Ethiopian Airlines Crash; Another 737 Max

Matthew said:
How does an Airworthiness Directive, from FAA, get to foreign airlines? I don't know how the Ethiopian Civil Aviation Authority and Ministry of Transport work with Boeing and FAA to get that information to their own airlines.
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The world is not in a vacuum....they have the internets over there.
 
Sluggo63 said:
If you want to see a good example of someone balling up an (almost perfectly) good airplane because they decided not not use checklists, here's a YouTube video:

And these weren't some fourth, third or even second world aviators. These were our guys.
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So after they brought the throttles down when they came back up they forgot which engine was TU? Too heavy to fly on two?
 
There's a great article posted on AW&ST this morning, "The Boeing 737 MAX MCAS Explained." Unfortunately, it's behind the paywall.

The bottom line is the last photo in the article provided by Collins Aerospace showing both the yoke-mounted electric trim switches and the STAB TRIM CUTOUT switches, and the following explanation.
Pilots can interrupt the MCAS in two ways: via the yoke-mounted electric trim switches, or using the STAB TRIM CUTOUT switches on the center console. The trim switches interrupt the MCAS for 5 sec. and establish a new stabilizer trim reference point. Toggling both cutout switches de-powers the MCAS and the speed-trim system.
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MCAS%204_zpsw7kpqit1.jpg
 
Checkout_my_Six said:
The world is not in a vacuum....they have the internets over there.
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Probably better than ours. But FAA is a US agency, do foreign agencies issue their own versions of an AD? Or do they forward ADs from the FAA? I know that foreign agencies grounded those 737 MAX before FAA did, so they did that much on their own. I guess each foreign agency has its own "in" with manufacturer's when making decisions like that. Probably Boeing is required to notify all the other agencies it deals with, just like FAA, and they all make their own decisions. FAA issued that AD on how to handle a suspected MCAS problem, but did other agencies do the same? I dunno.
 
Spring Ford said:
As simply as I can and surely with some errors:) :-

Never a Jet or multi-engine pilot.

LIONAIR Crash.
Data from preliminary report which includes some FDR parameters from accident flight and the previous flight.

www.flightradar24.com/blog/wp-content/uploads/2018/10/2018-035-PK-LQP-Preliminary-Report.pdf
"PRELIMINARY KNKT.18.10.35.04"
Other copies on Internet. PDF is better quality than my screenshot here.

View attachment 72718

Captains leg.

On rotate the Captain's stick shaker started - my understanding is that this is loud and unmissable and intrusive. Ran for entire flight except for a short gap.

At that time or very soon afterwards Airspeed disagree and Altitude disagree flags come up. Airspeed and altitude disagree were small - a few percent.

Start troubleshooting.

Small automatic trim pulses from various systems (NOT MCAS). About a dozen in 1m 30s.

1m 20s after take off.
2,000 feet flaps up. MCAS starts down trimming for 10s every 15s.

Master Caution asserted for a about 30 seconds.

Captain does a yoke thumb switch trim pulse for each down pulse but not sufficient and aircraft descends 500ft.

Stick shaker stops for 15-20sec.

2m 20s after take-off.
Flaps get put back down. MCAS stops trimming. Other systems still doing short trim pulses. Trim wheels still move about.

Climbs to 5,000 ft above airport by the looks of it.

4m after take-off
Flaps retracted. MCAS starts down trimming for 10s every 15s

Captain manages to accurately balance MCAS trim with yoke thumb switch trim on AVERAGE. Altitude varies constantly. Range about 1,000ft total but mostly smaller.

Call for return to airport at some stage. Quite a lot of radio work throughout.

Hand off from Tower. Many vectors from ATC. They flew much of a figure 8 path.

FO working with checklists.

Master Caution asserted for a few seconds.

11m after take off.
Captain passes control to FO. Maybe he wanted to focus on troubleshooting, maybe he was physically unable to deal with control column forces for longer? CVR may tell us in final report.

FO fails to yoke thumb switch trim sufficiently to counter 10s in 15s down. They crash very soon after. Perhaps 1 min. There are yoke thumb switch UP trim (ANU) pulses but they are not long enough to compensate.

On previous flight stick shaker ran for WHOLE 2 HOUR flight from rotate to weight on wheels. Completed scheduled route. Stick shaker not mentioned in Maintenance log.

On crash flight :-

There was AoA disagree of about 22 degrees as soon as AoA came alive on take off run. However, there is NO direct indication of this on flight deck. The MCAS system was using the bad one. +22 degrees ANU feed into FCC.

There is AoA compensation fed into the Airspeed and Altitude system (to compensate for static pressure variations with AoA?). This caused the airspeed disagree and alt disagree.

The crew had no knowledge of the existance of the MCAS system. It had been decided it was not a "need to know" system and the crew were not told of its existence.

