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Boeing 737 Max pilots complained to feds for months about suspected safety flaw

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Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#271

Post by callmeal »

hyperbovine wrote: post #256
cjbprime wrote: post #158

Earlier quoted context omitted.

Boeing fought extremely hard to avoid having this happen, since then any pilot wanting to fly the Max would have to first achieve a type rating certificate for the new type of plane, and the FAA would have to test and certify it instead of Boeing "self-certifying" that it was a type of 737. The determination to shoehorn what aerodynamically kind of is a new type of plane into the 737's type rating seems likely to be…

Initial eyewitness reports are of fire, smoke and debris trailing the aircraft before it went down. I would caution against the use of the word "likely" here.

Eyewitness testimony is some of the most unreliable there is. See the gorilla experiment for instance.

It's likely that people rewrote their memories of the event. It's also likely that the MCAS induced stresses on the plane caused a turbine flameout.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#272

Post by CompelTechnic »

dTal wrote: post #86
ordinaryradical wrote: post #72

Earlier quoted context omitted.

These all sound extremely serious and damning, but it's hard to know whether these match the typical tone and content of these kind of reports. Is this is well inside the standard for adjusting to a new aircraft or does this suggest a serious hazard left unaddressed?

> I would generally assume it was my automation error, i.e., aircraft was trying to acquire a miss-commanded speed/no autothrottles, crossing restriction etc., but frankly neither of us could find an inappropriate setup error (not to say there wasn't one). Regardless of the usual tone, I find this particular paragraph a fairly terrifying indictment of cockpit human factors across the board. Apparently it's not unusua…

If you ever have some time, you should try playing microsoft flight simulator and you will come to an understanding of this phenomenon.

Aircraft have many states, and there is a lot of information to process to fly an aircraft, even in normal flight. When situations develop in real time, it takes a lot of mental horsepower to understand the situation and react appropriately. Despite all this, aviation is safer than driving a car.

It is one of the reasons I find aviation to be inspiring. Conscientious humans have mastered this unforgiving domain through effort and power of will. When you talk to a real pilot, there are certain mannerisms that they share that tend to show that the practice of flying really makes you a thoughtful person.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#273

Post by dsfyu404ed »

marcus0x62 wrote: post #264
dsfyu404ed wrote: post #247

Earlier quoted context omitted.

Speaking of panel gaps. The panel gaps shrink in warm weather. In case anyone was wondering that was actually a thing with early plastic body panels. They eventually refined it to the point where the gaps don't change noticeably and now pretty much every car has some plastic body panels.

Saturn had a lot of fit-and-finish issues, but man the S-series was reliable. I had one for 13 years/250,000 miles and barely put more than tires, brakes, and oil into the car. The oil, though, was interesting. The s-series engine had a design flaw with the oil control piston ring where it would get stuck in its groove due to carbon build-up. The engine would then start burning prodigious amounts of oil — mine burned…

What I've heard (i.e. this may just be hearsay) was that for much of its history Saturn used engines that had bores with a fairly rough surface finish which resulted in them holding more oil and reducing wear on the bores and rings but at the cost of burning more oil. Sometimes they burned quite a lot of oil as they got old.

GM treated Saturn like a throwaway brand so they used them for a lot of R&D they didn't want to risk "important brands" over and consequently there's a bunch of random Saturn cars that have features that even some new cars don't have. My friend had one from the early 2000s that would vary radio volume with speed and window position.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#274

Post by marcus0x62 »

dsfyu404ed wrote: post #273
marcus0x62 wrote: post #264

Earlier quoted context omitted.

Saturn had a lot of fit-and-finish issues, but man the S-series was reliable. I had one for 13 years/250,000 miles and barely put more than tires, brakes, and oil into the car. The oil, though, was interesting. The s-series engine had a design flaw with the oil control piston ring where it would get stuck in its groove due to carbon build-up. The engine would then start burning prodigious amounts of oil — mine burned…

What I've heard (i.e. this may just be hearsay) was that for much of its history Saturn used engines that had bores with a fairly rough surface finish which resulted in them holding more oil and reducing wear on the bores and rings but at the cost of burning more oil. Sometimes they burned quite a lot of oil as they got old. GM treated Saturn like a throwaway brand so they used them for a lot of R&D they didn't want…

The rough cylinder bore didn’t help, but the root cause was the design of the bottom ledge of the oil control ring grooves and the lack of proper drainage.

