More on the 737 MAX

Kinja'd!!! "facw" (facw)
09/21/2019 at 23:16 • Filed to: Planelopnik, Boeing 737, Boeing, Boeing 737 Max, 737, New York Times, Fly The Airplane

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The Times has !!!error: Indecipherable SUB-paragraph formatting!!! . It’s well worth a read:

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It’s a bit different than other coverage I’ve seen in that it absolutely savages the pilots in the Lion Air and Ethiopian crashes, and the system that generates them. “ Airmanship” is the word the author (a pilot) keeps coming back to, basically claiming that even with the bad decisions Boeing made, a pilot who actually understood their airplane should have been easily manage these situations.

Still, as a software engineer, this is still the part I keep coming back to is this:

One of Boeing’s bewildering failures in the MCAS design is that despite the existence of two independent angle-of-attack sensors, the system did not require agreement between them to conclude that a stall had occurred. 

The idea that you would have redundancy inputs in a safety critical system and decide to ignore one seems unfathomable to me (indeed this article says there’s a third “standby” instrument that could be used to evaluate disagreement between the other two)   . The best explanation I’ve heard (not mentioned in this article) is that MCAS as originally conceived was really just please the FAA about an odd corner case that was extremely unlikely to happen, even given the huge number of 737 flight hours, so Boeing wasn’t concerned about the scenario where both that unlikely scenario and an instrument failure occurred at the same time, and then didn’t realize the increased risk when MCAS’s role was expanded.

Regardless, I don’t think this article so much absolves Boeing as says that we have another huge problem.


DISCUSSION (39)


Kinja'd!!! AestheticsInMotion > facw
09/21/2019 at 23:28

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If you had to equate the 737 MAX issues to a major automotive screw-up, what would you choose? Dieselgate? GM’s ignition woes? Mazda’s rust issues? I’m curious where this ranks in the sky  car business 


Kinja'd!!! JawzX2, Boost Addict. 1.6t, 2.7tt, 4.2t > facw
09/21/2019 at 23:30

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Yeah, I mean I agree, the pilots should have been able figure out what was going on, or at least checklist to diagnose the issue be fore it got out of hand... but... Boeing built a real POS bit of code , slapped an “I nspected by #20" tag on it and yelled “ship it!”


Kinja'd!!! JawzX2, Boost Addict. 1.6t, 2.7tt, 4.2t > AestheticsInMotion
09/21/2019 at 23:38

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I’d put it closer to GM ignition switches... I think it was neither as malicious as Di eselgate, or as hapless as rusty Mazdas. It showes clear evidence of cost cutting and disregard for established prac tices though.


Kinja'd!!! SmugAardvark > AestheticsInMotion
09/21/2019 at 23:44

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I’d compare it to the Firestone/Ford Explorer debacle of the 1990's that killed almost 300 people . Plenty of blame to go around, largely due to inaction and/or finger pointing. Firestone cut corners and built a crappy tire, and Ford cut corners and built a structurally deficient SUV.


Kinja'd!!! facw > AestheticsInMotion
09/21/2019 at 23:45

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In terms of practical effects, it’s probably similar to Toyota’s unintended acceleration (except this definitely did something, while it’s not clear that Toyota ever had a problem, aside from not deactivating the accelerator while the brake was pressed at the same time), or Tesla’s autopilot sometimes crashing the car when the driver isn’t paying attention to take over.

In terms of financial effects, it’s probably a lot closer to Dieselgate. Of Boeing’s 806 deliveries in 2018, 580 were 737s (many were older 737 NG models rather than MAXes, but those were tapering off as MAX production ramped up). Boeing has over 5000 outstanding MAX orders, so it’s a really big deal that they can’t actually deliver them. Instead they are paying late penalties, and continuing to bear production costs keeping the line operating in the hopes that they’ll be able to quickly push an update once the FAA has approved it. It’s a huge revenue hit for the company. It’s also a pretty big black mark on their image. It’s also similar in the sense that’s it’s frequently be portrayed as Boeing pulling one over on a naive and overly compliant FAA, though I’m in agreement with the article’s author that Boeing wasn’t trying to sneak something unsafe past the FAA, they were just so single-mindedly profit-driven that they didn’t realize they were building something with a glaring safety flaw.


Kinja'd!!! Spanfeller is a twat > facw
09/21/2019 at 23:49

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This article grinded my gears so much that I couldn’t even finish it.


Kinja'd!!! Highlander-Datsuns are Forever > AestheticsInMotion
09/21/2019 at 23:55

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This is like getting a defective airbag in a new car, it is very rare but the consequence are terrible.


