News Ethiopian Airlines 737 crash discussion

[Greg Bernhardt]

All 157 people on board an Ethiopian Airlines flight that crashed soon after taking off from Addis Ababa have been killed, the airline said on Sunday morning.

The plane, en route to Nairobi, Kenya, lost contact at 8:44 a.m. local time, six minutes after taking off from Bole International Airport in the Ethiopian capital.

https://www.cnn.com/2019/03/10/africa/ethiopia-airline-crash-nairobi-intl/index.html

There is now a lot of speculation about whether something is seriously wrong with the 737 MAX.
https://www.cnn.com/2019/03/10/africa/ethiopian-airlines-crash-boeing-max-8-intl/index.html

 

[Wrichik Basu]

Boeing planes seem to be seriously flawed. It's not the first time a Boeing has crashed. In past, a number of Boeing flights of different models have crashed unexpectedly.

 

[fresh_42]

That was my first thought, too. And I remember the previous discussion about it (JT 610) when I said, that the 737 is an old work horse and someone clarified, that they actually made many technical upgrades on the MAX version so it can barely be called old. It might well be the case that they ran through their development too fast, driven by the same thought as mine "old work horse - what can go wrong" and the pressure from the A 320-Neo competition.

Whatever they had done, they should have relied more on the old components rather than renewing them IMO. The pattern is effectively 7 years old, so it still counts as new.

 

[Dr Transport]

As a former Boeing employee (you'll see that I didn't say loyal, but that is another story) a vast number of the crashes of Boeing 737's are due to faulty maintenance. This becomes an issue outside of the US where the FAA has no jurisdiction. Foreign carriers tend not to perform the scheduled maintenance because they don't have the available assets, i.e. cash and qualified mechanics.

Also, statistically, think about it. if I remember correctly, the 737 model line has the most number of planes flying on the planet. Why do we see more 737 crashes than others, I don't know why.

 

[fresh_42]

Also, statistically, think about it. if I remember correctly, the 737 model line has the most number of planes flying on the planet. Why do we see more 737 crashes than others, I don't know why.

See my previous post #3. It is factually a new pattern. This doesn't contradict what you have said. On the opposite, the new pattern most likely requires new maintenance rules as well, and many airlines may not have correctly adjusted them, especially in some parts of the world. IIRC especially the incident with JT 610 required a change for the pilots in response to certain circumstances! So the question will be: have they all enjoyed this additional management training? I have my doubts.

 

[Dr Transport]

Upon looking at the article that Greg linked to, there was a temporary grounding in 2017 due to engine issues. That isn't Boeing, I think all the 737 line runs GE engines, that's where I'd start looking.

I agree with @fresh_42 , it is essentially a new line, updated air-frame with new avionics.

 

[Greg Bernhardt]

GE engines, that's where I'd start looking

If you haven't sold their stock already in the past few years...

 

[Vanadium 50]

Boeing planes seem to be seriously flawed. It's not the first time a Boeing has crashed.

With all due respect, that's a terrible argument.
Airbus planes seem to be seriously flawed. It's not the first time an Airbus has crashed.
Embraer planes seem to be seriously flawed. It's not the first time an Embrair has crashed.
Tupolev planes seem to be seriously flawed. It's not the first time a Tupolev has crashed.

 

[Dr Transport]

http://aviationknowledge.wikidot.com/aviation:manufacturers

https://www.statista.com/statistics...ivered-global-aircraft-fleet-by-manufacturer/

When you have more airplanes in the sky than anyone else, statistically, you'll see more issues down the road. The first link shows that Boeing has 75% of the commercial planes in the world at the time (2009) and the second shows their deliveries to the global fleet. Can't argue with those numbers.

 

[fresh_42]

With all due respect, that's a terrible argument.
Airbus planes seem to be seriously flawed. It's not the first time an Airbus has crashed.
Embraer planes seem to be seriously flawed. It's not the first time an Embrair has crashed.
Tupolev planes seem to be seriously flawed. It's not the first time a Tupolev has crashed.

A bit short, your list: Lockheed, Ilyushin, Antonow, McDonald Douglas, Bombardier, Cessna, ... , and now for the helicopters ...

