Ethiopian Airlines Crash; Another 737 Max

cowman said:
I've been seeing this talk of a warning light go around
https://www.cbsnews.com/news/boeing...d-light-warning-pilots-of-sensor-malfunction/

So when they say indicator light- does that mean a separate physical light on the panel? Wouldn't this same information be displayed on flight displays?

Also- $80,000 for an indicator light? Seriously? It takes $80k to run a wire from what would have to be a computer output pin to a little light bulb/LED on the panel?
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Ya but....just think of the lives it woulda saved. :eek:
 
I think the NTSB gets involved for three reasons with foreign investigation even though they do not have authority. First. They certified the aircraft, and most small nations do not have their own certification process so they basically sign off on the FAA's.

Second, many small nations do not have the specialized equipment or aviation experts to do a complete investigation. So they basically contract it out to us.

Finally, since our FAA signed off on these planes and wrote the majority of the regulations, rules, and procedures used to fly them, which are then adopted by foreign nations, they want to see if there are problems that could affect us at home.

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Tantalum said:
are there any such items? If you are after V1 is there any published thing that would cause you to stay on the ground, or is that left up to the pilot's ADM to judge how catastrophic the situation is
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Pilots Discretion. I would say in most cases you should continue departure after V1. I would only RTO after V1 if I was certain there was an issue that made the aircraft unable to fly. In the case of the guys flying with the stick shaker all the way, here is my thought... If the shaker activates on rotation, I am assessing whether the airplane is indeed in a stalled condition. Once I confirm it is flying, I fly the airplane, and immediately return. I am not going to put up with that for the rest of the flight. As well, as previously mentioned a critical safety feature of the aircraft is malfunctioning. I do not know what else is wrong, so I return. Am I anxious when it goes off on rotation when I am sure there is no stall? No. Am I declaring an emergency? No... Probably ask for priority though.

Now, if that shaker goes off mid flight or after leveling off, I am doing the same assessment of whether the airplane is flying or not. For some pilots it is going to become a tougher call to return. Now I am thinking about what resources I have at the airport I just departed... is there maintenance, is there any staff still there to accommodate PAX etc. These things (not saying it is right) play into the decision of whether to return. Many pilots would elect to continue to a base with resources and maintenance, and a lot of times that is the destination airport.
 
Tantalum said:
are there any such items? If you are after V1 is there any published thing that would cause you to stay on the ground, or is that left up to the pilot's ADM to judge how catastrophic the situation is
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Very nature of V1 is the fact that it takes the decision process out of the equation at a very dangerous time in flight. The only possible reason I can think of, is if the airplane simply will not fly.
Most of the runways I operate off of, if you reject after V1, you're going off the runway and probably hurting somebody.


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Tantalum said:
JFC. I didn't know about that. Even if you can deal with the stick shaker for 2 hrs.. you've lost a lot of key safety components

and why did they continue?..because they're a garbage airline with crap training that now Boeing is feeling the pain for
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I think most are aware that you have an agenda. You have a foregone conclusion, that you do PR for the manufacturer, about blame without all the information.

Luckily, I think that investigators aren’t big on that concept. They, good ones, wait until the facts are in.

Anything less is just prejudice. Facts are facts. If, as it seems, the training wasn’t there for this situation,” just fly the plane” is a great idea, but if the software and hardware fights you and there is little time, that should have been anticipated and been required that pilots went through the procedure in an actual simulator.

Conjecture is one thing, you keep making flat out statements blaming the pilots, and you have no basis for it because you don’t have all the facts. It’s pretty obvious though, the design was and is not optimal.
 
LongRoadBob said:
I think most are aware that you have an agenda. You have a foregone conclusion, that you do PR for the manufacturer, about blame without all the information.

Luckily, I think that investigators aren’t big on that concept. They, good ones, wait until the facts are in.

Anything less is just prejudice. Facts are facts. If, as it seems, the training wasn’t there for this situation,” just fly the plane” is a great idea, but if the software and hardware fights you and there is little time, that should have been anticipated and been required that pilots went through the procedure in an actual simulator.

