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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

#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.

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

#42
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…

Of all the many problems of the Boeing 737Max situation, and there are several, for once I don't think the media reporting is one of the biggest. But, your basic point stands.

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

#43

Earlier quoted context omitted.

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…

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?

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

#44

The computers are all part of the problem with this and it's a trend I've noticed for a long time now. Regarding critical output and human input.

I see your point. At some point computers simply cannot help us anymore for certain tasks and can actually begin to be a detriment.

Software bugs notwithstanding, too much computer means less human piloting and less actual hand flying experience. It might lead to a lower bar of acceptance to be a pilot, or discourage the types of people who actually love flying (since it's mainly done by the computer). More software can mean more complacency, less attention and engagement, less feeling of authority (by being so conditioned to surrender to the computer) and less "feeling" for what is right and wrong in any situation ("the light is green, that means no issue with this thunderstorm, company policy says fly the route when the light is green") .

It's perfectly okay to let some jobs (or mechanical assemblies) be manual even when they could be made auto.

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

#45
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?

They could, but it would mean that a lot of the supporting infrastructure at airports would have to change, essentially negating much of the advantage from avoiding a new clean-sheet design.

As long as it remains sufficiently 737-shaped airlines can keep flying it to all the place they've been flying 737s for decades.

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

#46

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?

Ah, you mean why did they originally do it? Sorry, I misunderstood. The original reason was that the 737 was designed that way so that it could be boarded with just stairs instead of a skybridge: https://simpleflying.com/737s-low-to-the-ground/

This was super helpful to small carriers at the time, but as time has gone on it's caused problems.

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

#47
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?

They could, but my understanding is then it would count as a new airplane, with more training required for pilots to fly it. They were trying to pretend it was not a completely new airplane, so that pilots wouldn't need much new training to be certified to fly it.

It is turning out to have been a pretty bad decision, even from a mercenary point of view.

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

#48
post #30

Earlier quoted context omitted.

Boeing doesn’t make engines, GE does

Boeing doesn't make a lot of the components on their planes. The plane doesn't fly until Boeing is satisfied with how those components work.

Ok but having to overcome an engine problem isn't boeings problem its the manufacturers.

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

#49

Earlier quoted context omitted.

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?

Ah, you mean why did they originally do it? Sorry, I misunderstood. The original reason was that the 737 was designed that way so that it could be boarded with just stairs instead of a skybridge: https://simpleflying.com/737s-low-to-the-ground/ This was super helpful to small carriers at the time, but as time has gone on it's caused problems.

[deleted]

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

#50
post #30

Earlier quoted context omitted.

Boeing doesn’t make engines, GE does

Boeing doesn't make a lot of the components on their planes. The plane doesn't fly until Boeing is satisfied with how those components work.

You are of course, correct. My first engineering job fresh out of university was for GE. I worked at a (big) site in the British countryside in the Midlands.

One of our clients was Boeing, and we made a lot of sensors for them: anything from landing gear stuff, cabin oxygen and pressure sensors... you get the picture. Quite a lot of them were ultimately destined for the 787.

I also remember manufacturing sensors for Hamilton-Sunstrand... who would then fit them in 737 rudder assemblies and then sell them to Boeing. The whole subcontracting business was very byzantine in its complexity!

I also distinctly remember Boeing execs coming over very frequently to give updates, feedback, etc.

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