Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

[L39Guy]

Ethiopian investigators no doubt.

So how is it that the Lion Air incident crew was able to fly their MCAS airplane for an hour and a half using the manual trim wheel after the Stab Trim shut-off switches were used to turn off all electrical trim.

There can be no doubt that the control forces (manual trim wheel) forces increase as the airspeed increases. Similarly, control forces decrease as the IAS decreases too, like when one is flying around at 180 kts rather than 250+.

The skeptic in me thinks this is a case of having a predetermined conclusion then finding justification for that conclusion.

[mbav8r]

Ethiopian investigators no doubt.

So how is it that the Lion Air incident crew was able to fly their MCAS airplane for an hour and a half using the manual trim wheel after the Stab Trim shut-off switches were used to turn off all electrical trim.

There can be no doubt that the control forces (manual trim wheel) forces increase as the airspeed increases. Similarly, control forces decrease as the IAS decreases too, like when one is flying around at 180 kts rather than 250+.

The skeptic in me thinks this is a case of having a predetermined conclusion then finding justification for that conclusion.

For the crew that flew it manually, what was the maximum trim that was reached prior to disabling the MCAS?

[L39Guy]

The preliminary and final reports are both online and have that information.

[Gear Jerker]

What's everyone figuring for a timeline on max recertification at this point? Summer 2020?

[7ECA]

What's everyone figuring for a timeline on max recertification at this point? Summer 2020?

Seems unlikely, what with a pandemic ongoing.

[Heliian]

Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.

[iflyforpie]

Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.

The problem with capitalism is that you eventually run out of other people’s money.

[goldeneagle]

Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.

The claim to fame for the Max, it burns about 10% or so less fuel than earlier models.

I thought oil futures were looking awful last friday at 18 dollars. This morning at 11 dollars I figured they cant go any lower. 7.83 is the quote for WTI as I type this.

Today it's cheaper to haul a -200 out of storage and pour fuel into it than it is to pay interest on loans to buy a max.

We will see how long the oil collapse runs for, but, airlines wont need the capacity for a couple more years at a minimum, and if they do need some short term capacity in the interim, lots of gas guzzlers in the desert that will look pretty economical to run this summer.

[goldeneagle]

double post

[telex]

Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.

The claim to fame for the Max, it burns about 10% or so less fuel than earlier models.

I thought oil futures were looking awful last friday at 18 dollars. This morning at 11 dollars I figured they cant go any lower. 7.83 is the quote for WTI as I type this.

Today it's cheaper to haul a -200 out of storage and pour fuel into it than it is to pay interest on loans to buy a max.

We will see how long the oil collapse runs for, but, airlines wont need the capacity for a couple more years at a minimum, and if they do need some short term capacity in the interim, lots of gas guzzlers in the desert that will look pretty economical to run this summer.

Available airframes? Spare parts?
Qualified engineers?
Qualified pilots?
Available training facilities?

[goingnowherefast]

A lot of the first NGs are running out of cycles and aren't worth doing another D check on. Spend X money for Y cycles, the cost ends up being cheaper to get a max.

I'd imagine airlines will be parking the planes nearing a big inspection and flying the ones with lots of cycles left. Defer the maintenance until cash flow improves

[W5]

https://www.avweb.com/aviation-news/nts ... al-report/

http://www.avherald.com/h?article=4c534c4a/0095&opt=0

On Dec 28th 2022 the NTSB issued a press release and their comments submitted to the draft final report. In their press release the NTSB writes:

The NTSB took the unusual step of publishing the comments on its website after Ethiopia’s Aircraft Accident Investigation Bureau (EAIB) failed to include the NTSB’s comments in its final report on its investigation into the March 10, 2019, crash of Ethiopian Airlines flight 302, a Boeing 737-800 MAX.

...

The EAIB provided the NTSB with its first draft of the report last year. The NTSB reviewed the report and provided comments on several aspects of the accident the NTSB believed were insufficiently addressed in the draft report. The comments primarily were focused on areas related to human factors.

After the EAIB reviewed the comments, it provided the NTSB with a revised draft report for its review. The NTSB determined the revised report failed to sufficiently address its comments. As provided by the ICAO Annex 13 process, the NTSB provided the EAIB with more expansive and detailed comments.

Instead of incorporating the most recent and expanded comments into their report, or appending them as had been requested, the EAIB included a hyperlink in their final report to an earlier and now outdated version of the NTSB’s comments.

