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Ethiopian Airlines 737 MAX Investigation Preliminary Report

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Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#281

Post by refurb »

geofft wrote: post #268
VBprogrammer wrote: post #251

Earlier quoted context omitted.

Just to add an extra element to what you've already said. It's quite likely that the pilots themselves would have been reluctant to accept another entry level narrow body jet. In the current climate it's often the pilots themselves who are paying for the type rating, at least the first one they acquire.

That's fair, but also, salaries for pilots are not great, and Boeing's former CEO got a salary of $865K/year + $1.3M/year bonus + stock and now that he's retired gets a pension of $730K/year. I'm sort of curious what exactly it would have cost Boeing to say, "This is not a 737, but we will pay to retrain any 737-trained pilot who's interested." (Which still would have given them a negotiating advantage over Airbus!)

Reading the r/aviation subreddit apparently airline pilot salaries have really improved over the last 5 years.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#282

Post by treis »

msbarnett wrote: post #245
treis wrote: post #228

Earlier quoted context omitted.

>They couldn't land with the stabilizers mis-trimmed. If the wheel wouldn't budge, re-enabling it and trimming electronically was the only option likely to occur to them, since the only other possible option (release the column, let the plane nose down so that the forces on the screw ease and they can trim manually) is completely counter-intuitive and was removed from Boeing's documentation and simulator training 30-…

> They could have just kept flying. They weren't in any immediate danger and had time to reach out for help. Worst case scenario, you fly straight for the next 30 minutes while ascending to 20-30k until you figure out what's going on. The stabilizer's trimmed down. The pilot is repeatedly requesting the co-pilot's assistance in maintaining elevator trim up, and says to the co-pilot at 05:43:04 that the pitch is not e…

>They're absolutely not climbing 14,000 feet in that condition. The control forces on the column in this situation are absurd. Their arms couldn't have held them level for more than a few minutes max.

If I'm reading the charts right it took them about a minute to go from 5,000 to 7,000 feet. So even if they hold on for just a few minutes more they're almost to 14,000 feet.

And you're taking speculation based on assumed facts too seriously. If they were struggling to keep the plane level then their simulation was different. In reality the plane was climbing all the way up until they enabled the electric trim and MCAS kicked in.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#283

Post by objektif »

darkpuma wrote: post #271
throwaway713 wrote: post #248

Earlier quoted context omitted.

I've been on HN for years, and lately some of the downvotes have really been blowing my mind. See this post I made a couple of months ago: https://news.ycombinator.com/item?id=18937864 . Someone actually downvoted and argued against me that their dog's life is more valuable than "a stranger's". I have no doubt it's the same people downvoting your comment. I can't tell if these people are just really good trolls, or t…

I think you probaby struck a raw nerve with that dog issue in particular. Some people have family and dogs, but other people have no family (or not the one they want) and use dogs as surrogates. Pointing out the difference between family and dogs can provoke an intense emotional reaction, not rooted in their feelings towards dogs but rather rooted in the phantom pain they feel where their family should be. So what se…

Anyone who equates human life and dog needs to be evaluated immediately. I am not kidding, it means they have lost touch with the society.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#284

Post by ambicapter »

treis wrote: post #61
msbarnett wrote: post #10

Earlier quoted context omitted.

> If there are issues with manually rectifying trim after it went haywire because of any reason, that might be a problem. It's not so much a "problem" as it is "physics". If the stabilizers are forcing the nose down, and the pilot pulls back on the stick (engaging the elevators) to pull the nose up, the forces exerted on the stabilizer are such that, in extreme cases, human force is insufficient to move the manual wh…

>less great at a height of 1,000 feet. Am I reading the chart on page 27 wrong? Because it looks like they reached a maximum height of 7,000 feet. Also looks like they were continuing to slowly climb until they re-enabled electric trim. EDIT TO ADD: Page 12 also says: >about 32 seconds before the end of the recording, at approximately 13,400 ft Which is a bit under 6,000 feet higher than the airport.