A popular shade tree mechanic fix was to drill drain back holes in the oil control ring groove: https://m.youtube.com/watch?v=UrnblJ8VZtY

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#275

Post by cjbprime »

hyperbovine wrote: post #256
cjbprime wrote: post #158

Earlier quoted context omitted.

Boeing fought extremely hard to avoid having this happen, since then any pilot wanting to fly the Max would have to first achieve a type rating certificate for the new type of plane, and the FAA would have to test and certify it instead of Boeing "self-certifying" that it was a type of 737. The determination to shoehorn what aerodynamically kind of is a new type of plane into the 737's type rating seems likely to be…

Initial eyewitness reports are of fire, smoke and debris trailing the aircraft before it went down. I would caution against the use of the word "likely" here.

The Ethiopian Airlines CEO has disclosed that the pilot experienced a control issue. So a fire, if one existed, was probably a consequence, not a cause.

It wouldn't even be surprising if the aerodymanic stress had caused a breakup, though that doesn't seem to have happened judging by the crater.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#276

Post by cjbprime »

woofcat wrote: post #255
cjbprime wrote: post #181

Earlier quoted context omitted.

It sounds like you're going for a "innocent until proven guilty" approach to the Max's airworthiness, if I'm understanding your comment correctly. That seems opposite to the culture of air safety, where planes are certified airworthy because the data prove them to be so. I don't think the data prove airworthiness of the Max anymore.

However no data that originally certified it as airworthy has changed. All we have is two incidents, one of which we have no information about. For all we know it was a hijacking, or a drunk pilot. Absurd ideas, however in my mind without any evidence it is equally likely. They have the CVR and I'm sure very shortly we'll know for sure. If it turns out to be MCAS then we can ground the fleet, the extra day of delay d…

That's not really true. MCAS can not be argued to meet https://www.risingup.com/fars/info/part25-672-FAR.shtml, so it's not airworthy. The FAA's allowed them to continue flying anyway while they disclose the problem and workarounds, and deploy a fix which is now very delayed. That's a much more questionable decision now that another flight with similar characteristics has crashed.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#277

Post by cjbprime »

chopin wrote: post #214
cjbprime wrote: post #174

Earlier quoted context omitted.

And on a less individual level, just the MAX order book alone is larger than the market cap of Apple. Boeing is the largest exporter in the US.

But how would it help to not grounding the plane in the US if it is grounded pretty much elsewhere? I am pretty sure orders will get canceled or at least postponed over this. And Boeing pretty sure cannot risk another incident.

It helps because it influences other authorities and buyers not to do anything drastic.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#278

Post by mobilemidget »

nocture wrote: post #209
mobilemidget wrote: post #164

Is it time to buy Boeing put options already?

wait until the mounting pressure makes FAA ground the plane, then buy shortly after

https://edition.cnn.com/2019/03/12/investing/boeing-stock-up...

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#279

Post by magnamerc »

hyperbovine wrote: post #256
cjbprime wrote: post #158

Earlier quoted context omitted.

Boeing fought extremely hard to avoid having this happen, since then any pilot wanting to fly the Max would have to first achieve a type rating certificate for the new type of plane, and the FAA would have to test and certify it instead of Boeing "self-certifying" that it was a type of 737. The determination to shoehorn what aerodynamically kind of is a new type of plane into the 737's type rating seems likely to be…

Initial eyewitness reports are of fire, smoke and debris trailing the aircraft before it went down. I would caution against the use of the word "likely" here.

Engine flame outs could occur at high AoA due to stall turbulence in the inlet.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#280

Post by zbobet2012 »

dpwm wrote: post #91
ehsankia wrote: post #64

Earlier quoted context omitted.

It would be ironic if the lack of 737-MAX category for reports is why these reports never made it to the people who needed to see them, which caused the issue to go unnoticed.

1555013 is pretty damning in telling how the airlines treated the MAX as the same type as the 737-800: "I had my first flight on the Max [to] ZZZ1. We found out we were scheduled to fly the aircraft on the way to the airport in the limo. We had a little time [to] review the essentials in the car. Otherwise we would have walked onto the plane cold.My post flight evaluation is that we lacked the knowledge to operate th…

I've got to say it's massively comforting to see that many pilots treat this stuff with such a level of professionalism and sense of duty.
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