Ethiopian airliner down in Africa [Archive]

ExBA_tech

10th Mar 2019, 08:40

Accident to Ethiopian Airlines flight number ET 302
Ethiopian Airlines regrets to confirm that its flight ET 302/10 March in schedule service from Addis Ababa to Nairobi was involved in an accident today around Bishoftu (Debre Zeit).

The aircraft B-737-800MAX with registration number ET- AVJ took off at 08:38 am local time from Addis Ababa, Bole International Airport and lost contact at 08:44am. At this time search and rescue operations are in progress and we have no confirmed information about survivors or any possible causalities. Ethiopian Airlines staff will be sent to the accident scene and will do everything possible to assist the emergency services.
It is believed that there were 149 passengers and 8 crew onboard the flight but we are currently confirming the details of the passenger manifest for the flight.
Ethiopian Airlines is establishing a passenger information center and telephone number will be available shortly for family or friends of those who may have been on flight ET 302/10 March.
Ethiopian Airlines will release further information as soon as it is available. Updated information will also be on Ethiopian Airlines website at

procede

10th Mar 2019, 08:55

Another AoA / stall recovery / horizontal stabilizer autotrim problem?

bumpy737

10th Mar 2019, 08:57

Just took a look at Flightradar, it shows a climb to 8000ft, then a slight drop to 7600ft and a climb back to 8600ft where the data ends at a speed of 383kts...

SigWit

10th Mar 2019, 09:03

IF this is the MCAS fault again, then the consequences will be enormous, probably a grounding of the MAX fleet.

rog747

10th Mar 2019, 09:05

From the Prime Minsters office sending his condolences to the relatives the accident sounds very bad.

The 737 took off (08.38) from Bole and reached **8600' crashing just east of the city. Radar Contact lost at 08.44
No reports yet of any survivors. 157 tob.

edit ** Bole airport is over 7000' ASL

c_coder

10th Mar 2019, 09:08

Crash site seems to be on land, so it should be easier to recover the recorders. Maybe there will be some early information about the cause. The age of the aircraft is interesting. Is there a systematic issue with AoA sensors?

double_barrel

10th Mar 2019, 09:09

Just took a look at Flightradar, it shows a climb to 8000ft, then a slight drop to 7600ft and a climb back to 8600ft where the data ends at a speed of 383kts...
please confirm that was et302. I have people on that route

Evey_Hammond

10th Mar 2019, 09:11

It was ET302.

re FR24 data, they’ve tweeted that they don’t have the full flight data due to coverage.

LiamNCL

10th Mar 2019, 09:12

apebaron

10th Mar 2019, 09:13

Bishoftu is an Air Force town. If one had any time at all to aim for an airport (who knows?) it would be a good choice.

log0008

10th Mar 2019, 09:14

Its previous flight shows touchdown at around 7800ft a quick search shows the elevation of ADB about the same 7726ft. If thats the case it reached about 1000ft before it crashed taking into account the airports elevation ?

Airport Elevation is 7,656ft, it seems your correct because after take of altitude goes from 0 to 8025ft in one update.

LiamNCL

10th Mar 2019, 09:17

Airport Elevation is 7,656ft, it seems your correct because after take of altitude goes from 0 to 8025ft in one update.

Just think the 8000ft being said is misleading as the aircraft only climbed about 1000ft before it stops which brings it back closer to the initial climb of the lion air which encountered problems early in the climb.

Old King Coal

10th Mar 2019, 09:20

Just took a look at Flightradar, it shows a climb to 8000ft, then a slight drop to 7600ft and a climb back to 8600ft where the data ends at a speed of 383kts...

I suspect that the altitude data you see on FlightRadar is being referenced to AGL, wherein HAAB has an elevation of 7,625 ft whereas FlightRadar shows the flight starting out at 0 ft.... therein if one adds 8,000 ft onto the airfield elevation it then makes more sense... and the 'dip' you see would then consistent with the crew switching their altimeter reference settings from the QNH (1029) in Addis Ababa this morning over Standard (1013), and with a published Transition Altitude of 14,000 ft. (i.e setting the altimeter reference from 1029 to 1013 has the effect of winding height off the altimeter, and I suspect that would show-up on the ADS-B as a change of altitude).

HAAB 100600Z 07010KT 9999 FEW025 18/09 Q1029
TAF HAAB 092130Z 1000/1106 09008KT 9999 SCT028 SCT090 BECMG 1007/1011 12008KT BKN026

Cows getting bigger

10th Mar 2019, 09:28

Crash site is quite a few miles south of the airfield.

Old King Coal

10th Mar 2019, 09:34

FlightRadar altitudes are MSL when planes are in the air. When on the ground it shows 0. A little confusing.
If that were the case, the moment the aircraft leaves the ground the altitude readout it would jump to the airfield elevation plus a few feet, would it not? (but that isn't what we see here)

log0008

10th Mar 2019, 09:36

If that were the case, the moment the aircraft leaves the ground the altitude readout it would jump to the airfield elevation plus a few feet, would it not? (but that isn't what we see here)

Yes it is, the first reported height is 8025ft, 250 or so feet AGL. The coverage in the area isn't great so updates aren't as regular.

SigWit

10th Mar 2019, 09:36

Calibrated AltitudeCalibrated altitude values reflect the aircraft’s altitude above Mean Sea Level, a constant value used in aviation and other applications. 0 feet/meters above Mean Sea Level does not necessarily reflect an aircraft’s altitude above the ground.
https://www.flightradar24.com/blog/the-flightradar24-glossary/

SteinarN

10th Mar 2019, 09:53

ManaAdaSystem

10th Mar 2019, 09:58

Takeoff from a high altitude airport with limited performance is a threat, but these guys do this all the time.
As for MCAS issues, are there any MAX pilots out there not familiar with this?
My guess is we are looking at something else this time.
Not good news for the MAX.

henra

10th Mar 2019, 10:07

Independent of the cause of the crash, this must be the worst start of any new aircraft or major derivative in modern times in terms of number of deadly crashes and numbers of fatalities divided by cumulative flight hours? It must be worse than the DC-10, and second to the Comet only? Truly an unbelievable bad start for the Max.
Indeed. Probably coincidence. But if I had to board a MAX tomorrow I would be slightly concerned. Purely statistically this is pretty much unparalleled in Airliners in the last 40 years...
In Chicago there will be 'panic mode'.

MungoP

10th Mar 2019, 10:11

We have no ideas beyond some possibly educated guess-work as to what happened here but I do have a question that can be answered by someone with the relevant experience. As a 10,000 + hr career pilot I'm not exactly a newby but have not any experience with the latest sophisticated systems being introduced on modern aircraft.
Q. Is there something preventing pilots of these aircraft from simply hitting a 'disconnect' button, listening for the 'C' tone and then getting on with flying manually ? Not suggesting that this is relevant to this accident.

KelvinD

10th Mar 2019, 10:13

Bishoftu is more like 40 Kms SE of Addis. There is a town named Mojo (Yes, I know!) around 60 Kms SE of Addis. Bishoftu itself has an airport with a 2.5 mile long runway.

log0008

10th Mar 2019, 10:15

bucoops

10th Mar 2019, 10:17

In response to SteinarN's post, I initially thought Comet - but that of course was a cycles issue, so didn't manifest until some time later. The Lion Air incident is still being investigated, and this one is far too soon to know anything.

Watching with interest.

Intrance

10th Mar 2019, 10:23

I’m no expert on FR24, but the screenshots quite clearly show the level as ‘GPS altitude’.

Just for your future understanding of FR24, the type of altitude is listed above the value of the altitude. So it is Calibrated Altitude. The GPS altitude has a lock icon below, it is a premium feature and needs a subscription.

krismiler

10th Mar 2019, 10:26

Unless this accident is quickly proven to be the result of a different cause then the recent Lion Air disaster then its likely to result in a grounding of the type until the defect is fixed. If the cause is the MCAS again then a software update isn’t going to be enough, it’s back to the drawing board and no certification authority is going to allow it back into the air until the rectification is conclusively proven to restore safety.

Airlines are likely to ground their aircraft anyway before being directed by Boeing or their local CAA.

AN2 Driver

10th Mar 2019, 10:36

Per avherald:
"The last transponder data were received from position N9.027 E39.153 about 21nm east of Addis Ababa at FL086. Terrain elevation at that point is 8130 feet MSL, FL086 corrected for QNH indicates the aircraft was flying at 8173 feet MSL at that position."

Note that this data is very suspicious to me because corrected for QNH the aircraft hardly reached 500ft AGL at any time on the whole flight.

That has been corrected.

The last transponder data were received from position N9.027 E39.153 about 21nm east of Addis Ababa at FL086. Terrain elevation at that point is 8130 feet MSL, FL086 reported by the Mode-S Altimeter (which always measures to standard pressure 1013 QNH) corrected for QNH indicates the aircraft was flying at 9027 feet MSL at that position.

rudolf

10th Mar 2019, 10:55

https://et.usembassy.gov/security-alert-addis-ababa/

c_coder

10th Mar 2019, 10:56

https://et.usembassy.gov/security-alert-demonstration-in-meskel-square-and-the-oromia-region-8-march-2019/

Event: The U.S. Embassy is aware of calls for a protest to be held on Sunday, March 10, 2019 at Meskel Square. It is unknown whether the protest has been or will be approved by Ethiopian authorities. Protests have already occurred in many parts of the Oromia region since March 6, and additional protests may materialize.U.S. Embassy personnel are advised to avoid Meskel Square and limit movement around Addis Ababa on Sunday, March 10. U.S. Government travelers have been advised not to arrive or depart Bole International Airport on Sunday, March 10, and U.S. Embassy personnel are also temporarily prohibited from traveling to Oromia.Actions to Take:

Monitor local media for updates.
Avoid crowds
Avoid demonstrations.
Be aware of your surroundings.
Keep a low profile.

Assistance:

U.S. Embassy Addis Ababa, Ethiopia

+251-111-306-000

Also:Eyewitness: The blast and fire were so strong

Our colleague Jibat Tamirat from BBC Amharic has just spoken with a man, Bekele Gutema, who says he was near the crash site around the town of Bishoftu, which is 60km (37 miles) south-east of the capital.He says: "The blast and the fire were so strong that we couldn’t get near it. Everything is burnt down. The firefighters arrived around 11 and the crash happened around 8. There are four helicopters at the scene now. No one will survive."

https://www.bbc.com/news/live/world-africa-47513534

The Ancient Geek

10th Mar 2019, 10:56

loob

10th Mar 2019, 10:56

There is an interesting tweet purporting to be from the US State Department circulating on Twitter in which it advises American citizens not to arrive or depart from the airport in Addis Ababa on March 10.

I would not put too much stock in that. My American friends in a small Tanzanian town used to get alarmist emails from them on a regular basis.

SigWit

10th Mar 2019, 10:59

Unlike many african operators, ethiopian has an excellent reputation and a good safety record.
Was an emergency declared ?, my first guess for a problem so early in a flight would be possible fuel issues but until we know more we really have no idea.

Judging by the FR24 raw data, propulsion or energy-related issues don't seem to be the problem, as the forward speed is rapidly increasing.
The problem seems to lie in the fact they were unable to convert the forward speed into altitude.

(Which may be related to a nose down trim runaway, indeed...)

meleagertoo

10th Mar 2019, 11:02

Much confusing 'info' so far.

Flight radar seems to show the flight ending 20 odd miles due E of Addis on flat high plateau terrain at 280Kts having apparently barely achieved 500ft agl in all that distance.

Airline and media report the accident at Debre Zeit/Bishoftu, miles away in a completely different direction. Wouldn't they know where the accident occurred?

Raffles S.A.

10th Mar 2019, 11:13

The RNAV SID calls for 10500' and max speed 215 KT on runway track before turning right.

Timmy Tomkins

10th Mar 2019, 11:18

Whilst Ethiopian have a good record they have had a couple when flocks of pigeons were ingested. I am not familiar with this airport but if they are prevalent that could explain the lack of climb

etrang

10th Mar 2019, 11:20

IF this is the MCAS fault again, then the consequences will be enormous, probably a grounding of the MAX fleet.

This is only the second 737 Max accidents since the aircraft was launched, so it is premature to be calling for its grounding.

halfofrho

10th Mar 2019, 11:24

Flight radar seems to show the flight ending 20 odd miles due E of Addis on flat high plateau terrain at 280Kts having apparently barely achieved 500ft agl in all that distance.

That's because Flight Radar 24 lost coverage beyond that distance. It's not where the flight ended.

Just the fax maam

10th Mar 2019, 11:24

MCAS is operational only on flaps up and autpilot off I believe. Is that likely to be consistent with the last known (FR24) altitude/speed etc?

Would a potential AOA sensor error be known prior to selecting flaps up?

Nothing implied, just a query.

SigWit

10th Mar 2019, 11:25

This is only the second 737 Max accidents since the aircraft was launched, so it is premature to be calling for its grounding.

If the same faulty system crashed two planes within the first two years of its existence, then grounding the planes until the issue is fixed does not seem premature to me.

Raffles S.A.

10th Mar 2019, 11:25

Picture just received shows a crater with nothing bigger than 2 feet, I can't confirm the origin of the picture at this stage, it might show up here shortly though.

Edit: It's on avherald.

AN2 Driver

10th Mar 2019, 11:26

Wouldn't they know where the accident occurred?

I guess so. And FR even sais themselfs they don't have good coverage in the area. So it is widely premature to define the crash site next to the last FR position. The exact position of the crash site will be quite important to what happened in between, if anything.

At this stage of an accident there is ALWAYS a lot of confusing information, that is normal. The US Travelwarnings will probably also make for some hot air by the news outlets, we should be aware of that. Until more is known, all of this is speculation. Read it or leave it...

Raffles S.A.

10th Mar 2019, 11:29

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/750x511/ethiopian_b38m_et_avj_190310_1_14a0aab2424d300494cd58c168099 c7d5a254e0a.jpg

bunk exceeder

10th Mar 2019, 11:32

The RNAV SID calls for 10500' and max speed 215 KT on runway track before turning right.

So they never got to 10,500, hence no turn. Where FR shows the flight ending and Bishoftu are NOT the same place. It has a “density altitude” feel to it. You know, the guy who shoots a moose and loads it into his Piper Cub, grossly overloading it, on a hot and high day. He gets just enough juice to lift off in ground effect but is never able to climb out of it. Trees getting bigger....