Conjecture is one thing, you keep making flat out statements blaming the pilots, and you have no basis for it because you don’t have all the facts. It’s pretty obvious though, the design was and is not optimal.
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I think you have an agenda, too. And no, I don't think most of the people here are really trying to do any PR for Boeing. I think most of us feel that Boeing DID mess up here, just maybe not to the degree that is being portrayed by foreigners with agendas...
Look, everyone's got some degree of bias. Fact is though that some of the data IS out on the internet, and is being used for various agendas and there ARE glaring and serious crew, maintenance, and safety culture issues here from what we are being told regardless of the fact that Boeing made some bad choices that they will rightfully be asked to rectify. What's annoying is the media treatment and politicization of this particular situation.
 
Larry in TN said:
AoA display and disagree are more associated with the HUD installation and its use for lower than standard approaches and departures (CAT II/III). I've never flown an airplane with a HUD (or an AoA indicator for that matter) but those airplanes use the HUD to hand-fly approaches and departures in lower than CAT I ILS or standard reduced visibility takeoff minimums (RVR 5/5/5). I believe the AoA indicator is required for those operations (can anyone confirm?) so the airlines that use the HUD for those operations would have them. Airlines that use autoland for CAT II/III operations likely would not have the AoA indicators.
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I didn't realize you guys don't have AoA indicators at all. We have an indicator displayed on each primary flight display, and if a miscompare is detected, an "AOA DISAGREE" message will appear in the bottom right of the PFD (down around where you'd set BARO or RA minimums). Also, in the case of a signal failure or if the data is determined to be invalid (above 80 knots), the respective indicator will go blank and be replaced with a fail flag. The same AoA presentation is displayed in the HUD, but it's unclear in our manuals whether that display merely parrots the AoA data from the captain's PFD or if the HGS (Heads-Up Guidance System) computer creates its own presentation directly from one of the AoA probes. It's a small distinction, but I mention it because when using the HUD, activating the AII or AIII modes (for a CAT II or CAT III approach respectively) require a bunch of conditions to be met, one of which is "all inputs to the HUD computer are valid". That'd seem to validate what you said about AoA being required for CAT II/III operations with the HUD. But interestingly if you dig into our MEL - it shows two AoA systems installed with zero required, and deferral of either or both systems doesn't change the LMP status of the aircraft. Same with the QRH - checklists for a failed AoA indicator (or a miscompare) don't mention anything about going down to CAT I only.

So I *think* you're right, but there's just enough ambiguity there (at least for my simple brain) that I fired off a text to a check airman to see what he has to say.
 
cowman said:
I've been seeing this talk of a warning light go around
https://www.cbsnews.com/news/boeing...d-light-warning-pilots-of-sensor-malfunction/

So when they say indicator light- does that mean a separate physical light on the panel? Wouldn't this same information be displayed on flight displays?

Also- $80,000 for an indicator light? Seriously? It takes $80k to run a wire from what would have to be a computer output pin to a little light bulb/LED on the panel?
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I do not believe there is a warning light but rather an amber caution message that pops up on the PFD. So it is not a light and it is not a warning. At least that is my limited understanding.

And I believe the $80,000 price tag was for the complete AOA indication system that just happened to have the AOA disagree logic. Again, limited knowledge here.
 
RyanShort1 said:
I think you have an agenda, too. And no, I don't think most of the people here are really trying to do any PR for Boeing. I think most of us feel that Boeing DID mess up here, just maybe not to the degree that is being portrayed by foreigners with agendas...
Look, everyone's got some degree of bias. Fact is though that some of the data IS out on the internet, and is being used for various agendas and there ARE glaring and serious crew, maintenance, and safety culture issues here from what we are being told regardless of the fact that Boeing made some bad choices that they will rightfully be asked to rectify. What's annoying is the media treatment and politicization of this particular situation.
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Oh come on. One of us is outright predicting and stating. He’s also made remarks blaming the pilots, which I’ve seen in other situations (American pilot taking off in fog, etc.) where that is just not done. Maybe unless they are foreign pilots?