The NTSB also noted that the final report included significant changes from the last draft the EAIB provided the NTSB. As a result, the NTSB is in the process of carefully reviewing the EAIB final report to determine if there are any other comments that may be necessary.

In their 9 pages comments to the last draft final report the NTSB stated:

Overall, the US team concurs with the EAIB’s investigation of the MCAS and related systems and the roles that they played in the accident. However, many operational and human performance issues present in this accident were not fully developed as part of the EAIB investigation. These issues include flight crew performance, crew resource management (CRM), task management, and human-machine interface. It is important for the EAIB’s final report to provide a thorough discussion of these relevant issues so that all possible safety lessons can be learned.

With respect to the cause of the crash the NTSB commented:

We agree that the uncommanded nose-down inputs from the airplane’s MCAS system should be part of the probable cause for this accident. However, the draft probable cause indicates that the MCAS alone caused the airplane to be “unrecoverable,” and we believe that the probable cause also needs to acknowledge that appropriate crew management of the event, per the procedures that existed at the time, would have allowed the crew to recover the airplane even when faced with the uncommanded nose-down inputs.

We propose that the probable cause in the final report present the following causal factors to fully reflect the circumstances of this accident:

- uncommanded airplane-nose-down inputs from the MCAS due to erroneous AOA values and

- the flight crew’s inadequate use of manual electric trim and management of thrust to maintain airplane control.

In addition, we propose that the following contributing factors be included:

- the operator’s failure to ensure that its flight crews were prepared to properly respond to uncommanded stabilizer trim movement in the manner outlined in Boeing’s flight crew operating manual (FCOM) bulletin and the FAA’s emergency airworthiness directive (AD) (both issued 4 months before the accident) and

- the airplane’s impact with a foreign object, which damaged the AOA sensor and caused the erroneous AOA values.

The NTSB states with respect to airframe/system aspects:

The EAIB draft report states that the erroneous AOA data resulted from an AOA sensor failure yet omits key findings about the root cause of the AOA erroneous data: damage from impact with a foreign object/bird. Thus, the report misses the opportunity to address improvements for wildlife management at the flight’s departure location—Bole International Airport, Addis Ababa, Ethiopia.

- Cause of the AOA erroneous data: Collins Aerospace, the manufacturer of the airplane’s AOA sensor, was named as a technical advisor to the US team in April 2019 after the EAIB requested assistance investigating the most likely failure modes for the AOA sensor based on the accident data. Although the EAIB draft report acknowledges Collins’ factual report, the EAIB draft report does not acknowledge Collins’ fault tree analysis, which demonstrated that the recorded FDR data from the accident were not consistent with any internal failure of the AOA sensor; instead, those data were fully consistent with previous instances of partial AOA vane separation due to a bird strike.

...

- Bird activity at Addis Ababa airport: The EAIB draft report omits factual information, analysis, findings, contributing factors, and safety recommendations regarding bird hazards and the effectiveness of bird mitigations at Addis Ababa airport.

+ The EAIB draft report provides some details regarding a runway area search after the accident but inappropriately suggests that the lack of bird remains or AOA vane remnants indicates that the airplane was not impacted by a foreign object. The EAIB report fails to state that the search occurred 8 days after the accident and that the search did not include the area surrounding taxiway D, even though FDR data indicated that the airplane would have been positioned above the taxiway when the left AOA sensor data became erroneous.

+ On November 11, 2019, the EAIB published its final report regarding the November 26, 2018, engine failure event involving a Boeing 767-300, registration ET-AMG, caused by engine ingestion of a Steppe or Tawny eagle weighing 2.0 to 3.4 kilograms (4.4 to 7.5 pounds). The report stated that Steppe and Tawny eagles are common around Addis Ababa airport. The EAIB found that a bird strike hazard existed at the airport and made a recommendation in this area.

- The EAIB draft report includes multiple findings that question the functionality of the manual electric trim system but presents no facts to support these findings. In addition, the findings contradict the evidence from this investigation indicating that the system was functioning as intended.

+ Per the request of the EAIB, Boeing conducted a thorough assessment of potential trim system failures and provided the results to the EAIB in October 2019.

+ This assessment found that no trim system failure scenarios were consistent with the FDR data and that the behavior of the electric manual trim parameter recorded on the FDR was consistent with flight crew input.