 

[fresh_42]

It must be allowed to ask: Why Delta, KLM or United don't have issues?

 

[Greg Bernhardt]

Live updates here
https://www.cnn.com/world/live-news/ethiopian-airlines-plane-crash/index.html

Ethiopian Airlines CEO Tewolde GebreMariam told reporters at a press conference that the pilot of flight ET 302 that crashed Sunday morning had reported technical difficulties and asked for clearance to return to Addis Ababa.

He was given clearance to turn back, according to Mr. GebreMariam, citing the Air Traffic Controllers record.

The senior Ethiopian Airlines pilot had flown more than 8,000 hours. He had an “excellent flying record,” according to the CEO.

A routine maintenance check didn't reveal any problems, he said. GebreMariam said they have not yet determined the cause of the crash.

 

[Dr Transport]

It must be allowed to ask: Why Delta, KLM or United don't have issues?

They are carriers, not manufacturers, with excellent maintenance records.

 

[fresh_42]

They are carriers, not manufacturers, with excellent maintenance records.

... and all operate the 737-800. Most of European carriers have fleets of several manufacturers, mainly Boeing and Airbus. They also have well trained pilots which are up to date to latest changes, and I assume the same is right for US carriers, even though they might operate less Airbusses. Nevertheless, maintenance and training are essential in my opinion. Incidents like AWE 1549, QF 32, or AF 66 show that well trained pilots can deal with technical failures; and that modern aircrafts can cope with many technical failures, too. It wasn't only Sullenberger, it was also a reliable aircraft.

History shows, that crashes are usually due to quite a few causes which all have to come together to make a crash happen. It is for a reason that studies take so long until they are published.

 

[Dr Transport]

... and all operate the 737-800. Most of European carriers have fleets of several manufacturers, mainly Boeing and Airbus. They also have well trained pilots which are up to date to latest changes, and I assume the same is right for US carriers, even though they might operate less Airbusses. Nevertheless, maintenance and training are essential in my opinion. Incidents like AWE 1549, QF 32, or AF 66 show that well trained pilots can deal with technical failures; and that modern aircrafts can cope with many technical failures, too. It wasn't only Sullenberger, it was also a reliable aircraft.

History shows, that crashes are usually due to quite a few causes which all have to come together to make a crash happen. It is for a reason that studies take so long until they are published.

See my previous post (#4) The crashes of late have been with aircraft from non-first world countries, not what I'd call a major carrier. You say they operate 737's, sure, but they have a better maintenance record and operate under a different set of rules. Maintenance, maintenance, maintenance, that's what I been saying since thread one.

 

[Klystron]

While my direct experience in flight safety research is too dated to be relevant to the new Boeing 737 models, an old discussion deserves to be revisited. Throughout my career serious safety concerns about 'fly by wire' aircraft control were raised not only by pilots but by engineers and scientists in a variety of fields but particularly avionics control systems, risk management and crew factor research, not to mention maintenance experts. If the MCAS (see OP links) becomes implicated in this second 737 event, a review of basic concepts seems warranted from engine redesign where fuel costs remain a paramount factor to updated crew training procedures.

Not suggesting nor advocating return to 'stick and rudder seat-of-the-pants' flight regimes, but an unbiased review of manufacturers decision making particularly when adopting new technology, scheduling maintenance, and developing training models.

 

[256bits]

From the link in the opening post

"As it is a fresh incident, we have not been able to determine the cause. As I said, it is a brand new airplane with no technical remarks, flown by a senior pilot and there is no cause that we can attribute at this time."
"The routine maintenance check didn't reveal any problems," GebreMariam added

Ethiopian Airlines has a reputation of being one of the best airlines in Africa. It has a good safety record and the newest fleet of planes on the continent

No details of the technical difficulties the pilot experienced, and for the subsequent crash have yet been released or determined.
As such no link with another flight that faced difficulties and crashed can be made.

 

[Vanadium 50]

but they have a better maintenance record and operate under a different set of rules. Maintenance, maintenance, maintenance, that's what I been saying since thread one.

Lion Air (the previous crash) was formerly banned from flying into EU airspace for that reason.

 

[Dr Transport]

Lion Air (the previous crash) was formerly banned from flying into EU airspace for that reason.