He’s also posted nothing but defense of Boeing, absolving them, many, many times with zero evidence. He’s a dog with a bone on this.

It just now out in the news here in Norway that the pilots both had been checked out on the procedure for the known problem. It was again mentioned though, there was no actual simulator that has software that could reproduce it. That seems to be fact, and just as a passenger, customer of airlines, that disturbs me plenty, and also makes me question the decisions of these airlines and the FAA. Saying I would expect pilots to have available an actual simulator to train in for a known possible issue isn’t exactly pretending I know what happened here. It seems we do know what didn’t happen.

And the planes here in Norway, it is reported the airline Norwegian opted not to pay for an alert annonuciator when the AOA indicators were in disagreement, and in defense they are basically sayin “yeah but lots of airlines chose the same”. So yes, I’m saying whatever the cause of the actual accidents, what is coming out now is alarming.

And pilots here with what I see as in depth knowledge have posted the problems in design, in implementation of it (one aoa polled..CG problem that caused them to fix with this solution, etc.) and in Boeing marketer get this as not needing retraining or extra.

I’m not claiming to know the cause, but those pilots having trained for this is also pretty worrisome. It could hint that they tried to do the procedure. Fact that it was grounded even in the US after some find the investigors discovered.

But I’m waiting to hear the report.

I think this is my second post on this, and you are telling me I’m doing the same as Tantalum? Sure...ok.
 
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SkyDog58 said:
I do not believe there is a warning light but rather an amber caution message that pops up on the PFD. So it is not a light and it is not a warning. At least that is my limited understanding.

And I believe the $80,000 price tag was for the complete AOA indication system that just happened to have the AOA disagree logic. Again, limited knowledge here.
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As I mention, here in Norway, Norwegian airlines didn’t spring for the light. It is optional apparently.
 
LongRoadBob said:
I think most are aware that you have an agenda.
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Occam's razor will dictate typically that the simplest explanation is the most likely. looking at the actual facts all we know is that two countries with very dodgy aircraft safety records crashed a certain type of airplane. Crews have dealt with similar issues and not crashed, and all of the US, Canadian, and European carriers who were operating much larger fleets both individually and collectively were fine. It is not just dumb luck that both accidents came from the same part of the world.

LongRoadBob said:
blame without all the information.
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isn't that exactly what the media and everybody has done?

I was in line at Costco yesterday and the person in front of me was talking to their friend and said they canceled their Southwest ticket and instead bought a JetBlue ticket because they did not want to fly on Boeing.. and that is not an isolated incident. One of the New York Times headlines flat out blanket statement said that Boeing jets were to be grounded. you can't tell me that the international and domestic media do not have an agenda here

LongRoadBob said:
Luckily, I think that investigators aren’t big on that concept. They, good ones, wait until the facts are in.
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In a perfect world, but if you look at past accident investigations from certain cultures there is a very strong desire to not blame their own pilots. In this case we have American built it certified aircraft and a political climate where the United States is not in great favor. It seems that everybody, outside of me and a few others here, are doing exactly what you have advocated against, which is issuing judgment without all the facts, and in the face of what I consider very obviously poor airmanship. No CRM, confusion in the cockpit with flying papers, and prayers. When all it needed was one system disabled, something which they are trained for how to handle runaway trim. And as other people correctly responded to my thing about the stick shaker, apparently it is fairly common to have an erroneous stick shaker go off and still safely fly the plane

LongRoadBob said:
that should have been anticipated and been required that pilots went through the procedure
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An AD was issued back in November that very clearly stated this, and all pilots are trained inin wh to do with runaway trim

LongRoadBob said:
optimal
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how do you define optimal? Free of the possibility of human error and accident? the more we design things to be human proof the more we dumb down people and make them that much less capable of handling an emergency.

RyanShort1 said:
What's annoying is the media treatment and politicization of this particular situation.
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You sir, are 100% right
 
SkyDog58 said:
I do not believe there is a warning light but rather an amber caution message that pops up on the PFD. So it is not a light and it is not a warning. At least that is my limited understanding.