Kinja'd!!! wafflesnfalafel > facw
09/21/2019 at 23:56

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I was out in Moses Lake the last couple days - lots of 737 max being stored out there now.  There were a couple c-17s that seemed to be doing touch and goes out there too which seemed a bit unusual.  Got buzzed by an old P-3 up north in the coulee - I’m thinking a training run out of NAS Whidbey maybe.


Kinja'd!!! Highlander-Datsuns are Forever > facw
09/21/2019 at 23:59

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I’m not a pilot, but pilots have been doing training on this system since these accidents and you just never know if you would have the correct actions at the right time to save the plane retrospectively. Some say they would have done the right thing but this should never have been an issue in the first place.


Kinja'd!!! DipodomysDeserti > Spanfeller is a twat
09/22/2019 at 00:02

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Somebody grab TAE new synchros.


Kinja'd!!! facw > wafflesnfalafel
09/22/2019 at 00:03

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Boeing Field was looking like it was getting quite full when I was up there a month ago, and I’m pretty sure there were MAXes being stored at Paine Field, as well, though they were at the far end (the ramp closer to the factory was full of widebodies), so it was hard to see how full that space was, or if they were actually MAXes, but it seemed like they could be pretty full there too. I can’t imagin e Renton is any better. I’m not surprised they’ve had to start stashing them elsewhere.


Kinja'd!!! facw > Highlander-Datsuns are Forever
09/22/2019 at 00:06

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It’s certainly true that knowing what to do in a dispassionate situation is different then when you are in a plane trying to crash itself. Still it seems pretty shocking that after the first crash, the Ethiopian pilots were confused about what to do. Pet the article, it does seem like they knew that MCAS would be disabled if they turned on the article, but then didn’t know that in that situation the autopilot wouldn’t be allowed to engage.


Kinja'd!!! ranwhenparked > facw
09/22/2019 at 00:20

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There is probably credence to that. The MCAS problem was reported by a number of 737 MAX pilots in several countries , but all of them were able to circumvent it and maintain control of the aircraft, except for the two crashed ones. It does seem like more experienced, seasoned pilots were, unsurprisingly, able to deal with it. Of course, it is still Boeing’s fault that the problem existed in the first place, and they did ignore a number of warnings from 737 MAX pilots in the US and pretty much  kept on ignoring them until the second plane crashed.


Kinja'd!!! Spanfeller is a twat > DipodomysDeserti
09/22/2019 at 00:42

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I needed a full rebuild the moment the author mentioned “Airmanship” for the third time. 


Kinja'd!!! VS > facw
09/22/2019 at 02:58

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Bullshit, they ran simulations with pilots that knew what was going to happens and they still had issues controlling the plabe. Now you have Boeing that lied to companies that the plane was identical and that they didn’t have to train their pilots on the changes. Fuck Boeing. Don’t blame the pilots. Why wukd yiu build a car that can by itself do a 90 degree turn randomly and repeatedly. I guess when you try to save money and outsource to third world country to d evelopers that don’t know anything about aviation you end up with alm ost 400 deaf people...


Kinja'd!!! Rexford L > SmugAardvark
09/22/2019 at 12:21

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Sstructurally deficient SUV? My son rolled my 2001 Explorer Sport and it was able to be driven away and he had zero injuries.. I'm VERY impressed by its structure a


Kinja'd!!! paulCIA > facw
09/22/2019 at 12:58

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Fact is, regardless of maintenance and training practices on the part of these airlines it was only brand new 737 Maxes literally falling out of the sky. No other aircraft seems to have that particular problem even on those airlines. Maybe American pilots could have saved them, maybe not, it’s still broken by design if MCAS is necessary in the first place, and even worse that it didn’t actually work and in fact directly contributed to said falling out of sky issue, and all this without being mentioned in the flight manual.


Kinja'd!!! thatsmr > facw
09/22/2019 at 14:02

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Hope I’m not too grayed here...

Sold a car to a retired Boeing engineer recently and couldn't resist asking his take on this. He was glad to be out, as the beancounting stockholders took over a company which used to be one of engineers pursuing excellence 


Kinja'd!!! Matt Arntson > facw
09/22/2019 at 15:54

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What about Boeings decision to ignore airframe issues when installing the new fuel conserving engine? They were afraid of the timeline and lost sales to their competitor who was already ahead on the fuel saving selling point. I haven’t seen anymore on this issue. Is it too much to say unless there is a major airframe change to fully accept the air worthiness of a new power plant this aircraft will never be as safe as it should be?


Kinja'd!!! For Sweden > facw
09/22/2019 at 16:46

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This article reflects a growing consensus , and it’s freaking me out.