I don't think I have ever seen Ethiopian Air flying outside of Africa, same reason. This was a fairly new plane, many of the air-frames in use in the third world are bought from other air carriers after they deem they have exceeded their useful lifespan.

 

[fresh_42]

I don't think I have ever seen Ethiopian Air flying outside of Africa, same reason.

Ethiopian is a member of the star alliance and has a good reputation with a modern fleet. So it's not one of the usual suspects.

 

[russ_watters]

With all due respect, that's a terrible argument.
Airbus planes seem to be seriously flawed. It's not the first time an Airbus has crashed.
Embraer planes seem to be seriously flawed. It's not the first time an Embrair has crashed.
Tupolev planes seem to be seriously flawed. It's not the first time a Tupolev has crashed.

Well, maybe that last one...

 

[russ_watters]

It must be allowed to ask: Why Delta, KLM or United don't have issues?

Could you elaborate on what your point is please; KLM was involved in the worst aircraft accident in history.

 

[fresh_42]

Could you elaborate on what your point is please; KLM was involved in the worst aircraft accident in history.

Yes, and it was mainly a human error by the then inexperienced pilot, combined with bad crew management plus language issues.

I have looked up which airlines operate the in my eyes new pattern 800 MAX, and observed, that the carriers I mentioned haven't had issues with it - as of yet. My main concern regarding the last two accidents is, the first of which is almost certain and the second can only be speculated, that MCAS played a major role. This system requires a special handling different from previous 737 patterns in certain situations, and my personal suspicion is, that not all pilots on a 800 MAX have received an according training resp. might not be aware of the difficulties MCAS can make.

@256bits is right when he says

No details of the technical difficulties the pilot experienced, and for the subsequent crash have yet been released or determined.
As such no link with another flight that faced difficulties and crashed can be made.

so this is at best a working hypothesis based on the similar flight phase. The observation that the other 800 MAX clients didn't have those troubles however stands.

 

[russ_watters]

I have looked up which airlines operate the in my eyes new pattern 800 MAX, and observed, that the carriers I mentioned haven't had issues with it - as of yet.

Ok, that make more sense - it sounded like a very broad statement at first read.

 

[russ_watters]

Here's the radar track for Ethiopian Airlines 302:
https://www.flightradar24.com/data/flights/et302

The flight is very short and it looks like some of the early data is interpolated and smoothed. It skips from 5:38:18 (0', 76kts) to 5:38:44 (8,025', 250kts). I don't think the plane was broadcasting altitude when on the ground, as the airport is at 7,660 feet elevation (Jakarta, on the other hand, is just above sea level). So that would make it 365 feet off the ground and struggling to maintain altitude, much less climb. The speed is also unusually high. High speed, not climbing...that could be an indication of the same problem as Lion Air.

Here's the profile from the previous day, showing it was gradually building speed to 400kts about 5 minutes into the flight (not sure if there is a way to zoom in...):
https://www.flightradar24.com/data/flights/et302#1fbe5988

And for reference, Lion Air 610:
https://www.flightradar24.com/data/pinned/jt610-1e5ff318#1e5ff318

 

[russ_watters]

If this eyewitness account is reliable, it points to an engine problem:

"I was in the mountain nearby when I saw the plane reach the mountain before turning around with a lot of smoke coming from the back and then crashed at this site," said the 25-year-old, who was collecting firewood on the mountain with three other locals when it happened.

"It crashed with a large boom. When it crashed luggage and clothes came burning down.

"Before it crashed the plane was swerving and dipping with a lot of smoke coming from the back and also making a very loud unpleasant sound before hitting the ground."

https://www.cnn.com/world/live-news/ethiopian-airlines-plane-crash/index.html

 

[fresh_42]

If this eyewitness account is reliable, it points to an engine problem:

... which makes the problem even stranger and the question mark bigger.

 

[fresh_42]

I'm not 100% sure, but if I remember correctly, then there have been similar reports on JT 610 at the beginning. Maybe witnesses tend to "see" engine fire in order to explain the rest of their experience. Especially the wording "from the back" is a bit mysterious, and a fire would very likely have been reported by the pilot.