And I believe the $80,000 price tag was for the complete AOA indication system that just happened to have the AOA disagree logic. Again, limited knowledge here.
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I believe you're correct. We have the disagree logic, and the caution message looks like this:

AoA.jpg

It's not just a MAX thing - our NG's have the same setup.
 
kayoh190 said:
I believe you're correct. We have the disagree logic, and the caution message looks like this:

View attachment 72781

It's not just a MAX thing - our NG's have the same setup.
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Thank you for that. I would imagine the logic for displaying that messsge would be the same for a NG and a Max. I.e. X degree variance between the sensors over a set time.
 
SkyDog58 said:
I would imagine the logic for displaying that messsge would be the same for a NG and a Max. I.e. X degree variance between the sensors over a set time.
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Yep! According to our manual it's identical - more than 10 degrees for more than 10 seconds.
 
drotto said:
I think the NTSB gets involved for three reasons with foreign investigation even though they do not have authority. First. They certified the aircraft, and most small nations do not have their own certification process so they basically sign off on the FAA's.
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The NTSB does not certify aircraft. And the NTSB is not a part of the FAA.

drotto said:
Second, many small nations do not have the specialized equipment or aviation experts to do a complete investigation. So they basically contract it out to us.
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Wrong. The NTSB gets involved because it's a US built product. But the NTSB cannot run the investigation, the country operating the aircraft, or the country where the aircraft had the accident runs the investigation. The NTSB is only there to assist.

drotto said:
Finally, since our FAA signed off on these planes and wrote the majority of the regulations, rules, and procedures used to fly them, which are then adopted by foreign nations, they want to see if there are problems that could affect us at home.

Sent from my SM-G950U using Tapatalk
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Wrong again. While the FAA indeed certified the aircraft, most foreign countries get their rules and regulations through ICAO, not the FAA. Also foreign operators can develop their own procedures to operate the aircraft in conjunction with their own aviation authority.
 
I may be somewhat anachronistic here, just a person who helped run the trainers on the "newfangled" 727 when it first came out and saw the stark terror on a few very senior pilots when they got below the descent curve on approach and plowed through the runway lights no matter how much power they applied way too late.

Give me all the foreign pilots who never had to go through basic flight instruction for a weekend. Let me take them to altitude in a Cessna 172 or 182 and let them pull a full power relatively abrupt stall and see the stark terror on their faces when the son of a ***** goes over on its back and heads for the hangar. Then teach them what recovery from unusual attitudes looks like and how to deal with it.

In my PERSONAL (and admittedly naive mind) the problem is Boeing trying to solve fundamental pilot grass roots training problems with electronic solutions that should not take the controls out of the pilot's hands. Phugoid oscillations plagued the Wright Brothers and they have not disappeared in over a hundred years.

Just my 8% of two-bits.

Jim
 
The number of ridiculous articles and statements in the media blaming mostly Boeing and US air carriers is staggering.

The damning statements that implicate the misunderstood facts of how each carrier can select whether they wand a particular OPTIONAL system or device are partly based on ignorance and mostly based on hatred of Boeing, air carriers in general and the FAA. Pretty much a focused effort by very biased groups of people to affect Boeing's bottom line.

Some of these statements ridicule Boeing for not simply adding "an AOA sensor, which for airlines is cheap." They make no mention of the existing AOA sensor installed on the basic aircraft. Very deliberately misleading and typical of all the usual [Big City Name] press. Oh yeah, they call it "safety equipment."

It is too late to make readers believe it isn't all Boeing's fault, so I fear the campaign has been successful... Sad.
 
kayoh190 said:
"AOA DISAGREE" message will appear in the bottom right of the PFD
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I looked it up and we have the AOA DISAGREE as well, just no AOA displays. No HUDs. AA/DL/WN all have HUDs and all have AoA displays. UA has neither the HUD nor the AoA display. Seems like a correlation but need more data for a conclusion.

LongRoadBob said:
It was again mentioned though, there was no actual simulator that has software that could reproduce it.
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Every 737 pilot (at least in the US, I assume worldwide) has had a runaway stabilizer in (at least) their initial training. I've done that procedure in training on every airliner I've flown. That's all the invalid MCAS activation is.

