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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

#141

Post by joshcain »

rsynnott wrote: post #100
vkou wrote: post #71

Earlier quoted context omitted.

> 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. You wouldn't, but the thing is - you don't get the option. Your airline won't tell you which plane you'll be flying until boarding time. You then have the option of cancelling your flight witho…

Most airlines only use one manufacturer for this size class; it’ll be 737-XXXs, or a32Xs, but rarely both. So just choose an appropriate airline. Not always an option, of course, but on the biggest routes it generally is.

Many airlines use both Airbus and Boeing within the same size class. American, United, and Delta all operate both 737s and A320-class planes.

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

#142

Post by tw04 »

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…

>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.

Something tells me their competitors (who aren't flying 737 Max) are going to advertise that they don't and the ones who are refusing to tell you what plane you're flying on are going to lose a ton of business.

Delta is already a dominant player, making a move like you've stated will just cement their position.

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

#143

Post by fsckboy »

dimitrios1 wrote: post #30
shajznnckfke wrote: post #17

Earlier quoted context omitted.

Even though this model has big design flaws and a relatively bad safety record, the absolute level of risk is still pretty low. I knowingly expose myself to larger risks in my day-to-day life. So I won’t lose any sleep over booking a flight on this type of plane.

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.

Yours is not a good argument. You can't assess this type of risk, let alone control it.

Even if you are an aeronautical engineer, you won't convince me that you can assess these risks, because teams of aeronautical engineers designed this plane and did it overall very safely like they did the planes that came before it, and I'd have no reason to believe your claims. None of them assessed this level of risk as risky, they were willing to fly in it, and the only thing that seems absurd is you thinking you know better.

There are flaws of varying severity in every large scale human endeavor, kinks get worked out, this one is stochastically late in the game.

In terms of controlling this risk, that is exactly what "we" are doing, that's what this article is about, removing an identified risk from this plane's design. There is no reason to think that the plane now has bad juu-juu, that's superstition.

Air travel is incredibly safe, this plane is too.

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

#144

Post by tjmc »

imglorp wrote: post #66
kevin_thibedeau wrote: post #4

They need to implement triple redundant AOA indicators. It's obscene that these failure modes are even possible much less approved. Knowing there is a disagreement just lets you know you are close to being fucked.

Triple is not needed, just double with a redundant "disagree" alarm. Once the pilot knows there's one bad AOA, they can lock out the bad one as an input to the autopilot/MCAS, or hand fly without automation. Of course this is all a bunch of new software and training though.

Wasn't the second AOA sensor an optional upgrade? Seems it should be mandatory for a start.

Edit: It had 2 AOA sensors but the indicators showing each reading and the disagree light if they differed were optional (https://www.nytimes.com/2019/03/21/business/boeing-safety-fe...)

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

#145

Post by caconym_ »

curryst wrote: post #116
shock wrote: post #101

Earlier quoted context omitted.

> However the method, it's far more likely to injure you than flying on a 737 MAX. That depends. If you take a bus to go to the airport and it takes you an hour to get there, then your flight also lasts an hour (for simplicity's sake), you are almost 3 times more likely(on average) to die during the flight than you are during the bus ride [0]. In terms of number of journeys by plane and bus, for the same number of jo…

Measuring the risk of travel in terms of hours seems largely pointless, unless I'm missing something. It equates an hour bus ride with an hour plane ride, which are not interchangeable, so it makes sense that the associated risks are also not interchangeable. You could account for the additional time it takes to go on a bus to adjust for the longer duration of risk, but at that point it seems like you're just approxi…

I think it makes a lot more sense to look at risk per time, because it's basically the same thing as risk per trip, and that's what I really care about.

If you tell me I can fly to Mars in a few days on a brachistochrone torchship and it's safer per mile than any other mode of transport, you may be right, and a few days cooped up in a cramped cabin might be a small price to pay for such an exotic vacation destination, but that risk calculus is really very misleading. The distance involved is so vast that per mile it could be an absurdly low figure by any terrestrial standard while still carrying an absurdly high (by the same standards) risk of death during the trip.

In other words, if the odds are e.g. 1 in 10 that the trip will kill me, I don't give a shit how low the risk per mile is.

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

#146

Post by phire »

simion314 wrote: post #55
yellow_postit wrote: post #12

Earlier quoted context omitted.

Given the amount of additional scrutiny these models are getting I wouldn’t be surprised if in the long run of their lifetime they have a better safety record.

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.

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

#147

Post by plasma »

fsckboy wrote: post #143
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.