Was the correct Perf data entered into the FMC? As trees get bigger, the temptation to pull back more, despite insufficient power, becomes enormous, hence many of these things ending in a stall/spin situation. Then there’s that MCAS “unpublicized” feature. This explains it well:

https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/

If, meaning IF, they had insufficient power and pulled back a bit too much, right into the MCAS zone of operation, which would definitely not help right then, well, there are a couple of potential links in the old chain. Or Swiss cheese holes. I’m surprised that a thing that moves your trim around when you’re in a bad corner of the envelope could
be deemed as too much information for the pilots, hence not make it into the manual.

loob

10th Mar 2019, 11:32

This is only the second 737 Max accidents since the aircraft was launched, so it is premature to be calling for its grounding.
When the aircraft are so new and Boeing admitted to omitting information after the previous crash then I don't think it's premature at all. Concorde was grounded after decades even though the crash was nothing to do with the craft.

SOPS

10th Mar 2019, 11:33

Is the above picture the crash site?

CargoOne

10th Mar 2019, 11:35

This is only the second 737 Max accidents since the aircraft was launched, so it is premature to be calling for its grounding.

There are 370 MAXes in operation, 99% of them are less than 2 years old. So the loss of 2 aircraft is alarming, loss of 2 aircraft in the same phase of flight (and not the most dangerous phase statistically speaking) is even more alarming. But obviously no one will ground the fleet without sufficient evidence...

fox niner

10th Mar 2019, 11:35

Is the above picture the crash site?

yes it is...
Source:

https://mobile.twitter.com/BenjAlvarez1/status/1104703580181807105

SOPS

10th Mar 2019, 11:37

There is nothing left. From that picture it looks like it must have gone straight in at high speed!!

helimutt

10th Mar 2019, 11:37

Fr24 data being updated

SigWit

10th Mar 2019, 11:37

So they never got to 10,500, hence no turn. Where FR shows the flight ending and Bishoftu are NOT the same place. It has a “density altitude” feel to it. You know, the guy who shoots a moose and loads it into his Piper Cub, grossly overloading it, on a hot and high day. He gets just enough juice to lift off in ground effect but is never able to climb out of it. Trees getting bigger....

Was the correct Perf data entered into the FMC? As trees get bigger, the temptation to pull back more, despite insufficient power, becomes enormous, hence many of these things ending in a stall/spin situation. Then there’s that MCAS “unpublicized” feature. This explains it well:

https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/

If, meaning IF, they had insufficient power and pulled back a bit too much, right into the MCAS zone of operation, which would definitely not help right then, well, there are a couple of potential links in the old chain. Or Swiss cheese holes. I’m surprised that a thing that moves your trim around when you’re in a bad corner of the envelope could
be deemed as too much information for the pilots, hence not make it into the manual.

Judging by the FR24 raw data their forward speed kept increasing, which does not point to any performance problems.
The question is why they couldn’t convert to forward speed into altitude.

SteinarN

10th Mar 2019, 11:39

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/750x511/ethiopian_b38m_et_avj_190310_1_14a0aab2424d300494cd58c168099 c7d5a254e0a.jpg

Can this really be the crash site?
If it really is, then it is safe to say the aircraft reached a significant altitude AGL in order to be able to reach sufficient speed at impact to create a crater like this.

vmandr

10th Mar 2019, 11:46

SOURCE and COMMENT : FlightRadar24.com tweet

Additional data from Flightradar24 ADS-B network
show that vertical speed was unstable after take off.

https://twitter.com/flightradar24/status/1104676048317362177

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/1363x1127/et502_10mar2019_2993c88344b6b62efee0d6fd5ff30d5b317f8700.jpg

rcsa

10th Mar 2019, 11:54

Unlike many african operators, ethiopian has an excellent reputation and a good safety record.
Was an emergency declared ?, my first guess for a problem so early in a flight would be possible fuel issues but until we know more we really have no idea.

Respectfully, and as someone who lives in africa and travels extensively round the continent, ET is a dreadful airline, running what we call a ‘chicken bus’ service (think of an African bus with chickens tied to the roof). Bole Airport is absolutely one of the worlds worst, and I’ve had more scary flights on ET than I have had on any other airline - and I am not a nervous flier at all.

Trundling around africa I’d rather fly KQ/SAA/RAM/THY before ET.

Personally I would wait a while before blaming the aircraft. It’s also possible it was something more akin to human (pilot/ground handling/security/ATC) error.

Magplug

10th Mar 2019, 11:59

This is a very sad day for one of the most respected airlines in Africa. What few images that have emerged from the crash site so far show an impact crater without a scattered debris field. The crater contains lots of small debris indicating a very high energy impact from a very steep trajectory. So far indications are that the aircraft was intact at impact.

From the ADS-B numbers above this looks more like an unreliable airspeed event than a trim runaway. The aircraft hardly climbed at all before striking high ground at a very high speed.

Skyjob

10th Mar 2019, 12:04

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1363x1127/d1sxk_kwoaaqeii_f7bed4c68fdcd58582e543304bd195870a1f5827.png
Looks like:
- a long takeoff roll (normal at high altitudes);
- a reduction in vertical speed as accelerating for flap retraction (approximate 250 kts groundspeed shows this);
- then a sharp altitude loss and speed gain (could be similar to previous MCAS or AOA issue)

Time will tell...

TallInTheSaddle

10th Mar 2019, 12:04

yes it is...
Source:

No smoke, no real residue, no other people on scene?

rog747

10th Mar 2019, 12:14

No smoke, no real residue, no other people on scene?

There are plenty of folk standing in the background of this crater photo from ETHIOPIAN AIRLINES Facebook page.

https://www.facebook.com/EthiopianAirlines.GB/photos/a.1965182780378688/2338588339704795/?type=3&theater

Kenya press reports 7 Brits on board

Sallyann1234

10th Mar 2019, 12:17

What else have Boeing put into this airplane to adjust its flight, but left out of the FCOM because pilots 'don't need to know' ?

mryan75

10th Mar 2019, 12:19

vmandr

10th Mar 2019, 12:26

strange coincidence. in both LTI610 and ET502 final groundspeed 383kts...:confused:

AN2 Driver

10th Mar 2019, 12:29

Guys, please be careful with these flight data, which many regard as God given correct.

I really think the Ethiopians know where that plane ended up and if it did where they posted then it is pretty far from that ominous last position. FR24 themselfs writte that they do not have close reception there, it is a hilly area and if they never got above 9000 ft MSL they could well have been in terrain shadow or simply out of reception for the remainder of the flight.

I follow small airplans with ADS-B here often (mine amongst others) and have lost count when they lost my track so many times in areas I would not assume they have bad quality reception, at 3000 ft AGL and so on. To assume that in this case,where a plane flew at barely 1000 ft over Ethiopian hills and lower than low, where they have maybe one or two receivers, is simply fishing for information we don't have.

Yes, it is a new Max which went down, but before calling for grounding or producing other media trash food, let's get a grip of what happened. It usually doesn't take that long.

Without a proper crash position, we know absolutely nothing other than the ADS-B feed stopped at that position which was at approx 9000 ft MSL and in the runway extention. We do not see the descent we do not see the impact. So WAIT for a proper position before trying to guess what happened.

PerPurumTonantes

10th Mar 2019, 12:29

Within minutes of the news we are speculating already ??

Seriously ?
There's one in every thread :rolleyes: Amazes me when someone logs on to the PPRumourNetwork and then complains about rumours.

Presumably they're the ones who buy houses at the end of runways so they can complain about aircraft noise...

rcsa

10th Mar 2019, 12:30

Casualty nationalities ex- BBC Africa service et al

32 Kenyan

18 Canadian

9 Ethiopian

8 Chinese

8 Italian

8 American

7 French

7 British

6 Egyptian

5 Dutch

4 UN passports

4 Indian

3 Russian

2 Moroccan

2 Israeli

1 Belgian

1 Ugandan

1 Yemeni

1 Sudanese

1 Togolese

1 Mozambican

1 Norwegian

nojwod

10th Mar 2019, 12:33

Respectfully, and as someone who lives in africa and travels extensively round the continent, ET is a dreadful airline, running what we call a ‘chicken bus’ service (think of an African bus with chickens tied to the roof). Bole Airport is absolutely one of the worlds worst, and I’ve had more scary flights on ET than I have had on any other airline - and I am not a nervous flier at all.

Trundling around africa I’d rather fly KQ/SAA/RAM/THY before ET.

Personally I would wait a while before blaming the aircraft. It’s also possible it was something more akin to human (pilot/ground handling/security/ATC) error.

Oh puh lease which planet are you on? Ethiopian has always been a very professional airline with an excellent safety record and mostly excellent service and reliability. They were managed by TWA during the 60s and 70s and have always kept their professionalism intact. I find your comments offensive.

JCviggen

10th Mar 2019, 12:35

If that earlier picture shows the main crash site I wonder if there is anything left of the FDRs.

rcsa

10th Mar 2019, 12:41

Oh puh lease which planet are you on? Ethiopian has always been a very professional airline with an excellent safety record and mostly excellent service and reliability. They were managed by TWA during the 60s and 70s and have always kept their professionalism intact. I find your comments offensive.

Three hijacks and four hull loss (two of those with loss of all souls) in 25 years is not exactly an ‘excellent’ safety record by my standards. I
live on planet Africa. I fly +/- 50 trans-African routes a year, and have done for 25 years. Based on my experience, my choice is to avoid ET wherever and whenever possible.

Ganzic

10th Mar 2019, 12:42

No is the answer.
B737 Max differences training takes approx 2.5 hours to complete, mostly it talks about differences in indications on the screens, temp control and PSEU light has been replaced. Engine differences and some procedures.

There is nothing to say that it has to be flown differently than an NG considering a Trim Runaway option, same drills apply. Disconnect AP, switch off AP trim and than Backup trim, use manual trim wheel... In short.

NumptyAussie

10th Mar 2019, 12:49

https://www.bbc.com/news/live/world-africa-47513534

"'Captain wanted to return' The CEO of Ethiopian Airlines Tewolde Gebremariam is speaking at a press conference. He said the captain of the crashed plane had told controllers at Bole airport that he was having difficulty and wanted to return, and that he had been given clearance. He also said that the plane had arrived on Sunday morning from South Africa. “[The] plane had more than three hours of ground time after coming from South Africa, it arrived with no remark and was dispatched with no remark.” Mr Tewolde said smoke was still smouldering at the crash site when he visited."

SteinarN

10th Mar 2019, 12:50

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1280x720/1_w_1512_q_low_c_0_bild_4d45ead5a8dd824b2ab71084eadc74e63ba8 e624.jpg

Another picture fron the crash site.

Consol

10th Mar 2019, 12:51

Firstly condolences to those who have lost loved ones in a part of the world where this can mean a great deal of additional hardships.

Pprune falling into a few of it's regular traps with debates on whether it's AMSL or GPS altitude and so on. With the usual major provisos about FR24 data (it does show the aircraft airborne at 93kts), it is reasonably clear that it never achieved a normal climb rate for more than a few seconds and therefore it is obvious it never climbed much higher than the surrounding terrain. I'm not current on B737 MAX but my understanding is that MCAS would not be active with flaps out as they must have been at that stage. It did however accelerate in forward speed considerably so it was not short of power.

Bear in mind there is a new reformist PM running Ethiopia who is of a different tribe to the previous power holders and that the flight was to Kenya which has, along with Ethiopia had some security issues with Somalian groups. Nonetheless the profile tends to indicate the cause may lie in the territory of spatial disorientation, configuration, mishandling or technical failure. Not casting unfair aspertions but that is often where the cause lies.

RIP

Arrowhead

10th Mar 2019, 12:51

https://et.usembassy.gov/security-alert-demonstration-in-meskel-square-and-the-oromia-region-8-march-2019/

terrorism?

rcsa

10th Mar 2019, 12:52

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1024x569/660b345e_8599_4840_bc66_1c603ef0a1b1_138cfe4ee0fa9e66323f2fd b59f1fdfe098a3351.jpeg
New crash site photo

Ganzic

10th Mar 2019, 12:52

I thinks it's an expensive option...

To have telemetry data streamed live via satcom.

fox niner

10th Mar 2019, 12:53

Whether or not the MCAS is to blame, remains to be seen.
Fact is, that someone at Boeing RIGHT NOW is saying to himself: “I sure hope that the MCAS has nothing to do with it...!”

What a tragedy.

mryan75

10th Mar 2019, 12:55

It's absurd that flight telemetry and data is not transmitted in real time to satellites and sent back to the aircraft manufacturer.rather than being recorded on FDRs that are lost at sea or destroyed
Same discussion every crash. It's a massive technical undertaking for very little benefit. FDR and CVR are nearly always found.

And now back to your flight simulator.

MungoP

10th Mar 2019, 12:55

MRyan GANZIC..
Thank you for that. Much appreciated.

ChicoG

10th Mar 2019, 13:03

"Captain asked to return" .... also same as JT610.

ChicoG

10th Mar 2019, 13:10

https://et.usembassy.gov/security-alert-demonstration-in-meskel-square-and-the-oromia-region-8-march-2019/

terrorism?

Unlikely.

"Security Alert: Addis Ababa (Ethiopia), Bole International Airport
Aviation
Africa > Ethiopia > Addis Ababa
3/9/2019
Location: Addis Ababa

Event: U.S. Government travelers may arrive or depart from Bole International Airport on Sunday, March 10. This updates the Security Alert sent on March 8, 2019. "

downdata

10th Mar 2019, 13:13

Given the MCAS software update was delayed ubtil after Apr... this seems to point to a MCAS issue

slack

10th Mar 2019, 13:15

I bet boeing are there big time. Will wait for report of course. RIP paxs and crew.

RoyHudd

10th Mar 2019, 13:18

More rubbish than usual on this one. Ethiopian have a poor safety record for an airline its size. That is clear. And colleagues who fly for them have privately expressed concern about many safety-related issues at the airline. No details to share.

No conclusions can be drawn until the CVR and FDR are recovered and their contents analysed.

silverstrata

10th Mar 2019, 13:18

Whether or not the MCAS is to blame, remains to be seen.
Fact is, that someone at Boeing RIGHT NOW is saying to himself:
“I sure hope that the MCAS has nothing to do with it...!”

The other problem, is not talking about it. I am not on the Max, so don't know if specific instructions were given to operators. But within NG crews there are quite a few who still do not know and understand the MCAS system and its problems. So can history repeat itself? You bet.

And I still have to question the engineers who created MCAS. I can understand MCAS as a cheap (and semi-back-door) stick pusher system. It is far from ideal, but is a software change rather than a complete new system. Money rules, and MCAS was a cheap and simple fix....