The book of non-normal and emergency procedures is thick. There is a procedure for every red light, yellow light, and warning message in the airplane. Simulator training would stretch out for months if we were required to train each and every one of them. We train all of the emergency procedures and a representative sample of the non-normals so as to ensure that we understand the procedure and application of the Quick Reference Handbook (QRH) and can run those procedures properly.
 
Im not in any way an expert on this, as well as a number of folks here. Then too, we do have professional airlin pilots here too. Correct me if I’m wrong but things that have been coming out, her and in the news (which I tend to read with a skeptical mindset but if well written and as far as I can see, technically correct I tend to give credence to) at this point I believe some facts are these...

Correct me if I’m wrong on these not being facts, but it is the information I see.

- Boeing needed to compete with the newest Airbus and mounted different engines than have been used til now, in a manner that caused more instability in the CG, which resulted in a tendency for nose up attitude.

- they solved the issue by a new variation on the MCAS...I’m reading here it is not engaged when autopilot is on.

- they som optional, costly add-on (som report this as software, but seems to have hardware components to it too) that each airline could decide for themselves if that add on was worth buying.

- so far, even now, they don’t have a software model for actual simulators to model the situation and procedure for recovery if the MCAS glitches or has faulty input from the single aoa sensor that is used. Even though the plane has two of them, they rely on one st a time (and for some reason it switches each flight?)

- Boeing was selling this plane with the incentive that it would not require extra training to be checked out on this.

- at some point, there was an app pilots could use, that informed them of the new, different behavior and recovery procedure.

- pilots had been reporting instability and issues with the airplane. I don’t know if this is “normal” with any new model, but they voiced concerns over this issue and some reported having problems with the recovery. procedure. Just prior to the Lion air flight that crashed, pilots on that flight had the problem, and a dead heading pilot in the jump seat helped them recover, up to that point the pilot and copilot were struggling, and his suggestion to them saved the day. It is not known if they had been aware of the different procedure.
Unclear if this was reported to the company? One would hope it was.

- an AD was issued.

- yesterday I read that the Ethiopian pilots had been trained in the procedure. They knew about it, both pilots. We can’t know at this time if they recognized the actual issue.

- the stabilizer or trim was supposed to only travel a certain amount, but indications show it travelled quite a bit further in both crashes?

- some here are saying it is nor different than earlier models, at least it seems like they are, yet others are pointing out the CG and other points mean this is a significantly different situation. I don’t know. But I think if it has more tendency to a problem that is not a problem in earlier models, that seems like a big deal.

Some here seem to be jumping to blaming the pilots. I’ve seen reports that are disturbing about all the automation and pilots losing their stick skills, and believe that can be a problem, but we don’t know if that was the case here. The PIC had many hours of flying time. I’ve seen other threads where what seems to me to be bad decision (particularly the GA one in Florida where it was fogged in, I think the plane was were maintenance issues etc. ) where many folks here came to the defense of the pilot and said it was “up to him” and actual anger at what was seen by some as jumping the gun, to blame them. Seems not to be an issue here as much.

Many people died a horrible death, including the pilots that were trained in the recovery procedure.

This is disturbing to me, but I am only a student pilot. As an airline passenger this is very disturbing.
I would tend to think that Boeing would never take a chance on their reputation, on lost lives, by being negligent. Even if you take away the the human cost of lives, just looked at the bottom line, this kind of thing if negligent could hurt profits and reputation. On the other hand, corporate culture has a profit version of “get-there-itis” specially concerning sales/delivery deadlines. I’m a programmer, and though not in any life/death critical programs (banking though...next on the list after life and death) I’ve seen such horrible decisions based on deadlines, programmers not allowed to make the product robust and bug free as possible, etc.
Executives using “hope” as a plan.

I don’t know, and am waiting for the actual report. I do have a tendency to see the above issues as disturbing and am not satisfied, if I have it right, that they were not to blame and it all was the pilots fault.

