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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

#31

Earlier quoted context omitted.

Boeing doesn’t make engines, GE does

Engine Alliance (GE and Pratt & Witney) and Rolls Royce are the 2 players. Because engines are purchased separately from the aircraft, the buyers and engine manufacturers must be in a bind, since the buyer needs to pay for the engines for Boeing to fit them, whether the plane enters service or not.

I don’t think boeing uses Rolls Royce anymore after the Trent 1000 fiasco on the dreamliner. The GE9X is a fantastic engine and far quieter than the Trent engines.

https://m.youtube.com/watch?v=dDU1cvANdDQ

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

#32
post #29

Earlier quoted context omitted.

On the flip side, all airplanes have flaws to some degree or else they would never crash. A deep audit of everything in the end should make things safer. And Boeing also has a solid safety record on their other models 777 and 767

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

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

#33

Earlier quoted context omitted.

On the flip side, all airplanes have flaws to some degree or else they would never crash. A deep audit of everything in the end should make things safer. And Boeing also has a solid safety record on their other models 777 and 767

Aircraft don't have to have flaws to crash, unless you count the human pilots, air traffic controllers, maintenance crews etc. as flaws. You could have a perfect aircraft with no flaws, and a human could still manage to crash it. See the Germanwings flight for a good example.

The flaw was allowing a single pilot in the cockpit and allowing the co-pilot to get locked out. But yes I do agree that in theory its possible to have a perfect aircraft and still crash due to some act of God. Nevertheless the context was with respect to making an aircraft with known flaws safer

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

#35
post #26

Earlier quoted context omitted.

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

You can check the model before purchase.

I just tried this on Southwest's website, and it was hard to find but I was able to do this. Thanks!

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

#37
post #26
post #9

Not going to trust that model, like dc10 (?). May work not engineer. But as customer, only get 1 life. Not as software beta tester.

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 with that carrier at least for the next few years.

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

#38
post #24

Earlier quoted context omitted.

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.…

Upgrades to the 737 do have a particularly constrained design space, though (due to the oft-mentioned very low ground clearance).

Why can’t they change the ground clearance and remove the constraint?

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

#39
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.…

It's worse than other such planes. For instance, the accident on Qantas Flight 72 is superficially similar - faulty data caused the Airbus A330's flight computer to ignore pilot input and abruptly pitch down, injuring a number of passengers - but it really wasn't. The Airbus engineers knew that angle-of-attack sensors fail, so unlike Boeing they designed their system to compare the input from multiple AOA sensors and ignore bogus data.

Unfortunately, that comparison algorithm had a flaw - it got confused when it received spikes of invalid data with a certain timing pattern and erroniously used the invalid data. That pattern shouldn't have been possible. No-one has been able to figure out any possible cause for it even in retrospect, and they certainly didn't anticipate it. However, the engineers designing the system did realise that the flight computers could have subtle bugs triggered by specific data timing - so not only did every flight computer have a monitoring channel running independently-written code checking its calculations, that monitoring channel was intentionally not synchronized with the main channel or any other flight computers. This meant every time one of the flight computers acted on bogus data and forcibly pitched down, the monitoring channel calculated values so different that the fault detection disabled its ability to do so within a few seconds.

The maximum allowed authority and the altitude at which the system was enabled were also much more carefully restricted than MCAS, so it couldn't take such erroneous actions in situtations where the pilot might be unable to recover. Combine the two safeguards, and something like Qantas Flight 72 with a few passenger injuries but no crash was pretty close to the worst-case scenario that could be caused by this weird and incredibly unlucky issue.

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

#40
post #24

Earlier quoted context omitted.

Upgrades to the 737 do have a particularly constrained design space, though (due to the oft-mentioned very low ground clearance).

Why can’t they change the ground clearance and remove the constraint?

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 trying to make sure the 737 MAX flew the same as previous models.
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