It’s not a fighter jet; it’s a bus. You shouldn’t need to be Chuck Yeager to fly it.


Kinja'd!!! Spanfeller is a twat > facw
09/22/2019 at 19:48

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I appreciate that this articles raises serious questions about standards for pilots across the world, it was like two years ago that Aeromexico crashed a jet in part because of pilot error, but Boeing and the FAA built and certified a product that simply did not work as advertised. Certainly they could’ve trained the pilots better and instructed “airmanship” through more thorough practice in smaller jets.

But that’s, to an extent, like arguing that bus drivers in Arizona should go to a winter rally school in case their bus suddenly fails in an unexpected manner that they wouldn’t even be trained to handle in said school; it’s ridiculous. To an extent it even perpetuates that other countries and their institutions are inept, which is not necessarily true.

In an industry that is growing this fast, you just can’t expect to have airman at the “helm” of every jet. We should expect however that pilots are bettered trained to handle stressful situations, Boeing shouldn’t forego training or security features for the sake of better marketing, and that FAA should be cautious about giving type ratings.

The comments to this Op-ed were smarter than the piece itself. 


Kinja'd!!! SBA Thanks You For All The Fish > facw
09/22/2019 at 23:30

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I’m in a weird spot on this whole debacle, having worked in embedded systems design for decades— start ing in avionics and flight controls— with a long stint doing safety analysis of software systems in military programs. I never took the job offer from Boeing many years ago, but have worked with a lot of their suppliers. And had a full minor of aerospace credits before I took BSEE and MSEE degrees and then moved into management.

Purely from a software design perspective (aside from the fundamental FAIL in the first round of the FMEA analysis... which never happened, apparently) this MAX disaster is posing some serious questions for me:

1) Like, how do you implement a “life critical” embedded software routine without implementing “watchdog/heartbeat” oversight? A monitor routine that says basically “I’ve fallen through this MCAS clusterfuck nose-down routine TWO , THREE , FOUR , FIVE times and my AoA input still says the nose is pointed at the sky even as I see the poor carbon-based schmucks pulling back on the stick. Maybe I should knock this shit off?”
WTF? Nobody implemented some basic error checking?

2 ) Along those same lines, I keep hearing that d-bag CEO (Why hasn’t that guy been fired?) talk about MCAS as an integrated control system to augment flight envelope issues..... What kind of “control system” only can send the nose “down”, not up... and has no linearity in the response, has a 10 second bandwidth limitation and DOESN’T EVEN LOOK AT NET CHANGE in aircraft attitude? It violates pretty much every basic rule for a stable control system design.

3) And, yeah, obviously a single component failure should never bring down a plane.

This one still feels like they gave it to the unskilled Summer Intern to work on as a side project, with no oversight and no review. And, somehow, it got into the final build. Boeing deserves every bit of the shit they are getting on this one. It’s unacceptable.

I personally (and this is me only, perhaps) HATE the “blame the pilots” angle that the US Pilot’s Union puts out there. Were the ET pilots not good enough to fly Boeing aluminum that day? Apparently not. But, the thing Boeing needs to keep in mind, if they want to persist in that narrative, is that there’s still a worldwide pilot shortage— and those ET guys were plenty skilled enough to fly an Airbus.


Kinja'd!!! SBA Thanks You For All The Fish > facw
09/22/2019 at 23:39

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Part of the problem is that as soon as they cleaned up the airplane (gear up, flaps retracted) which they did precisely according to their company’s flight ops book— well, all hell broke loose with a half dozen warnings, voice alerts, alarms and buzzers. You’re at a high density altitude already... Would you REALLY know that the STALL@! warning was a red herring? Not obvious in the heat of the moment. You have no altitude to work with— no room to “work the problem” and all hell is breaking loose.

The US pilots all claim to be able to “SOLVE THE PROBLEM” but the reality is that nobody knows for sure. You only had 40 seconds and a few hundred feet above terrain the solve the Puzzler. The military guys and gals are probably a better shot, but the vast number of pilots that have only flown highly-automated Embraer and CRJs? It’s conjectural.

I’ll say again what I did in the other post... at the end of the day, the software and sensor redundancy on an Airbus meant those ET guys were plenty good enough to have a successful flight in an Airbus that morning. Blaming the pilots for a scenario (especially the second crash, which was totally avoidable) that’s purely a Boeing fuck-up? Not a good look for Boeing , despite what America ’s arrogant pilots say.


Kinja'd!!! facw > SBA Thanks You For All The Fish
09/23/2019 at 00:37

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Yeah, I don’t think it’s safe to say that US (or western pilots in general) would necessarily respond all that much better. They are probably better trained than pilots in the developing world, but it’s not like we’ve never seen the mess up, and cost-cutting efforts exist everywhere. I would have been interested to see reporting on how much of this is problem elsewhere.

