morrisond wrote:

No they did not have proper control of the aircraft. That is basic aviation 101. They had a system (Electric Trim) that wasn't acting as they expected it too - they had no idea why it wasn't acting as it should but the first reaction should have been to turn it off - just like any system that wasn't acting properly.

If the Autopilot was turning you 90 degrees in the wrong direction would you keep using it turning yourself back on course 22 times or turn it off?

If you did not have the comfort to turn it off you shouldn't be in the cockpit. It should not be an unrealistic expectation that a commercial airplane pilot can fly the plane manually with no electronic helpers - that is why we have pilots to take over when the systems fail - through bad design or outright failure just because sometimes things break - which can and will happen no matter how well a system is designed or made fault tolerant.

Yes the MAX has a systems problem that doesn't appear to be fault tolerant enough - however MCAS was basically designed to help pilots with poor piloting skills from entering a stall.

Both MAX's crashed due to inadequate basic training - they were both perfectly capable of flying in Manual mode. Even if you didn't know about MCAS (understandable on Lionair -inexcusable on the ET flight) - any reasonably competent Pilot should have been able to realize that a system wasn't doing what it was supposed to and turn it off.

Have we really entered the realm of it's always the planes fault and never the Pilot's?

fabian9 wrote:

morrisond wrote:

My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

I can’t find the part of the report that says the electronic trim was switched back on. Could you point me at it?

PS: I posted this question earlier, but I think it got deleted.

hivue wrote:

2175301 wrote:

They did not have sufficient surplus altitude AGL to sacrifice.

fabian9 wrote:

I can’t find the part of the report that says the electronic trim was switched back on. Could you point me at it?

hivue wrote:

litz wrote:

And that's the saddest thing of all right there ... both of these crashes would never have happened had the crew simply re-extended the flaps,and returned for an emergency landing.

The ET crew could not have deployed flaps at the kinds of airspeeds they were traveling. As I said in a post up-thread, it looks like they were caught in an awful trap. How much of that was due to MCAS and how much to crew actions is yet to be determined.

mzlin wrote:

What's doubly odd is there was no callout by either pilot asking or confirming reactivation of electrical trim power. There was also no callout or confirmation of the use of manual electrical trim. So it makes me wonder if one pilot reactivated electrical trim without notifying the other, and if the same pilot also did not realize that they would then have to counter MCAS with manual electrical trim. This may then be very much like the Lion Air situation where the caption countered MCAS with manual electrical trim to keep neutral trim 20 times, then passed control over to the FO, who then only countered MCAS with single manual inputs which were insufficient to keep trim at neutral, allowing MCAS to push trim to the fully down position.

Planetalk wrote:

So to sum up the key action of the pilots as compared to the checklist.

- They did trim up to counter the MCAS movement before hitting the trim cutout switch.
- They did try to use manual trim as the procedure states when they still couldn't control the aircraft.
- Manual trim didn't work.

What exactly could they have done except reengage electric trim at this point? Note the checklist has now ended. The same checklist various posters insisted the pilots obviously hadn't followed.

patplan wrote:

ET-AVJ Preliminary Accident Report, pp26-27

..

..
..

Eyad89 wrote:

2175301 wrote:

Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,

+1

Jetty wrote:

PixelFlight wrote:

At 05:38:44, shortly after liftoff, the left and right recorded AOA values deviated. Left AOA
decreased to 11.1° then increased to 35.7° while value of right AOA indicated 14.94°. Then after, the
left AOA value reached 74.5° in 3⁄4 seconds while the right AOA reached a maximum value of 15.3°.

Which shows that the plane didn't even need to compare the 2 AoA sensors to establish a malfunction. Such quick changes are impossible and should never be relied upon to automatically adjust the trim in any decently designed plane even with only 1 sensor present. And if one AoA sensor provides logical outputs and the other does not it should have been plain obvious to rely on the sensor that makes sense, no need to disable MCAS in that scenario as Boeing is planning to do with the software update.

dragon6172 wrote:

As you see... still 2.3 units short of where they started, requiring excessive control forces to maintain level flight. Probably have to be spelled out even more clearly to use electric trim to return the aircraft to an "in trim" state before using cutout switches.

PixelFlight wrote:

At 05:43:20, approximately five seconds after the last manual electric trim input, an AND automatic
trim command occurred and the stabilizer moved in the AND direction from 2.3 to 1.0 unit in
approximately 5 seconds. The aircraft began pitching nose down. Additional simultaneous aft
column force was applied, but the nose down pitch continues, eventually reaching 40° nose down.
The stabilizer position varied between 1.1 and 0.8 units for the remainder of the recording.

