China Eastern 737 Crash
03-31-2022, 04:29 AM
#121
Gets Weekends Off
Joined APC: Jul 2013
Posts: 10,067
Originally Posted by JohnBurke
Wrong again.
The Chinese had nothing to do with the Ethiopian mishap, and the CVR and flight data recorders were removed and sent to France, for analysis. The mishap occured on March 10. BEA didn't get the CVR and FDR in France until the 14th. On the 17th, the Ethiopian aviation authority (a term to be used loosely) jumped the gun and made an announcement that the FDR showed similarity to the Lion Air mishap. In the interim, on the 13th of March, the FAA announced ,based not on CVR or FDR data, but initial observation of wreckage, that the stabilizer jackscrew appeared to be fulll down. The Ethiopians released a preliminary report on April 4, over three weeks later, and didn't mention MCAS, and did note that the captain didn't touch the throttles, correctly identified and verbalized the correct procedure, executed it...and later reports verified that the captain undid this action and ultimately caused the loss of control.
You HAVE read the reports and not just wikipedia, haven't you?
The Ethiopians announced, one year after the mishap that the final report was coming. A day prior they released an interim report.
When you stated that "they have had both black boxes for a while now," knowing that it had been two days at the time of your statement, what did you mean, exactly? Two days is "a while," suggesting that the data should be available within two days? When you stated that it was available with the Ethiopian crash, knowing this wasn't true either, what did you mean there? You know these things aren't true: why are you saying them?
You've linked the preliminary report, not the interim (https://web.archive.org/web/20200310...209%202020.pdf), published a year later, and are clearly not very familiar with it. Two points for your ability to use google.
As for the Ethiopian crash, read the damn report. Educate yourself. You have no idea what you're talking about, and so far as "every major aviation authority in the world" disagreeing, again, do your research. You'll find that the opposite was true, and that most were reluctant to ground the aircraft. The initial grounding wasn't by the Indonesians or the Ethiopians; it was the Chinese and it was very much a political move in the face of a political trade war with the US. The last agency to respond? The FAA. Go figure. The events were largely political, and even Sullenberger noted the pilot inexperience and actions, particularly a 200 hour copilot (the 25 year old copilot had 360 hours, with 200 in type...all of it in the prior 90 days. His entire flight experience outside of primary training, less than 3 months total).
Go read the report and familiarize yourself with the events, before you spout off again. You're embarrassing yourself. If you read the Lion Air report, you'll find that the flight crew wound up with a flight control force of 103 lbs; that force isn't just dependent on flght control positioning, but on airspeed; in both cases, the flight crews flew the airplane right out of the envelope by accelerating and ultimately causing the loss of control. If airspeed had been kept at the time the crew became aware, both aircraft were fully controllable. When faced with a potential flight control problem, airmanship 101: don't change anything, including airspeed. The stab trim procedure, regardless of the cause, is the same in every 737, and has been since inception; also the same in every other Boeing. Stab trim cutout switches to cutout. The cause of any unscheduled trim, at that point, is irrelevant. Again, airmanship 101, basic procedures, and in the case of the Ethiopian flight, read the report and you'll learn that the captain verbally identified the problem, stated it, reiterated the memo, applied the correct procedure so far as stab trim cut out (after trying repeatedly to solve his problem by resorting to autopilot). Even the prelim report notes that stab trim stopped moving, coincident with application of the stab trim cutout switches. The captain didn't touch the power again, let the airplane keep accelerating, then changed the stab trim cutout switches, violating the procedure and even his own verbally stated identification of the problem. The captain caused that crash. Read the report.
The Chinese had nothing to do with the Ethiopian mishap, and the CVR and flight data recorders were removed and sent to France, for analysis. The mishap occured on March 10. BEA didn't get the CVR and FDR in France until the 14th. On the 17th, the Ethiopian aviation authority (a term to be used loosely) jumped the gun and made an announcement that the FDR showed similarity to the Lion Air mishap. In the interim, on the 13th of March, the FAA announced ,based not on CVR or FDR data, but initial observation of wreckage, that the stabilizer jackscrew appeared to be fulll down. The Ethiopians released a preliminary report on April 4, over three weeks later, and didn't mention MCAS, and did note that the captain didn't touch the throttles, correctly identified and verbalized the correct procedure, executed it...and later reports verified that the captain undid this action and ultimately caused the loss of control.
