Wash.) announced the redesignation of one of the subcommittees, which now will be the Subcommittee on Aviation Safety, Operations, and Innovation. It is suggested by a few sources that this is more than nomenclature or semantics, and instead reflects an increasing legislative focus on the designated subject matter areas. Which would make sense, in light of the passage at the end of the previous Congress of legislation reforming FAA in various potentially if not actually already significant ways (the Aircraft Certification, Safety, and Accountability Act).

Even an SLF/atty is not usually naive enough to think things improve quickly based on what your Friendly Federal Government does or does not do, but then steps in the right direction are better than when they're wrong.