Etheereal wrote:

PixelFlight wrote:

At 05:43:20, approximately five seconds after the last manual electric trim input, an AND automatic
trim command occurred and the stabilizer moved in the AND direction from 2.3 to 1.0 unit in
approximately 5 seconds. The aircraft began pitching nose down. Additional simultaneous aft
column force was applied, but the nose down pitch continues, eventually reaching 40° nose down.
The stabilizer position varied between 1.1 and 0.8 units for the remainder of the recording.

So the pilots re-enabled the switches, trimmed manually to get their desired pitch, and then forgot to disconnect them again after MCAS trimmed down again?

Also, that recording shows they used Column which has been stated at some point here that has insufficient authority compared to nose trim wheel.

tphuang wrote:

I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.

tphuang wrote:

I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.

mzlin wrote:

This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,

zuckie13 wrote:

1) Why did they not reduce thrust?

hivue wrote:

mzlin wrote:

This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,

I don't think they would have touched the stab trim switches again unless they were getting desperate.

Jetty wrote:

morrisond wrote:

No they did not have proper control of the aircraft. That is basic aviation 101. They had a system (Electric Trim) that wasn't acting as they expected it too - they had no idea why it wasn't acting as it should but the first reaction should have been to turn it off - just like any system that wasn't acting properly.

If the Autopilot was turning you 90 degrees in the wrong direction would you keep using it turning yourself back on course 22 times or turn it off?

If you did not have the comfort to turn it off you shouldn't be in the cockpit. It should not be an unrealistic expectation that a commercial airplane pilot can fly the plane manually with no electronic helpers - that is why we have pilots to take over when the systems fail - through bad design or outright failure just because sometimes things break - which can and will happen no matter how well a system is designed or made fault tolerant.

Yes the MAX has a systems problem that doesn't appear to be fault tolerant enough - however MCAS was basically designed to help pilots with poor piloting skills from entering a stall.

Both MAX's crashed due to inadequate basic training - they were both perfectly capable of flying in Manual mode. Even if you didn't know about MCAS (understandable on Lionair -inexcusable on the ET flight) - any reasonably competent Pilot should have been able to realize that a system wasn't doing what it was supposed to and turn it off.

Have we really entered the realm of it's always the planes fault and never the Pilot's?

Seems you were as wrong as could be. We have entered the realm of you consistently finding excuses for the badly designed MAX and never taking responsibility for the spreading of misinformation, even after you've been proven wrong.

mzlin wrote:

tphuang wrote:

I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.

Actually we do like to do that, because we are interested in learning more about civil aviation, including understanding the risks involved when getting on an airplane, and that is why we are on this site.

fabian9 wrote:

zuckie13 wrote:

1) Why did they not reduce thrust?

Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?

kalvado wrote:

mzlin wrote:

tphuang wrote:

I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.

Actually we do like to do that, because we are interested in learning more about civil aviation, including understanding the risks involved when getting on an airplane, and that is why we are on this site.

There is a difference between looking at what was done, what could be done, and understanding why things went wrong; and plainly blaming pilots for "doing stupid things"
It is OK - actually its a must - to learn on other's mistakes. Blaming people for mistakes in critical situation - especially if they have no chance to respond - is stupid at best.

morrisond wrote:

Eyad89 wrote:

2175301 wrote:

Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,

+1

This explanation is my understanding as well however I will differ on the interpretation of #2.

I would not want to be in any Aircraft that was piloted by a Pilot that was not capable of pulling the power back to reduce speed below the max limits - they way above above stall speed at 94% Power ( at least 100 knots). You do not need 94% power to maintain level flight at 14,000. According to the 737 Memory list (which pilots are required to memorize - and remember there are two of them - one should have remembered) - if faced with unreliable airspeed set power to 75% - they practice this in the simulator (or are supposed to).

The unnatural thing would to keep the thrust levers where they were.

They initially saved it (Hats off to them) however they then allowed a perfectly controllable aircraft with Manual controls get outside the flight envelope - in this case excess speed.

Do I feel bad about the Pilots and the loss of life - Yes

However I am lot more angry at the fact that professional pilot standards are this low.

morrisond wrote:

Eyad89 wrote:

2175301 wrote:

Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,

+1

This explanation is my understanding as well however I will differ on the interpretation of #2.

I would not want to be in any Aircraft that was piloted by a Pilot that was not capable of pulling the power back to reduce speed below the max limits - they way above above stall speed at 94% Power ( at least 100 knots). You do not need 94% power to maintain level flight at 14,000. According to the 737 Memory list (which pilots are required to memorize - and remember there are two of them - one should have remembered) - if faced with unreliable airspeed set power to 75% - they practice this in the simulator (or are supposed to).

The unnatural thing would to keep the thrust levers where they were.