Still sound easy?

A mentioned by someone earlier much about this incident at pprune.org. Many, very, very good posts amongst the usual variable quality posts.

https://www.pprune.org/rumours-news/619272-ethiopian-airliner-down-africa.html
https://www.pprune.org/tech-log/615709-737max-stab-trim-architecture.html - signal to noise ratio very good here.

Other Threads too in these sub-forums :-
https://www.pprune.org/rumours-news-13/
https://www.pprune.org/tech-log-15/
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Y'know, after having the stick shaker on for two hours, having to be rescued by a jumpseater, and other failures, maybe the previous crew should have... I dunno... SAID something?!?!? :eek:
 
Matthew said:
Probably better than ours. But FAA is a US agency, do foreign agencies issue their own versions of an AD? Or do they forward ADs from the FAA? I know that foreign agencies grounded those 737 MAX before FAA did, so they did that much on their own. I guess each foreign agency has its own "in" with manufacturer's when making decisions like that. Probably Boeing is required to notify all the other agencies it deals with, just like FAA, and they all make their own decisions. FAA issued that AD on how to handle a suspected MCAS problem, but did other agencies do the same? I dunno.
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You'd hope that anyone operating a given airplane with a given engine type would sign up for the free FAA AD distribution. I get all of them, which can be from zero to ten every single day. Many fewer if you just choose the equipment that your airline operates. Some are downright silly, some are really big deals. Of course, that's only my opinion—it could be that a certain operator was on the list, did get the memo, and did distribute it to their pilots. If there is no point at which we can trust the pilots to gather all information necessary for safe flight, then we should eliminate them.
 
Yes some of the things being left out of the hysteria are Lion Air's culpability in ignoring a maintenance issue and using an aircraft that shouldn't have been in the air. Then there is the question of whether the Ethiopian Air pilots had ever read that AD because you'd think they would have immediately drawn a correlation and thought "hey, this is exactly what they were talking about"
 
Checkout_my_Six said:
for those interested....an AD for the MCAS system was issued Nov 7, 2018.
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As far as I can tell, there has been no mention whatsoever in the press about this AD. I didn't know it existed.

I'm not going to defend Boeing. The single AoA input driving a system that directly affects the primary flight controls in the manner it does is nuts, as was the fact the MCAS wasn't part of the instructions for differential training.
 
Bill Jennings said:
Every new level of idiot proofing seems to take more control away from those who know that they're doing.
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Brad Smith said:
We are now fighting the computer for control of our modern airliners.
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If this were the case then surely it would be easy to show correlation between automation, specifically envelope protection systems, and an increase in accidents.

So let's see it.

Nauga,
and his snipe hunt
 
The pilots should have known better. But so should Boeing. A single failure mode on something that controls 2.5 degrees of elevator at a time? Definitely a design failure.
 
ircphoenix said:
A single failure mode on something that controls 2.5 degrees of elevator at a time?
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But the question remains, how come the jump seat pilot on the Lion Air flight the day previous to the accident flight knew what do when the crew flying did not nor the crew of the accident flight???
 
Bell206 said:
But the question remains, how come the jump seat pilot on the Lion Air flight the day previous to the accident flight knew what do when the crew flying did not nor the crew of the accident flight???
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Not saying that's not a good question. But I'm also saying that it is a worthy question to ask Boeing why they thought that a single failure mode that could fly the plane into the ground was acceptable.
 
ircphoenix said:
a single failure mode that could fly the plane into the ground was acceptable.
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That's the issue--it doesn't fly the aircraft into the ground. By following the existing procedure, i.e., flip the cutoff switches, just like the Lion jump seat pilot stated, it doesn't fly into the ground.
 
This just in: the guy was praying instead of flying the plane

That's criminal
 
nauga said:
If this were the case <automation fighting us for control of the airplanes) then surely it would be easy to show correlation between automation, specifically envelope protection systems, and an increase in accidents.

So let's see it.

Nauga,
and his snipe hunt
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A doctor friend tells me "Almost every treatment has a side effect. The goal is for the side effects to be less severe than the original problem."

Envelope protection is kind of the same. It is generally better than no envelope protection, but sometimes...
 
kyleb said:
Envelope protection is kind of the same. It is generally better than no envelope protection, but sometimes...
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The same could be said for most any major system on an airplane. Landing gear, fuel, engines, brakes, hydraulics... They make most part 121 flights a lot better, but sometimes they really mess things up and it gets even worse if they're mishandled. Want to leave any of them behind?

Nauga,
who presses to test
 
ircphoenix said:
instead of "oh ****."
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Makes no difference if he said Lord Xenu is great, or that the Flying Spaghetti Monster is great.. if people want to believe in a higher power to give them a moral compass or whatever that's fine, but that stuff has no place in a professional working cockpit.

