Ethiopian Air ET302, Boeing 737 crashes - 157 souls - 10 March 2019

[JudgeJudi]

Details have begun to emerge of the final moments of the Ethiopian Airlines crash.

Reports suggest the anti-stall system on has been highlighted as the cause of the crash.

Two minutes into the flight - at just 450ft (137m) above the ground - the aircraft's nose began to pitch down, according to the Wall Street Journal.

The newspaper, which says it's spoken to people close to the ongoing crash investigation, says the captain fought to control the plane when it began to dive.

One pilot said to the other "Pitch up, pitch up!" before the radio went dead and as the plane "accelerated" towards the ground. It crashed six minutes into the flight.

The WSJ says the information it has "paints a picture of a catastrophic failure that quickly overwhelmed the flight crew".

Leaks from the Ethiopian crash investigation and in the US suggest the automatic anti-stall system was activated at the time of the disaster.

'Pitch up, pitch up!' - Ethiopian pilot

 

[human]

murderous as far as I am concerned

 

[PrairieWind]

Why was the plane only at 450 ft 2 minutes into the flight? That can’t be right.

 

[MsMarple]

Why was the plane only at 450 ft 2 minutes into the flight? That can’t be right.

What happened (or at least according to the current theory) was that right after takeoff the AOA (angle of attack) sensor, a small exterior probe that feeds data into the flight computer, malfunctioned, making the flight computer think the nose was too high. That in turn kicked on the MCAS which turned the nose down.

So the pilots were fighting to bring the nose up. But as soon as they did the MCAS pushed it down again. The plane was going up and down like a roller coaster; every foot of altitude it gained was canceled out when the nose turned down. The pilots increased the airspeed in an attempt to gain altitude but the excessive airspeed (380 knots/437mph) caused rapid altitude loss when the nose turned down.

Had it happened at 10,000 feet they would have had more time to recover but in this case it started right after takeoff. The plane never reached more than about 1,000 feet altitude.

Here's a link which explains it better than I can:
Ethiopian Airlines crash

 

[PrairieWind]

Thanks MsMarole. I just got a little confused the way that other article was written. They had never gained much altitude and were only 450 ft the last time MCAS pitches the nose down.

So why are AOA sensors so prone to error?

 

[drama_farmer]

Thanks MsMarole. I just got a little confused the way that other article was written. They had never gained much altitude and were only 450 ft the last time MCAS pitches the nose down.

So why are AOA sensors so prone to error?

I just found this at the bottom of the above link, posted by MsMarple:

CORRECTION: 165 seconds after takeoff, Ethiopian Airlines flight ET 302 reached an altitude of 975 feet above ground level. An earlier version of the ground altitude graphic incorrectly charted the altitude of flights ET302 and JT610.

 

[MsMarple]

I just found this at the bottom of the above link, posted by MsMarple:

Thanks, I didn't see that! But it's a minimal difference in any case; a plane traveling over 400 mph is going to lose altitude very quickly once the nose turns down. The pilots increased the airspeed in an attempt to gain altitude as quickly as possible but that also worked against them. That's nearly double the usual takeoff and landing speed of a 737. Things happened fast.

As for the AOA sensor I can't provide an explanation as to why it malfunctioned so I'll just say that the sensor is sensitive and can be adversely affected in multiple ways; water, ice, bird strikes, etc.

And that's part of what's at issue. The MCAS collects data from a single sensor. The planes have two sensors. An "AOA disagree" warning light and AOA indicator would have given the pilots a heads up that one of the sensors was malfunctioning. But those are optional (and expensive) add-ons.

Boeing will add the AOA disagree warning light to the flight display and it will be standard rather than optional. I believe they are also planning to retrofit planes sold without the warning light. Most U.S. airlines did purchase at least one of the options.