You HAVE read the reports and not just wikipedia, haven't you?
The Ethiopians announced, one year after the mishap that the final report was coming. A day prior they released an interim report.
When you stated that "they have had both black boxes for a while now," knowing that it had been two days at the time of your statement, what did you mean, exactly? Two days is "a while," suggesting that the data should be available within two days? When you stated that it was available with the Ethiopian crash, knowing this wasn't true either, what did you mean there? You know these things aren't true: why are you saying them?
You've linked the preliminary report, not the interim (https://web.archive.org/web/20200310...209%202020.pdf), published a year later, and are clearly not very familiar with it. Two points for your ability to use google.
As for the Ethiopian crash, read the damn report. Educate yourself. You have no idea what you're talking about, and so far as "every major aviation authority in the world" disagreeing, again, do your research. You'll find that the opposite was true, and that most were reluctant to ground the aircraft. The initial grounding wasn't by the Indonesians or the Ethiopians; it was the Chinese and it was very much a political move in the face of a political trade war with the US. The last agency to respond? The FAA. Go figure. The events were largely political, and even Sullenberger noted the pilot inexperience and actions, particularly a 200 hour copilot (the 25 year old copilot had 360 hours, with 200 in type...all of it in the prior 90 days. His entire flight experience outside of primary training, less than 3 months total).
Go read the report and familiarize yourself with the events, before you spout off again. You're embarrassing yourself. If you read the Lion Air report, you'll find that the flight crew wound up with a flight control force of 103 lbs; that force isn't just dependent on flght control positioning, but on airspeed; in both cases, the flight crews flew the airplane right out of the envelope by accelerating and ultimately causing the loss of control. If airspeed had been kept at the time the crew became aware, both aircraft were fully controllable. When faced with a potential flight control problem, airmanship 101: don't change anything, including airspeed. The stab trim procedure, regardless of the cause, is the same in every 737, and has been since inception; also the same in every other Boeing. Stab trim cutout switches to cutout. The cause of any unscheduled trim, at that point, is irrelevant. Again, airmanship 101, basic procedures, and in the case of the Ethiopian flight, read the report and you'll learn that the captain verbally identified the problem, stated it, reiterated the memo, applied the correct procedure so far as stab trim cut out (after trying repeatedly to solve his problem by resorting to autopilot). Even the prelim report notes that stab trim stopped moving, coincident with application of the stab trim cutout switches. The captain didn't touch the power again, let the airplane keep accelerating, then changed the stab trim cutout switches, violating the procedure and even his own verbally stated identification of the problem. The captain caused that crash. Read the report.
I'm assuming you've not seen what this situation looks like I'm the sim. I have. It's not fun. And unlike these crews, we were briefed on ways fix the trim once it had runaway. In the second accident, do you know why he turned the electric trim back on?
03-31-2022, 05:23 AM
#122
Gets Weekends Off
Joined APC: Jul 2008
Posts: 854
Originally Posted by Nantonaku
This report doesn't say a single thing about the CA trying to re-engage the A/P when they were battling the airplane, just after takeoff before their airplane was trying to kill them.
For me, the key in these accidents, and the incident flight, is that the primary trim continued to work normally throughout. Clicking the yoke trim switches stops the MCAS activation and allows you to remove all of the trim inputs that MCAS applies. The Lion Air accident Captain kept the airplane in-trim through 21 MCAS activations by doing this. It can be seen clearly on the DFR plot. The airplane didn't become seriously out-of-trim until the Captain transferred control to the First Officer who, after five additional MCAS activations, allowed the trim to reach the full nose-down position.
Of course, none of this has anything to do with the accident in China.
04-01-2022, 04:54 PM
#123
Gets Weekends Off
Joined APC: Dec 2013
Posts: 2,236
Originally Posted by JohnBurke
Wrong again.