 

[russ_watters]

I'm not 100% sure, but if I remember correctly, then there have been similar reports on JT 610 at the beginning. Maybe witnesses tend to "see" engine fire in order to explain the rest of their experience. Especially the wording "from the back" is a bit mysterious, and a fire would very likely have been reported by the pilot.

Eyewitness reports are notoriously unreliable. Even if the person really did see something, it could have been a vapor trail, not smoke.

 

[256bits]

Black box revovered.
https://www.msn.com/en-ca/news/world/black-box-from-crashed-ethiopian-airlines-flight-recovered-state-tv/ar-BBUCDyA?li=AAggFp4&OCID=ansmsnnews11

 

[russ_watters]

It looks like at this point most of the worlds' aviation authorities are banning use of the 737 Max, including the UK which forced some planes to turn around mid-flight.
https://www.cnn.com/world/live-news/boeing-737-max-8-ethiopia-airlines-crash/index.html

This has the feel to me of a largely media driven hysteria. At this point there are some *potential* similarities and some *potential* differences with Lion Air 610, and the leading crash explanation for LA610 (we don't have a final report yet) is that the issue experienced should not be an emergency situation.

There's been a lot of crazy talk over at Airliners.net about the groundings and I had planned on avoiding bringing it here, but the idea of turning planes around in flight takes it to a new level I thought worth comment. Otherwise, I'd prefer to wait what should only be a few more days for more information before making further judgement.

 

[russ_watters]

[edit]
Content re-located to this thread:
https://www.physicsforums.com/threads/boeing-737-max-mcas-system.967958/#post-6146292

 

[davenn]

This morning's news
Australia has banned all flights of this aircraft into and out of Australia

 

[PeterDonis]

This has the feel to me of a largely media driven hysteria.

To me as well. In the other thread over in the Mech Eng forum, I linked to a Hacker News thread that contains some excerpts from reports filed by US pilots concerning incidents with the 737 MAX. The one key takeaway from all of them: all of those pilots were well prepared and were able to quickly take control of the aircraft when a problem surfaced, and all of those flights completed safely. So I don't see any reason to be turning planes around in flight.

Not to mention that the particular incidents in question all happened shortly after takeoff, so if a plane is in the middle of its flight at cruising altitude, it's already passed the danger regime anyway. Which makes it even less justified to turn it around mid-flight.

 

[Greg Bernhardt]

Max 8 and 9 are now grounded in US
https://www.cnn.com/world/live-news/boeing-737-max-8-ethiopia-airlines-crash/index.html

 

[PeterDonis]

Max 8 and 9 are now grounded in US

I note, apropos of previous comments, that the announcement said planes in the air will continue to their destinations, no turning back in mid-flight.

 

[berkeman]

Max 8 and 9 are now grounded in US
https://www.cnn.com/world/live-news/boeing-737-max-8-ethiopia-airlines-crash/index.html

Wow. I wonder what this "new evidence" is...

It was a turnabout from the administration's earlier position, which deemed the planes safe to fly even as dozens of other nations banned them after they were involved in two fatal disasters.
Trump said the decision to ground the Max 8 and Max 9 was made in light of new information about last week's crash, which killed 157 people. The Federal Aviation Administration said new evidence had been collected at the sight of the crash on Wednesday, and that information -- along with new satellite data -- led to the grounding decision.

 

[Borg]

Wow. I wonder what this "new evidence" is...

I briefly caught a story that stated that the Ethiopian COE said that the pilots stated that they were having control issues. If so, that may be just too many coincidences until the facts come out.

 

[russ_watters]

I briefly caught a story that stated that the Ethiopian COE said that the pilots stated that they were having control issues. If so, that may be just too many coincidences until the facts come out.

That was known on Monday.

Several sources including the FAA directive cited but did not detail additional satellite tracking data and evidence at the scene. It is speculated that evidence at the scene could be evidence the flaps were fully retracted at impact.

 

[nitsuj]

I wonder just how much economics plays into a decision such as a governments "transport Agency" grounding a particular airplane

Boeing stock dropped 10% on opening Monday. Airbus trending up slowly, +2. something % since the Sunday crash.

