News Ethiopian 737 crashed on way to Kenya, 157 people on-board

[Urwumpe]

And the US has grounded all 737-8 and -9 MAXes, per the President.

Now Marijn really has a reason to complain about populist political decisions. :lol:


Was that really the first wise decision of President Trump? Time will tell.

 

[MaverickSawyer]

And it turns out that Canada and Iraq have also grounded the MAX. Looks like the grounding is almost completely global now.

 

[dbeachy1]

...and the 737 MAX is grounded globally now:

Boeing 737 Max 8 planes grounded after Ethiopian crash
Boeing says it will tell the FAA to ground its 737 Max planes "out of an abundance of caution".

Personally, I think the global grounding is long-overdue, so I'm glad to see that safety won out here.

More info here.

 

[Marijn]

Yes - and that assumes...

That's a whole new series of open doors you are kicking in. And I don't like being framed this way. I fully trust every individual and organization in the chain and I never said I didn't. I seriously ask you politely now to stop these insinuations. I said it's weird that politicians can precede the official authorities in important decision making about things like airworthiness. I care because I DO trust these official authorities and that's why I think there is a problem if they don't get to act first. You keep missing this point and react with irrevant questions and obvious statements. But I do disagree with your attempts to explain it's business as usual. It's not. That's my opinion and you have to respect that.

Did you know EASA introduced a new subject to the theoretical exams? It's called human factors. It's about alcohol, medicine, drugs, mental-health and so on. But it's also about the problems of too much autohority at various levels in aviation and how everyone is expected to deal with it. Basicly, it boils down that it's eveyone's responsibility to voice any concerns and not be afraid to be blamed, framed or shamed.

Do you have a decision making job in aviation? Do people take orders from you? How much room is there for critism around you? How do you deal with it? The same as with me?

Now Marijn really has a reason to complain about populist political decisions. :lol:

It's you who includes political rhetoric on a steady basis. I carefully refrain from that because it degrades the value of whatever you have to say.

 

[Thorsten]

Can't they just switch the autopilot off and take manual control? Why should you keep fighting a system if you can disable it?

Somewhat sorry to jump right to the beginning, but this sort of struck me...

I (and a few other folks I know) have some experience programming virtual autopilots for all kinds of simulated craft (that's... Flightgear simulator...). Needless to say, these virtual APs never undergo the same level of testing and certification their real counterparts experience, so they're more prone to failures.

We also get to see the reports from virtual crashes. It's a fact that never ceases to amaze me - the AP goes out trying to kill people, it's obviously doing very dangerous things (like, well, diving a Shuttle steep down into the atmosphere while the temperature is already at the limit, or pulling an airliner up while stall speed is approaching) - but they never disengage it, they wait for the minute till they're actually killed and then complain that something went wrong.

There must be some deep-rooted trust in people that the machine somehow knows better, that there must be some sort of plan behind the seemingly irrational behavior.

On the other hand, to the people who have actually coded APs, the idea that the beast will handle every situation is plainly ridiculous - they switch them off in a heartbeat the moment anything starts to go off-nominal.

So my theory is that people who do not understand what an AP fundamentally is and does place unreasonable faith into it and tend to believe that it's still acting rationally even when it manifestly does not. Perhaps one ought to train pilots by letting them write AP codes - then they'd understand the failure modes better...

 

[Notebook]

Its probably a poor analogy, and I've never written any software except for my own amusement and curiosity.
I did work for a long time in television transmission and inevitably it got more and more automated with fewer and fewer staff.
Usually it all worked well, and with some systems you learned the warning signs when something was going to go wrong.
The more "exciting" systems were where a tape system was modified to a mix of early video-servers and tape robotic system from an all tape system.

Thinking behind this was the short-length material(commercials and promotions) would come off the video-servers, programmes would stay on tape. Early video-servers didn't have much capacity

This gave problems from the start, the video-server didn't behave exactly like a tape machine. It didn't give the same status signals back to the automation controller as a tape machine at the correct times.

Each of the three manufacturers blamed each other, eventually it got sorted.
I was talking to one of the software engineers who was based at the site till it got fixed. I asked him why they had a "bounce" mode on the video-server. Bounce mode plays the item forward to the end, then in reverse to the start.
He said it was an easy software function, and they thought it would be useful.
I did ask why they thought playing an item backward in a transmission area would be useful, didn't get an answer.

Sometimes you are better off starting again, rather than put new equipment in an existing system?

N.

Edit: found an old video of one of the tape robots:

Sony Flexicart:
[ame="https://www.youtube.com/watch?v=DQ-JavZ_sWM"]Flexi dvcam in action - YouTube[/ame]

With the Sony the robotics stopped when you opened the door. Naturally all the safety interlocks were disabled...