- The EAIB draft report incorrectly states that design changes to the 737-8 MAX were not official and were not approved by the FAA.

+ Boeing’s changes to the MCAS design were official in March 2016 and were communicated to the FAA in July 2016, as described in the NTSB System Safety and Certification Specialist’s Report, section H, Certification of the MCAS Implementation and Function.

+ Boeing applied for and, in March 2017, was granted an amended type certificate for the 737-8 MAX. For further information, see the NTSB System Safety and Certification Specialist’s Report.

- The EAIB draft report incorrectly states that Boeing did not respond or failed to respond appropriately to Ethiopian Airlines’ request for more information about the MCAS after the Lion Air accident.

+ Boeing provided information to all 737 MAX operators in November 2018 (after the Lion Air accident but before the Ethiopian Airlines accident) to address uncommanded MCAS inputs. This information included operations manual bulletin (OMB)/FCOM bulletin ETH-12, FAA emergency AD 2018-23-51, a multi-operator message, dedicated meetings, and email messages.

+ Boeing’s response to Ethiopian Airlines’ request for more information about the MCAS, dated December 3, 2018, provided specific guidance about the OMB and checklist prioritization. In particular, the response indicated, “As is stated in the OMB, ‘If uncommanded stabilizer trim movement is experienced in conjunction with the erroneous AOA flight deck effects, the instructed course of action is to use the Stabilizer Cutout switches per the existing [runaway stabilizer] procedure.’”

With respect to human factors the NTSB commented:

- The EAIB draft report inappropriately states that the IAS (indicated airspeed) DISAGREE and ALT (altitude) DISAGREE messages were not displayed to the crew during the accident flight, and the EAIB used this incorrect assumption as a basis for its assessment of the crew’s performance.

+ Although the FDR was not programmed to record the presence or absence of the IAS DISAGREE and ALT DISAGREE messages, all conditions were met for the alerts to be presented to the crew. The systems logic (presented to the EAIB in September 2019) and flight simulations (conducted in December 2019) demonstrated the expected timing for the presentation of these alerts on the crew’s primary flight displays.

+ The EAIB report improperly states that, because the AOA DISAGREE message did not appear, the IAS DISAGREE and ALT DISAGREE messages also did not appear. As explained in detail in the report, a software discrepancy caused the AOA DISAGREE message not to appear, but the software discrepancy was unrelated to, and had no effect on, the display of the IAS DISAGREE and ALT DISAGREE messages.

+ Given that the conditions were met for the IAS DISAGREE and ALT DISAGREE messages to be annunciated to the crewmembers, their lack of conversation or action in response to the annunciations should be explored in the context of the flight deck environment, workload, crew experience, and training. The report’s assumption that those messages did not appear, which is contrary to Boeing’s description of the alerting system and the results of simulator testing during the investigation, severely limits the opportunity for recognizing and addressing potential crew training and experience improvements.

- The EAIB draft report states that no flight crew reference document explained that autothrottle thrust commands could be affected by erroneous AOA inputs.

+ Even if such a reference document did not exist, the flight crew should have been trained on 737-8 MAX non-normal procedures. Because crew response to in-flight anomalies is time critical, these in-flight reference documents are not intended to provide flight crews with an in-depth understanding of a system before responding to an anomaly. Rather, non-normal procedures are designed to provide flight crews with information to diagnose and respond to a system-related issue in a timely manner based on observable flight deck effects.

+ Non-normal procedures related to erroneous AOA inputs instruct the crew to disengage both the autopilot and autothrottle, thereby preventing the erroneous AOA inputs from affecting flight control and throttle movements. The observable flight deck effects associated with erroneous AOA inputs include the activation of the stickshaker and the annunciation of the IAS DISAGREE and ALT DISAGREE messages.

- The EAIB draft report incorrectly states (in several locations) that the MCAS made control of the airplane “impossible” but neglects to state that, if the crew had manually reduced thrust and appropriately used the manual electric trim, the airplane would have remained controllable despite uncommanded MCAS input.

+ The flight crew’s failure to reduce thrust manually and the excessive airspeed that resulted played a significant role in the accident sequence of events.

+ Upon either the activation of the stickshaker or the annunciation of the IAS DISAGREE message, the expected crew response is to turn off the autothrottle. The report could be strengthened if it discussed, from a human performance perspective, possible reasons why the flight crew did not respond as expected to the stickshaker and the IAS DISAGREE message.