On the issue of confusion over whether it is a real stall, I wonder if that’s at least part of the reason the Ethiopian flight stayed at full thrust, since for stall recovery you do want full power. Obviously at some point they should have realized that based airspeed and the fact only the captain’s shaker was going that it wasn’t real , but I guess that’s the article’s point, these pilots weren’t good enough to quickly intuit such things under pressure, and react accordingly.

Regardless, personally I believe we can make strides improving safety even if the crew has limited talent, though the MAX indicates that you then have to demand excellence from automated systems.


Kinja'd!!! pip bip - choose Corrour > facw
09/23/2019 at 03:48

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https://simpleflying.com/australia-boeing-737-max-storage/


Kinja'd!!! facw > pip bip - choose Corrour
09/23/2019 at 04:29

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Hopefully Boeing will get this sorted out before that airport needs to expand just to store planes (though they may want an Australian  boneyard for other reasons). Honestly haven’t heard much about where the fix is since the FAA said Boeing’s first go wasn’t good enough.


Kinja'd!!! SBA Thanks You For All The Fish > facw
09/23/2019 at 07:39

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I know several 737 drivers personally... and they ALL immediately go to “oh, what dumbasses, they kept full power”. There’s several things that argue against the “oh they didn’t follow the checklist”... 1) no tably that they did initially and 2) Density altitude being so high at ADD. The airport is higher than any airport in the USA that can handle a MAX.

My point is just that, with such thin air immediately after takeoff, you are inherently at higher risk of stall anyway. So, with stall warnings (and Terrain!) going off you’d have to second-guess your automation

Amidst all that confusion, you’d have to basically figure out that the A0A and velocity data was bad, then zero in on MCAS. And do it while flipping through the QRH guessing what was going on. And do it within 40 seconds or by definition you’re dead.

It was just a human factors nightmare, complicated by the fact that Boeing’s implementation of MCAS was pretty weak. And, all catalyzed by a single sensor failure, which could never happen in an Airbus. I’m not selling Airbus, but Boeing cut some strange corners.

It gets even weirder if you dig into how the design evolved to this point... Obvious questions emerge like “Why are there TWO Electric Trim Cutout switches to turn OFF, but only a single Trim Motor?”

Strangely, there USED to be TWO trim motors, one for electric- manual trims and one for the Auto Pilot, Auto Speed and automated systems. The two switches were labeled appropriate to those. HOWEVER, apparently prior to t he NG series they cost-reduced the second motor out of the design, but left the two switches the same labeling. If these pilots had the redundant motor, with the stronger clutches that “used” to be in the design? Everybody would still be alive....

Oddly, in the move from NG to MAX, both those switches got re-labeled, but there are still two switches.

All of which leaves you with the obvious question, “For a design that couldn’t be changed because Boeing didn’t want to have to re-certify and re-train thousands of pilots , Boeing sure made a helluva lot of running cost-reducing changes that affected how the plane flew...”


Kinja'd!!! ttyymmnn > facw
09/23/2019 at 09:04

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Indeed, this was a fascinating read. I have been saying since day one that the pilots had their own share of the blame to carry here. Max’s weren’t dropping out of the sky all over the world, that’s for sure.

One of Boeing’s bewildering failures in the MCAS design is that despite the existence of two independent angle-of-attack sensors, the system did not require agreement between them to conclude that a stall had occurred.

Boeing definitely has egg on their face here, but the article also points a big finger at the companies that manufacture and repair these sensors. Something else I learned from this article, and that is related, is that the stick shakers were happening only on one side of the plane. Sitting at home in front of the computer with a cup of coffee, it’s easy to say that the pilots should have taken that into consideration when they were trying to work the problem. But when the timeworn mantra is “Fly the plane” and you don’t have the skills necessary, then you’ve got a bigger problem still.

I was also interested by the author’s description of the different design ethos between Airbus and Boeing. I had always heard that Boeing was more pilot-centered, right down to the decision to use a yoke rather than a side stick. But I hadn’t heard the assertion that Airbus specifically designed its aircraft around less skilled pilots. I keep coming back to AF 447. As I understand it, one of the circumstances that led to the fatal stall was that one pilot was giving full back stick and the other pilot didn’t know it because the controls aren’t mirrored.

At the end of the day, I believe the MAX is a safe airplane, and it’s only safer now. The sad part is that all the testing and design work going in to making it safer should have been done in the first place. 