However, I do have to question the logic of a pseudo-stick-push that keeps operating until you get full forward trim. Have you tried this MCAS-trim-runaway in the sim? According to the sim, the aircraft is only just about controllable with two gorillas hauling back on the stick (about 40 kg pressure on each stick). And that was in level flight with the CofG in the central position. Ok, now try a recovery from a stall-dive, with a forward CofG, 20º nose down pitch, and speed rapidly building back up to 250 kt. Absolutely impossible - you are doomed. And doomed by an anti-stall system that is supposed to save you. But who in the world would want to recover from a stall with the trim-stabiliser set fully forward? The stabiliser is more powerful than the elevator. Heck, even the Wright Brothers knew not to do something like that.

And I also have to question an aircraft that has not been designed by anyone. The 737 was designed for the 727 (or 707) back in the 50s (the type-certificate is 1967), but since that time there has been mod after mod after mod. Never going back to basics, but simply a series of mods upon mods. It is like driving a Model-T Ford, with a new 300 hp engine and a new dashboard. For instance, the 737 is still the only aircraft I have flown, where the controls cannot be split if there is a control jam. And still it flies...

Silver

ajamieson

10th Mar 2019, 13:18

If that earlier picture shows the main crash site I wonder if there is anything left of the FDRs.
Recorders were recovered from the Germanwings Airbus that was all but vapourised on a French mountainside.

NEDude

10th Mar 2019, 13:18

Sailvi767

10th Mar 2019, 13:21

SMT Member

10th Mar 2019, 13:25

This is only the second 737 Max accidents since the aircraft was launched, so it is premature to be calling for its grounding.

One could replace the word 'only' with 'already' which, in my opinion, is a more faithful representation of the present situation.

To wit, a brand new derivative of a 50-year old design, engineered and built by one of the two premier commercial airframe manufacturers, should not have suffered two crashes within such a short time-span. Particularly not if the first may have had a questionable piece of software, relying on a single sensor input, as a major contributing factor. If this, second, accident is in any way linked to the first by a common failure, the only prudent cause of action will be to ground the fleet and allow the manufacturer to get things straightened out.

ChicoG

10th Mar 2019, 13:25

The U.S. government sends these email/twitter alerts out to U.S. citizens almost as often as Nigerian Princes ask for help in recovering lost money. I get about 20-30 of these alerts every year in Copenhagen.

And as I mentioned above, this one had already been superceded.

gsxrpilot

10th Mar 2019, 13:26

A very sad day for Ethiopian Airlines. My grandfather was the very first Flight Surgeon and Chief Medical Officer of Ethiopian Airlines. I've personally been flying them since 1976. And it's my go to airline when flying to/from or in Africa. So all the way from Austin, TX, this one hits close to home.

Smythe

10th Mar 2019, 13:26

Looking at the crash site, there is virtually nothing left.

Compare this with the MH17 crash site, shot down from 33,000 feet.

Ganzic

10th Mar 2019, 13:28

Boeing will be hit hard by this accident, regardless of the issue that caused it, all news agencies already speculating just as bad as ppruners here.

4runner

10th Mar 2019, 13:30

Oh puh lease which planet are you on? Ethiopian has always been a very professional airline with an excellent safety record and mostly excellent service and reliability. They were managed by TWA during the 60s and 70s and have always kept their professionalism intact. I find your comments offensive.

erhiopian isn’t a “chicken bus”. They have new aircraft and the loveliest cabin crew of any airline I’ve travelled on. Their management is a different lot altogether. Pilots are flown well over any legal or normal limits. Rest rules are blatantly ignored. This is a known fact with the airline and well documented.

rcsa

10th Mar 2019, 13:35

And colleagues who fly for them have privately expressed concern about many safety-related issues at the airline. No details to share.

Absolutely right. And absolutely right not to share.

EternalNY1

10th Mar 2019, 13:38

From AH:
The last transponder data were received from position N9.027 E39.153 about 21nm east of Addis Ababa at FL086. Terrain elevation at that point is 8130 feet MSL, FL086 reported by the Mode-S Altimeter (which always measures to standard pressure 1013 QNH) corrected for QNH indicates the aircraft was flying at 9027 feet MSL at that position.

Not too far above terrain on the last return.

meleagertoo

10th Mar 2019, 13:44

imho and from local knowledge the terrain shown doesn't look like the flat plateau to the E Bole where trees are scarce and the wooded area in the photo is much more like that found to the south but that isn't a very scientific judgement.
However media are reporting that Bole lost contact at 0844 while the flight radar table above shows contact lost at 0841. Since it took them 3 minutes or so to reach the FR "lost contact" area and Debre Zeyt is about the same distance beyond in a right hand turn (due to terrain you wouldn't turn left/to the N to do that) to recover back to Bole that does look like a better location for the accident. It is also right about where you'd be 6 mins after deprture en route to NBO.
They'll be lucky to find recoverable recorders in that impact I suspect.

Denti

10th Mar 2019, 13:46

Rest rules are blatantly ignored. This is a known fact with the airline and well documented.

Quite apparently so, with the CEO pictured at the crash site handling parts of the wreckage. Which is of course a clear breach of protocol. A member of an interested party in an investigation disturbing an investigation scene probably corrupting evidence.

Ian W

10th Mar 2019, 13:48

It's absurd that flight telemetry and data is not transmitted in real time to satellites and sent back to the aircraft manufacturer.rather than being recorded on FDRs that are lost at sea or destroyed

It is and with modern antennas and bandwidth and auto-sharing between VDL and SATCOM it would be easily done (see for example INMARSAT Iris (https://www.inmarsat.com/news/inmarsat-and-esa-to-modernise-atm-over-europe/)). Future aircraft can be expected in any case to have 'always on' broadband IP communications for other operational reasons, adding continual background recording would not be an issue. The days of hugely expensive 1200Bd intermittent SATCOM are well over bandwidths today are huge and continually increasing. However, there are those that do not want the recorder information, particularly the CVR information, 'shared' due to distrust in their operator's management. Yes in a completely unstabilized state after a loss of control some connection could be lost but the lead up to the LOC would all be there. Within a few hours the recorder information of initial lead up to an incident could be in investigator's hands. For example all of AF447 information could have been available at the time of the crash instead of a 2 year wait.

Ian W

10th Mar 2019, 13:59

I thinks it's an expensive option...

To have telemetry data streamed live via satcom.

Not when you have an 'always on' link you have the bandwidth and then you have to compare it to the cost of retrieval of an often damaged DFDR/CVR. I have always thought that if these costs were levied on the aircraft operators then streaming DVDR/CVR would be operational now. The costs of search and retrieval of the recorders would bankrupt most airlines. Why should tax payers in a foreign country be liable to pay the sometimes huge costs for recovery of your airline's DFDR/CVR?

Late addition: DFDR data rates are 'up to 256 12bit words per second' - or around 3K bps. That is one '10 millionth' of the potential bandwidth of a connection on INMARSAT's new Global Express SATCOM just tested at 330Mbps.

WHBM

10th Mar 2019, 14:10

Ethiopian has always been a very professional airline with an excellent safety record and mostly excellent service and reliability..
I realise you may have interests in them, but the fact is this is their third major high fatality jet accident in my recollection, these having been in 1996, 2010 and now 2019, for what is in all truth a relatively small fleet. I don't believe any other African carrier has this record. The previous two went into the sea. I can't reconcile that with stating their record is "excellent".

The notably high foreign passenger count is due to their extensive marketing of 5th Freedom tickets through their hub, from all of North America, Europe and Asia to Addis, and onward to all across Africa, as well as some Europe-Asia traffic. They are of course known in the industry for having achieved this by offering some of the most competitive fares.

SOPS

10th Mar 2019, 14:14

Umm .. did not one of the aircraft that went into the sea was being piloted by a person who was being attacked with an axe by an hijacket?

CaptainProp

10th Mar 2019, 14:15

”And colleagues who fly for them have privately expressed concern about many safety-related issues at the airline.”

And they are still there?

If I had real safety concerns about the airline I worked for I would leave, with immediate effect.

CP

QDM360

10th Mar 2019, 14:25

... around 3K bps. That is one '10 millionth' of the potential bandwidth of a connection on INMARSAT's new Global Express SATCOM just tested at 330Mbps.

Math isn't one of your strengths, right?

klintE

10th Mar 2019, 14:25

If that earlier picture shows the main crash site I wonder if there is anything left of the FDRs.

I think both recorders should be fine.
Required impact tolerance is above 3400G.
Almost impossible to exceed (930km/h to 0km in 1 meter)
More dangerous is high temperature and here think it's very unlikely boxes were exposed to fire - since probably both plunged into the soil.

Seat4A

10th Mar 2019, 14:38

Global News (Canada) has video showing locals walking on the site of the wreckage.

Not enough posts to add the link here.

caulfield

10th Mar 2019, 14:50

Is this the same Ethiopian Airlines that only pays 8000USD to its 737 Captains and doesnt pay until Final Line Check and keeps extending that FLC so that payment can be delayed?Actions have consequences.
Treat your crews and passengers well.Or pay the price.

JamesT73J

10th Mar 2019, 15:03

So they never got to 10,500, hence no turn. Where FR shows the flight ending and Bishoftu are NOT the same place. It has a “density altitude” feel to it. You know, the guy who shoots a moose and loads it into his Piper Cub, grossly overloading it, on a hot and high day. He gets just enough juice to lift off in ground effect but is never able to climb out of it. Trees getting bigger....

Was the correct Perf data entered into the FMC? As trees get bigger, the temptation to pull back more, despite insufficient power, becomes enormous, hence many of these things ending in a stall/spin situation. Then there’s that MCAS “unpublicized” feature. This explains it well:

https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/

If, meaning IF, they had insufficient power and pulled back a bit too much, right into the MCAS zone of operation, which would definitely not help right then, well, there are a couple of potential links in the old chain. Or Swiss cheese holes. I’m surprised that a thing that moves your trim around when you’re in a bad corner of the envelope could
be deemed as too much information for the pilots, hence not make it into the manual.

From that article:
https://i.imgur.com/Rq95L56.png

This is highly unusual, right? Aviators have been expected and encouraged to learn such things.

Silver Pegasus

10th Mar 2019, 15:13

SigWit

10th Mar 2019, 15:15

From that article:
https://i.imgur.com/Rq95L56.png

This is highly unusual, right? Aviators have been expected and encouraged to learn such things.

No, this is actually the modus operandi for all modern jets. Give the pilots basic background knowledge about the plane and an QRH that covers most failures.
Giving pilots to much information can lead to over-analysis and wrong decisionmaking.

763 jock

10th Mar 2019, 15:16

The first thing I thought when I saw the photo of the CEO in the crater was what was he doing there? Can you imagine that being allowed in the UK? This is quite possibly a crime scene and yet evidence is being handled by people who have no right (by our standards) being there.

Cordon it off, move everyone well away and let the proper authorities deal with it.

QDM360

10th Mar 2019, 15:16

What chance any plastic and resin parts in the digital recorders e.g. circuit boards and components.

The "crash recorders" aren't just crash-proof, they are also protected against fire and heat. Minimum ICAO requirement is to withstand 260°C for 10 hours, and an direct exposure to a 1100°C flame for 30 minutes. So, yes, FDR/CVR can fail when exposed to fire - but it's not likely.

b1lanc

10th Mar 2019, 15:30

Just as a point of reference and not pointing any fingers at quals, the Capt is reported to have 8,000+ hours and attained capt on 737 type in November (source CEO on WSJ). AVH reporting FO as having 200 flight hours. The average fleet age is 5.4 years according to airfleet - on the youngish side and mostly wide-body.
Regardless, Boeing has some serious soul-searching to do no matter the ultimate cause and IMHO crew/maintenance training, experience, procedure blame will not be sufficient.

dsky

10th Mar 2019, 16:09

Regarding Satcom links and bandwidth discussion ...

Discussion out of topic and out of knowledge.

Can you imagine keeping an active sat link from a plane experiencing bad attitudes?

Satcom is not magic.

klintE

10th Mar 2019, 16:13

You're having a giraffe ? Presumably crashed fully fuelled. Locals said they couldn't get near it for some time because of the conflagration. And the fire appears to have been hot enough to disappear any vestige of the alu/mag structure of the aircraft. What chance any plastic and resin parts in the digital recorders e.g. circuit boards and components.
More PR comfort food ?
But do you know BBoxes are certificated to withstand at least 1100 C deg over 30 minutes?
And as I mentioned boxes probably are buried (that's why they are not found yet) underground. It makes additional isolation layer.
Anyway, there is nothing to worry about a prori.
Almost every serious accident is with fire and boxes are unusable very rarely.

dsky

10th Mar 2019, 16:14

Recorders were recovered from the Germanwings Airbus that was all but vapourised on a French mountainside.

Recovering the whole FDR/CVR is not important. What it is important is to recover the crash survivable memory units, which are on separate boxes, very resistant to shock, vibration, high temperatures (i.e. flames). They are based on solid state memory components. Even if these very sturdy units are damaged there is the option to open up the very chips and recover the silicon die that can be probed for data using special tools.

PAXboy

10th Mar 2019, 16:17

Global News (Canada) has video showing locals walking on the site of the wreckage.
This is Africa. You may ask them to work to Western rules but they will do what they feel is right. Also, the emergency staff who are first on site - what chance they will have been fully trained in protection of the scene? Not going to happen.

Indelible Spirit

10th Mar 2019, 16:18

“One high-ranking Boeing official said the company had decided against disclosing more details to cockpit crews due to concerns about inundating average pilots with too much information — and significantly more technical data — than they needed or could digest.”

So they:
1) Design an aircraft that has an inherent tendency to pitch up
2) Impliment an a system to persistently add control inputs during critical phases of flight
3) Do NOT disclose system description to pilots in FCOM

How about fundamental rules:
Understanding what automation systems do.
Control the automated systems according to strong pilot skills.

* MCAS may or may not have been a contributing factor in this tragedy

Seat4A

10th Mar 2019, 16:21

This is Africa. You may ask them to work to Western rules but they will do what they feel is right. Also, the emergency staff who are first on site - what chance they will have been fully trained in oritection of the scene? Not going to happen.

Understood. Thank you.
https://globalnews.ca/news/5040395/canadians-ethiopian-airlines-plane-crash/
Another side to the story.

DaveReidUK

10th Mar 2019, 16:24

That has been corrected.The last transponder data were received from position N9.027 E39.153 about 21nm east of Addis Ababa at FL086. Terrain elevation at that point is 8130 feet MSL, FL086 reported by the Mode-S Altimeter (which always measures to standard pressure 1013 QNH) corrected for QNH indicates the aircraft was flying at 9027 feet MSL at that position.