Interesting Boeing stock recovered from todays news closing a half % up. At 2:00edt it dropped 3% in 45 minutes

That was known on Monday.

Several sources including the FAA directive cited but did not detail additional satellite tracking data and evidence at the scene. It is speculated that evidence at the scene could be evidence the flaps were fully retracted at impact.

Canada's transport minister (Marc Garneau; first Canadian Astronaut to go to space AND my mom went on a date with him lol) said it was specifically seeing additional correlation between these two accidents that persuaded them to ban the jet from airspace. Including GPS data.

I agree, given these activities have so much safety built in, when something does go wrong, I figure it would nearly implicitly be a NEW safety issue/concern, which have long since been at the point of being a series of "faults" leading to a complete failure. Correlation of some data points may indicate a systemic issue.

With all those types of concerns spoken of, imo the biggest loss by any and all measure is the types of individuals lost on that flight. I don't mean to place any more value on one life over another, but "humanitarians" imo are particularly special people who "add" far more than they "use"; who are in aggregate altruistic AND have a remarkably neutral bias.

 

[Vanadium 50]

Now that it's the "Trump 737MAX ban" everyone at the lunch table knew which side they were on.

The comparison with Lion Air is stretched. While we don't have a final report, JT610 had a failed Angle-Of-Attack sensor, and was deemed not airworthy by the head of the Indonesian transportation committee, and in fact had flown multiple times in this condition. It also turns out that for a Lion Air pilot to certify on the 737 MAX they don't even need to train in a simulator: they take a 3 hour online course. And, as I mentioned earlier, they have quite a history with safety, or rather the lack of it.

Ethiopian is different. The plane has not had any problems like this reported in the press. The FO was very inexperienced (200 flight hours; the US typically requires 1500) which may or may not be a factor.

One question is whether it's sensible to damn an airframe because of a single incident. More quantitatively, how long should it be grounded for?

The more interesting question is given a technology with long-term safety improvements may have early teething issues rendering it less safe in the short term, what do you do?

 

[Greg Bernhardt]

It also turns out that for a Lion Air pilot to certify on the 737 MAX they don't even need to train in a simulator: they take a 3 hour online course. And, as I mentioned earlier, they have quite a history with safety, or rather the lack of it.

I took Lion Air this past summer knowing their record . I've taken Ethiopian too, but they are one of the better African airlines.

 

[nitsuj]

Now that it's the "Trump 737MAX ban" everyone at the lunch table knew which side they were on.

The comparison with Lion Air is stretched. While we don't have a final report, JT610 had a failed Angle-Of-Attack sensor, and was deemed not airworthy by the head of the Indonesian transportation committee, and in fact had flown multiple times in this condition. It also turns out that for a Lion Air pilot to certify on the 737 MAX they don't even need to train in a simulator: they take a 3 hour online course. And, as I mentioned earlier, they have quite a history with safety, or rather the lack of it.

Ethiopian is different. The plane has not had any problems like this reported in the press. The FO was very inexperienced (200 flight hours; the US typically requires 1500) which may or may not be a factor.

One question is whether it's sensible to damn an airframe because of a single incident. More quantitatively, how long should it be grounded for?

The more interesting question is given a technology with long-term safety improvements may have early teething issues rendering it less safe in the short term, what do you do?

News in Canada is the issue is the MCAS (specifically how it's implemented), which is separate from auto pilot and "always" on unless deactivated with some multi step process; which is not part of training. There apparently is a procedure for this issue (MCAS trying to do it's thing based of false readings), and is to simply use the trim if i recall correctly.

MCAS was created as a solution to the "imbalance" caused by the heavier than usual engines (for the fuselage) which causes the nose to pitch up.

Isn't that why pilots are there, to fly the plane?

The similarity between the crashes is it was the MCAS that "brought them down". The false reading from the AoA sensor was being acted upon because MCAS is just a series of logic based on VERY few variables all meant to try and keep a plane in the air.

It could be argued the design is to crash the plane with MCAS if the data it's fed is faulty, unless the pilot can intervene the "ghost pilot" the actual pilots were not formally informed was part of the design. I too would presume a major mechanical failure, not a piece of software making the plane behave as though it has a major mechanical failure.