ETA: Here's a nice graphical presentation:
The Dangerous Flaws in Boeing’s Automated System

 

[human]

Thanks, I didn't see that! But it's a minimal difference in any case; a plane traveling over 400 mph is going to lose altitude very quickly once the nose turns down. The pilots increased the airspeed in an attempt to gain altitude as quickly as possible but that also worked against them. That's nearly double the usual takeoff and landing speed of a 737. Things happened fast.

As for the AOA sensor I can't provide an explanation as to why it malfunctioned so I'll just say that the sensor is sensitive and can be adversely affected in multiple ways; water, ice, bird strikes, etc.

And that's part of what's at issue. The MCAS collects data from a single sensor. The planes have two sensors. An "AOA disagree" warning light and AOA indicator would have given the pilots a heads up that one of the sensors was malfunctioning. But those are optional (and expensive) add-ons.

Boeing will add the AOA disagree warning light to the flight display and it will be standard rather than optional. I believe they are also planning to retrofit planes sold without the warning light. Most U.S. airlines did purchase at least one of the options.

ETA: Here's a nice graphical presentation:
The Dangerous Flaws in Boeing’s Automated System

An option? Seriously!

An option to me would be back seat video screens not a safety ddvice.

 

[JudgeJudi]

And that's part of what's at issue. The MCAS collects data from a single sensor. The planes have two sensors. An "AOA disagree" warning light and AOA indicator would have given the pilots a heads up that one of the sensors was malfunctioning. But those are optional (and expensive) add-ons.

As expensive as losing two planes, 346 lives, the grounding of all 737 Max planes, cancelled orders, empty seats on planes and lawsuits, are going to cost a huge amount of money plus ...

"A break in deliveries that long would have significant financial implications. Boeing’s cash flow will be drastically reduced as long as the planes are grounded. And it will have to offer compensation to airlines for the losses accrued from parking planes.

Ken Herbert, an industry financial analyst with Canaccord Genuity, estimated the immediate fix as a $500 million investment with another $1 billion in cash flow lost monthly.

“We then see the potential monthly risk of up to another $1 billion depending on how much of the airline operating revenues Boeing ultimately reimburses,” Herbert told investors".

Investigators find new clues pointing to potential cause of 737 MAX crashes as FAA details Boeing’s fix

They saved money by not training the pilots, not supplying manuals to all pilots, and then suggested that the pilot error or inexperience were to blame. Boeing isn't what I'd call a small company. Life is cheap when it comes to governments and huge corporations. The whole thing is a complete disgrace.

 

[Justice101]

Why was the plane only at 450 ft 2 minutes into the flight? That can’t be right.

Might be counting take off time from full throttle.

 

[Justice101]

As expensive as losing two planes, 346 lives, the grounding of all 737 Max planes, cancelled orders, empty seats on planes and lawsuits, are going to cost a huge amount of money plus ...

"A break in deliveries that long would have significant financial implications. Boeing’s cash flow will be drastically reduced as long as the planes are grounded. And it will have to offer compensation to airlines for the losses accrued from parking planes.

Ken Herbert, an industry financial analyst with Canaccord Genuity, estimated the immediate fix as a $500 million investment with another $1 billion in cash flow lost monthly.

“We then see the potential monthly risk of up to another $1 billion depending on how much of the airline operating revenues Boeing ultimately reimburses,” Herbert told investors".

Investigators find new clues pointing to potential cause of 737 MAX crashes as FAA details Boeing’s fix

They saved money by not training the pilots, not supplying manuals to all pilots, and then suggested that the pilot error or inexperience were to blame. Boeing isn't what I'd call a small company. Life is cheap when it comes to governments and huge corporations. The whole thing is a complete disgrace.

Boeing would be doing several things simultaneously from these horrible events. 1) Damage control to the public 2) Damage control to the company stock, 3) Find out what the hell went wrong and fix it!

 

[JudgeJudi]

Reports from Addis Ababa indicate that a preliminary report is expected today (1 April), three weeks after the incident which claimed 157 people. Embattled plane maker Boeing said it was reviewing the report.