Though it still isn't correct.

A pressure altitude of 8600' equates to approximately 9125' AMSL, so about 100' higher than the figure quoted by Avherald (they appear to have used the SL pressure lapse rate, which is greater than that at altitude).

VGCM66

10th Mar 2019, 16:36

Maneuvering Characteristics Augmentation System (MCAS). I wonder what the Augmentation word really refers to. Don't use software to correct design deficiencies. It is two too many for a new aircraft especially coming from this manufacturer. It might not be the case on this one but the bad wrap is already lasting too long to be put to rest. ... is monitoring closely the situation is becoming meaningless at this point.

Cheers,

Raptor Systems TT

10th Mar 2019, 16:37

Looking at the crash site, there is virtually nothing left.

Compare this with the MH17 crash site, shot down from 33,000 feet.

That one fell in many many pieces,this one seems to have struck the ground like a missile in one piece at high speed,hence the substantial cratering...

wingview

10th Mar 2019, 16:43

Three Boeing nose down crashes in a few month's...?!

Longtimer

10th Mar 2019, 16:44

Global News (Canada) has video showing locals walking on the site of the wreckage.

Not enough posts to add the link here.

https://globalnews.ca/news/5040395/canadians-ethiopian-airlines-plane-crash/

cappt

10th Mar 2019, 16:46

Understood. Thank you.
https://globalnews.ca/news/5040395/canadians-ethiopian-airlines-plane-crash/
Another side to the story.

literally thousands of people walking around in the crash site looking at stuff, picking it up and walking on???

Air Snoop

10th Mar 2019, 16:48

It is sad to see a pik of the CEO demonstrating to the world what you should not do on a crash site! The site is the 'property' of the investigators (and maybe police) and the last people to be meddling with the wreckage are airline management. Surely he must know that!

IFixPlanes

10th Mar 2019, 16:53

The MAX Crews are Informed:
AD 2018-23-51 (https://ad.easa.europa.eu/blob/2018-23-51_FR_Correction.pdf/AD_US-2018-23-51_1)

RTFM....

bunk exceeder

10th Mar 2019, 16:59

No, this is actually the modus operandi for all modern jets. Give the pilots basic background knowledge about the plane and an QRH that covers most failures.
Giving pilots to much information can lead to over-analysis and wrong decisionmaking.

You have to have the ashtray on the outside of a 747 lavatory door or else you have to lock the whole lav off for the entire flight as per the MEL. Lots of dumb anomalies exist everywhere. Now MCAS is being refereed to in here as a de facto stick pusher. Spose it is. That’s not a superfluous bit of info. Colgan Buffalo? Dynamic system that could mess you up if you didn’t know about it? Now a Certain plane maker likes you to know that fire loops contain Eutectic Salt. That is not worth the brain cells necessary to learn it. I only remember it as it’s such a dumb thing to know. What, is it from Eutectia? A trim thing, I think I’d like to know about.

Intrance

10th Mar 2019, 16:59

The MAX Crews are Informed:
AD 2018-23-51 (https://ad.easa.europa.eu/blob/2018-23-51_FR_Correction.pdf/AD_US-2018-23-51_1)

RTFM....

It only took one fatal accident :D . I feel this is not the thread for discussion or speculation about MCAS until further facts are known that might suggest it being involved. But please do not defend the design choice to use software to fix a bad design and leaving the crew flying the planes out of the loop intentionally until one falls from the sky.

Lonewolf_50

10th Mar 2019, 17:02

There was an extended discussion on PPRuNe about what pilots need to know - as opposed to what was commonly in the conversion course content - about the MAX's flight control system after the LionAir crash in October.

Asking anyone who flies the 737 Max: What, if any, guidance and training have you received since the LionAir accident regarding the potential issues that accompany an AoA sensor failure?
Why do I ask this?
A data point from a bit further up: the captain of this flight was recently qualified in this model (November). His previous experience was in other aircraft. (perhaps previous 737 models, that info will doubtless become available in due course).
Would his conversion training have had the benefit of what came to light after the LionAir accident, or, would that training course have been before the LionAir accident?
LionAir crash was in October of last year. As I understand the info provided, this Captain's qualification on the new model was in November of last year.
The question is of particular interest if a flight control anomaly was major hole in the layered slices of swiss cheese. (Another point made earlier was "on the ground three hours, no significant write ups" which is a significantly different case than LionAir's situation).
If the key cause(s) was(were) something else, it's still of interest in terms of how training and systems operations information is disseminated.

Information like this one: the FAA emergency airworthiness notice of 7 November 2018. (https://www.flightradar24.com/blog/wp-content/uploads/2018/10/2018-23-51_Emergency.pdf)

Given the recency of the LionAir accident, and that the FAA issued that to all owners and operators, then I'd expect all operators to have taken an active interest in making sure their flight crews were up to speed on this feature of the Max. Under that assumption (perhaps valid, perhaps faulty) air crews would have some awareness of what to do if that same problem cropped up. It being some months since that accident, would all operators have updated their SOPs, procedures, etc, given the seriousness of this particular malfunction at low altitude?

NWA SLF

10th Mar 2019, 17:11

How unaware people to say a CEO at the site is contaminating data instead of showing concern for passengers, employees, everybody. I see footage of the Lauda crash with Niki at the site as he had a great interest in the investigation and in fact if not for Niki the real problem may not have been uncovered as it was stated that reverser deployment in flight would not cause a crash. He forced it to the point where a test crew on a DC-8 determined a reverser deployment in flight is extremely serious and would in the case of a 767 unrecoverable. A CEO at a crash site is an important sign of a company commitment.

guadaMB

10th Mar 2019, 17:19

After all of my career in SAR, It's absolutely "regular" to find non-authorized people on wreck sites...

EternalNY1

10th Mar 2019, 17:22

Super VC-10

10th Mar 2019, 17:22

Meanwhile, over at Wikipedia...

https://en.wikipedia.org/wiki/Ethiopian_Airlines_Flight_302

NWA SLF

10th Mar 2019, 17:30

All this trashing of Boeing's incorporation of software using AOT sensor input to prevent a stall being a bad design - does it take into account the A320 Roussillan crash in which improper maintenance of the AOT sensors provided bad data to the software from which the crew was unable to resolve the problem and crashed. Although the Lion Air investigation is not yet complete people are now ready to ground the MAX and change a solution that involved AOT sensor input through software to avert an accident. I assume their grounding will involve Airbus as they also use AOT sensor input to prevent stalls. Have we reverted to the DC-10 times of grounding a plane destroying a company only to find that a maintenance base used an unauthorized procedure that resulted in carnage. Maybe there is an inherent problem but I've never seen a such a crowd of "shoot first and ask questions later" people. And yes, I do own Boeing stock but I also am invested in Airbus.

DaveReidUK

10th Mar 2019, 17:34

Flight profile from runway to last captured ADS-B point:

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/657x535/eth302_a8866165ee589122ffbc2a5d072c72c701b07701.jpg

Altitudes AGL are shown to scale, corrected for QNH, although I can't vouch for the accuracy of GE's terrain elevations.

763 jock

10th Mar 2019, 17:39

Yep. The CEO should be there. But tinkering with the wreckage? Nobody should be touching anything apart from the investigators.

b1lanc

10th Mar 2019, 17:40

T
A data point from a bit further up: the captain of this flight was recently qualified in this model (November). His previous experience was in other aircraft. (perhaps previous 737 models, that info will doubtless become available in due course).
Would his conversion training have had the benefit of what came to light after the LionAir accident, or, would that training course have been before the LionAir accident?

That was kind of where I was headed. But, the Max is now in Comet territory I'm afraid. Waiting another 6 months until another augers in should not be an option - again making no assumptions as to cause.

physicus

10th Mar 2019, 17:41

NWA SLF Read the AD. Loss/malfunction of a SINGLE AOA sensor can result in nose down trim input being automatically applied. The fact that there’s an automated system producing flight control input is in contravention to the fundamental operating philosophy of Boeing aircraft, and it has consequentially and not surprisingly caught out the crews. It is also now evident that the MCAS system (implemented due to a certification requirement for pitch stability during high power applications like G/As) appears to have been written in a bit of a hurry, without taking the usual redundancy philosophy into account.

We don’t know whether that was a factor in this accident until FDR/CVR are located and analysed.

Airbus operating philosophy is very different, and has been proven in the past to not do anything stupid to the aircraft unless a) multiple sensor inputs have been disabled/crippled, and b) pilots do stupid stuff like resetting flight stability essential computers in-flight by getting out of their seat and pulling CBs on maintenance panels meant for ground and engineering use only.

derjodel

10th Mar 2019, 17:46

Three Boeing nose down crashes in a few month's...?!

Four. Fly Dubai also crashed nose down. Also, all last major airliners crashed were Boeings...

What if modern planes are so stretched when it comes to performance attributes that FBW is safer at this point? E.g., MCAS is a non-FBW hack to make max certifiable.

Lonewolf_50

10th Mar 2019, 17:48

Read the AD. Loss/malfunction of a SINGLE AOA sensor can result in nose down trim input being automatically applied.
would rather we not get into an A versus B thing, those just add noise to no good end.
The point you mention there was raised in the LionAir thread about two versus three on the AoA gages: if only two, one's vote wins, the good one or the bad one?
If the "bad one's" vote wins, what then? The AD was issued with the understanding of the system (as you note) folded in.
We don’t know whether that was a factor in this accident until FDR/CVR are located and analysed.
Yes, we agree on that. What I was thinking was that with the recency of LionAir accident, MAX crews would tend to be aware of the procedure in the AD, so perhaps looking at that failure mode first is a red herring? No idea. Not enough info. One hopes the FDR/CVR data remain intact.

Nieuport28

10th Mar 2019, 17:55

From that article:
https://i.imgur.com/Rq95L56.png

This is highly unusual, right? Aviators have been expected and encouraged to learn such things.

IMO, the industry needs to look at this especially with the Max and the upcoming 797. I’m totally opposed to designing any inherent aerodynamic instability into a commercial airframe corrected by software. The statement from Boeing scares the hell out of me. It also scares the hell out of me that we are heading in the direction of ATP’s requiring F-35 levels of training.

MCAS was implemented due to the forward placement of the engines on the Max. Any commercial FBW aircraft should be an aerodynamically stable design. FBW should only be for control surfaces, not to allow the airframe to actually “fly.” This “improved efficiency at all cost” factor may be at a critical point.

CRM is challenging enough today.

excrab

10th Mar 2019, 17:58

Four. Fly Dubai also crashed nose down. Also, all last major airliners crashed were Boeings...

What if modern planes are so stretched when it comes to performance attributes that FBW is safer at this point? E.g., MCAS is a non-FBW hack to make max certifiable.

I didn’t realise that the Flydubai crash happened “in the last few months”,
and it was totally different circumstances (night / IMC / poor weather). And an 800,
not a MAX.

TylerMonkey

10th Mar 2019, 18:00

Copilot had 200 hours on type ?

or 200 hrs total career . . . ?

CONSO

10th Mar 2019, 18:01

SLF here- I'm amazed at the stampede to MCAS blame absent any other info. The last I heard re MCAS was that it was disabled until flaps UP. It ***seems *** that from the altitude figures above terrain and time after takeoff- that flaps were**** probably **** not up. Beyond that admitted speculation, including rants about chicken.... airlines, why not wait till more facts and data as from tower, fdr and cockpit voice data/facts. ??

jimjim1

10th Mar 2019, 18:01

I can't vouch for the accuracy of GE's terrain elevations.

GE seems to use a radar satellite survey with 30m vertical resolution on a 90m grid. Some areas are much better with a laser survey. I guess this case is likely to be a radar area.

https://www.quora.com/How-accurate-are-relative-elevations-in-Google-Earth

https://productforums.google.com/forum/#!topic/earth/3Th8MuHzKtE

https://dds.cr.usgs.gov/srtm/version2_1/Documentation/MIL-PDF-89020B.pdf
PERFORMANCE SPECIFICATION DIGITAL TERRAIN ELEVATION DATA (DTED)
(their caps)

Chronus

10th Mar 2019, 18:05

Judging by the picture of the CEO inspecting what appears to be the largest piece of wreckage around, with the crater in the background, it must have involved considerable kinetic energy to dig that size of a crater and displace the apparent volume of surface soil banked around it, particularly given it is hard African terra firma. The extensive scorched earth around the area of impact is evidence of instant atomisation and simultanious explosion of the on board fuel. It is somewhat reminiscent of the early B737`s un-commanded rudder deployment accidents. Wing over and almost a vertical dive, 80t +, at over 400kts. Considering the height reached before the event, somehow I cannot quite envisage stab/elevator to have achieved what must have been a very aggressive control input.

Flyingmac

10th Mar 2019, 18:08

"This emergency AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. This condition, if not addressed, could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain."

That's enough to keep me off them.

eppy

10th Mar 2019, 18:10

Very quick response from the NY Times - especially for a Sunday.Are There Problems With the Boeing 737 Max? A Second Deadly Crash Raises New Questions https://www.nytimes.com/2019/03/10/world/africa/boeing-737-max-8-crash.html

L337

10th Mar 2019, 18:13

Boeing's statement sounds to me like the current corporate vogue of down playing everything that's a non-smiley event, "Move along, nothing to see here".
Trouble is once you've been exposed to 600C temperature there's not much left to put "Some cream on it".

A software device that alters the trim during flight transition from one stage to another, possibly without notifying the aircrew - unbelievable. Why haven't aircrew, en masse, especially seniors, raised objections to this ?

N

It happens all the time. The software and hardware is constantly adjusting in the background. As speed increases and decreases trim and control sensitivity is being modified, all the time. All without the pilot being told, and totally unaware. It is called a well designed aeroplane.

Gilles Hudicourt

10th Mar 2019, 18:19

Correct me if I’m wrong, but in the case of the Lion Air accident, from what I understood, an AOA probe fault caused the MCAS to put a forward trim on the horizontal stabiliser, causing a fault that essentially looked like a runaway trim, a situation that a pilot could have recovered from by treating it like a runwaway trim.

If the above statement is correct, my question is this : did the MCAS also activate the stick shaker or any other kind of stall warning?