+ Because the autothrottle remained engaged and responsive to the erroneous AOA inputs, the autothrottle did not transition to N1 mode and remained in the ARM mode with takeoff thrust. The expected crew response is to manually control thrust in this situation; however, the lack of manual control and the absence of flight crew conversation regarding the thrust settings indicate that the crew did not notice the autothrottle’s failure to transition to N1, even when the aural overspeed warning triggered as the airplane accelerated beyond about 340 knots. As airspeed increased, the required control forces increased on both the control column and the manual trim wheel.

+ Appropriately countering uncommanded nose-down inputs with manual electric trim nose-up inputs, as was expected per crew procedure described in the FCOM bulletin and the emergency AD, would have resulted in control column forces remaining in a controllable regime during the flight, including when the stabilizer trim cutout switches were in the CUTOUT position. (See section 2.4 below for further information about the crew moving the switches to the CUTOUT position.) The report could be strengthened if it evaluated, from a human performance perspective, the crew’s failure to apply manual electric trim nose-up inputs.

+ The draft report does not examine the flight crew’s understanding of the effect of airspeed on the control forces required to move the control column and trim wheel.

+ The draft report states that the FCOM did not include details on the higher trim forces required with airspeed. However, the FCOM states that “the effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions.” Further, even though the FCOM did not include the effect of airspeed on the manual trim wheel forces, that information is specifically noted in the manufacturer’s flight crew training manual. For example, that manual states, “if manual stabilizer trim is necessary, ensure both stabilizer trim cutout switches are in CUTOUT prior to extending the manual trim wheel handles. Excessive air loads on the stabilizer may require effort by both pilots to correct the mistrim. In extreme cases it may be necessary to aerodynamically relieve the air loads to allow manual trimming. Accelerate or decelerate towards the in-trim speed while attempting to trim manually.”

+ Although the draft report mentioned the dates of the crew’s training on the “use of trim wheel,” the report does not address whether the training included airspeed effects on the trim wheel or the forces required to trim as airspeed increases.

+ The report misses an opportunity to evaluate the effectiveness of air carrier training related to the relationship between airspeed and manual trim control forces and make safety recommendations, as appropriate, to improve industry training.

+ The EAIB draft report incorrectly states (in several places) that the “Summary of FAA’s Review of Boeing 737MAX” document indicates that the MCAS denies pilot control and trim authority. However, this document states the opposite: “if MCAS is erroneously activated, the MCAS system preserves the flightcrew’s ability, using basic piloting techniques, to control the airplane after the activation.”

- The EAIB report inaccurately states that the crew performed actions “per the procedure.” Evidence shows that the crew did not appropriately perform non-normal procedures after receiving annunciations relating to unreliable airspeed, stall warning, and runaway stabilizer. The crew also did not respond as expected to the overspeed warning by disconnecting the autothrottle and reducing power.

+ Emergency AD 2018-23-51 and FCOM Bulletin ETH-12 instruct flight crews to conduct the runaway stabilizer checklist, which requires them to “control airplane pitch manually with control column and main electric trim,”

+ If the crew had conducted the procedure in the emergency AD and the FCOM bulletin, the crew would have used manual electric trim to reduce control forces. However, FDR data show minimal crew use of manual electric trim.

+ If the crewmembers had performed the memory items for the airspeed unreliable and/or runaway stabilizer checklists, they would have disengaged the autothrottle. A manual reduction of thrust would have further assisted in reducing control forces. However, FDR data show that the autothrottle remained engaged and that thrust remained at full power.

+ All these actions were expected per procedure and were to be conducted before moving the stabilizer trim cutout switches to the CUTOUT position.

+ Even after moving the stabilizer trim cutout switches to the CUTOUT position, the crew decided to return the switches to the NORMAL position, contrary to the FCOM bulletin and the emergency AD, which direct crews to ensure that the switches “stay in the CUTOUT position for the remainder of the flight.” The available evidence for this accident did not indicate why the crew performed this action. By not evaluating the human factors associated with this crew action, the report provides a limited understanding of the circumstances leading to the airplane’s nose-down pitch before impact.

- The EAIB draft report includes details and analysis of the OMB/FCOM bulletin and emergency AD information provided after the Lion Air accident but does not include details about the effectiveness of the operator’s dissemination of the bulletin or flight crew understanding of that information.