Even I could design a mechanical level, (which a plane like this likely has many of) as part of a congruency test to verify the data prior to mcas doing it's thing.

I wouldn't be surprised if the software update boeing did the day after the Ethiopian crash contained a similar verification.

 

[PeterDonis]

Technical discussion of MCAS and related issues is here:

https://www.physicsforums.com/threads/boeing-737-max-mcas-system.967958/

 

[russ_watters]

The similarity between the crashes is it was the MCAS that "brought them down". The false reading from the AoA sensor was being acted upon because MCAS is just a series of logic based on VERY few variables all meant to try and keep a plane in the air.

I don't think that is necessarily well established yet, however the crash site evidence cited by the FAA in their grounding directive was apparently a full nose down trim position, which would indicate that the MCAS was likely the cause. The FDR should tell us if the angle of attack sensor was faulty similar to the Lion Air crash.

A screw-like device found in the wreckage of the Boeing 737 Max that crashed last Sunday in Ethiopia indicates the plane was configured to dive, a piece of evidence that helped convince U.S. regulators to ground the model, a person familiar with the investigation said late Thursday night...

The piece of evidence was a so-called jackscrew, used to set the trim that raises and lowers the plane's nose, according to the person, who requested anonymity to discuss the inquiry.
[sloppy wording italicsd...let that go]

http://www.freerepublic.com/focus/news/3734927/posts?page=67

 

[Vanadium 50]

I chatted with a pilot yesterday, and he made some interesting points. One was that disabling MCAS is simple. But knowing that MCAS should be disabled as a response to a particular behavior is something that takes training and experience, something lacking in both accidents.

The other is that if a sensor fails and sends MCAS faulty data, that same faulty data is being sent to the cockpit.

Another thing to keep in mind is that even with two hull losses, that's a rate of about 1.8 per million departures. That's better than the DC-10, better than the MD-11, better than the A300, and I think better than the 727. So while no number above zero is good, the rate is comparable to older aircraft still flying.

 

[russ_watters]

I chatted with a pilot yesterday, and he made some interesting points. One was that disabling MCAS is simple. But knowing that MCAS should be disabled as a response to a particular behavior is something that takes training and experience, something lacking in both accidents.

This is a tough one to judge. It would appear that Boeing and the FAA considered this a normal "runaway trim" type of situation (based on the fact that they certified the plane and decided they didn't need to tell the pilots about it), which happens from time to time. Sometimes it contributes to crashes and sometimes pilots respond correctly to it and carry on as normal.

The MCAS system may be harder to deal with, though, if it gives the faulty trim intermittently and repeatedly. That could make it harder to diagnose -- while the plane is losing altitude with each trim runaway.

Another thing to keep in mind is that even with two hull losses, that's a rate of about 1.8 per million departures. That's better than the DC-10, better than the MD-11, better than the A300, and I think better than the 727. So while no number above zero is good, the rate is comparable to older aircraft still flying.

Where do you get the number of departures? That's a lot higher than I would have guessed (by like a factor of 10).

Either way, I definitely think decisions on things like the grounding should be made based on real information, not guesses. Finding the jackscrew position to me makes the cause of the two crashes likely to be the same and the grounding justified. But waiting an extra day or two despite media pressure did not carry much risk.

 

[Vanadium 50]

Where do you get the number of departures?

Got it for all 737's and scaled by the fraction of MAX's in service for 2017-2019. It works out to ~3/day which seems reasonable. (Another more ballparky estimate would be 300 planes for 1000 days times 3 departures/day is a million.)

 

[Astronuc]

Here's the profile from the previous day, showing it was gradually building speed to 400kts about 5 minutes into the flight (not sure if there is a way to zoom in...):
https://www.flightradar24.com/data/flights/et302#1fbe5988

Just a note: The flight 302 the day before used a 787-8 rather than a 737-8. It appears that the 787-8 uses more powerful engines, probably different avionics and perhaps different control systems.

CNN showed some flight data plots that indicated similarities between the Lion Air flight (JT610/LNI610) and Ethiopian Airline flight 302. I cannot find them at the moment.

 

[fresh_42]

I have seen a pilot in a simulator in a news show, where he easily repeated the incident and due to the lack of altitude crashed.