A mystic hand is not going to come down and save your life, even if you believe in this stuff then its very own writings state that we have free will and the ability to guide our own fate

Why give up? Die fighting
 
Tantalum said:
Makes no difference if he said Lord Xenu is great, or that the Flying Spaghetti Monster is great.. if people want to believe in a higher power to give them a moral compass or whatever that's fine, but that stuff has no place in a professional working cockpit.

A mystic hand is not going to come down and save your life, even if you believe in this stuff then its very own writings state that we have free will and the ability to guide our own fate

Why give up? Die fighting
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Why can’t one do both?
 
Greg Bockelman said:
Why can’t one do both?
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fair enough, I acknowledge that the way I think may be different than others. If I got to a point where I was desperate enough to have to start praying (not unreasonable if you're expecting to die) then that would indicate that I've given up

One thing if I'm alone, but if I have over 100 people behind me.. then really??

I digress. Pardon. it is just crazy to me that the solution to avoid this was so simple.. who knows, maybe it is all Boeing's fault for not training this more properly.. but what does that say about basic airman (person) judgment and commercial aviation
 
Tantalum said:
fair enough, I acknowledge that the way I think may be different than others. If I got to a point where I was desperate enough to have to start praying (not unreasonable if you're expecting to die) then that would indicate that I've given up

One thing if I'm alone, but if I have over 100 people behind me.. then really??

I digress. Pardon. it is just crazy to me that the solution to avoid this was so simple.. who knows, maybe it is all Boeing's fault for not training this more properly.. but what does that say about basic airman (person) judgment and commercial aviation
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You also should consider that the words uttered aren't much different the saying "Oh, God" or "Jesus Christ" in the midst of an impending catastrophic situation. It need not be a specif prayer or sign of resignation regarding the current situation. There's a religious/cultural aspect to it which may have been an innate vocalization of the stress while still fighting to recover. Difficult to say what will come out of one's mouth when the most dire of consequences is staring you in the face. Hope to never have to find out what I might say myself.
 
Word is that the NTSB, and other key U.S. players have not been provided details from the flight & voice recorders yet? Seems to me if you wanted to get to the root causes, you would let those well versed in investigations in on the specifics?
 
nauga said:
If this were the case then surely it would be easy to show correlation between automation, specifically envelope protection systems, and an increase in accidents.

So let's see it.

Nauga,
and his snipe hunt
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I will concede that the brake/throttle interrupt on cars probably lowers accident levels. Doesn't mean I have to like it though.
 
Sluggo63 said:
Honestly, don't go away. Civil discussion is good.

I'll let you in on a little secret. We use checklists for everything at the airlines. We don't shut engines down without the checklist. We don't (generally) flip switches in an abnormal situation without the checklist directing us to. There's a very good reason for that. Safety.
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Sluggo63 said:
That's what the airlines learned. When pilots rushed, they missed things. Important things. So we use a checklist. Always.
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Thanks for the post, civil discussion is indeed good. Definite value in checklists, we use SWI (standard work instructions) in our place of work for largely the same reason.. sure it's not life or death but costs, quality, and turn time improvement. However, my thing with checklists you touched on here:

Sluggo63 said:
My caveat to all that is to never forget to "Maintain Aircraft Control." If I thought that flipping off the Stab Trim Switches was going to save my life, you better be sure I would take that chance and do it without the checklist.
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..and that's where some people fail the Tantalum litmus test.
 
I'm sure plenty of praying has happened in cockpits, including Alan Shepard's prayer.

But I think it should be limited to the cockpit:

>>>
...the Captain asked everyone to remain seated and announced the plane would return to Perth.

“He said ‘I hope you all say a prayer, I’ll be saying a prayer too and let’s hope we all get back home safely’,” ...
<<<


https://www.news.com.au/travel/trav...h/news-story/283bd0f448e0b78359ea7a09970fe69e
 
Nobody knows exactly what these guys were dealing with here. Probably a lot of confusing and conflicting information such as attitude and airspeed disagree, stick shaker, aural warnings, flashing lights and only a minute to figure it out. If the MCAS does have a single failure point there's also then the fact that there have apparently been two failures on virtually brand new aircraft within a few months of each other so there's that on top of everything else to consider. It would seem that there were a lot of weak links in this chain, not just one.
 
Silvaire said:
Nobody knows exactly what these guys were dealing with here. Probably a lot of confusing and conflicting information such as attitude and airspeed disagree, stick shaker, aural warnings, flashing lights and only a minute to figure it out. If the MCAS does have a single failure point there's also then the fact that there have apparently been two failures on virtually brand new aircraft within a few months of each other so there's that on top of everything else to consider. It would seem that there were a lot of weak links in this chain, not just one.
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and we know that the flight before the Lion Air accident....was able to disable the system and safely fly the aircraft. The next crew....not so much.
 
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