737 Max 8 jets have been grounded globally with its shares plummeting on the stock market.

The plane had taken-off – and was only 450ft (137m) above the ground – when its nose began to pitch down. It crashed six minutes into the journey in the town of Bishoftu.

A lawsuit against Boeing was filed in U.S. federal court on Thursday in what appeared to be the first suit over the crash that killed 157 people. The complaint was filed by Musoni’s three minor children, who are Dutch citizens residing in Belgium. The crash of Boeing’s passenger jet in Ethiopia raised the chances that families of the victims, even non-U.S. residents, will be able to sue in U.S. courts, where payouts are much larger than in other countries, some legal experts have said.

The lawsuit says Boeing failed to warn the public, airlines and pilots of the airplane’s allegedly erroneous sensors, causing the aircraft to dive automatically and uncontrollably.

Boeing gathered hundreds of pilots and reporters to unveil the changes to the MCAS stall prevention system, which has been implicated in the crashes in Ethiopia and Indonesia, as part of a charm offensive to restore the company’s reputation.

Among the changes, the MCAS will no longer repeatedly make corrections when the pilot tries to regain control, and will automatically disconnect in the event of disagreements between the two “angle of attack” (AOA) sensors, the company said. [I thought there was only one sensor]

The initial investigation found that one of the AOA sensors failed but continued to transmit erroneous information to the MCAS.

Boeing also will install a warning feature — at no cost —- called a “disagree light” to indicate to the pilot when the left and right AOA sensors are out of sync.

The company also is revising pilot training, including for those already certified on the 737, to provide “enhanced understanding of the 737 MAX” flight system and crew procedures.

Ethiopian crash hub: Preliminary report expected today - Ministry | Africanews

 

[human]

A feature at no cost. Isn’t that special.

 

[JudgeJudi]

Boeing’s software update for its 737 Max jetliners has been delayed and won’t be ready for weeks. The FAA says more work is needed on the fix before it can be submitted for approval.

Boeing 737 Max software fix delayed for weeks

 

[gregjrichards]

The doomed Ethiopian Airlines Boeing 737 Max that crashed and killed 157 people last month reportedly had its angle-of-attack sensor damaged on takeoff from a foreign object or bird.

The damaged sensor went on to trigger inaccurate data and resulted in the pilots turning the anti-stall software - known as MCAS - off, but it re-engaged and pushed the jet downwards, sources told ABC News.

The pilots are said to have tried to manually bring the nose of the plane back up before restoring power but they were unable to regain control - ultimately resulting in the plane crashing to the ground.

Ethiopian Airlines Boeing 737 had sensor damaged by foreign object at takeoff | Daily Mail Online

These sensors shouldn’t be able to be damaged in my opinion.

The initial accident report will be released tomorrow.

 

[drama_farmer]

The doomed Ethiopian Airlines Boeing 737 Max that crashed and killed 157 people last month reportedly had its angle-of-attack sensor damaged on takeoff from a foreign object or bird.
<snip>
Ethiopian Airlines Boeing 737 had sensor damaged by foreign object at takeoff | Daily Mail Online

These sensors shouldn’t be able to be damaged in my opinion.

<snip>

BBM for emphais.
Or, redundant systems should be in place. I think that if this (apparently, IMO) MCAS-related crash had come before the Lion Air crash, it would have taken longer for the primary danger of what appears to be a poorly designed engine placement to be identified. I can imagine that the Ethiopian incident would be initially blamed on a pseudo-unforseeable incident of a bird or foreign-object strike, followed by something like "pilot confusion" leading to a death-battle with a plane in rollercoaster mode.

Who knows how many additional lives would have been at risk if the Lion Air crash had not introduced the MCAS issue as something for pilots to at least be aware, if not wary, of.
IMO

 

[MsMarple]

The doomed Ethiopian Airlines Boeing 737 Max that crashed and killed 157 people last month reportedly had its angle-of-attack sensor damaged on takeoff from a foreign object or bird.