Kinja'd!!! facw > ttyymmnn
09/23/2019 at 09:21

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Yeah, I found the contrast in philosophy between Boeing and Airbus interesting. I don’t know how true it is, but I do know tellings of this joke often specify an Airbus:

The plane of the future will have a crew of two, one pilot and one dog. The pilot’s job is to make sure the dog has food and water, the dog’s job is to bite the pilot if they try  to touch the controls.


Kinja'd!!! ttyymmnn > facw
09/23/2019 at 09:29

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Kinja'd!!! ttyymmnn > facw
09/23/2019 at 09:42

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they were just so single-mindedly profit-driven that they didn’t realize they were building something with a glaring safety flaw.

I think this had more to do with the belief that any situation where MCAS would be needed was so far outside the normal envelope of operations that it didn’t require more rigorous testing or consideration of worst-case scenarios. That’s a pretty huge roll of the dice, though. That said, the whole single data input design is nearly criminal. 


Kinja'd!!! ttyymmnn > facw
09/23/2019 at 09:44

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The fact that they thought the autopilot would save them speaks volumes about the lack of airmanship the author is portraying. 


Kinja'd!!! Ash78, voting early and often > facw
09/23/2019 at 10:17

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I know I’ve posted this before, but my dad and his old-school aviation buddies (mostly general aviation and corporate, but some airline captains ) are all in their early 70s and were talking about Flight Safety and similar training firms. Until the early 90s or so, the idea of a “runaway trim tab” situation was commonly trained for in the simulator, since it was a rare-but-plausible situation that could cause confusing pitch behavior and trick you into bad decisions .

I’ve heard some of the newer heavy simulators don’t even have the software to replicate it. I guess when you only have so many hours, you have to prioritize. Unfortunately, that means the crews lose one more aspect on how to control the plane


Kinja'd!!! Turbineguy: Nom de Zoom > facw
09/23/2019 at 17:14

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I flew small turboprops (C208, PC-12) which didn’t have the same kind of stability augmentation the Max has, but one of the memory items included yanking the trim motor breaker in case of a runaway. I just assumed something big like a 737 would have a similar emergency procedure. 


Kinja'd!!! Chan - Mid-engine with cabin fever > SmugAardvark
09/23/2019 at 19:24

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Agreed.  This is one of the better analogies.


Kinja'd!!! Chan - Mid-engine with cabin fever > SBA Thanks You For All The Fish
09/23/2019 at 19:27

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Good commenting here. These systems are supposed to be foolproof or at last badpilotproof, so that a crappy or inexperienced pilot wouldn’t lose the plane because of a single component failure.

I still can’t get over the fact that the weight balance makes the plane inherently pitch-unstable and literally requires active controls to maintain attitude. I still don’t want to ride on a 737MAX, ever.  This is a travel workhorse, not an F-22.


Kinja'd!!! SBA Thanks You For All The Fish > Chan - Mid-engine with cabin fever
09/23/2019 at 19:51

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The pilots (who generally don’t really have any formal aeronautics training) keep repeating the Boeing script that the system “is stable” in all axes, but that’s not actually the case in the pitch axis. At higher thrust, as at take-off, the pitch up of the nose does in fact move the center of lift forward unacceptably. The large, forward placed, airfoil that is those huge nacelles does move Center of Lift forward of Center of Gravity— and this is not a good thing for commercial aircraft.

I’m a cynic, but at this point I really don’t trust a thing Boeing says about this aircraft.  There’s too much weird stuff they’ve gotten by with.  When the European Aviation authorities sign off?  I’m interested. Until then?  Unsafe at any altitude.


Kinja'd!!! ttyymmnn > facw
09/23/2019 at 21:45

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The plot thickens. And the shit deepens.

FAA misled Congress on inspector training for Boeing 737 Max, investigators say

Investigators examining a whistleblower complaint have concluded that safety inspectors who worked on training requirements for Boeing 737 Max pilots were themselves “underqualified” — and that the Federal Aviation Administration provided misleading information about the issue to Congress.

It’s WaPo, so there’s a paywall. I can email it to you if you are blocked.


Kinja'd!!! SmugAardvark > Rexford L
09/25/2019 at 18:23

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That’s fine as anecdotal evidence, and I’m genuinely glad your son was entirely uninjured. But that was not the case for 271 other individuals that rolled an Explorer.

I t is a documented fact that Ford removed material from the roof and the structural supports of the Explorer to lower the center of gravity and improve fuel efficiency. The revised roof was unable to support the weight of the vehicle if the windshield was damaged (as it often was in a rollover collision). So yes, tread separation is what caused many of those Explorers to ultimately rollover. But the weak structural sections caused many of the fatalities.