Didn't know Odetics history, they were well engineered and very reliable.
http://www.company-histories.com/Odetics-Inc-Company-History.html
Hopefully still going.

 

[Linguofreak]

We also get to see the reports from virtual crashes. It's a fact that never ceases to amaze me - the AP goes out trying to kill people, it's obviously doing very dangerous things (like, well, diving a Shuttle steep down into the atmosphere while the temperature is already at the limit, or pulling an airliner up while stall speed is approaching) - but they never disengage it, they wait for the minute till they're actually killed and then complain that something went wrong.

The time it takes from the first sign of something going wrong to an unrecoverable upset can be surprisingly short. Add in a few moments of doubt as to whether it's the AP or something else causing an unusual attitude, or whether the observed movement is a momentary transient, and you may already be screwed by the time you hit the disconnect. A bit of post-mortem analysis generally makes clear what the AP was trying to do, and often it's not a bug in the autopilot*, but you can very much be taken by surprise.

*Or, at least, not in the channel that killed you. If a bug in the roll channel flips you inverted, it's the selected pitch mode working as designed that will kill you. In the case I'm thinking of, I exacerbated the situation by killing the roll channel first, rather than killing the pitch channel first or killing the whole autopilot at once. I was getting near to 90 degrees of roll when I realized that it wasn't going to come back to center, and by the time I had actually disengaged, I was already past it, and the pitch channel was frantically attempting to pull up to bring me back to zero vertical velocity. By the time I got pitch disengaged and the throttles retracted, I had lost something like half my altitude and gained enough velocity that I couldn't pull out without structural overload.

 

[Marijn]

Meanwhile, at Sofia airport, tour operator TUI has brought the passengers, who got stranded there yesterday because their 737 was denied access to EU airspace while in flight for safety reasons, back to their hotels for another night. Their replacement plane did have problems. There are quite a few elderly people on the flight, who escaped the European winter cold in Africa for health reasons. They now report health problems because it's freezing in Sophia and some of them have run out of medicine.

 

[dbeachy1]

Quoting from the FAA order to ground all 737 MAX planes earlier today (emphasis added):

FAA emergency order grounding 737 MAX planes

BASIS FOR ORDER

Based on the initial investigations and the reliable and credible evidence presently
available, the Acting Administrator finds that:

1. On October 29, 2018, a Boeing Company Model 73 7-8 operated by Lion Air as flight
JT610 crashed after taking off from Soekarno-Hatta Airport in Jakarta, Indonesia. Flight JT610
departed from Jakarta with an intended destination of Pangkal Pinang, Indonesia. It departed
Jakarta at 6:20 am. (local time), and crashed into the Java Sea approximately 13 minutes later.
One hundred and eighty-four passengers and five crewmembers were on board. There were no
survivors. An Indonesian-led investigation into the cause of this accident is ongoing, supported
by the National Transportation Safety Board (NTSB), FAA, and Boeing.

2. On March 10, 2019, Ethiopian Airlines flight ET302, also a Boeing Company Model
737-8, crashed at 8:44 am. (local time), six minutes after takeoff. The flight departed from Bole
International Airport in Addis Ababa, Ethiopia with an intended destination of Nairobi, Kenya.
The accident site is near Bishoftu, Ethiopia. One hundred and forty-nine passengers and eight
crewmembers were on board. None survived. An Ethiopian-led investigation into the cause of
this accident is ongoing, supported by the NTSB, FAA, and Boeing.

3. The Boeing Company Model 737-8 and the Boeing Company Model 737-9 comprise
the Boeing 737 MAX series, sharing nearly identical design features. The Boeing 737 MAX
series airplanes are narrow-body airplanes with two high-bypass turbofan engines. The Boeing
737 MAX series airplanes are used for passenger carrying operations and are equipped with new
CF engines and larger cockpit displays.

Under 49 U.S.C. 46105(c), the Acting Administrator has determined that an emergency
exists related to safety in air commerce. On March 13, 2019, the investigation of the ET302
crash developed new information from the wreckage concerning the aircraft's configuration just
after takeoff that, taken together with newly refined data from satellite-based tracking of the
aircraft's fight path, indicates some similarities between the ET302 and JT610 accidents that
warrant further investigation of the possibility of a shared cause for the two incidents that needs
to be better understood and addressed. Accordingly, the Acting Administrator is ordering all
Boeing 737 MAX airplanes to be grounded pending further investigation.

This Order is effective immediately. While this Order remains in effect, the FAA intends
to initiate a proceeding, as appropriate, to address the factors that contributed to the two
previously discussed accidents involving Boeing 737 MAX series airplanes.

Full report here on cnn.com.

 

[Urwumpe]

If its really necessary...

Do you have a decision making job in aviation? Do people take orders from you? How much room is there for critism around you? How do you deal with it? The same as with me?