The Chinese had nothing to do with the Ethiopian mishap, and the CVR and flight data recorders were removed and sent to France, for analysis. The mishap occured on March 10. BEA didn't get the CVR and FDR in France until the 14th. On the 17th, the Ethiopian aviation authority (a term to be used loosely) jumped the gun and made an announcement that the FDR showed similarity to the Lion Air mishap. In the interim, on the 13th of March, the FAA announced ,based not on CVR or FDR data, but initial observation of wreckage, that the stabilizer jackscrew appeared to be fulll down. The Ethiopians released a preliminary report on April 4, over three weeks later, and didn't mention MCAS, and did note that the captain didn't touch the throttles, correctly identified and verbalized the correct procedure, executed it...and later reports verified that the captain undid this action and ultimately caused the loss of control.
You HAVE read the reports and not just wikipedia, haven't you?
The Ethiopians announced, one year after the mishap that the final report was coming. A day prior they released an interim report.
When you stated that "they have had both black boxes for a while now," knowing that it had been two days at the time of your statement, what did you mean, exactly? Two days is "a while," suggesting that the data should be available within two days? When you stated that it was available with the Ethiopian crash, knowing this wasn't true either, what did you mean there? You know these things aren't true: why are you saying them?
You've linked the preliminary report, not the interim (https://web.archive.org/web/20200310...209%202020.pdf), published a year later, and are clearly not very familiar with it. Two points for your ability to use google.
As for the Ethiopian crash, read the damn report. Educate yourself. You have no idea what you're talking about, and so far as "every major aviation authority in the world" disagreeing, again, do your research. You'll find that the opposite was true, and that most were reluctant to ground the aircraft. The initial grounding wasn't by the Indonesians or the Ethiopians; it was the Chinese and it was very much a political move in the face of a political trade war with the US. The last agency to respond? The FAA. Go figure. The events were largely political, and even Sullenberger noted the pilot inexperience and actions, particularly a 200 hour copilot (the 25 year old copilot had 360 hours, with 200 in type...all of it in the prior 90 days. His entire flight experience outside of primary training, less than 3 months total).
Go read the report and familiarize yourself with the events, before you spout off again. You're embarrassing yourself. If you read the Lion Air report, you'll find that the flight crew wound up with a flight control force of 103 lbs; that force isn't just dependent on flght control positioning, but on airspeed; in both cases, the flight crews flew the airplane right out of the envelope by accelerating and ultimately causing the loss of control. If airspeed had been kept at the time the crew became aware, both aircraft were fully controllable. When faced with a potential flight control problem, airmanship 101: don't change anything, including airspeed. The stab trim procedure, regardless of the cause, is the same in every 737, and has been since inception; also the same in every other Boeing. Stab trim cutout switches to cutout. The cause of any unscheduled trim, at that point, is irrelevant. Again, airmanship 101, basic procedures, and in the case of the Ethiopian flight, read the report and you'll learn that the captain verbally identified the problem, stated it, reiterated the memo, applied the correct procedure so far as stab trim cut out (after trying repeatedly to solve his problem by resorting to autopilot). Even the prelim report notes that stab trim stopped moving, coincident with application of the stab trim cutout switches. The captain didn't touch the power again, let the airplane keep accelerating, then changed the stab trim cutout switches, violating the procedure and even his own verbally stated identification of the problem. The captain caused that crash. Read the report.
The Chinese had nothing to do with the Ethiopian mishap, and the CVR and flight data recorders were removed and sent to France, for analysis. The mishap occured on March 10. BEA didn't get the CVR and FDR in France until the 14th. On the 17th, the Ethiopian aviation authority (a term to be used loosely) jumped the gun and made an announcement that the FDR showed similarity to the Lion Air mishap. In the interim, on the 13th of March, the FAA announced ,based not on CVR or FDR data, but initial observation of wreckage, that the stabilizer jackscrew appeared to be fulll down. The Ethiopians released a preliminary report on April 4, over three weeks later, and didn't mention MCAS, and did note that the captain didn't touch the throttles, correctly identified and verbalized the correct procedure, executed it...and later reports verified that the captain undid this action and ultimately caused the loss of control.