Because recovering from a down trimming runaway trim (pulling back on a very heavy control wheel) while at the same time having a stick shaker and some other indication telling you you are about to stall (which normally would require lowering the nose).....

derjodel

10th Mar 2019, 18:26

I didn’t realise that the Flydubai crash happened “in the last few months”,
and it was totally different circumstances (night / IMC / poor weather). And an 800,
not a MAX.

well, luckily we are are at the stage where airlinners don’t crash so often that monthly data would be relevant. So by looking at “few months” (how much is few btw?), we are cherry picking data. Admittedly the sudden spike, specially the last two, could be due to random chance alone.

That said, Fly Dubai and the Amazon 767 nosedived under similar circumstances. And as fsr as I remember some people disputed the official Fly dubai story that the pilot keptnholding the trim button.

in any case, with 3 boeing nosedives officially unexplained yet, the situation is interesting to say the least, mcas or not (and since ET probably happened before flaps up, we might have 3 boings nosediving without mcas, whic is actually even worse, isn‘t it?)

duinsel

10th Mar 2019, 18:28

Aireon's satellite constellation (Iridium Next) has actually been completed as of January of this year, and they state their systems would be operational Q1 2019. It is quite possible part or all of their hardware was collecting data today.They advertise an 'Alert' service that is free but still needs to be enrolled in by operators. I am curious if such data would be made available, either publicly or to the airline or investigators.
Their data would overlap with the ADS-B data collected by FR24, but was collected on superior receivers that are much less sensitive to terrain from their orbit, so more datapoints may well be available.

MemberBerry

10th Mar 2019, 18:44

Correct me if I’m wrong, but in the case of the Lion Air accident, from what I understood, an AOA probe fault caused the MCAS to put a forward trim on the horizontal stabilisor, causing a fault that essentially looked like a runaway trim, a situation that a pilot could have recovered from by treating it like a runwaway trim.

If the above statement is correct, my question is this : did the MCAS also activate the stick shaker or any other kind of stall warning?

Because recovering from a down trimming runaway trim (pulling back on a very heavy control wheel) while at the same time having a stick shaker and some other indication telling you you are about to stall (which normally would require lowering the nose).....

The stick shaker was indeed activated on the Lion Air flight due to the incorrect AoA sensor readings, but the stick shaker has nothing to do with MCAS, its triggering mechanism is independent from MCAS.

In fact the stick shaker has also been active for almost the entirety of the previous flight, 90 minutes, for the same reason: incorrect AoA sensor readings.

And the pilots from the previous Lion Air flight seemed to fail to mention that the logs, for some unfathomable reason. Also not sure how they could stand having a stick shaker active for 90 minutes and not return to the departure airport. They might have pulled its circuit breaker to silence it.

The previous Lion Air crew also failed to mention in the logs they had to disable the automatic trim, after fighting with it for 5 minutes, to make the plane flyable.

Having done so would have helped the next Lion Air crew to diagnose the issue faster and apply the workaround before the plane become uncontrollable and crashed.

PastTense

10th Mar 2019, 18:47

The U.S. National Transportation Safety Board will send four people to assist in the fatal Ethiopian Airlines crash, an NTSB spokesman said on Sunday.The U.S. Federal Aviation Administration is also monitoring developments concerning the crash, a statement said. “We are in contact with the State Department and plan to join the NTSB in its assistance with Ethiopian civil aviation authorities to investigate the crash,” an FAA statement said.
https://af.reuters.com/article/topNews/idAFKBN1QR0JL-OZATP

Is four the usual size of the team? I would have expected a larger team.

Daysleeper

10th Mar 2019, 18:49

https://af.reuters.com/article/topNews/idAFKBN1QR0JL-OZATP

Is four the usual size of the team? I would have expected a larger team.

Four would be pretty normal, remember this is not a US investigation , it's an Ethiopian investigation which the NTSB is a participant in. Their main role is being the conduit between the Ethiopians and Boeing / CFM / FAA / suppliers and also providing specific requested technical expertise.

lomapaseo

10th Mar 2019, 18:53

There seems to be in this thread an early fixation on a previously known cause. This flies in the face of the ability of the industry to assimilate previous causes and promulgate corrective actions world wide.

I'm not about to give much credence to anybody suggesting a cause unless equal arguments include previously identified corrective actions being missing

gums

10th Mar 2019, 19:02

Salute!

@Gilles
Correct me if I’m wrong, but in the case of the Lion Air accident, from what I understood, an AOA probe fault caused the MCAS to put a forward trim on the horizontal stabilisor, causing a fault that essentially looked like a runaway trim, a situation that a pilot could have recovered from by treating it like a runwaway trim.
I am willing to bet that most of us think of "runaway trim" as a fairly constant uncommanded trim that we didn't expect. The MCAS trim implementation is maybe ten seconds of nose down unless you use the manual trim switch or wheel, then it "rests" for 5 seconds and tries to kill you again!!! So sympton is like "intermittent trim" or basically FUBAR trim, especially if not briefed on the MCAS implementation and realizing that the stick shaker and stall alarm was telling me to push over, but Hal was overdoing it.
The previous Lion Air crew turned off the trim and until we hear their testimpny, they may not have realized that their own plane had MCAS failure. And looking at their FDR plots, it was classic MCAS. just like flight 610 the next day.

@CONSO The flap retraction altitude/procedure for the 737MAX is not in my memory bank Seems that normal retraction requires a trim change in most planes ( Airbus, Viper, Raptor, maybe 777 excepted), but not flying that type I am not sure. In any case, it's a configuration change and that is not a great time to have uncommanded trim you are not expecting or trained for.

For the "shut up and wait" folks!! This is a "rumor" forum, but if I were flying this type I would sure as hell be reviewing everything I could get my hands on about the systems' operation ofter gear up and establishing a stabilized climb, and talking with other pilots flying the beast.

Gums opines....

Rananim

10th Mar 2019, 19:17

There seems to be in this thread an early fixation on a previously known cause. This flies in the face of the ability of the industry to assimilate previous causes and promulgate corrective actions world wide.
You would think so but it seems not.
The Flight Radar data fits another MCAS event and not much else.
737s dont just augur in.
Flap retraction can be initiated as low as 400 feet,more commonly 800 feet.
So MCAS event is entirely feasible.
Skipper new to type<-------red flag
Co-pilot 200 hrs<-------red flag
New Skipper rostered with inexperienced co-pilot<------huge red flag
Ethiopian track record<------red flag

PastTense

10th Mar 2019, 19:21

There seems to be in this thread an early fixation on a previously known cause. This flies in the face of the ability of the industry to assimilate previous causes and promulgate corrective actions world wide.

I'm not about to give much credence to anybody suggesting a cause unless equal arguments include previously identified corrective actions being missing
See thread:
https://www.pprune.org/rumours-news/618252-boeing-737-max-software-fixes-due-lion-air-crash-delayed.html
Thus Boeing hasn't implemented any fixes of the MCAS problem yet. While many airlines probably did some additional pilot instruction and other pilots learned of the problem in places like PPRUNE, many other pilots probably didn't.

And of course even if a pilot was informed of something doesn't mean he will remember it in a critical situation.

Lonewolf_50

10th Mar 2019, 19:30

The Flight Radar data fits another MCAS event and not much else.
I will comment on your "not much else" line.
(1) This was mentioned some pages back, but (https://www.pprune.org/showthread.php?p=10412258) ... given the altitude, "high hot heavy," and location, another possibility is a bunch of birds being eaten by two engines.
Crew is playing catch up the whole way down, high task saturation, very little altitude to work with. (And I think it's rising terrain? Not familiar with the area).
That's a guess, since there's not a lot of supporting information. The FDR would be able to identify that kind of thing early in the analysis.
(2) Here's another one that is far less likely, but that also fits: bad fuel. (Didn't they just fill up after unloading from the previous flight?)
Lose one, lose two, and now you have to do your best-ever engine out drill at high gross weight and (I think?) rising terrain. (If that part is wrong, rising terrain, map study failure on my part).
Why I think it wasn't that second one.
The reported radio call about "return to field" (https://www.pprune.org/showthread.php?p=10412369) ... but that could be for a variety of things going wrong.
More detail hopefully soon.

I don't make this post to belittle your analysis, because I think that in the main you are thinking the problem through.

I am jumping on the band wagon with lomapaseo: we might be dealing in a little bit of confirmation bias in the early reaction to this tragic loss of life.

Smythe

10th Mar 2019, 19:40

What I am pointing out is jumping on the wagon with what lomapaseo was getting at: we might be dealing in a little bit of confirmation bias in the early reaction to this tragic loss of life.

yes, that is certainly true. now, on the flip side, considering how many hours the MAX has vs hull loss.4 months to a hull loss. times 2

there is a problem.

marie paire

10th Mar 2019, 19:40

And... B737 Max 8, RED flag,,,

gums

10th Mar 2019, 19:42

Salute!
This might be a workable URL from Past Tense post above.Original may have been corrupted.
The certification issue is mentioned, as well as informing crews and such.

https://www.pprune.org/rumours-news/618252-boeing-737-max-software-fixes-due-lion-air-crash-delayed.html

Gums sends...

scr1

10th Mar 2019, 19:43

a report of possible engine problems

https://www.timesofisrael.com/israeli-says-he-was-on-ethiopian-jet-days-before-it-crashed-it-had-engine-woes/?utm_source=dlvr.it&utm_medium=twitter

silverstrata

10th Mar 2019, 19:55

Not sure exactly about which controls are you talking about, and what exactly do you mean, but as far as I know at the very least the elevator controls can be split on the 737.
There is a breakout connection between the two control columns that can disconnect if the torque applied on it becomes too high, for example if the elevator on one side of the aircraft is stuck.

Not true, there is a ruddy great toque tube that connects both elevators on the 737. You can (supposedly) disconnect the control columns, but you cannot separate the elevators. So if one jams, the other is too. Oh, and BTW, have you ever come across anyone who has done a control colum disconnect in the sim? Ever?

Face facts, the 737 would not pass certification today. Its rests its entire certification upon its 1967 grandfather rights.

Silver

Running Ridges

10th Mar 2019, 19:57

a report of possible engine problems

Does that not sound more like an APU issue than an engine issue?
Lack of Air Conditioning before start + unusual start procedure

Before takeoff, “the passengers understood there was a problem. It was hot, they didn’t give out water,” he said.

Israeli Ambassador to South Sudan Hanan Godar (screen capture: Channel 13)The pilot informed them of a problem with one of engines, telling them: “We’ll operate one engine to see if it catches, and if it catches, we’ll start the other engines,” Godar said.

Photonic

10th Mar 2019, 19:58

A CEO at a crash site is an important sign of a company commitment.

A CEO standing outside the roped-off area at a press conference is how that's normally done, as a sign of company commitment. A CEO standing in the middle of the wreckage and handling crash parts, is just setting a terrible example for others to follow.

Lonewolf_50

10th Mar 2019, 19:59

a report of possible engine problems

https://www.timesofisrael.com/israeli-says-he-was-on-ethiopian-jet-days-before-it-crashed-it-had-engine-woes/?utm_source=dlvr.it&utm_medium=twitter (https://www.timesofisrael.com/israeli-says-he-was-on-ethiopian-jet-days-before-it-crashed-it-had-engine-woes/?utm_source=dlvr.it&utm_medium=twitter)
Also a possible passenger who knows not very much about aircraft and engines. :hmm: That "report" is rather low on the credibility list, given that the gent was on the aircraft on Thursday. We'll see what the FDR has (hopefully) in due course.

Lonewolf_50

10th Mar 2019, 20:04

yes, that is certainly true. now, on the flip side, considering how many hours the MAX has vs hull loss.4 months to a hull loss. times 2

there is a problem. Or there may be two different problems. We'll see.

Raffles S.A.

10th Mar 2019, 20:08

While those who are arguing about the CEO holding a piece of wreckage, have you seen the vidoes of 100s of locals walking over the crash site?

A message recieved from a pilot friend who was at the holding point when the doomed aircraft took off, he says that the takeoff seemed normal but shortly after the aircraft declared an emergency stating unreliable airspeed and difficulty controlling the aircraft.

silverstrata

10th Mar 2019, 20:12

There seems to be in this thread an early fixation on a previously known cause. This flies in the face of the ability of the industry to assimilate previous causes and promulgate corrective actions world wide.

What do you expect? MCAS is a cheap (and semi-back-door) stick pusher system. It is far from ideal, but was a simple software change rather than a complete new stick-push system, which is what should have been fitted. Face facts, MCAS was a hurried and ill-thought-out fix, to yet another upgrade to a 60-year old airframe - and it is known to have already caused one tragic loss, iin very similar circumstances to the oresent incident. You think it is not justified to bring up the MCAS system again - because I have not heard that the system has been changed in any way. It is still sitting there, like a brooding gremlin, ready to pluck aircraft out of the sky at any minute.

And Boeing have still not explained the logic of of a pseudo-stick-push that keeps operating again and again and again, until you get full forward trim. Have you tried this MCAS-trim-runaway in the sim? According to the sim, the aircraft is only just about controllable with two gorillas hauling back in unison, with both feet up on the foot-bar and hauling about 40 kg pressure on each stick. And that was in level flight with the CofG in the central position. Ok, now try a recovery from a stall-dive, with a forward CofG, with 20º nose down pitch, and with the speed rapidly increasing to 250 kt. It is absolutely impossible - you are doomed. And doomed by an anti-stall system that is supposed to save you. But who in the world would want to recover from a stall, with the trim-stabiliser set fully forward? Who thought that ine up? The stabiliser is more powerful than the elevator, and will take you straight down to terra-firma. Heck, even the Wright Brothers knew not to design something like that.

Silver

b1lanc

10th Mar 2019, 20:13

I don't mean to be a wiseass, but the graph shows that it was climbing when it hit. (Or am I reading the graph incorrectly?) Is someone using non standard notation there?

I don't think you are being a wiseass - take it for what it's worth - posted on Daily Mail. Like I said, they didn't site a source. Do we really know how long it was airborne? Also doesn't seem to mirror the earlier plot posted. Compares to #56 permalink.

Lonewolf_50

10th Mar 2019, 20:17

I don't think you are being a wiseass - take it for what it's worth - posted on Daily Mail. Like I said, they didn't site a source. Do we really know how long it was airborne? Also doesn't seem to mirror the earlier plot posted. Thanks, I deleted my post, no value added. :)

Raffles S.A. Interesting. Also disconcerting (https://www.pprune.org/rumours-news/619272-ethiopian-airliner-down-africa-11.html#post10412807). (Sounds eerily familiar to some other accidents ...)

fsfaludi

10th Mar 2019, 20:21

wobblywings

10th Mar 2019, 20:25

W
A message recieved from a pilot friend who was at the holding point when the doomed aircraft took off, he says that the takeoff seemed normal but shortly after the aircraft declared an emergency stating unreliable airspeed and difficulty controlling the aircraft.