:threadjacked:

As you asked about my professional code of conduct:

1. I left aerospace industry behind 9 years ago and went into automotive as software developer. Working for non-financial reasons does not help you pay the rent. And car manufacturers have the bigger number crunchers, which makes this an especially good place if you have a HPC background. Got turned into a system analyst and PLM specialist by my management against my career plans and I am still not convinced if success alone makes me happy. I grow old much faster than I am used to. :thumbsdown:
2. I work in a much more shallow hierarchy as you. We are usually forming classic tiger teams for each customer from a pool of specialists available in my team. My team doesn't need orders from me. People ask for my advice and opinion. My team members are no idiots and I don't allow idiots in a team that messes with the crown jewels of our customers (Their CAD and project data) under the eyes of our customers. If I would need to micromanage them while working hundreds of kilometers apart at a different customer, the whole business would break down. If I can't trust them to ask for help before customer data is lost, they couldn't work in this team. We are in a business where a word-of-mouth recommendation by our customers is the only working marketing. And I am really looking forward to the next user group fair this year, after a very successful 2018 with a great team.
3. I encourage criticism on my own person. But if you think destructive criticism is the best choice, don't be surprised about getting ignored. Yes, I can be very grumpy if critized correctly for being an idiot sometimes. Especially if the other person is absolutely right in his criticism. Its not about him, I am angry about me. I am just a human.
4. I react absolutely allergic against destructive criticism against any member of my team. There is no excuse for it. I already lost very good people in the past ten years to customers who thought it helps them if the employees of the contractor are literally destroyed to let them look better. See #2 there. You can't replace them socially and it often takes multiple new employees to almost replace a single lost veteran.
5. I am wrong on almost every day during the week. Sometimes multiple times. My ambition is to make better errors every day, not trying to never get caught again. Todays biggest error was a wrong SQL join expression out of five in a statement when handling test program reports with multiple parts involved. Also I likely did the new batch of suspension geometry data wrong, but then, it was the first time I was doing the task after the only expert for that software at the customer "died". For doing better errors tomorrow, I need to be aware of the errors I did today.
6. I absolutely hate yes-sayers, as you can expect there. I know to be wrong, and I would like to know it ASAP and not in front of the customers management.
7. Failure is always an option.
8. You seem to feel like I think you are a big idiot, but be assured, I still have full confidence that you are none at all. If I would consider you an idiot or incompetent, I would not bother discussing with you at all, because I would not even expect you to ever understand my point of view. Why waste my time then?

I still have hope to end this in a civil way, what about you? And can we keep this out of this thread?

 

[Thorsten]

The time it takes from the first sign of something going wrong to an unrecoverable upset can be surprisingly short. Add in a few moments of doubt as to whether it's the AP or something else causing an unusual attitude, or whether the observed movement is a momentary transient, and you may already be screwed by the time you hit the disconnect.

That's certainly true for some cases - if you're operating an aircraft near the coffin corner, then you might have a few seconds to stall, if you're in a Shuttle at max heating, then.. well...

I guess generally the pre-requisites to successful intervention are:

a) you need to recognize the off-nominal situation, i.e. be aware what the current situation is, what needs to be done and that the AP is not doing it

That requires that you're actually using the freedom the AP gives you to keep your attention on the situation - are the sensor readings plausible? Does airspeed match and Mach number match AoA? That kind of thing. If you're making a cup of tea while the AP flies, you won't react...

b) you need to be confident of your manual piloting skills - I guess that's something I've primarily seen from virtual Shuttle pilots - the majority of them who got killed by the AP simply do not know how to fly an entry manually, so they would also be lost when disengaging the AP. This seems to be less true for simulated airliner pilots, who generally appear to have a good grasp of manual flying

c) you need to know the disengagement procedure and the ability to manually deal with transients and the off-nominal situation

In many planes, it is quite possible to even end a flat spin if you have some altitude left - but not every virtual pilot knows how this is done.

***

Among many other experiences during testing, I've had my Shuttle AP try to invert me during entry once as well, I've never found the root cause, probably an integrator windup - what tripped me off was already the attempt to roll beyond 80 degree bank angle, this seemed completely not justified given the situation and in fact is beyond the coded limit angle, so at that point I disengaged and flew manually - turned out I was unable to re-engage in any phase, so in the end I made it to a location a few meters off the runway at Easter Island (I had cloud cover and was so busy piloting I failed to intercept TACAN, by the time I discovered my inertial position was massively off, it was a bit too late... a co-pilot would have helped a lot...)