Someone in a comment on a web site mentioned how it was similar to some automation in cars and that nothing is idiot proof, the driver had to be able to monitor and take over. Totally right, but another pointed out “yeah, but if the design was faulty and resulted in the car tending to veer into the opposite lane?” And that also seems to fit.

I know I don’t know, but what I’ve been seeing as facts bothers me a lot. And passenger with zero experience or knowledge of flying...I think they are reacting a lot to the “you mean they had more safety features but they were add ons??? And they skimped??”
 
Tantalum said:
no experience with big iron...
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Tantalum said:
This would also be an immediate and obvious indication that something is gravely F***'d.. so even if you're after V1 I'd cut the power and slam on the brakes. Going off the end at 60 knots will be better than taking a very clearly defective plane into the sky.
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Tantalum said:
chances are that both MAX planes that crashed could also have been flown safely..
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Tantalum said:
Even if you can deal with the stick shaker for 2 hrs.. you've lost a lot of key safety components.

and why did they continue?..because they're a garbage airline with crap training that now Boeing is feeling the pain for
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.
 
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Tantalum said:
It is not just dumb luck that both accidents came from the same part of the world.
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Same part of the world? You mean... Planet Earth? Or you just mean literally anywhere other than the western world? Africa and Southeast Asia are not exactly the same place.

We have a relatively brand new aircraft already providing faulty data to a flight control computer with zero redundancy on at least two separate occasions which result in fatal crashes... and it's 100% the crew's fault? That's hard for me to swallow.

Again, I think absolving the crew of responsibility is just as foolish as absolving Boeing of it.
 
Sluggo63 said:
I'm trying to limit my discussion on this topic but I thought this was an extremely good (albeit a bit technical) article.

https://leehamnews.com/2019/03/22/bjorns-corner-the-ethiopian-airlines-flight-302-crash-part-2/
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Wow. If that theory holds, Boeing really did push the airframe. The correct answer to the instability in pitch should have been a redesign of the tail control surfaces and actuators, not a technological patch. Of course, that would mean time and lots of money, as in the end you have a different airplane.
 
I'm a "let's wait for the reports" guy, and I am anything but one of the blame-the-media crowd. I read the NYT every day, have for 25 years. Their coverage of this has been absolutely appalling. Not only such poor depth that the articles should be written in crayon, but inflammatory to boot. (If you want some great reporting on this, try the Seattle Times: https://www.seattletimes.com/busine...-max-system-implicated-in-the-lion-air-crash/)

I'll make two points: the Chinese, who are developing a competing aircraft, the C919, were the first to ground the MAX. That's no coincidence. Second, the BEA have every incentive to blame Boeing, to the benefit of their compatriots at Airbus.

My feelings are that it's no coincidence where these two accidents happened (and I believe the deadheading pilot that saved the Lion flight the night before the crash was British), and I would get on a MAX tomorrow and sleep like a baby, so long as the crew is from the US.

Lastly, the copilot in the Ethiopian crash having 200 hours TT is absolutely criminal.

PS. Is it me or would AF447 not have happened had that aircraft had MCAS?
 
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kayoh190 said:
Yep! According to our manual it's identical - more than 10 degrees for more than 10 seconds.
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That's really, really sloppy, since that 10° can cover a spread where the plane may be flying normally or deeply stalled. I would have thought they need to be within a couple of degrees.
 
Kenny Phillips said:
That's really, really sloppy, since that 10° can cover a spread where the plane may be flying normally or deeply stalled. I would have thought they need to be within a couple of degrees.
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I kind of thought it was a wide range as well. The actual values weren't something I knew - it was just a result of digging into the manual for @SkyDog58 . In case you're curious, here's a little more information about our AoA indicators:

AoA2.jpg

Again, the MAX and NG are identical in this regard.
 
mryan75 said:
I'll make two points: the Chinese, who are developing a competing aircraft, the C919, were the first to ground the MAX. That's no coincidence. Second, the BEA have every incentive to blame Boeing, to the benefit of their compatriots at Airbus.
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I agree the Chinese grounding the plane was political. But when within days you saw basically the rest of the world ground it, I'm not sure that was unfounded.