+ The bulletin and emergency AD provided information to ensure that flight crews were aware of the possibility for repeated nose-down trim commands after an erroneously high single AOA sensor input and had specific guidance for recognizing the event and responding appropriately.

+ Performance of the correct action depends on flight crews having access to, understanding, and applying the information presented in those documents.

+ The report states that the bulletin and emergency AD were disseminated to Ethiopian Airlines flight crews via the logipad system, but the report does not discuss the effectiveness of this dissemination method or opportunities to improve crew access to, and understanding of, the disseminated information, which could benefit other operators that use a similar system to provide flight crews with critical information.

- The EAIB draft report describes how CRM could have been affected by the flight deck environment but does not fully evaluate the CRM that occurred during the accident flight.

+ International Civil Aviation Organization investigative guidance states that a human performance investigation “should be as methodical and complete as any other traditional area of the investigation.”

+ The CRM aspects not discussed in the report include, but are not limited to, the following:

# Division of duties
# Operator CRM training
# Expected/as-trained CRM performance
# Flight deck communication
# First officer’s limited flight experience
# Potential authority gradient

[DanWEC]

Of course the Americans are going to say this. No issue that a brand new plane suddenly has 2 catastrophic crashes 6 months apart with the same failure mode.
Must be the crew.

It wasn't until the fatalities that a spotlight was put on the airplane and revealed dozens of previous uncommanded pitch events. Perhaps better trained crews delayed the inevitable fatalities elsewhere in the world, but it was just a matter of time. A ticking bomb.

[pelmet]

Of course the Americans are going to say this. No issue that a brand new plane suddenly has 2 catastrophic crashes 6 months apart with the same failure mode.
Must be the crew.

It wasn't until the fatalities that a spotlight was put on the airplane and revealed dozens of previous uncommanded pitch events. Perhaps better trained crews delayed the inevitable fatalities elsewhere in the world, but it was just a matter of time. A ticking bomb.

It is important to look at all aspects of an accident. Crew performance is nothing new. I seem to remember that the Indonesian Max that crash had a copilot flying the jet that for some strange reason, was not even using the trim button to counteract the nose-down trim inputs.

[DanWEC]

Of course the Americans are going to say this. No issue that a brand new plane suddenly has 2 catastrophic crashes 6 months apart with the same failure mode.
Must be the crew.

It wasn't until the fatalities that a spotlight was put on the airplane and revealed dozens of previous uncommanded pitch events. Perhaps better trained crews delayed the inevitable fatalities elsewhere in the world, but it was just a matter of time. A ticking bomb.

It is important to look at all aspects of an accident. Crew performance is nothing new. I seem to remember that the Indonesian Max that crash had a copilot flying the jet that for some strange reason, was not even using the trim button to counteract the nose-down trim inputs.

I'll reiterate....

Perhaps better trained crews delayed the inevitable fatalities elsewhere in the world, but it was just a matter of time. A ticking bomb.

It's about as big as a swiss cheese hole can get.

[pelmet]

Of course the Americans are going to say this. No issue that a brand new plane suddenly has 2 catastrophic crashes 6 months apart with the same failure mode.
Must be the crew.

It wasn't until the fatalities that a spotlight was put on the airplane and revealed dozens of previous uncommanded pitch events. Perhaps better trained crews delayed the inevitable fatalities elsewhere in the world, but it was just a matter of time. A ticking bomb.

It is important to look at all aspects of an accident. Crew performance is nothing new. I seem to remember that the Indonesian Max that crash had a copilot flying the jet that for some strange reason, was not even using the trim button to counteract the nose-down trim inputs.

I'll reiterate....

Perhaps better trained crews delayed the inevitable fatalities elsewhere in the world, but it was just a matter of time. A ticking bomb.

It's about as big as a swiss cheese hole can get.

The problem with your statement in response to the NTSB is that you make it sound as if they are trying to ignore the design faults.....

Of course the Americans are going to say this. No issue that a brand new plane suddenly has 2 catastrophic crashes 6 months apart with the same failure mode.
Must be the crew.

The NTSB has made it very clear that MCAS was part of the accident. But they also believe that flight crew issues are part of the problem.

To not mention this would be similar to not mentioning in an accident report that the pilot put in the wrong rudder input for an engine that failed due to a faulty design and ignoring the pilot aspect.