Yours is not a good argument. You can't assess this type of risk, let alone control it. Even if you are an aeronautical engineer, you won't convince me that you can assess these risks, because teams of aeronautical engineers designed this plane and did it overall very safely like they did the planes that came before it, and I'd have no reason to believe your claims. None of them assessed this level of risk as risky,…

> Even if you are an aeronautical engineer, you won't convince me that you can assess these risks, because teams of aeronautical > engineers designed this plane and did it overall very safely like they did the planes that came before it, and I'd have no > reason to believe your claims.

That feels really really naive and an unfair judgement to make. I don't need to be an aeronautical engineer to know about other market force at play, and a repeated lack of ownership of the issue by Boeing: incentive for Boeing to not go out of business, airlines to get a return on the airlines they bought, etc. They reek of dishonesty on this matter.

As a traveler I would absolutely bucket that airplane model into the "Something is fundamentally wrong" and distrust.

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

#149

Post by mitchellgoffpc »

WatchDog wrote: post #135
Someone1234 wrote: post #87

Earlier quoted context omitted.

> they can lock out the bad one as an input to the MCAS The 737 MAX didn't support that as delivered. Even with the warning (which some US airlines paid for), you couldn't "lock out the bad one" even assuming you knew which one that was (you don't). All you could do is disable the electronic horizontal stabilizer completely, so that MCAS couldn't command it into a dangerous and unrecoverable state. MCAS has been fixe…

> Even with the warning (which some US airlines paid for) Are you saying that a bad input warning was an optional(paid) extra?

Yep. The "AOA sensor disagreement" light is built into every cockpit, but it won't turn on unless the airline purchased a specific premium add-on. Boeing claims they initially didn't realize the light was bundled as an add-on, and then once they did realize, they decided it wasn't critical to the airplane's safety and just kept selling it as an add-on, which is... kind of alarming, to put it mildly. https://www.nytimes.com/2019/05/05/business/boeing-737-max-w...

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

#150

Post by thatswrong0 »

RandallBrown wrote: post #139
thatswrong0 wrote: post #83

Earlier quoted context omitted.

Yeah 2 out of 387 hull losses over 2 years is a pretty awful record. I will stick to not 737 MAX thanks.

My understanding is that the crashes were due to properly functioning (but awkward and confusing) MCAS systems. I have to imagine that any pilot flying a 737 MAX is going to have a very solid understanding of how that system works and how to tell if it's malfunctioning and avoid the same situation. Also, it was 2 crashes in 500,000 flights. It seems a little misleading to just compare it to hull losses.

> properly functioning (but awkward and confusing) MCAS systems

It had almost unlimited pitch authority, used only one (potentially faulty) AOA indicator to decide to activate, and could activate repeatedly unless purposefully deactivated. Even the way in which it was certified was extremely suspect. I'm curious as to how you think that is "properly functioning". Its initial implementation was straight up dangerous, as should be plainly obvious by the 346 deaths it caused. (https://www.seattletimes.com/business/boeing-aerospace/faile...)

In the cases of the Ethiopian crash, they _were_ aware of the "proper" procedure to deactivate the MCAS:

> But on the Ethiopian Airlines flight, the pilots appear to have recognized the errant MCAS problem and flipped the cutoff switches as described in the checklist. But then it appears that the pilots were unable to move the manual wheel, likely because the forces on the tail made it physically challenging to turn.

> The bottom of Boeing’s runaway stabilizer checklist seems to acknowledge the possibility of this physically challenging scenario. It suggests that the pilots can first use the electric trim to neutralize those potential forces before hitting the cutout switches.

> After failing to manually control the stabilizer, the Ethiopian Airlines pilots appear to have flipped the cutoff switches back on, which awakened the MCAS system. It soon sent the plane diving to Earth.

(https://www.seattletimes.com/business/boeing-aerospace/boein...)

They let their airspeed get too high, so they were unable to manually trim because of the physical forces involved. But making this mistake during this phase of flight this is somewhat understandable, as they encountered the problem just one minute after takeoff (which is a pretty critical / task heavy phase of flight) and were still very close to the ground. Chelsea Sullenberger (the guy who ditched into the Hudson) commented that "Even knowing what was going to happen, I could see how crews would have run out of time and altitude before they could have solved the problems." (https://www.bloomberg.com/news/articles/2019-06-20/fight-for...)

> Also, it was 2 crashes in 500,000 flights. It seems a little misleading to just compare it to hull losses.

If we're talking about the relative safety of different aircraft, no it's not. Compared to, say, the Airbus A320neo (which has had 0 hull losses over ~1300 aircraft over 10 years), it's terrible. It's a far less safe plane.

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