mryan75 said:
My feelings are that it's no coincidence where these two accidents happened (and I believe the deadheading pilot that saved the Lion flight the night before the crash was British), and I would get on a MAX tomorrow and sleep like a baby, so long as the crew is from the US.
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This is what I have a problem with. US crews have shown their ability to ball up a good airplane again and again. In fact if you look a couple threads below this one (at the time of writing), there's a thread about a US crew that landed a jet off of the runway. Not on the runway and slid off, but not even on the tarmac. I don't know what Ethiopia's ab initio pilot training program is like, but ET's safety record is pretty good (if you take out the hijackings).

mryan75 said:
Lastly, the copilot in the Ethiopian crash having 200 hours TT is absolutely criminal.
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I had just over 200 hours when I was in the right seat of a heavy, 4-engine jet flying internationally.
 
Sluggo63 said:
I'm trying to limit my discussion on this topic but I thought this was an extremely good (albeit a bit technical) article.

https://leehamnews.com/2019/03/22/bjorns-corner-the-ethiopian-airlines-flight-302-crash-part-2/
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Thanks for posting that link. "Elevator blowback" is a term I've never heard in my 55 years as a pilot, albeit all my experience has been in low speed piston airplanes.

Quote from Bjorn's Corner: "Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong."

It's an interesting theory.
 
Sluggo63 said:
I agree the Chinese grounding the plane was political. But when within days you saw basically the rest of the world ground it, I'm not sure that was unfounded.
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Once you get the ball rolling...

Sluggo63 said:
This is what I have a problem with. US crews have shown their ability to ball up a good airplane again and again. In fact if you look a couple threads below this one (at the time of writing), there's a thread about a US crew that landed a jet off of the runway. Not on the runway and slid off, but not even on the tarmac. I don't know what Ethiopia's ab initio pilot training program is like, but ET's safety record is pretty good (if you take out the hijackings).
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Twenty-six complete hull losses in 40 years for an airline that flies 1/10th the volume of American Airlines is good? I think it's appalling.

Sluggo63 said:
I had just over 200 hours when I was in the right seat of a heavy, 4-engine jet flying internationally.
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I think that's insane. Nothing personal. I honestly think that's insane.
 
LongRoadBob said:
pilots had been reporting instability and issues with the airplane
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I've seen one incident reported (each pilot filed a separate report on the same incident). It involved an unexpected pitch-down when the autopilot was engaged. That would be unrelated to MCAS as MCAS only operates when the autopilot is disengaged and MCAS don't not operate the elevator, only the stabilizer trim. The A/P problem could have been a failure in the autopilot system or the crew could have had the vertical mode misprogrammed when they engaged the A/P. We've also seen the pilots' reports but not what the result of their maintenance write up which would have told us what problems, if any, were found.

The other report was a pilot who was complaining about what Boeing's differences training included. He didn't report any occurrence with the airplane.

Some here seem to be jumping to blaming the pilots.
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No final reports or conclusions have been issued for either of the two accidents. We (still) know very little about the Ethiopian accident but we have quite a bit of information on the Lion Air accident.

What we know about Lion Air.

1. The accident airplane had AoA related issues on its last FIVE flights yet the airline continued to dispatch it.
2. On the flight immediately prior to the accident flight the aircraft experienced a stabilizer runaway due to an unschedule activation of the MCAS system due to invalid AoA data being fed to the air-data and flight control computers.
3. On that flight the operating crew were unable to handle the problem until their jumpseater pointed out the runaway stabilizer and reminded (?) them of the runaway stabilizer procedure.
4. Once the electric trim was disabled, the Captain elected to continue their two-hour flight with the electric trim disabled, no stall warning system (because the stick shaker continued to activate from liftoff until touchdown), and no autopilot system (because the electric trim was disabled). That type of decision would likely result in certificate action in the US and, I presume, most other countries.
5. The maintenance write-up that has been released for that flight did not mention that the stick shaker was activating for the entire flight.
6. The airline dispatched the airplane again for what turned out to be the accident flight.
7. On the accident flight the Captain was successfully flying the airplane after takeoff (with the stick shaker activating from liftoff). He had 21 MCAS activations and used the electric trim to return the aircraft to a trimmed state all 21 times.
8. The First Officer was trying to find the applicable procedure (runaway stabilizer) in the QRH but wasn't able to find it. The Captain transferred control to the F/O so that we could look for the procedure.
9. The F/O received 5 MCAS activations. He stopped the first 4 activations but failed to continue to re-trim the airplane back to a trimmed condition each time as had the Captain. The 5th activation was not stopped and it brought the stab trim to the full nose-down position which resulted in the loss of control.