You HAVE read the reports and not just wikipedia, haven't you?
The Ethiopians announced, one year after the mishap that the final report was coming. A day prior they released an interim report.
When you stated that "they have had both black boxes for a while now," knowing that it had been two days at the time of your statement, what did you mean, exactly? Two days is "a while," suggesting that the data should be available within two days? When you stated that it was available with the Ethiopian crash, knowing this wasn't true either, what did you mean there? You know these things aren't true: why are you saying them?
You've linked the preliminary report, not the interim (https://web.archive.org/web/20200310...209%202020.pdf), published a year later, and are clearly not very familiar with it. Two points for your ability to use google.
As for the Ethiopian crash, read the damn report. Educate yourself. You have no idea what you're talking about, and so far as "every major aviation authority in the world" disagreeing, again, do your research. You'll find that the opposite was true, and that most were reluctant to ground the aircraft. The initial grounding wasn't by the Indonesians or the Ethiopians; it was the Chinese and it was very much a political move in the face of a political trade war with the US. The last agency to respond? The FAA. Go figure. The events were largely political, and even Sullenberger noted the pilot inexperience and actions, particularly a 200 hour copilot (the 25 year old copilot had 360 hours, with 200 in type...all of it in the prior 90 days. His entire flight experience outside of primary training, less than 3 months total).
Go read the report and familiarize yourself with the events, before you spout off again. You're embarrassing yourself. If you read the Lion Air report, you'll find that the flight crew wound up with a flight control force of 103 lbs; that force isn't just dependent on flght control positioning, but on airspeed; in both cases, the flight crews flew the airplane right out of the envelope by accelerating and ultimately causing the loss of control. If airspeed had been kept at the time the crew became aware, both aircraft were fully controllable. When faced with a potential flight control problem, airmanship 101: don't change anything, including airspeed. The stab trim procedure, regardless of the cause, is the same in every 737, and has been since inception; also the same in every other Boeing. Stab trim cutout switches to cutout. The cause of any unscheduled trim, at that point, is irrelevant. Again, airmanship 101, basic procedures, and in the case of the Ethiopian flight, read the report and you'll learn that the captain verbally identified the problem, stated it, reiterated the memo, applied the correct procedure so far as stab trim cut out (after trying repeatedly to solve his problem by resorting to autopilot). Even the prelim report notes that stab trim stopped moving, coincident with application of the stab trim cutout switches. The captain didn't touch the power again, let the airplane keep accelerating, then changed the stab trim cutout switches, violating the procedure and even his own verbally stated identification of the problem. The captain caused that crash. Read the report.
- The AOA Disagree message did not appear on the accident aircraft as per the design described on the flight crew operation manual
- AOA failure detection feature of the ADIRU did not detect the erroneous AOA from the left AOA sensor because it only considers the value to be erroneous when the AOA value is outside the physical range. Thus; SPD and ALT flag never appeared on the PFD
- MCAS design on single AOA inputs made it vulnerable to undesired activation.
04-01-2022, 04:59 PM
#124
Gets Weekends Off
Joined APC: Dec 2013
Posts: 2,236
Originally Posted by Larry in TN
It's on the FDR data on the Ethiopian accident. Just just after the AoA vane was damaged and separated, about 400' above the runway, the Captain started attempting to engage the autopilot (CMD A) that was using the invalid (left) data. He repeated tried to engage CMD A throughout the flight. Ironically, CMD B, using right-side data, would have worked.
For me, the key in these accidents, and the incident flight, is that the primary trim continued to work normally throughout. Clicking the yoke trim switches stops the MCAS activation and allows you to remove all of the trim inputs that MCAS applies. The Lion Air accident Captain kept the airplane in-trim through 21 MCAS activations by doing this. It can be seen clearly on the DFR plot. The airplane didn't become seriously out-of-trim until the Captain transferred control to the First Officer who, after five additional MCAS activations, allowed the trim to reach the full nose-down position.
Of course, none of this has anything to do with the accident in China.