They initially saved it (Hats off to them) however they then allowed a perfectly controllable aircraft with Manual controls get outside the flight envelope - in this case excess speed.

Do I feel bad about the Pilots and the loss of life - Yes

However I am lot more angry at the fact that professional pilot standards are this low.

WorldFlier wrote:

hivue wrote:

litz wrote:

And that's the saddest thing of all right there ... both of these crashes would never have happened had the crew simply re-extended the flaps,and returned for an emergency landing.

The ET crew could not have deployed flaps at the kinds of airspeeds they were traveling. As I said in a post up-thread, it looks like they were caught in an awful trap. How much of that was due to MCAS and how much to crew actions is yet to be determined.

What is the maximum airspeed for which you can deploy minimum flaps?

mzlin wrote:

hivue wrote:

mzlin wrote:

This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,

I don't think they would have touched the stab trim switches again unless they were getting desperate.

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.

UALWN wrote:

mzlin wrote:

hivue wrote:

I don't think they would have touched the stab trim switches again unless they were getting desperate.

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.

I don't think so. This is from just before the switch was re-engaged: "At 05:43:04, the Captain asked the First Officer to pitch up together and said that pitch is not enough." They were desperate.

hivue wrote:

2175301 wrote:

Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time.

That's MSL, not AGL.

2175301 wrote:

I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

They did not have sufficient surplus altitude AGL to sacrifice.

mzlin wrote:

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.

fabian9 wrote:

zuckie13 wrote:

1) Why did they not reduce thrust?

Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?

zhetenyi1973 wrote:

What I don't understand why there is no MCAS trim down action for a considerable time. Shouldn't we see MCAS activation during this time without the trim movement?
It happened once why did it not happen after that? Also, why did the crew not trim back to 5 units? Why did they stop at 2.3 before cutout? Can it be they thought 2.3 was 5?

hivue wrote:

mzlin wrote:

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.

Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.

Interested wrote:

What other gambles could they try at that stage?

mzlin wrote:

hivue wrote:

mzlin wrote:

This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,

I don't think they would have touched the stab trim switches again unless they were getting desperate.

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.

MSPNWA wrote:

Interested wrote:

What other gambles could they try at that stage?

It's not a gamble to properly manage your speed and manually trim the airplane when it is at a pitch up attitude.

It appears they put themselves into a box they couldn't get out of. Very sad.

morrisond wrote:

fabian9 wrote:

zuckie13 wrote:

1) Why did they not reduce thrust?

Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?

According to 737 pilots on another forum - this effect would be very-very minor - plus you would unload the stabilizer making easier to pull back to offset the slight nose down.

Interested wrote:

hivue wrote:

mzlin wrote:

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.

Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.

I've asked a few times now

Once the trim wheel wasn't working and once they together pulled back on the sticks with no success what would the next options be to try ?

What would be the next procedure to follow?

mzlin wrote:

Interested wrote:

hivue wrote:

Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.

I've asked a few times now

Once the trim wheel wasn't working and once they together pulled back on the sticks with no success what would the next options be to try ?

What would be the next procedure to follow?

And you've been answered a few times, but you may not have noticed, as you would have to read a lot of posts, so:

05:43:00 they are in stable flight with overspeed. Ideally, they would reduce thrust and regain control using the trim wheels. It would not be advised to turn back electrical power, but if they did (and they did), then they can use the manual electrical trim inputs (thumb tabs on the column) to get upward trim. Indeed one pilot did do this but then didn't counter MCAS when it kicked in again (5 seconds later).

mzlin wrote:

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe.

scbriml wrote:

mzlin wrote:

I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe.

Except that's MSL, not AGL. In reality, they were something like 5,000ft AGL. Not that comfortable with a struggling plane.

2175301 wrote:

Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,

Interested wrote:

So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?

MSPNWA wrote:

Interested wrote:

So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?

You're making assumptions that aren't in the report. We don't know if the manual trim truly didn't work, or if didn't they know enough about it/didn't execute it properly. If it's the former, then we have decades of design at question going back to the original 737. If it's the latter, which is very plausible looking at the report, we have a training/CRM issue.

MSPNWA wrote:

Interested wrote:

So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?

You're making assumptions that aren't in the report. We don't know if the manual trim truly didn't work, or if didn't they know enough about it/didn't execute it properly. If it's the former, then we have decades of design at question going back to the original 737. If it's the latter, which is very plausible looking at the report, we have a training/CRM issue.

Interested wrote:

Shall we just all agree no pilots should have had to figure out how to deal with all of this?

Would any of you volunteer to go on a test flight with the above conditions with any confidence?

And that's even with the test pilots knowing what to expect

The test pilots would be training like hell for weeks in advance