That's what we know at this point. Some of those things may be revised or expanded in the final report but, from what we know now, what blame do you think the airline and crew should receive?

The media, and almost everyone else, has assumed that the Ethiopian accident was the result of another unscheduled MCAS activation. Tomorrow will mark two weeks since the accident yet that simple fact has not been confirmed nor ruled out.

French subject matter experts have had the Ethiopian DFDR for about a week. Protocol says that the French can not release any of the information that they recover from the recorder. Their action would be to forward that data back to the investigating agency (the Ethiopian equivalent of the NTSB) and then they would control the release of the information. It should be pretty easy to either rule in, or rule out, an unscheduled MCAS activation as the trimming patter it produces is distinctive. Why hasn't that information been released? I have no idea.

The information that we do have is as follows.

1. MCAS is disabled when the flaps are not retracted and/or when the autopilot is engaged.
2. The departure airport elevation is 7,657'.
3. The unofficial Flightstats data (from ADS-B) indicate that the airplane reached a maximum altitude of about 8,600' and that their rate-of-climb excursions started well before that. The 8,600' reading was at the end of the available data.
4. The 737 is not authorized to takeoff with flaps up. Authorized takeoff configurations are Flaps 1, 5, 10, 15, and 25. Due to the high elevation of the airport, their likely takeoff flap setting was either Flaps 1 or Flaps 5.
5. The acceleration and clean-up schedule for a 737, using an NADP-2 departure, would be to climb to 800' AFL (8,467'), lower the nose to accelerate, then retract the flaps as each flap maneuvering speed is reached. With slower acceleration due to altitude, it's unlikely that they would have started to retract the flaps until somewhat above the 8,600'. (An NADP-1 departure wouldn't have them accelerating and cleaning up until 3,000' AFL/10,657' MSL).

Given this information, how could MCAS have activated on this flight? Lacking data, I can only speculate.

1. Flaps misset for takeoff?
2. Flaps retracted early?
3. Flightstats data wrong?
4. MCAS didn't activate and the problem was something else?

We won't know until the DFDR data and analysis is released. Why hasn't that been released yet?

So, given this, are you still convinced that both accidents were caused by the same problem or do you think we should withhold judgement pending data that shows a second unscheduled MCAS activation?

The US got a lot of criticism for not immediately grounding the MAX as many other countries did. Canada and the US did not ground the MAX until the Ethiopian jackscrew was found in a nose-down position similar to the Lion Air jackscrew. That was the first hard data suggesting that the proximate cause of both accidents was a loss of control due to an excessive nose-down trim and it was that link that justified the grounding.

We know how the Lion Air jackscrew ended up in the full nose-down position. We don't yet know why the Ethiopian jackscrew ended up in a similar position. The DFDR and CVR data will tell us. Considering that a fleet of over 300 airplanes are grounded pending this information, why hasn't anything been released? I don't know.

So, who's blaming the crew without information?
 
In regards to all this talk about optional AOA disagree lights and displays that are generating gasps from the general public I think it is a bit overblown. For one thing a split in AOA sensor data is going to cause an airspeed disagree so there's already a warning. In that sense an AOA disagree light is redundant and It's not certain that the pilots knowing it's because of an AOA sensor at that moment is going to necessarily be of any help. They still have to discern which airspeed reading is the correct one.

I think that, as pointed out in the above cited Leeham News article, there's more to this than just the software logic for the MCAS system or pilot training. It's odd in itself that two virtually brand new AOA sensors would have identical failures let alone the fact that such a single failure would cause the aircraft to fly itself straight into the ground.
 
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