For me, the key in these accidents, and the incident flight, is that the primary trim continued to work normally throughout. Clicking the yoke trim switches stops the MCAS activation and allows you to remove all of the trim inputs that MCAS applies. The Lion Air accident Captain kept the airplane in-trim through 21 MCAS activations by doing this. It can be seen clearly on the DFR plot. The airplane didn't become seriously out-of-trim until the Captain transferred control to the First Officer who, after five additional MCAS activations, allowed the trim to reach the full nose-down position.
Of course, none of this has anything to do with the accident in China.
04-01-2022, 06:08 PM
#125
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,026
Originally Posted by Nantonaku
I read the report and you are wrong, you said "the captain re-engaged the autopilot repeatedly". Which is wrong, your own link does not show this at all. He tried ONE time while fighting the MCAS. One time.
Originally Posted by Nantonaku
He tried a couple times early in flight before MCAS activation. Then he didn't try until the very end one more time after they were unable to hold altitude because of the force required. .... He tried twice on takeoff and then just one more time at the end.
I'm not a big fan of liars. I'm done with you.
Originally Posted by Nantonaku
This message is hidden because Nantonaku is on your ignore list.
04-01-2022, 06:38 PM
#126
Gets Weekends Off
Joined APC: Dec 2013
Posts: 2,236
Originally Posted by JohnBurke
As opposed to:
Make up your god damn mind. One time. No, three times. No...
I'm not a big fan of liars. I'm done with you.
Make up your god damn mind. One time. No, three times. No...
I'm not a big fan of liars. I'm done with you.
04-01-2022, 06:58 PM
#127
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,026
Reference the previously cited interim report:
CVR time 05:38:56 Captain called for autopilot engage ("Command")
CVR time 05:39:01 Captain called for autopilot engage ("Command")
CVR time 05:39:23 Crew attempted a third autopilot engagement
An obvious uncommanded trim issue was occurring, with stick force in excess of 90 lbs: the reaction to an uncommanded pitch trim has never changed, and is a memory item, involving placing both stab trim cutout switches to cutout. Not until 5:40:38 was this conducted. This is critical, because using the stab trim cutout is the catch-all response that deactivates the stab trim motors. The reason for the uncommanded trim is irrelevant; there are multiple reasons the uncommanded trim may occur, regardless of whether it's a Max or not: using the stab trim cutout addresses every possibility. It's a memory item because it's best done sooner than later. It was done later. Never the less, had the crew maintained their airspeed instead of continuing to accelerate, and had they stopped the trim, they had a flyable aircraft on a visual day; returning to land was very possible. The crew proceeded to fly it right out of the envelope, impacting well above 500 knots. Note that the faster they flew it, the greater the nose down trim forces.
Again, airmanship 101. Works the same in a Cessna. (In fact, many years ago I had an interview at a back country operation, and was given a ride in a Cessna 207; takeoff with the trim run full nose down, fly a left circuit, and land. Then takeoff with the trim full nose up, fly a right circuit, and land. The point of the exercise was that the airplane was flyable, and basic airmanship meant that it was easiest when flown slowly...works the same in big and small aircraft: control problem, maintain airspeed. Student pilot stuff, you see).
Note that at 5:40:43, when the crew stopped applying a nose up trim effort, the nose-down trim was triggered, but stab movement did not occur...because the stab trim motors were cut out. Stick force at that stage was 94 lbs.
CVR time 5:43:11 stab trim cutout switches were changed to the normal position, from cutout, restoring power to the trim motors (actuators). The autopilot was re-engaged (again). Note that this is the fourth re-engagement.
Last recorded speed exceeded 500 knots. Last recorded stick force exceeded 180 lbs. Note that this force is a product of speed, not just stab position, and that this would NOT have occurred had the stab trim cutout switches been left in the cutout position.
This thread, one should note, is not about the 737 max, despite the apparent attention of some to make it so. If they intend to do so, then the least they can do is read the report that they linked.
