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Boeing's Crashes Expose Systemic Failings

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Re: Boeing's Crashes Expose Systemic Failings

#2
> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim.

I thought these systems were all fly-by-wire now?

Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

Re: Boeing's Crashes Expose Systemic Failings

#3

> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim. I thought these systems were all fly-by-wire now? Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

My understanding is that the 737 does not use Fly by wire [1] and if I remember correctly it's because they wanted to piggyback on the original 737 certification. I could be wrong.

1: https://www.quora.com/Does-the-737-MAX-family-use-fly-by-wir...

Re: Boeing's Crashes Expose Systemic Failings

#5
post #3

> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim. I thought these systems were all fly-by-wire now? Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

My understanding is that the 737 does not use Fly by wire [1] and if I remember correctly it's because they wanted to piggyback on the original 737 certification. I could be wrong. 1: https://www.quora.com/Does-the-737-MAX-family-use-fly-by-wir...

> I could be wrong.

You're not :-) The 737 still has direct mechanical linkages to the control surfaces. Changing that would require completely redesigning the aircraft.

Re: Boeing's Crashes Expose Systemic Failings

#6
> Bickeböller's complaint endangered the planned inauguration of the 787, which had already been delayed due to technical difficulties. The problems identified by the engineer, however, weren't addressed by Boeing, which is why he turned to EASA in June. [...] In those papers, it states that management and top executives at Boeing had ordered that the coordination problems with the company's suppliers be "closed." The reason: "to get the 787 production certificate."

I, for one, hope this plane never flies again.

Re: Boeing's Crashes Expose Systemic Failings

#7
It's obvious to me neither the FAA nor Boeing attempted to accurately replicate the first crash scenario, because this could have wholly averted the second crash. As soon as the planes were grounded, we were getting all sorts of reports about the stablizer being too hard to move and basically an unrecover situation.

Jail time is the only outcome I will accept.

Re: Boeing's Crashes Expose Systemic Failings

#8

> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim. I thought these systems were all fly-by-wire now? Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

The 737 series, including the MAX, has mechanical linkages to the control surfaces.

Boeing’s recommendation for dealing with a runaway MCAS scenario, in fact, was to cut power to the stabilizer trim motors at just the right moment in a short window of opportunity between cycles of it running, and then have the pilot manually crank the trim by hand turning a wheel that pulls a cable.

With excessive speed, or too much counter-force being put on the stabilizer by pulling back on the stick (because the pilots didn’t cut the electricity fast enough inside the cycle window, leading to the stabilizers forcing the nose down and the pilots needing to counter that to keep above the ground), the wheel can require an enormous, potentially insurmountable amount of force to operate.

Re: Boeing's Crashes Expose Systemic Failings

#9
> What's more, over the course of his 55 years in the profession, he [lawyer Marc Moller] [has] learned that every plane crash can be traced back to a single, simple cause.

I don't know, that strikes me as nonsense. It's precisely the interplay of many factors that lead to an accident - and if any one of them had been different, the outcome might have been different. See Reason's "swiss cheese" model of accidents - all the holes have to line up [1].

How you can go and designate one of these holes the hole, the "single, simple cause" is beyond me. This doesn't do the complexity of engineering justice. Might help to win cases with juries, but I don't see how it could help to make flying safer.

[1] https://en.wikipedia.org/wiki/Swiss_cheese_model

Re: Boeing's Crashes Expose Systemic Failings

#10
post #3

> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim. I thought these systems were all fly-by-wire now? Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

My understanding is that the 737 does not use Fly by wire [1] and if I remember correctly it's because they wanted to piggyback on the original 737 certification. I could be wrong. 1: https://www.quora.com/Does-the-737-MAX-family-use-fly-by-wir...

Yeah, the regulatory incentives seem to be a substantial factor here.
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