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FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

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Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#51
post #27

There are a myriad of issues that put the planes at risk, but I think that the fact that when the control system (MCAS) is engaged causes it to ignore feedback is the biggest issue of all. "But with the MCAS activated, said Fehrm, those breakout switches wouldn’t work. MCAS assumes the yoke is already aggressively pulled back and won’t allow further pullback to counter its action, which is to hold the nose down. Fehr…

To be fair, ignoring user input could have potentially have saved Air France 447... I mean I actually can't think of an automated fool proof system that would've fixed 447, but incorrect input was a major factor.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#52

Earlier quoted context omitted.

The engines on the original 737 design were quite small by modern standards, and the wings were low as well. As such there aren't really a ton of places to put new, larger engines. They basically have to be placed further forward and higher up. This means the pitch moment created by throttling up/down is different on different versions of the 737, which is what required the MCAS device in the first place - they were…

I think you’re just repeating the impact of the low ground clearance, rather than explaining why there still has to be low ground clearance. You’ve said they can’t have larger engines because ground clearance is low... we already know that... but why must ground clearance be low?

Because they would have to redesign the parts of the fuselage that holds the landing gear when they are retracted - as far as I know, there's not enough room to house taller landing gear.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#53
post #29

Earlier quoted context omitted.

Boeing also has a solid safety record on their other models 777 and 767 and an incredibly poor safety record for their 737-MAX model. The problem for Boeing is the history of flying has many examples of planes with poor safety records being rejected by the flying public. Only time will tell if the 737-MAX joins that illustrious group, but the more the plane stays in the news for all the wrong reasons, the better are…

The original 737 had a terrible safety record at first because of a rudder hard-over flaw. It then went on to become the most used in history

That doesn't sound right. The 737 went into service in the late 60s. There were two confirmed fatal accidents involving rudder hardover in the 90s.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#54
post #5

This plane appears to be a (sorta) flying dumpster fire rushed to market against Airbus with tragic consequences. One design flaw after another is MAX failure.

The industry is pretty homogeneous and somewhat of a revolving door between the few OEMs. What are the odds that the code on this plane is orders of magnitude worse (in terms of code quality) than every other similar bit of code in the sky? Edit. I should have to say this but I'm not defending Boeing here. I'm saying it's not at al unforeseeable that the other planes, even ones by other manufacturers are just as bad.…

My instinct is that you're probably correct, and most planes are probably riddled with similar problems and would look bad if they came under the same scrutiny as the 737 Max is currently under. For example, I remember after the 787 was launched there was a few stories in the press about the batteries catching fire mid-flight, but it turned out the designers and engineers had accounted for that possibility and it wasn't really a big deal. They've improved the batteries, but it didn't actually hurt anybody.

However, the problem with the max seems to be that instead of designing for failure - assuming that critical systems might fail and the plane should recover gracefully from the failure of most internal systems - they seem to have designed for success, and made the assumption that no part of the plane will ever fail. And that's obviously not realistic, and we're seeing the consequences of it here.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#55
post #41

The FAA suffered a major loss of credibility in their handling of the first round of testing/accreditation of the MAX. The FAA can't afford another stuff up this second time around and as such I suspect they will be checking every aspect of the plane in very fine detail. That could spell more trouble for Boeing.

I think overall we should consider this process a very positive thing, FAA and Boeing (and Airbus as well) are all going to learn a lot from this process which will make air travel safer in the future. It's unfortunate that it took two tragedies to get us here but if you look at the history of aviation improvements this isn't the first and it won't be the last time.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#56
post #51
post #27

There are a myriad of issues that put the planes at risk, but I think that the fact that when the control system (MCAS) is engaged causes it to ignore feedback is the biggest issue of all. "But with the MCAS activated, said Fehrm, those breakout switches wouldn’t work. MCAS assumes the yoke is already aggressively pulled back and won’t allow further pullback to counter its action, which is to hold the nose down. Fehr…

To be fair, ignoring user input could have potentially have saved Air France 447... I mean I actually can't think of an automated fool proof system that would've fixed 447, but incorrect input was a major factor.

The incorrect user input on AF447 happened AFTER all of the automatic systems had failed due to sensor clogging. How could ignoring user input have helped the flight when the plane's computer giving up was the cause of the manual takeover in the first place?

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#57
post #37
post #26

Earlier quoted context omitted.

How can you practically avoid a model of plane, other than avoiding all airlines that operate them?

Just visit a flight tracking website before booking. In addition I'm sure airlines not flying the MAX will be using that fact as a marketing tool (i.e. we only fly Airbus etc) so you could limit your bookings with just those airlines. As an example of this, here in Australia I know one of the carriers is planning to fly the Max some time next year. If they go ahead with that plan, I will be making sure not to book wi…

Airlines never use safety angle there is industry wide consensus on that.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#58
post #51

Earlier quoted context omitted.

To be fair, ignoring user input could have potentially have saved Air France 447... I mean I actually can't think of an automated fool proof system that would've fixed 447, but incorrect input was a major factor.

The incorrect user input on AF447 happened AFTER all of the automatic systems had failed due to sensor clogging. How could ignoring user input have helped the flight when the plane's computer giving up was the cause of the manual takeover in the first place?

Yes, I guess that's where I say I don't know of a fool proof system, and then yeah how would it know it was incorrect input. I was simply saying incorrect input, given the actual situation, was an issue.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#59
I'd be pretty comfortable flying it after all this attention and review. It will probably be the best reviewed passenger plane software developed in America, if not the world once this is over.

Boeing deserves a 9-figure fine though, and its shareholders should lose massively to make sure this doesn't happen again.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#60

Earlier quoted context omitted.

The engines on the original 737 design were quite small by modern standards, and the wings were low as well. As such there aren't really a ton of places to put new, larger engines. They basically have to be placed further forward and higher up. This means the pitch moment created by throttling up/down is different on different versions of the 737, which is what required the MCAS device in the first place - they were…

I think you’re just repeating the impact of the low ground clearance, rather than explaining why there still has to be low ground clearance. You’ve said they can’t have larger engines because ground clearance is low... we already know that... but why must ground clearance be low?

Because the airlines use hangars that are built for the current dimensions of the 737, not a bigger airplane.

And also you can't just redesign the landing gear without redesigning a substantial portion of the wings.

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