CVR time 05:38:56 Captain called for autopilot engage ("Command")
CVR time 05:39:01 Captain called for autopilot engage ("Command")
CVR time 05:39:23 Crew attempted a third autopilot engagement
An obvious uncommanded trim issue was occurring, with stick force in excess of 90 lbs: the reaction to an uncommanded pitch trim has never changed, and is a memory item, involving placing both stab trim cutout switches to cutout. Not until 5:40:38 was this conducted. This is critical, because using the stab trim cutout is the catch-all response that deactivates the stab trim motors. The reason for the uncommanded trim is irrelevant; there are multiple reasons the uncommanded trim may occur, regardless of whether it's a Max or not: using the stab trim cutout addresses every possibility. It's a memory item because it's best done sooner than later. It was done later. Never the less, had the crew maintained their airspeed instead of continuing to accelerate, and had they stopped the trim, they had a flyable aircraft on a visual day; returning to land was very possible. The crew proceeded to fly it right out of the envelope, impacting well above 500 knots. Note that the faster they flew it, the greater the nose down trim forces.
Again, airmanship 101. Works the same in a Cessna. (In fact, many years ago I had an interview at a back country operation, and was given a ride in a Cessna 207; takeoff with the trim run full nose down, fly a left circuit, and land. Then takeoff with the trim full nose up, fly a right circuit, and land. The point of the exercise was that the airplane was flyable, and basic airmanship meant that it was easiest when flown slowly...works the same in big and small aircraft: control problem, maintain airspeed. Student pilot stuff, you see).
Note that at 5:40:43, when the crew stopped applying a nose up trim effort, the nose-down trim was triggered, but stab movement did not occur...because the stab trim motors were cut out. Stick force at that stage was 94 lbs.
CVR time 5:43:11 stab trim cutout switches were changed to the normal position, from cutout, restoring power to the trim motors (actuators). The autopilot was re-engaged (again). Note that this is the fourth re-engagement.
Last recorded speed exceeded 500 knots. Last recorded stick force exceeded 180 lbs. Note that this force is a product of speed, not just stab position, and that this would NOT have occurred had the stab trim cutout switches been left in the cutout position.
This thread, one should note, is not about the 737 max, despite the apparent attention of some to make it so. If they intend to do so, then the least they can do is read the report that they linked.
04-03-2022, 12:19 PM
#128
Gets Weekends Off
Joined APC: Dec 2017
Position: Retired NJA & AA
Posts: 1,919
CVR Sent to DC
https://www.cnbc.com/2022/04/01/us-n...oeing-jet.html
China sent the recovered CVR from the China Eastern crash to Washington to be processed. I'm a bit surprised by this since it **may** have been a mental issue with one of the pilots but maybe China doesn't have the tech needed to read a damaged CVR.
China sent the recovered CVR from the China Eastern crash to Washington to be processed. I'm a bit surprised by this since it **may** have been a mental issue with one of the pilots but maybe China doesn't have the tech needed to read a damaged CVR.
04-03-2022, 07:57 PM
#129
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,026
When you say "it may have been a mental issue with one of the pilots," are you referring to the wild speculation and conspiracy theory that this was planned months in advance, by a disgraced check airman on the verge of a forced retirement? The questionable conspiracy theory that looks more like "fake news," like what was already removed from this thread, presented without evidence and existing as little more than rumor? Or is there something credible, now?
04-04-2022, 10:01 AM
#130
Gets Weekdays Off
Joined APC: Feb 2007
Position: Economy Minus
Posts: 1,053
Originally Posted by JohnBurke
Reference the previously cited interim report:
CVR time 05:38:56 Captain called for autopilot engage ("Command")
CVR time 05:39:01 Captain called for autopilot engage ("Command")
CVR time 05:39:23 Crew attempted a third autopilot engagement
An obvious uncommanded trim issue was occurring, with stick force in excess of 90 lbs: the reaction to an uncommanded pitch trim has never changed, and is a memory item, involving placing both stab trim cutout switches to cutout. Not until 5:40:38 was this conducted. This is critical, because using the stab trim cutout is the catch-all response that deactivates the stab trim motors. The reason for the uncommanded trim is irrelevant; there are multiple reasons the uncommanded trim may occur, regardless of whether it's a Max or not: using the stab trim cutout addresses every possibility. It's a memory item because it's best done sooner than later. It was done later. Never the less, had the crew maintained their airspeed instead of continuing to accelerate, and had they stopped the trim, they had a flyable aircraft on a visual day; returning to land was very possible. The crew proceeded to fly it right out of the envelope, impacting well above 500 knots. Note that the faster they flew it, the greater the nose down trim forces.