The damaged sensor went on to trigger inaccurate data and resulted in the pilots turning the anti-stall software - known as MCAS - off, but it re-engaged and pushed the jet downwards, sources told ABC News.

The pilots are said to have tried to manually bring the nose of the plane back up before restoring power but they were unable to regain control - ultimately resulting in the plane crashing to the ground.

Ethiopian Airlines Boeing 737 had sensor damaged by foreign object at takeoff | Daily Mail Online

These sensors shouldn’t be able to be damaged in my opinion.

The initial accident report will be released tomorrow.

The sensor is sensitive - not much can be done about that since its job is to read the oncoming airflow. The AOA disagree light is there to inform the pilot that one sensor may have been damaged. So IMO the fault lies with Boeing for not installing it as a standard add-on and partially with the airlines for cutting costs. MOO.

However - and I'm not saying it happened in this case, I'm just noting other possibilities - the sensors can also be damaged by the ground crew when loading luggage or when pressure cleaning the plane.

https://aerospaceamerica.aiaa.org/departments/doing-no-harm/

Please note: I'm not saying this happened. I'm saying the sensors can be damaged by many different events. There's little that a design change can do to mitigate such risks so vigilance by the ground crew, the pilots during the walkaround and the maintenance crew is very important.

 

[JudgeJudi]

Pilot and aviation analyst Miles O'Brien gave his take on what could have happened in the cockpit once pilots reportedly turned off the automatic flight control system.

"They were left with a manual wheel to try to get the nose in the proper orientation and evidently what we are hearing is, that maybe the wheel didn’t have enough authority, that it was too hard to move, or could not move fast enough, given the amount of altitude they had in order to recover. So that put them in a situation where they followed the book, and the recovery procedure was not good enough.

The idea that they would have this troubleshooting system, they followed the book and it wasn’t good enough, is just horrifying," said pilot and CNN aviation analyst Miles O'Brien.

In the Lion Air crash, the MCAS forced the plane's nose down more than 24 times before it finally hit water, according to a preliminary investigation by Indonesia's National Transportation Safety Committee, which found the system was responding to a faulty sensor.

Live updates: The Ethiopian Airlines crash report set to be released - CNN

 

[JudgeJudi]

Will the report offer any conclusions?

Probably not. Preliminary reports often don’t come to conclusions, but rather offer early raw data as a way to help safety officials take initial steps.

It's the first official report from the disaster and is required by the investigating authority to be produced within 30 days of an incident.

The preliminary report into the Ethiopian Airlines crash has determined that “the crew followed all expected procedures without managing to take back control of the aircraft,” according to a Western diplomatic source briefed on the investigation.

The report is expected to say that the aircraft had normal certification and the crew was certified for flying this aircraft and had the necessary training.

The recommendations will include that the manufacturer should review the anti-stall system and that the certifying authority ensures that this issue has been dealt with before authorizing any further flights of this aircraft, the source added.

Live updates: The Ethiopian Airlines crash report set to be released - CNN

 

[JudgeJudi]

The preliminary report finds that the Ethiopian Airlines crew "performed all procedures repeatedly provided by the manufacturer but were unable to control the aircraft," according to Ethiopian safety investigators in the capital Addis Ababa.

Initial findings from Ethiopian investigators found that:

The aircraft possessed a valid certificate of air worthiness

1. The aircraft possessed a valid certificate of air worthiness
2. The crew obtained the necessary license and qualifications to conduct the flight
3. The take off role appeared very normal
4. The crew performed all the procedures repeatedly provided by the manufacturer but were not able to control the aircraft

Ethiopian Airlines put out a statement on Twitter following the press conference in Addis Ababa.

It said: The preliminary report "clearly showed" that pilots on Flight 302 followed the Boeing recommendations.

Airline CEO Tewolde GebreMariam said: "All of us at Ethiopian Airlines are still going through deep mourning for the loss of our loved ones."

Adding: "Meanwhile we are very proud of our pilots' compliances to follow the emergency procedures."

Live updates: The Ethiopian Airlines crash report set to be released - CNN