“We agree that the uncommanded nose-down inputs from the airplane’s MCAS system should be part of the probable cause for this accident. However, the [EAIB’s] draft probable cause indicates that the MCAS alone caused the airplane to be ‘unrecoverable,’ and we believe that the probable cause also needs to acknowledge that appropriate crew management of the event, per the procedures that existed at the time, would have allowed the crew to recover the airplane even when faced with the uncommanded nose-down inputs. We propose that the probable cause in the final report present the following causal factors to fully reflect the circumstances of this accident:

• uncommanded airplane-nose-down inputs from the MCAS due to erroneous AOA values and

• the flight crew’s inadequate use of manual electric trim and management of thrust to maintain airplane control. In addition, we propose that the following contributing factors be included:

• the operator’s failure to ensure that its flight crews were prepared to properly respond to uncommanded stabilizer trim movement in the manner outlined in Boeing’s flight crew operating manual (FCOM) bulletin and the FAA’s emergency airworthiness directive (AD) (both issued 4 months before the accident) and

• the airplane’s impact with a foreign object, which damaged the AOA sensor and caused the erroneous AOA values.”

[FICU]

The procedures required to deal with a stab trim runaway are essentialy the same to deal with an MCAS runaway.

The Lion Air crew that saved the aircraft from the first MCAS runaway most likely performed those actions while the second crew that lost the aircraft did not and nor did the Ethiopian crew.

[pelmet]

The procedures required to deal with a stab trim runaway are essentialy the same to deal with an MCAS runaway.

The Lion Air crew that saved the aircraft from the first MCAS runaway most likely performed those actions while the second crew that lost the aircraft did not and nor did the Ethiopian crew.

I haven't read the report but I think the Ethiopian crew did perform the action to turn off the stab switches and the stop automatic, intermittent nose-down trimming but found that a large pull force was required to not descend. Their attempt to manually trim nose-up was unsuccessful so they selected the trim switches back on in order to be able to electrically trim nose up but that allowed the trim to automatically go further nose-down creating nose down forces beyond their control.

[FICU]

I haven't read the report but I think the Ethiopian crew did perform the action to turn off the stab switches and the stop automatic, intermittent nose-down trimming but found that a large pull force was required to not descend. Their attempt to manually trim nose-up was unsuccessful so they selected the trim switches back on in order to be able to electrically trim nose up but that allowed the trim to automatically go further nose-down creating nose down forces beyond their control.

The manual nose up electric trim will over ride the MCAS nose down trim from what I understand, just as it does in a normal stab trim runaway. The procedure is to use manual electric trim to trim back to a stabilized condition then shut off the trim switches and manually trim with the handle on the trim wheel from then on. The big mistake the Ethiopian crew did was to not control the thrust by shutting off the auto-throttles and bringing the thrust back to help control the speed. MCAS and how it was handled was a factor but the thrust mismanagement was huge.

Ultimately, the first MCAS runaway on the Lion Air jet was handled and managed and the aircraft landed safely so it was possible to save the aircraft. Unfortunately the second Lion Air crew and the Ethiopian crew were not able to do it.

[pelmet]

I haven't read the report but I think the Ethiopian crew did perform the action to turn off the stab switches and the stop automatic, intermittent nose-down trimming but found that a large pull force was required to not descend. Their attempt to manually trim nose-up was unsuccessful so they selected the trim switches back on in order to be able to electrically trim nose up but that allowed the trim to automatically go further nose-down creating nose down forces beyond their control.

The manual nose up electric trim will over ride the MCAS nose down trim from what I understand, just as it does in a normal stab trim runaway. The procedure is to use manual electric trim to trim back to a stabilized condition then shut off the trim switches and manually trim with the handle on the trim wheel from then on. The big mistake the Ethiopian crew did was to not control the thrust by shutting off the auto-throttles and bringing the thrust back to help control the speed. MCAS and how it was handled was a factor but the thrust mismanagement was huge.

Ultimately, the first MCAS runaway on the Lion Air jet was handled and managed and the aircraft landed safely so it was possible to save the aircraft. Unfortunately the second Lion Air crew and the Ethiopian crew were not able to do it.

I don’t think there is such a thing as manual electric trim.

If I remember correctly, the excess speed led to higher forces on the stab preventing manual trim, which is already a difficult thing to operate. That is why the switches were selected back on. But one would think that electric nose up trim could have been used at that point but I’m not sure what the result is when the MCAS input is trimming the opposite way.