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U.S. FAA proposes requiring key Boeing 737 MAX design changes

reuters.com

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Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#241

Post by kayfox »

mcgoo wrote: post #239
Nacdor wrote: post #6

Given the option, would anyone choose to book a trip on one of these new Boeing aircraft rather than anything else? I know I wouldn't, my family wouldn't, and none of the friends or co-workers I've discussed this with would. Something tells me airlines are going to be making it even more difficult to determine which aircraft you'll be flying on when you book a ticket. As far as I know they're not required to tell you…

The MAX is also known as the 737-8200. Now that the product recognition is working against it, I think we will see the forgettable name a lot more. At least in the US you can typically cancel a flight for free within the first 24 hours if it is booked more than seven days out, if that helps. You are right that the airline can change the type of plane like that but it is uncommon. A much more common way to end up on a…

The 737-8200 is the 737-8 MAX 200 that Ryanair requested before all of this happened. Its a special ultra high capacity 737 MAX 8 with two more overwing exits and some knee unfriendly seat pitch.

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#242

Post by kayfox »

philjohn wrote: post #107
kube-system wrote: post #79

Earlier quoted context omitted.

This has happened with other planes before, like the DC-10.

Or the De Havilland Comet ... arguably killed off the nascent UK jet aviation sector until we joined Airbus.

There was the BAC One-Eleven, which BAC sold a modest number of.

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#243

Post by dharmab »

stevehawk wrote: post #227
dharmab wrote: post #22

Earlier quoted context omitted.

You have more confidence in the plane than the people who designed and built it. https://www.nytimes.com/2020/01/09/business/boeing-737-messa...

To my knowledge, we don't actually know that. None of the emails I've seen refer to anyone's title or name. For all I know it's a janitor who heard rumors around a water cooler.

That's a ridiculous statement. The "Would you put your family on a MAX simulator trained aircraft?" quote comes from page 103 of this PDF [1] and is in the context of a technical discussion of the aircraft's design by people who clearly understand the internals.

[1] https://int.nyt.com/data/documenthelper/6653-internal-boeing...

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#244

Post by toast0 »

salawat wrote: post #211
toast0 wrote: post #137

Earlier quoted context omitted.

Yes! If this was available, at least the second crash seemed likely preventable given the timeline of events. I didn't read the timeline for the first one.

Relevant article: https://www.seattletimes.com/business/boeing-aerospace/boein... That would allow a pilot to put the plane in a configuration for which it is not certified to transport passengers, however, and the triggering thereof should always be deemed an emergency if we're going to take our regulations with any level of seriousness.

That article has opposing viewpoints on if it would be a good idea.

But, imagine if the switches were as before --- the left turns off automation control of electric trim, and the right turns off all electric trim. In that case Boeing's notice for what to do in case of MCAS failure would be turn off the left switch and then they'd have advice about how immediate the need to land is. As opposed to their notice which was insufficient for Ethiopia Air pilots because they weren't able to trim the stabilizer manually and tried reenabling electric trim and MCAS continued to be broken.

Hopefully the MCAS changes described will be sufficient to prevent it from causing more crashes, and Boeing has republished a procedure to gain manual control by easing off the yoke temporarily, but it still seems to me that providing electric trim without automation input, as was available before (but never suggested to be used) would provide an additional tool for pilots in exceptional circumstances.

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#245

Post by cmurf »

phire wrote: post #146
simion314 wrote: post #55

Earlier quoted context omitted.

Do we know or is a reason to believe that FAA checked anything else then the MCAS and the systems related in the crashes? The MAX has probably many differences because is larger so all the new stuff should be put under the microscope since you can't trust the previous tests, measurements or decisions, Boeing guys were proud on how they mind tricked the FAA guys so FAA should now re=review everything then you can be 1…

The European equivalent of the FAA, the EASA are double checking all of the FAAs working here. The FAA are highly motivated to get everything correct this time in order to repair their reputation (which was tarnished by their original MAX approval). It would be highly embarrassing for if the EASA find anything the FAA missed.

There's every reason to believe EASA are being strong armed by U.S. State Department. This is an administration that thoroughly believes in bribery, extortion, and retribution. I have no more confidence in EASA than FAA.