First time I hear this in respect to this accident. If true, that'd be another indication pointing to MCAS in combination with erroneous sensor data.

Cows getting bigger

10th Mar 2019, 20:34

I’m pondering crew composition. On the one hand an experienced pilot although not ‘vastly’ so, on the other a new guy apparently fresh out of training (200hrs). If (BIG IF) this was one of the more unusual failure scenarios, you have to feel for the CRM side of the house.

klintE

10th Mar 2019, 20:48

IMO, the industry needs to look at this especially with the Max and the upcoming 797. I’m totally opposed to designing any inherent aerodynamic instability into a commercial airframe corrected by software. The statement from Boeing scares the hell out of me. It also scares the hell out of me that we are heading in the direction of ATP’s requiring F-35 levels of training.
MCAS was implemented due to the forward placement of the engines on the Max. Any commercial FBW aircraft should be an aerodynamically stable design. FBW should only be for control surfaces, not to allow the airframe to actually “fly.” This “improved efficiency at all cost” factor may be at a critical point.
Honestly, I think you are wrong.
1. FBW is exactly for that purpose. Not only, but for that too. To steer what is unstable. B2 Spirit nuclear bomber couldn't fly by a mile without FBW. It's great system and failed (probably) only once in all history.
And correction for aerodynamics in software is mandatory. For example, you can't build two exactly the same wings for A380. So without software correction in systems a/c can't fly in straight line by holding yoke/stick one position.
2. None of 737 is FBW equipped, including MAX. series (and that's a source of the problem IMO)

Raffles S.A.

10th Mar 2019, 20:53

First time I hear this in respect to this accident. If true, that'd be another indication pointing to MCAS in combination with erroneous sensor data.

I'm pretty sure the ATC tapes will be analyzed. Remember that only about 20% of posts here contribute something valuable to the conversation and this is exactly what it is, a conversation.

Kerosene Kraut

10th Mar 2019, 20:58

2. None of 737 is FBW equipped, including MAX. series (and that's a source of the problem IMO)

MAX roll spoilers are FBW. Emergency descends and approach speed management are FBW assisted.

positiverate20

10th Mar 2019, 21:13

Salute!

@Gilles

I am willing to bet that most of us think of "runaway trim" as a fairly constant uncommanded trim that we didn't expect. The MCAS trim implementation is maybe ten seconds of nose down unless you use the manual trim switch or wheel, then it "rests" for 5 seconds and tries to kill you again!!! So sympton is like "intermittent trim" or basically FUBAR trim, especially if not briefed on the MCAS implementation and realizing that the stick shaker and stall alarm was telling me to push over, but Hal was overdoing it.
The previous Lion Air crew turned off the trim and until we hear their testimpny, they may not have realized that their own plane had MCAS failure. And looking at their FDR plots, it was classic MCAS. just like flight 610 the next day.

@CONSO The flap retraction altitude/procedure for the 737MAX is not in my memory bank Seems that normal retraction requires a trim change in most planes ( Airbus, Viper, Raptor, maybe 777 excepted), but not flying that type I am not sure. In any case, it's a configuration change and that is not a great time to have uncommanded trim you are not expecting or trained for.

For the "shut up and wait" folks!! This is a "rumor" forum, but if I were flying this type I would sure as hell be reviewing everything I could get my hands on about the systems' operation ofter gear up and establishing a stabilized climb, and talking with other pilots flying the beast.

Gums opines....
Possibly off topic, but, why would brand new aircraft sensors and indicators fail within months? The software, MCAS, is reliant on good data, if the data was always good then there wouldn't be a problem with the software. The question is, why is the data so bad? Why is MCAS reliant on AOA sensors that fail within months of introduction? Yes, I agree that MCAS shouldn't have been slipped in by the backdoor, but we probably still wouldn't know much about it if it was actually functioning the way it was supposed to! Are all these billions of dollars spent on automation software being pumped into unreliable hardware?

At least Southwest took it's own initiative by adding an extra AOA indicator into 737 MAX for crew to cross-check erroneous data, but, shouldn't that be a Boeing responsibility and hence fitted to the worldwide fleet? I doubt Ethiopian purchased or insisted on these upgrades.

I'm not jumping the gun, and certainly not claiming this was the problem with this flight, just picking up on others comments on MCAS.

MLHeliwrench

10th Mar 2019, 21:13

It has to be more than just unreliable airspeed or the MCAS issue. Every pilot on the MAX must be versed in what happens with MCAS.

its a clear day, and if you can’t just grab the throttles and yolk and get your eyes out the window, while PNF cleans up the configuration - something very wrong had to happen. It must be something exceptional like a double bird strike creating partial power.

derjodel

10th Mar 2019, 21:23

Have you tried this MCAS-trim-Runway in the sim? According to the sim, the aircraft is only just about controllable with two gorillas hauling back in unison, with both feet up on the foot-bar and hauling about 40 kg pressure on each stick. And that was in level flight with the CofG in the central position.
Silver

So, you just took off, engines still at TO power, you retract the flaps... and start fighting Mcas as per above description. No time to manage engine power so you are gaining speed...
you remember mcas. Somehow you pull the circuir breaker. With both pilots pulling the stick the plane now goes into a steep climb. Followed by stall, and crash due to unsuccessful recovery...

Could it match, in theory?

silverstrata

10th Mar 2019, 21:26

777 crew behind ET302 at holding point report observing normal takeoff followed shortly by declaration of emergency. They heard ET302 on tower frequency transmitting “Wrong airspeed indications and difficulty controlling aircraft.”

Which is much the same as the Indonesian Max.
The airspeed was ok, of course, but the stick shaker going off and the MCAS anti-stall trim going off, tends to make you think the airspeed is wrong. So how much of a briefing have Max crews been given, on the inadvertent operation of the MCAS system?

Touch of the deja-vus, I would say. See my comment above, about the absurdity of the MCAS system.

Silver

henra

10th Mar 2019, 21:38

I will comment on your "not much else" line.
(1) This was mentioned some pages back, but (https://www.pprune.org/showthread.php?p=10412258) ... given the altitude, "high hot heavy," and location, another possibility is a bunch of birds being eaten by two engines.
...
(2) Here's another one that is far less likely, but that also fits: bad fuel.

While I wouldn't rule out anything at this point in time at least the FR24 data indicates that engines seemed to deliver power. Aircraft sped up to 383kts but was apparently never able to gain altitude. Even considering ambiguities and inaccuracies in FR24 data it appears the never got over 1000ft above ground while spearing along at a breathtaking 383kts. That is fighter jet low attack profile and does not really point big time towards engine trouble. The level of devastation also points towards a very high energy impact. This also rather contradicts any loss of propulsion scenarios.
Sadly, this carries many similarities with the other MAX Crash.

wobblywings

10th Mar 2019, 21:42

MAX 8 series drivers: is the timing of the intermittent operation of MCAS compatible with the timing interval for the vertical speed drops reported by FR24, in particular the first two pitch downs?

EI-mech

10th Mar 2019, 21:43

If it's true that the MCAS only becomes active after flap retraction then I doubt it was involved in this instance. Acceleration (and thus flap retraction) doesn't happen until at least 1500' AGL, and it looks like this flight never even attained that height.
That is only based on the ADS B data online which may be inaccurate so only time will tell.

silverstrata

10th Mar 2019, 21:47

So, you just took off, engines still at TO power, you retract the flaps... and start fighting Mcas as per above description. No time to manage engine power so you are gaining speed...
you remember mcas. Somehow you pull the circuir breaker. With both pilots pulling the stick the plane now goes into a steep climb. Followed by stall, and crash due to unsuccessful recovery...
Could it match, in theory?

Could be correct.

You see after take off the normal speed-trim system is always trimming anyway, so you are used to that 1930s (borrowed from the Ju-52) trim-wheel clanking and rotating. So it may take you a while to realise the trim is doing something very wrong.

Plus if the MCAS system is at fault again, you will have the stick shaker going off, which makes a hell of a racket, and is not cancellable. The stick shaker is supposed to be transient, just for the stall, but if yet another AoA vane has failed, the shaker will go off continuously, and is a serious distraction.

Plus you go for the stab-trim cutout switches, and you forget they are down for off, while all the other switches on the 737 are up for off. (Why is Boeing so stupid...?) So you shout to the f/o, above the noise of the shaker and the trimmer, 'did you turn the stab-tim switches off', to which he-she replies 'yes' - meaning he placed the switches upwards. But this turns the trim on, not off.

And then you reduce power, and the huge thrust-couple change plunges the nose downwards. So now the aircraft now has full trim forward, and is plunging to the ground like a home-sick troglodyte. (When does an aircraft ever want full trim?) And two people pulling on the stick is no longer sufficient to stop the dive. And Boeing thinks this is a great system to fit to a modern airliner, and a great ergonomic design for the 21st century? I have got news for Boeing....

And yes, this discussion is justified, because Boeing never gave any answers to the last crash. And nor, so far as I know, have they made any amendments to MCAS. So the 737-Max is still fitted with a system that will give full trim forward, and make the aircraft uncontrollable. Why is that? Does Boeing have an explanation for this - for why any aircraft would want full trim forward while pulling out of a stall's subsequent dive??

Silver

.

SeenItAll

10th Mar 2019, 21:49

positiverate20

10th Mar 2019, 22:00

It is my understanding that the 737MAX spits out a lot of data at short intervals via ACARS to maintenance systems (Boeing). If that applies to ET, Boeing should already have an idea what systems played a role in this accident. Anyone with more info on this?
Also be useful to know which data is correct. The data publicised so far is ADS-B, so if it is an onboard sensor problem causing bad data to flight control, then surely some of the FR data is bad too?

Dogma

10th Mar 2019, 22:02

Given how much all of the armchair experts on this forum seem to know about MCAS, it is extremely hard to believe that a B737-Max8 pilot who flies for a competent operator (and ET is in that group) would be oblivious to MCAS' effects and the way to stop them. Surely all of these pilots would have been deluged with training information about MCAS issues over the last several months. Indeed, given MCAS' recent infamy, I think it is more likely that pilots are now misinterpreting nonMCAS faults to be an MCAS ones than vice versa.

First mistake is to assume Pilots are deluged with Variant specific training and technical support. It’s woeful and inadequate in 90% of airlines. The accountants and sales office at Boeing have won the battle.. the lawyers have written the manuals and training package..

very sad sad state of affairs in most airlines

love the speculation about the non-normals, MCAS etc.. all nearly correct but very far from reality

henra

10th Mar 2019, 22:14

According to the same ADS-B data they were eventually flying with 383kts. They surely should have retracted flaps before accelerating to 383kts...
+1
With full slats and extended flaps it simply won't reach 383kts. So it is safe to assume they were retracted. And it is also pretty safe to assume they did not spear along on autopilot at below 1000ft - I'm not aware there is a TFR in a 737 MAX...
So both conditions for MCAS being active were pretty surely met in this case.
Does it mean MCAS was surely the cause? No.
Does it point into that rough general direction? Rather Yes.

10th Mar 2019, 22:39

1. Does MCAS require a fully clean wing or just flaps at 0? (i.e. Slats still extended).
2. Does the 738/Max have auto flap retract á la Airbus - on the Bus the flaps auto retract as speed increases (for protection).
3. Are the auto trim on/off switches guarded?
4. What state is the Auto throttle in after take off? Does it have to manually activated at thrust reduction altitude?
5. If the throttle levers are left untouched after take off, with a distraction (UAS) would thrust remain at take off thrust setting?

A4

The AvgasDinosaur

10th Mar 2019, 22:42

gums

10th Mar 2019, 22:43

Salute!

@Nieuport28, fsfaludi & silverstrata
Right on!

@klintE
Honestly, I think you, klintE are wrong.

As prolly the oldest pure FBW pilot here ( unless you were a Concorde dude or flew a test plane back in 1979), I wanna clear up the gross misunderstanding about FBW that many folks still have and exhibit.
And correction for aerodynamics in software is mandatory
No so. You can have a perfectly good B-17 and simply replace all the cables and such to each control surface, and maybe the horizontal stab with a single hydraulic line and a hydraulic actuator commanded by some wires. This is opposed to the original irreversible hydraulic flight control systems we saw in the 50's and later in most of the "fast jets" ( as the Brits say). No direct feedback but a few attempts to help. In other words, no ropes, pulleys, tubes, cables, etc.
Although you can use the FBW implementation for better stability, stall prevention and gee limits and ..... that's not the sole reason for FBW. And the new F-35 doesn't even have hydraulic lines to the surface actuators - they are electrically driven, local hydraulic or electric actuators. They are truly "electric jets", even tho we called my old Viper the original "electric jet"..

The B-2 FBW system did, indeed, command a bad pitch after WoW due to sensor contamination by water. Simple maintenance procedures and crew actions prevented future occurences.
The AF447 FBW system did not fail due a bad sensor. It commanded pitch trim so the pilot would not have to keep holding back stick, which he did for a long time, even after the other guy said they were climbing.

Lastly, there's at least one flight control surface on the 737 that is FBW.

Let's face it, the new mod to the very old plane that was certified 50 years ago would not have been certified back then. I have looked closely at the U.S. Part 25 requirements for trim, stall conditions, etc and I have a hard time believing the MAX version was certified.

Gums opines...

mryan75

10th Mar 2019, 22:44

Given how much all of the armchair experts on this forum seem to know about MCAS, it is extremely hard to believe that a B737-Max8 pilot who flies for a competent operator (and ET is in that group) would be oblivious to MCAS' effects and the way to stop them. Surely all of these pilots would have been deluged with training information about MCAS issues over the last several months. Indeed, given MCAS' recent infamy, I think it is more likely that pilots are now misinterpreting nonMCAS faults to be an MCAS ones than vice versa.
Not to mention the fact that the guys flying the Lion Air plane the day before (UK captain) had the same problem as the accident flight, hit the STAB TRIM CUTOUT switches and went on about their day. Even if this is MCAS, again, and even if it was the same for Lion Air, I still believe 100% that a US or European crew wouldn't have had any problem at all. A new captain and a 200-hour wonder is the absolute worst possible combination here... just saying.