A lot of people are thinking they maxed out at a height of ~1,000 ft because that is what the flight tracker website last showed.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#286

Post by nutjob2 »

davepage wrote: post #43
Rooster61 wrote: post #7

> The crew performed runaway stabilizer checklist and put the stab trim cutout switch to cutout position and confirmed that the manual trim operation was not working. This is very damning to Boeing. It's precisely the procedure they prescribed and intended to mitigate possible MCAS caused trim runaway. In light of the fact that they put this in place as a justification for moving the engines forward without reclassif…

It does not appear to be "precisely" the procedure, in that sufficient nose up trim was not selected by the yoke manual trim switch prior to pulling the trim cutouts. And then they did not work the mechanical trim wheel hard enough to reset the residual nose down trim. And, the crew left the power setting at climb throughout almost the entire sequence, so they oversped the airframe. And, when they (against procedure)…

So the procedure is too complex or otherwise lacking. It should reasonably accommodate pilot workload and stress under the situation it would be used.

It's interesting that the flight with three pilots in the cockpit survived.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#287

Post by cjbprime »

tuna-piano wrote: post #238
davepage wrote: post #43

Earlier quoted context omitted.

It does not appear to be "precisely" the procedure, in that sufficient nose up trim was not selected by the yoke manual trim switch prior to pulling the trim cutouts. And then they did not work the mechanical trim wheel hard enough to reset the residual nose down trim. And, the crew left the power setting at climb throughout almost the entire sequence, so they oversped the airframe. And, when they (against procedure)…

Just to put their "mistakes" in context - Sully, America's favorite hero pilot, accidentally put his airplane into an almost stall as he was performing the Miracle on the Hudson (due to the A320's design philosophy, the airplane prevented the stall...). It goes to show- even great pilots doing good work in a stressful time can make critical oversights.

That's the opposite to the actual conclusion of this story! He intentionally tried to flare, but the Airbus flight envelope protections disallowed it, so they hit the water harder than they ought to have.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#288

Post by thatoneuser »

darkpuma wrote: post #275
acqq wrote: post #262

Earlier quoted context omitted.

No. The redirection of demand would just give some more clients to Airbus and reduce the speed of the growth of the total number of planes flying. Nobody should accept this attempt to excuse Boeing of its responsibility and even less the possible variant of it "we are all guilty we will buy the cheapest flight."

It seems a bit unlikely to me that an airline like South West, that only flies 737s, would sooner buy Airbus planes than non-737 Boeing planes. I mean, stranger things have certainly happened, but it doesn't seem like the kind of existential threat that would force the hand of Boeing executives in such a way that takes blame away from them.

Even if there was an existential threat to Boeing the people making the decisions should have decided "we can't do this safely". They were never forced. Maybe they wouldn't get their million $ bonus - well tough titties. Plenty of people didn't get a 7 digit bonus this year.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#289

Post by nutjob2 »

Arnt wrote: post #128
smaili wrote: post #24

Earlier quoted context omitted.

Just out of curiosity, will there actually be any punishments handed out beyond just a slap on the wrist? Or is Boeing far too large of a corp to take on?

I've read a couple of these things (strongly recommended — aviation postmortems are a model for us all) and my impression is that "too large" or "slap" are foreign terms in their debugging culture. Their priority list is, AFAICT: 1. Find out what happened. 2. Find out why. 3. Find out how to make sure it doesn't happen again. 4. See point 3. 5. See point 3.

What happened is that they hacked on an inappropriate engine onto an old airframe, then they hacked a hidden automation to fix the prior hack.

The engineering fix is obvious, but management is the problem.

Re: Ethiopian Airlines 737 MAX Investigation Preliminary Report

#290

Post by matz1 »

throwaway713 wrote: post #248
rdiddly wrote: post #119

Reading through the chronology in section 1.1, it feels like a movie where the aircraft is a malevolent entity that's trying to kill them. So if I were in the cockpit I'm sure it would've been some mix of fear and anger. My life's not in danger though, so I'm only left with the anger, on their behalf, knowing some greedy bunch of assholes were effectively that malevolent entity, whose will was expressed via the aircr…

I've been on HN for years, and lately some of the downvotes have really been blowing my mind. See this post I made a couple of months ago: https://news.ycombinator.com/item?id=18937864 . Someone actually downvoted and argued against me that their dog's life is more valuable than "a stranger's". I have no doubt it's the same people downvoting your comment. I can't tell if these people are just really good trolls, or t…

This value are relative to the individual, not everyone value human life and dog life the same way. That's just reality.
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