Curious the FAA comes out with their position before any final crash reports by either country. NTSB usually also reports on accidents involving U.S. made aircraft, and that too isn't released yet.

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#246

Post by refurb »

mantap wrote: post #210
refurb wrote: post #191

Earlier quoted context omitted.

Maybe I need to brush up on my probabilities, but why would you have twice the failure rate? If each sensor failed 5% of the time and the sensor was chosen at random, wouldn’t the failure rate be the same?

Imagine flipping a coin. Your chance of tails is 50%. What is your chance of a tails if you flip two coins? It's now 75% clearly (TT, HT, TH but not HH). Now imagine it's not a coin but a normal distribution. If you sample from it twice then take the minimum of your samples, the chance that the minimum is below the mean is 75%. Just the same as with the coin but in another context. Obviously the time-before-failure i…

What is your chance of a tails if you flip two coins?

Thanks for explaining, but my understanding is the computer only looks at one sensor at a time, it doesn't look at both.

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#247

Post by [deleted] »

TylerE wrote: post #78
dimitrios1 wrote: post #30

Earlier quoted context omitted.

This is not a good argument. You can control this level of risk. Taking on any unnecessary risk when you don't have to is not a wise choice.

How are you getting to the airport? However the method, it's far more likely to injure you than flying on a 737 MAX.

[deleted]

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#248

Post by ac29 »

redis_mlc wrote: post #179
TaupeRanger wrote: post #88

Earlier quoted context omitted.

Nutrition epidemiology is a largely failed endeavor, so there's not much to be learned from someone's diet unless they're eating lots of trans fats or refined sugar on a regular basis.

The average American is eating about 5 pounds of HFCS weekly, since fat in processed food has been replaced with corn syrup, which is subsidized by the US govt. That is why nobody is fat in fotos from the 1960's, but most people are obese in fotos today. Coincidentally, this affects air crew. The standard airman is supposed to weigh 170 pounds (next time you're at the airport, note how thin the pilots in uniform look…

> The average American is eating about 5 pounds of HFCS weekly

Wow, that's over 6000 kcals per week, or nearly half of the required energy intake for a person of average height and healthy weight.

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#249

Post by philipkglass »

ac29 wrote: post #248
redis_mlc wrote: post #179

Earlier quoted context omitted.

The average American is eating about 5 pounds of HFCS weekly, since fat in processed food has been replaced with corn syrup, which is subsidized by the US govt. That is why nobody is fat in fotos from the 1960's, but most people are obese in fotos today. Coincidentally, this affects air crew. The standard airman is supposed to weigh 170 pounds (next time you're at the airport, note how thin the pilots in uniform look…

> The average American is eating about 5 pounds of HFCS weekly Wow, that's over 6000 kcals per week, or nearly half of the required energy intake for a person of average height and healthy weight.

It's wrong. Americans consume less than 1 pound per week per capita. Still a lot, but much less than claimed above.

https://www.statista.com/statistics/328893/per-capita-consum...

Re: U.S. FAA proposes requiring key Boeing 737 MAX design changes

#250

Post by WalterBright »

misanthropian00 wrote: post #236
WalterBright wrote: post #160

Earlier quoted context omitted.

The EA pilots were given an Emergency Airworthiness Directive which gave a two step process for recovering from MCAS malfunction: 1. use the electric trim switches to drive the trim to normal 2. cut off the trim system with the console cutoff switches. That's it. As simple as that. And it is NOT what the EA pilots did (they cut off the trim first). Here are the exact directions: "Initially, higher control forces may…

https://www.youtube.com/watch?v=_T5xhHzZjPQ https://www.youtube.com/watch?v=a5P8CkVckmA These are some links to youtube sims of the two events. It seems that the Lion Air pilot at least who of course did not know about the top secret MCAS system was trying to fight MCAS directly with electric trim and at first was successful but for some reason did not hit the cutout switches after getting back to level flight. So th…

My understanding is the EA crew had also initially successfully restored trim with the electric trim switches.

The LA flight prior to the LA crash flight did restore trim with the electric switches and then cut it off, and landed safely.

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