CONSO

10th Mar 2019, 22:46

FWIW
https://www.seattletimes.com/business/boeing-aerospace/a-sense-of-urgency-as-investigation-into-second-recent-crash-of-a-boeing-737-max-begins/

....The Lion Air flight data showed that airplane repeatedly losing and then regaining altitude for 12 minutes before the final dive into the sea, as the pilots struggled to pull the nose up (https://www.seattletimes.com/business/boeing-aerospace/black-box-data-reveals-lion-air-pilots-struggle-against-boeings-737-max-flight-control-system/) each time MCAS pushed it down.But MCAS cannot activate until the pilot has gained altitude and retracted the flaps that give the wings extra lift for takeoff. It’s not clear at this time what phase of flight the Ethiopian plane had reached and whether the flaps were retracted...

Loose rivets

10th Mar 2019, 22:48

Apropos comments made in recent posts: The Lion Air last moments of climb and then near vertical dive, were preceded by a huge handful of power - evidenced by a fuel-flow increase not bettered since the takeoff run.

picture

10th Mar 2019, 22:49

A few thoughts from a 737 Max 8 pilot .
The initial profile looks similar to the Lion air crash.
Boeing has stated that if the Lion air pilots had followed the STAB TRIM RUNAWAY. ( the new and revised version.)
the accident would not have occurred.
The Lion air pilots were initially dealing with a UNRELIABLE AIRSPEED drill . They should have then followed the Stab trim drill but were probably task saturated.
We have learned two pertinent things about the MCAS system .
The system arms when the flaps are up.
The system disarms when the Autopilot is turned on.

So so on Take off the auto pilot is off and the flaps are down.
Pilots are trained that on abnormalities on take off "Clean up and climb to a safe altitude". Before troubleshooting the situation .
The 737 Max flap limiting speed for flap5 is 250KIAS. That's a normal take off flap setting and more than enough airspeed for any configuration / abnormality.

So so untill a definitive directive is released for this type , when's faced with similar situations and deciding on Climb / return plan Flaps down during troubleshooting should be the default setting.

Airbubba

10th Mar 2019, 22:56

777 crew behind ET302 at holding point report observing normal takeoff followed shortly by declaration of emergency. They heard ET302 on tower frequency transmitting “Wrong airspeed indications and difficulty controlling aircraft.”

FR24 replay shows no 777 behind ET302

Could you give a source for this report? I don't see the 777 on FR24 either.

LDRA

10th Mar 2019, 22:56

Which is much the same as the Indonesian Max.
The airspeed was ok, of course, but the stick shaker going off and the MCAS anti-stall trim going off, tends to make you think the airspeed is wrong. So how much of a briefing have Max crews been given, on the inadvertent operation of the MCAS system?

Touch of the deja-vus, I would say. See my comment above, about the absurdity of the MCAS system.

Silver

The MCAS AD came out 6 monthes ago. It was supposed to be an interim measure with software change to permanently resolved the issue coming Jan 2019. The software update to permanently address the issue did not happen I believe...

10th Mar 2019, 22:57

Picture - what are the memory items and pitch/power settings on the Max for UAS below thrust reduction altitude and above it. Presumably it’s all autos OFF as well? So, potentially application of UAS memory items with an inadvertent flap retraction due to suspected (but erroneous) overspeed and you now have a clean wing, no auto pilot, a high AOA trying to reduce the “overspeed”.......into MCAS territory?

A4

DaveReidUK

10th Mar 2019, 23:12

KRUSTY 34

10th Mar 2019, 23:13

IF this is the MCAS fault again, then the consequences will be enormous, probably a grounding of the MAX fleet.

In a previous thread in Tech Log, I was fairly vocal regarding the grounding of all 737 Max aircraft. Particularly when it was revealed that disabling of the MCAS was dissimilar to the disabling of a “pitch trim” fault in the NG. While there was a lot of discussion surrounding how what sensor should be fitted where, even to the extent of some pretty impressive technical diagrams, the fact remains that the apparent failure of a sensor created a situation where the crew were unable to prevent their aircraft from descending uncontrollably, and crashing violently.

Now if this latest tragedy is something else, I’ll be happy to stand corrected. But the similarities seem disturbing to say the least.

canyonblue737

10th Mar 2019, 23:17

canyonblue737

10th Mar 2019, 23:21

In a previous thread in Tech Log, I was fairly vocal regarding the grounding of all 737 Max aircraft. Particularly when it was revealed that disabling of the MCAS was dissimilar to the disabling of a “pitch trim” fault in the NG. While there was a lot of discussion surrounding how what sensor should be fitted where, even to the extent of some pretty impressive technical diagrams, the fact remains that the apparent failure of a sensor created a situation where the crew were unable to prevent their aircraft from descending uncontrollably, and crashing violently.

Now if this latest tragedy is something else, I’ll be happy to stand corrected. But the similarities seem disturbing to say the least.

it is not dissimilar from a trim runway though, MCAS can be disabled in seconds using the standard trim runway procedure that has you flip two switches on the center pedestal.

Burleigh Effect

10th Mar 2019, 23:22

Rumour is China has suspended all 737-800 ops in the wake of ET302, no doubt more to follow.

Kazt

10th Mar 2019, 23:22

China has asked its domestic airlines to ground all 737 Max.

(Bloomberg) -- China asked domestic airlines to temporarily ground Boeing 737 Max after a same model operated by Ethiopian Airlines crashed on Sunday, Caijing reports, citing an unidentified industry participant.

NOTE: The Sunday crash is the second deadly accident for the model in 5 months

KRUSTY 34

10th Mar 2019, 23:29

it is not dissimilar from a trim runway though, MCAS can be disabled in seconds using the standard trim runway procedure that has you flip two switches on the center pedestal.

Fair enough.

But apparently beyond the capabilities of at least one crew?

rabidstoat

10th Mar 2019, 23:32

Rumour is China has suspended all 737-800 ops in the wake of ET302, no doubt more to follow.

737-800 or 737 MAX 8???

Airbubba

10th Mar 2019, 23:33

Doesn't that mean the crew (777) was still on ground taxiway ?:confused:

Yep, the holding point is on the ground just short of the runway. You would normally have tower frequency tuned waiting for your instructions to taxi onto the runway for takeoff.

Depending on terrain, receiver coverage and other factors sometimes you can see aircraft on the ground with FR24, sometimes you can't. And, even if you don't see the plane on the ground, you will normally see it when airborne after takeoff.

At ADD the ground coverage seems to be intermittent but I don't see a 777 within the minutes after the ET302 departure at about 0537Z.

Here is ET302 turning onto the runway:

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1087x695/eth302_ea23a2fd98851cc112387722b5c7f2bba6ed0ef3.jpg

The next departure I see about five minutes later is a B-788:

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1052x651/eth535_1d697142dfcf5df120f0b80bb0e32a72e3563a84.jpg

Burleigh Effect

10th Mar 2019, 23:34

737-800 or 737 MAX 8???

Correction - it’s the 737-8 MAX.

svhar

10th Mar 2019, 23:35

300 and something deaths in 80,000 flights is not acceptable in 2019.

bud leon

10th Mar 2019, 23:46

300 and something deaths in 80,000 flights is not acceptable in 2019.

No deaths are acceptable ever. But so far no one knows what the cause of this crash was and if it was related to type. Nonetheless it's understandable these days that there will calls or requirements to ground the type.

svhar

10th Mar 2019, 23:54

But everything points that way. Waiting two years for a final report might cost some more hundreds deaths.

Burleigh Effect

11th Mar 2019, 00:14

But everything points that way. Waiting two years for a final report might cost some more hundreds deaths.

If I recall correctly, many people made very early calls regarding the causes behind JT610. The vast majority of these (if not all) pointed the finger at the aircrew - I’m not saying Indo does not have systemic aviation safety issues - only to find after initial investigations that MCAS probably was a causal factor. With the number of foreigners on board you can be assured they will make some initial determinations pretty quickly.

krismiler

11th Mar 2019, 00:17

jimtx

11th Mar 2019, 00:31

Aerobatic, crop spraying and fighter aircraft have to be unstable to allow for rapid maneuverability. A crop sprayer pilot described flying the Ayers Turbo Thrush to me as "like balancing on a beach ball".

Some of the latest fighters are so unstable that they have to be fly by wire or control would be rapidly lost by most pilots.

The certification requirement of not needing undue "skill, alertness or strength" needs to be remembered. IF the MCAS has to be watched like a hawk and requires a couple of night club bouncers to overcome a simple failure then it has no place on a civil aircraft. Imagine two slightly built female pilots trying to overcome a runaway system.

What I don't understand is that if you have an MCAS failure and recognize it and apply the AD from FAA/Boeing they don't tell you to be worried about the flight regimes it is supposed to protect you from. Why not turn the thing off all Max now if that can be done even if this occurrence was not due to an MCAS failure.

RickNRoll

11th Mar 2019, 00:32

What I don't understand is that if you have an MCAS failure and recognize it and apply the AD from FAA/Boeing they don't tell you to be worried about the flight regimes it is supposed to protect you from. Why not turn the thing off all Max now if that can be done even if this occurrence was not due to an MCAS failure.

The certification requires MCAS.

RickNRoll

11th Mar 2019, 00:36

Often the companies have a good idea what has happened before everyone else. Would Boeing already know what happened here?

Kazt

11th Mar 2019, 00:48

Cayman Airways Suspends Operations of Both Its 737 Max 8 Planes
2019-03-11 00:43:29.973 GMT

By Derek Wallbank, Jihye Lee and Kyunghee Park
(Bloomberg) -- Cayman Airways, the flag carrier airline of
the Cayman Islands, says it is suspending operations of both its
Boeing 737 Max 8 aircraft effective March 11 "until more
information is received."
* Southwest Airlines says it remains "confident in the safety of
our fleet" including its 34 Boeing 737 Max 8 aircraft
* Singapore Airlines in tweet says it’s closely monitoring the
situation, though at this time the 737 Max 8 flights operated by
SilkAir are operating as scheduled
* Icelandair says it has had no issues with its three 737 Max 8s
* Spokeswoman at Korean Air, which is expected to take delivery
of its first MAX late April, said the airline is monitoring the
situation

Ccjung

11th Mar 2019, 01:16

I’m not a pilot. Just a mechanical engineer who’s an armchair quarterback.

I come here when I need facts on air incidents.

A 14% increase in fuel efficiency from a simple move like that indicates vastly different aerodynamic performance. How much does bypass ratio add? How much does adding an extra row of compressor blades increase performance?

this indicates that there are some interesting boundary layer effects happening to this aircraft. I’m curious if somehow there are vortexes being generated at higher AoAs that somehow interfere with the pitot tubes.

Bring the wrath. I know I’m just an observer.

Sailvi767

11th Mar 2019, 01:17

See thread:
https://www.pprune.org/rumours-news/618252-boeing-737-max-software-fixes-due-lion-air-crash-delayed.html
Thus Boeing hasn't implemented any fixes of the MCAS problem yet. While many airlines probably did some additional pilot instruction and other pilots learned of the problem in places like PPRUNE, many other pilots probably didn't.

And of course even if a pilot was informed of something doesn't mean he will remember it in a critical situation.

What is there to fix. There are numerous failures that can cause a trim runaway. They have been happening since the first electric trim systems were installed in aircraft. The 737 more than any aircraft currently in service provides a very positive indication of a trim issue via the trim wheels. Solution, disconnect the automatic trim system and continue the fight using manual trim.

WingNut60

11th Mar 2019, 01:24

While many airlines probably did some additional pilot instruction and other pilots learned of the problem in places like PPRUNE, many other pilots probably didn't.

I can't believe that there would be a MAX pilot anywhere who isn't fully aware of the MCAS implications from the Lion incident.

Tailspin Turtle

11th Mar 2019, 01:32

A cautionary tale about assuming that the correct response to a failure is obvious and straightforward:

Once upon a time, I was involved with the addition of a FADEC (Full Authority Digital Engine Control) to the turbine engine on a single-engine helicopter. I forget why but it was single channel. In the unlikely event that it failed, the pilot was obligated to control rotor rpm with the throttle twist grip on the collective just as you did when flying a helicopter powered by a reciprocating engine back in the day.
Before deliveries began, I took it upon myself to fly and land one in manual mode and even though I hadn’t twisted a throttle in some years, there was no drama involved.

Unfortunately, as subsequent events proved, many pilots had never flown a helicopter with a reciprocatiing engine, having learned to fly ones powered by turbine engines with mechanical fuel controls that kept the rotor rpm constant, and training to fly this helicopter in manual mode not as prevalent or extensive as it should have been.
What was worse, the FADEC manufacturer had a circuit-board quality-control problem, which meant that pilots were being presented with the need to manually control rotor rpm after the FADEC had packed up fairly often and at least a few were not up to it, fatally in at least a couple of cases. The quality-control issue was subsequently resolved of course and after perhaps too many early incidents, more emphasis placed on training and occasional practice in manual mode. Moreover, my understanding is that the FADEC now has dual channels.

FIRESYSOK

11th Mar 2019, 01:39

I can't believe that there would be a MAX pilot anywhere who isn't fully aware of the MCAS implications from the Lion incident.

Crews may be aware now, but remember- the Lion Air accident were dealing with unreliable flight instruments along with the MCAS trimming. Merely shutting off the electric stab trim does not eliminate the bad air data indications on the affected side. In itself, a bad set of PFD indications can be a handful wether or not the stab trim is cut off by the crew as recommended.

Clearly, there is no final report from the Indonesians, but unreliable airspeed, etc. was one of the problems as far as I’m aware.

WingNut60

11th Mar 2019, 01:48

fdr

11th Mar 2019, 01:52

The certification requires MCAS.

True. The MMEL does not provide any relief for a MCAS system. The MMEL does however provide relief for the MLA system, which is curiously a factor itself in reduced longitudinal stability. Accepting the operational constraints of the MLA system inop would remove to an extent the necessity for MCAS.

A couple of aerodynamic effectors can be applied to alter downwash at the tail plane, one of which we trialled in 2015 on a B737. It had been trialled years back on a B742 with similar outcomes. The downside of the aero effectors is that altering the downwash is going to be undesirable from a load alleviation standpoint, and is like eating your own tail, unless sufficient increase in downwash is obtained in the near wake to reduce the downwash affecting the tailplane.

Control system counter weights exist to an extent at every bell crank, and that is the simplest means to alter control response during manoeuver.

Any control system or aerodynamic alteration would be a major PITA for alteration of the product, whereas taking MLA out of he equation may remove the necessity for the MCAS to a great extent and remove the issue until resolved.

ET's loss has too many similarities to 610's to be discounted as a system-crew problem.