Generally, I'd say that I get rarely killed by a virtual AP, probably 9/10 times I manage to disengage in time and save the day - I suspect largely not because I'm a brilliant well-trained pilot, but because I've programmed too much to trust a piece of code overly much. Most of my virtual crashes are classic human errors in judgement (weather doesn't look that poor, I should be able to do that...) or a learning curve of course :lol: (for learning to land helicopters you need either an instructor or patience and frustration tolerance...)

 

[Urwumpe]

And it was decided the black boxes go to the evil empire: Germany.

The BFU (federal agency for aircraft accident investigation) will do the analysis... so, the blackboxes will be next to my former workplace. :rofl:

Aaaaaaaand... its already old news. The BfU rejected because they lack the equipment to read the FDR, because it is a newer model with newer software. Instead of talking nonsense about aircraft carriers, our politicians should better invest the money into the BfU...



Now the BEA of France will do the analysis.

 

[MaverickSawyer]

Unconfirmed reports that the stabilizer incidence jackscrew has been located in the wreckage field... and that its all the way to the (aircraft) pitch down stop.

 

[Urwumpe]

Unconfirmed reports that the stabilizer incidence jackscrew has been located in the wreckage field... and that its all the way to the (aircraft) pitch down stop.

Had the part been recovered at Lion Air 610 as well? The suspected MCAS behavior exactly predicts this state of the part, the MCAS driving the pitch trim to pitch down stop in pulses.



Confirmed reports also state that the pilot of Ethiopian Air 302 reported problems to control the aircraft already a few minutes after take-off and requested to return to the airport for an emergency landing.

 

[MaverickSawyer]

No clue on Lion Air 610, but I would expect they have found it by now.

 

[Urwumpe]

No clue on Lion Air 610, but I would expect they have found it by now.

Well, it could be in a too bad state to draw any conclusions about the trim before crash.

 

[GLS]

I've not really been following this in depth, and I don't know the 737 (or others), but it looks like the pitch trim was driven with data from a single sensor.... maybe I'm too much into the space shuttle and its quadruple systems but, on a plane full of people, isn't having systems with a single sensor asking for trouble?

 

[MaverickSawyer]

I've not really been following this in depth, and I don't know the 737 (or others), but it looks like the pitch trim was driven with data from a single sensor.... maybe I'm too much into the space shuttle and its quadruple systems but, on a plane full of people, isn't having systems with a single sensor asking for trouble?

It is. That's what is so disturbing to me as a mechanic. We JUST covered flight instruments this quarter, and the fact that MCAS is using a single sensor feed is, while legal, flying in the face of over half a century of conventional wisdom. Most instruments used for IFR flight use separate and parallel sensors/inputs to ensure at least one is working at all times. Your artificial horizon gyros even go so far as to use separate power sources, typically electrical for pilot and vacuum for copilot, so that the failure of one power source won't take out all your gyros.
Furthermore, the fact that this was allowed to fly by the FAA raises some... disturbing questions about the FAA's ability to remain impartial in their oversight of Boeing. Combine that with the extended delay before grounding the MAX family altogether, and I'm increasingly of the opinion that the FAA and Boeing are a little too intertwined right now. :dry:

Also, although not directly related to the accident, but still in the "this isn't exactly a coincidence" category... the production line for the KC-46 up at the Everett widebody facility has been having issues with leaving tools, parts, and assorted other FOD inside the fuselages of KC-46s, sometimes not being found until acceptance by the USAF. I'm seeing a pattern beginning to emerge that Boeing is having some serious internal issues that need to be addressed, and quickly.

 

[skyeboy]

I've not really been following this in depth, and I don't know the 737 (or others), but it looks like the pitch trim was driven with data from a single sensor.... maybe I'm too much into the space shuttle and its quadruple systems but, on a plane full of people, isn't having systems with a single sensor asking for trouble?

I agree; especially since I've heard (perhaps I'm wrong) that most MCAS systems never rely on just one sensor; (not just for space shuttles) but use at least two primary and a few secondary sensors to correlate. So, if they're using only ONE malfunctioning angle of attack sensor on the MAX to trim elevator down every 5 seconds; then we're reaching the level of absurdity on Boeing's part and makes one wonder where they're finding their "engineers".... or has political correctness with quotas meant too much sacrificing of competence? Or is this just bad over-all cultural corruption problem in Boeing these days--not even identifying the MCAS stall recovery function in the POH? (Unless I've been misled with this news as well).

 

[Urwumpe]

I've not really been following this in depth, and I don't know the 737 (or others), but it looks like the pitch trim was driven with data from a single sensor.... maybe I'm too much into the space shuttle and its quadruple systems but, on a plane full of people, isn't having systems with a single sensor asking for trouble?

Exactly - now, that isn't far below civil airflight standards, for example on Airbus, one sensor supplies one computer and one half of the cockpit, but then, two ELAC computers together make up the FBW. (conflicting sensors result in downgrade of FBW)