Again, airmanship 101. Works the same in a Cessna. (In fact, many years ago I had an interview at a back country operation, and was given a ride in a Cessna 207; takeoff with the trim run full nose down, fly a left circuit, and land. Then takeoff with the trim full nose up, fly a right circuit, and land. The point of the exercise was that the airplane was flyable, and basic airmanship meant that it was easiest when flown slowly...works the same in big and small aircraft: control problem, maintain airspeed. Student pilot stuff, you see).
Note that at 5:40:43, when the crew stopped applying a nose up trim effort, the nose-down trim was triggered, but stab movement did not occur...because the stab trim motors were cut out. Stick force at that stage was 94 lbs.
CVR time 5:43:11 stab trim cutout switches were changed to the normal position, from cutout, restoring power to the trim motors (actuators). The autopilot was re-engaged (again). Note that this is the fourth re-engagement.
Last recorded speed exceeded 500 knots. Last recorded stick force exceeded 180 lbs. Note that this force is a product of speed, not just stab position, and that this would NOT have occurred had the stab trim cutout switches been left in the cutout position.
This thread, one should note, is not about the 737 max, despite the apparent attention of some to make it so. If they intend to do so, then the least they can do is read the report that they linked.
CVR time 05:38:56 Captain called for autopilot engage ("Command")
CVR time 05:39:01 Captain called for autopilot engage ("Command")
CVR time 05:39:23 Crew attempted a third autopilot engagement
An obvious uncommanded trim issue was occurring, with stick force in excess of 90 lbs: the reaction to an uncommanded pitch trim has never changed, and is a memory item, involving placing both stab trim cutout switches to cutout. Not until 5:40:38 was this conducted. This is critical, because using the stab trim cutout is the catch-all response that deactivates the stab trim motors. The reason for the uncommanded trim is irrelevant; there are multiple reasons the uncommanded trim may occur, regardless of whether it's a Max or not: using the stab trim cutout addresses every possibility. It's a memory item because it's best done sooner than later. It was done later. Never the less, had the crew maintained their airspeed instead of continuing to accelerate, and had they stopped the trim, they had a flyable aircraft on a visual day; returning to land was very possible. The crew proceeded to fly it right out of the envelope, impacting well above 500 knots. Note that the faster they flew it, the greater the nose down trim forces.
Again, airmanship 101. Works the same in a Cessna. (In fact, many years ago I had an interview at a back country operation, and was given a ride in a Cessna 207; takeoff with the trim run full nose down, fly a left circuit, and land. Then takeoff with the trim full nose up, fly a right circuit, and land. The point of the exercise was that the airplane was flyable, and basic airmanship meant that it was easiest when flown slowly...works the same in big and small aircraft: control problem, maintain airspeed. Student pilot stuff, you see).
Note that at 5:40:43, when the crew stopped applying a nose up trim effort, the nose-down trim was triggered, but stab movement did not occur...because the stab trim motors were cut out. Stick force at that stage was 94 lbs.
CVR time 5:43:11 stab trim cutout switches were changed to the normal position, from cutout, restoring power to the trim motors (actuators). The autopilot was re-engaged (again). Note that this is the fourth re-engagement.
Last recorded speed exceeded 500 knots. Last recorded stick force exceeded 180 lbs. Note that this force is a product of speed, not just stab position, and that this would NOT have occurred had the stab trim cutout switches been left in the cutout position.
This thread, one should note, is not about the 737 max, despite the apparent attention of some to make it so. If they intend to do so, then the least they can do is read the report that they linked.
that said, JB, it disturbs me greatly that we agree!!!
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