[Note: AOT is an acronym most famous for the Apollo Lunar Lander's Alignment Optical Telescope... the CM also had one, but it was known as a sextant and part of the PGNCS. :) ]

positiverate20

11th Mar 2019, 01:53

Crews may be aware now, but remember- the Lion Air accident were dealing with unreliable flight instruments along with the MCAS trimming. Merely shutting off the electric stab trim does not eliminate the bad air data indications on the affected side. In itself, a bad set of PFD indications can be a handful wether or not the stab trim is cut off by the crew as recommended.

Clearly, there is no final report from the Indonesians, but unreliable airspeed, etc. was one of the problems as far as I’m aware.

What is there to fix. There are numerous failures that can cause a trim runaway. They have been happening since the first electric trim systems were installed in aircraft. The 737 more than any aircraft currently in service provides a very positive indication of a trim issue via the trim wheels. Solution, disconnect the automatic trim system and continue the fight using manual trim.

it is not dissimilar from a trim runway though, MCAS can be disabled in seconds using the standard trim runway procedure that has you flip two switches on the center pedestal.

Yes, sounds easy if you're 100% confident that MCAS is wrong. But, MCAS is reacting to sensor data- the same data that the instruments in front of your eyes are relaying to you. If your AOA indicator goes haywire, or your ASI is showing lower than stall speed, then you'll have a difficult situation. What MCAS does... it controls flight surfaces to prevent a stall that is likely to occur given the sensor inputs that it's receiving. If you're flying you'll usually trust the instruments- the same instruments as MCAS. Maybe other MCAS interventions haven't been noticed or reported because the rest of the time it's actually functioned the exact same way as the pilots have operated anyway.

If you've just taken off on most other aircraft, if you get a low reading from ASI, or even stick shaker, your first priority is to try to control the aircraft, stabilize flight, level off if at a safe altitude, call a pan and go through the checklists... whereby you eventually should discover that the ASI sensor is bad, Air speed is fine and switch to the alternate input and go on your merry way. Why MCAS is scary is that it 100% relies on sensor data- you're now in the exact same situation as described above, with the exception being that your aircraft has just trimmed nose down by itself, any breathing space you had to troubleshoot has been eroded by MCAS nose down, and any time you could have used to figure out the problem is now spent trying to pull back on the yoke as hard as you can.

It's very easy to say "just pull a couple of CBs, disconnect trim switch, everything will be fine", but in those circumstances, you're on climb out of airport XYZ, suddenly the stick-shaker goes, the ASI in front of your eyes IS showing a reading that's abnormally 'low', the aircraft just trimmed itself nose down to prevent stall, before you have any chance to diagnose the problem you're fighting against the MCAS nose down attitude, your right hand man has 200 hrs all-in and is panicking.

Again, like I said earlier, absolutely not jumping to conclusions as to what caused this tragedy. Again, just re-examining the MCAS issue that has been brought up. Again, stating that MCAS in and of itself should not be a problem- providing the inputs are 100% reliable the software goes unnoticed and may even act as a safety net in the manner it was designed to be. Again, the problem that I see that I haven't seen highlighted previously is the hardware! MCAS relies on data, sensors are the source of the data, why are the sensors so fallible?? Why can't they spend more money on the hardware- ensuring sensors are foolproof with adequate redundancies that can always be relied upon?

Again, Southwest knew the problem and had a quick fix for their own 738 MAX orders, providing an additional AOA indicator for crew to easily cross-check if needed. Note that their statement on 738 MAX listed above is qualified- they're happy with 'their fleet' Possibly their quick & simple solution might be sought by other 738 MAX operators, or even demanded of Boeing to retrofit.

KRUSTY 34

11th Mar 2019, 01:55

The certification requires MCAS.

That just might turn out to be the Oxymoron of the Century!

Lantern10

11th Mar 2019, 02:08

SHANGHAI (Reuters) - China's aviation regulator has ordered domestic airlines to suspend their Boeing 737 Max aircraft, Chinese media outlet Caijing reported on Monday, following a deadly crash on Sunday of a 737 MAX 8 operated by Ethiopian Airlines.
Citing industry sources familiar with the matter, Caijing said domestic airlines, which operate some 60 such airplanes, had received orders from the Civil Aviation Administration of China (CAAC) and halted their use on Sunday.
A Boeing spokesman declined to comment. The CAAC could not be immediately reached for comment.
An Ethiopian Airlines 737 Max 8 bound for Nairobi crashed minutes after take-off on Sunday, killing all 157 people on board.
This is the second crash of the 737 MAX, the latest version of Boeing’s workhorse narrowbody jet that first entered service in 2017.
In October, a 737 MAX flown by Indonesian budget carrier Lion Air flying from Jakarta on a domestic flight crashed 13 minutes after take-off, killing all 189 passengers and crew on board.
The cause of that crash is still being investigated. A preliminary report issued in November, before the cockpit voice recorder was recovered, focused on airline maintenance and training and the response of a Boeing anti-stall system to a recently replaced sensor but did not give a reason for the crash.
Caijing, a state-run news outlet that covers finance and economics, said many flights scheduled to use 737 Max planes would instead use the 737-800 models.
China Business News also reported on its website the 737 Max suspension, saying the regulators' order had been issued orally.
According to flight tracking website FlightRadar24 there were no Boeing 737 Max 8 planes flying over China as of 0043 GMT on Monday.
Most of Air China's 737 MAX fleet of 15 jets landed on Sunday evening, with the exception of two that landed on Monday morning from international destinations, according to FlightRadar24.
It did not list any upcoming scheduled flights for the planes.
China Eastern’s four 737 MAX jets landed on Sunday evening and no further flights were scheduled until Tuesday, FlightRadar24 data showed.
Cayman Airways has grounded both of its new 737 MAX 8 jets until more information was received, the Cayman Islands airline said in a statement on its website.
Fiji Airways said it had followed a comprehensive induction process for its new Boeing 737 MAX 8 aircraft and it had full confidence in the airworthiness of its fleet.
"We continue to ensure that our maintenance and training programme for pilots and engineers meets the highest safety standards," the airline said.
(Reporting by Josh Horwitz and John Ruwitch; Editing by Richard Pullin)

https://forum.thaivisa.com/applications/core/interface/imageproxy/imageproxy.php?img=http://assets.thaivisa.com/forum_news_logos/reuters_logo.jpg&key=a71a0ca278f8bd2b683eea1e5be55e00d3963b1b928af95302d5caed b94709ce (http://www.reuters.com/)

-- © Copyright Reuters 2019-03-11

jimtx

11th Mar 2019, 02:08

The certification requires MCAS.

So when it fails you are flying an uncertified aircraft and you are not told to do anything different.

CONSO

11th Mar 2019, 02:41

Simple question - WHO and WHY did anyone allow a SINGLE flight critical sensor to override all previous methods of recognizing and controlling the aircraft and NOT document it ??

Shades of HAL !

downdata

11th Mar 2019, 02:58

Learned Contributors,
please excuse if this is considered thread drift. If this Ethiopian crash and the Indonesian previously covered on here are proved to be linked. Is
not it odd that out of the total number of B.738M departures since entry to service, no one has been subject to this upset and caught it without loss of life ? Especially since Indonesia as I expect all B.738 Max crews are looking out for a recurrence?
Your time and trouble much appreciated,
Be lucky
David

Even after knowing the DC10 had a design fault wrt to the cargo door, it didnt stop the ground crew of TK981 to not lock the damn cargo door that killed 300 odd people. There must have been tens of thousands of t/os and landings on the DC10 without incidents between AA96 and TK981.

positiverate20

11th Mar 2019, 03:08

Simple question - WHO and WHY did anyone allow a SINGLE flight critical sensor to override all previous methods of recognizing and controlling the aircraft and NOT document it ??

Shades of HAL !

It is shocking how this system was introduced- only being documented and publicised following the death of 189 people.

I can see the logic as to why they'd build it in- if it was 100% operational and reliable it would act as a safety measure. AF447 for example would have been saved by a nose down attitude to recover stall. The junior PF of AF447 continued nose up throughout a 40,000 ft flop. However, in that case it was faulty sensors too- frozen pitot tubes from memory, so the input data was bad anyway. Nose down however could have been useful for stall recovery in any case.

pattern_is_full

11th Mar 2019, 03:23

Just a general reminder - MCAS and "autopilot" are mutually exclusive. MCAS is only active during manual flight.

While I'm in general agreement with comments to the effect that the MAX8 MCAS is an engineering kludge, poorly thought-out, and as such dangerous (in combination with insufficient redundancy in AoA sensors) - there are other ways to put a 737 into the ground after take-off. So I'm looking for a few more dots to be connected before jumping one way or the other - in this event.

I'm also not convinced that all pilots - robot-like - fly every takeoff to such an exact profile that, for example, flaps come up exactly and only this precise amount at this precise altitude or speed and such, on every single take-off. I do respect physical impossibilities, however.

"Pilots do the darndest things..." - apologies to Art Linkletter. But don't take that as automatically meaning "pilot error."

reefrat

11th Mar 2019, 03:25

No smoke, no real residue, no other people on scene?

A Super Mystere flew in to the ground 75 metres from me in Normandy in 1960. I thought it was a gas bottle explosion and walked over to check .The crater looked exactly like this; no visible debris save a half a dozen hand size fragments of alloy, there was no fire, almost no smoke apart from a few gently smouldering clods of earth which soon went out. The crater to me, an old country boy, most strongly resembled a recently ploughed and harrowed paddock. The was absolutely no sign of an aircraft

Capt Kremin

11th Mar 2019, 03:40

China has grounded its fleet of 737 MAX aircraft and Boeing has cancelled all media and social events related to the rollout of the 777X next week.

Ganzic

11th Mar 2019, 04:01

China has grounded its fleet of 737 MAX aircraft and Boeing has cancelled all media and social events related to the rollout of the 777X next week.

There will be a chain reaction most likely. Surely EASA will do the same, if its not too busy with Brexit.. You wouldn't think that in modern day age the manufacturer like Boeing can make such a big error with a crucial system of a not so new aircraft. Imho they should have started from clean sheet, instead of modding 737.

Sailvi767

11th Mar 2019, 04:04

Simple question - WHO and WHY did anyone allow a SINGLE flight critical sensor to override all previous methods of recognizing and controlling the aircraft and NOT document it ??

Shades of HAL !

The pilot has complete control. In the event of a trim runaway you simple disconnect the trim via the provided switch, trim manually and continue the flight. The 737 provides far better indications of a trim issue than any current airliner via the trim wheels.

log0008

11th Mar 2019, 04:19

It was discussed early on about the ground elevation and it does appear that the crash location is on bit of a hill

https://i.imgur.com/zNC7TpV.jpg

A30_737_AEWC

11th Mar 2019, 04:29

It's absurd that flight telemetry and data is not transmitted in real time to satellites and sent back to the aircraft manufacturer.rather than being recorded on FDRs that are lost at sea or destroyed

It may appear 'absurd', but remember that the CVR/FDR provisions that exist in FAR 25 aircraft are there by regulation. Yes, technology has advanced since those regulations were first enacted, however, it would be an interesting exercise to review the regulations to see if the off-board real-time transmission of the FDR/CVR data would satisfy the current regulations, or a case could be made in respect of an equivalent safety finding. A great idea. Another fail-safe avionics subsystem for the major airframers to develop and certify means someone is going to have to pay for it. I wonder if the commercial airlines are going to push for this ? You'd think it would be a 'no brainer' ?

pilotguy1222

11th Mar 2019, 04:34

It is not to say that 737 Max pilots don’t know how to disconnect the trim. It is NOT a new procedure, and has been around since the NG.(maybe longer)
Time, to stop a trim issue, is not your friend when all the other issues are taking place at the same time. Even worse that the reason for MCAS is during higher AOA, when the engine nacelles on the Max are producing lift, which would be more prevalent during takeoff and arrival.(slower speeds, but still in a clean config)

Here are 2 links to some interesting reading, imo

1. https://leehamnews.com/2018/11/14/boeings-automatic-trim-for-the-737-max-was-not-disclosed-to-the-pilots/

2. https://leehamnews.com/2018/11/07/boeing-issues-737-operations-manual-bulletin-after-lion-air-accident/

MD80767 Driver

11th Mar 2019, 05:06

Dutch250

11th Mar 2019, 05:14

Plus you go for the stab-trim cutout switches, and you forget they are down for off, while all the other switches on the 737 are up for off. (Why is Boeing so stupid...?) So you shout to the f/o, above the noise of the shaker and the trimmer, 'did you turn the stab-tim switches off', to which he-she replies 'yes' - meaning he placed the switches upwards. But this turns the trim on, not off.

.

Are you kidding me? Are you flying a 737?
I think that all 737 pilots know this switch goes down instead of up to turn it off.
We are not a bunch of monkey’s. Pilots that dont know the direction a switch goes should not be allowed to fly.

Perhaps Boeing also should change the direction of the Engine Start levers. We might do it wrong.

jugofpropwash

11th Mar 2019, 05:23

jolihokistix

11th Mar 2019, 05:39

Who makes these sensors?

krismiler

11th Mar 2019, 05:53

After the Lion Air crash I posted that the B737 Max has undesirable flight characteristics and Boeing weren’t keen to advertise this to potential buyers or certification authorities. The MCAS is a quick and cheap patch job to avoid a complete redesign of the flight control system or a new stall avoidance system which may have required a new type certificate.

Boeing need to realise the limitations of the basic airframe and should have stopped with the 800 series. A complete new 21st century design is required which incorporates all modern safety features and allows for foreseeable improvements rather than bolting on ad hoc to a fuselage which has its roots in the 1950s.

LEOCh

11th Mar 2019, 05:55

The underlying issue here seems to me that regardless of whether the MCAS is a good system, it's not going to cause a problem unless there's a sensor failure. If this crash turns out to have the same cause as the first, then that means two bad sensors, on virtually new aircraft belonging to two different airlines. Wouldn't this be an abnormally high failure rate on a critical part?

One thing that was I wondering after the Lionair accident, was what are failure rates of the AoA vanes in general. Are they more or less reliable than the pitot-static systems they complement? This is fairly critical when a single vane in the MAX can provide the input to move the stab in MCAS.

My understanding is on the NG, a single vane failure indicating high alpha will generate indications only, i.e a stick shaker on one side and a probable IAS disagree due to an AoA input to IAS calculation. This is somewhat confusing with no AoA disagree annunciation (it certainly seemed to confuse Lionair maintenance who paid attention to to the working pitot-static system and not the failed AoA vane prior to the accident flight.

For any 737 pilots present, would an erroneous stick shaker activation due to faulty AoA data be something not incredible within a career?