AA 757 off runway excursion at JACKSON, Wyo

[Fear_of_Flying]

Originally Posted by orangehuggy

as there was no gross negligence or intent to harm, there should not or would not be any negative impacts on the pilots' careers. this is a great thing that happened, after thorough analysis many important safety related concepts will be learned and contribute to minimizing future overrun occurrences - and no one got hurt!

Do you know for a fact that gross negligence or intent are the only categories of error that would impact a pilot's career? The pilot certainly seemed to believe otherwise, since "end of career" were the first words past his lips once the dust (in this case snow) had settled.

[orangehuggy]

Originally Posted by Fear_of_Flying

Do you know for a fact that gross negligence or intent are the only categories of error that would impact a pilot's career?...

no I don't and would welcome input from someone that does (and i did use the word "or" not "nor")

[MCM]

If you want this sort of stuff as an official "memory item" then you're going to have far far too many to ever practically remember. Besides which, checking deployment is part of the normal landing procedure.

The procedure requires you to check speedbrake deployment on every landing - and I believe in this case they "checked" deployment and called "deployed". However, the speedbrake quite possibly deployed and then restowed - this is confirmed by the article provided by aardvark. The location of the speedbrake, particularly when the F/O calls it, makes it difficult to see, and quite often the "noise" of the deployment and seeing the lever start its movement is the queue that it has deployed.

If it restows, it should be observed by one of the crew. But add in the distraction of the reversers not being able to move, I'm not entirely surprised it was missed.

And as for the control bit:

I'm not surprised the F/O didn't release them - if the F/O is the pilot flying during the landing, they're his reversers. If the Captain wanted control of the aircraft, then normally he would take control of the entire aircraft, including steering and braking. Taking over part of the controls is unusual, and such a call would surprise the F/O. The reversers can be a significant part of directional control on a slippery runway, and the responsibility of the PF.

[Gabriel]

Originally Posted by Fear_of_Flying

Interesting to note that when asked to review the transcript, the pilot's only addendum was to note that one of the clicks alluded to was the sound of the spoilers deploying, clearly giving a case for why he didn't deploy them manually. However, I also read that it is indeed a procedure (I believe from the airline) to manually deploy them upon encountering a braking anomaly.

This issue has been mentioned a few times in the last few threads, and confessing that I know nothing about this accident other than this CVR transcript, I would like to give my view on this issue.

Unlike Airbus, Boeing has a fulll feedback control system, so when the automation does something, the cockpit controls move as the pilot would move them. If the AP pulls up, the control column moves back, if the AT increases thrust, the throttle levers move forward, and if the spoilers self deploy during landing, the spoilers lever moves to the the ground spoilers detent.

The sound of the spoilers deploying can not be heard from the cockpit, and if it cuold, I bet it would not be a click. The "the click of the spoilers deploying" is in fact the click of the spoiler levers clicking into the ground detent. Once the spoiler levers are there, there is really nothing else the pilot can do to "manually deploy" the spoilers. So here is a scenario (warning: I don't know the Boing systems that well so take what follows with a grain of salt):

The airplane touches down. The plane goes to ground mode which, since the ground spoilers were armed, triggers the automatic spoilers extension.

But for whatever reason, while the spoilers lever does moves and reaches the ground detent, the spoiles don't actually deploy.

The pilot listen the spoiler lever sound (the click) and visually checks that it's in the ground detent, and calls "spoilers deployed". Now, there is a spoilers indicartor that actually sense the position of the spoilers regardless of the position of the lever, and that is what should be used to check the status of the spoiler. Doing what I propose that the pilot did would be like checking the flaps with the flaps levers instead of the flaps indicator. And I must say that this is (wrongly) done sometimes, because the pilots know that there is a flaps disagree warning that alerts of difference between the commanded position of the flaps lever and the actual position of the flaps "so if I look at the flaps lever and there is no flaps disagree warning, then the flaps are where the lever is" (that is a human factor error called primmary-backup inversion: the warning is a backup for the pilot failing to detect the problem with the indicator which is the primary means, but if the pilot usually relies on the warning then the warning becomes the primary and the pilot detection the back-up). I would not be surprised if this is what happened here, and yes, the pilots would be to blame for that: Not for not deploying the spoilers manually (after all the spoilers levers were already where the pilot would have to put it for the manual extention), not for not monitoring the spoilers deployment, but for doing it incorrectly and falling in the primmary-backup inversion trap.

Finally, if this scenario happens to be real, I wonder if the failure of the spoilers to deploy even when the spoilers lever did move to the extended position has something to do with the thrust reverser levers being jammed. Since the application of thrust reverse triggers the spoiler extension even in the spoilers are not armed, maybe there is some mechanical link between the spoiler lever and the thrust reverser lever and the malfunction was peciselly around there.

In this way a single malfunction could explain a lot of things: That the spoilers levers did move to the ground position, that the pilot confirmed the spoilers deployment, that the pilot did not manually extend the spoilers, that nevertheless the spoilers did not deploy, and that the thrust reverser levers were jammed. That would be much more satisfactory than needing to explain different independent human and mechanical failures

Just a thought... maybe too good to be true.

[Gabriel]

Re: memory items.

There are lots of memory procedures. Basically, all normal procedures are done by memory. And before someone mentions checklist, let me explain this a bit:

A procedure is a sequence of actions required. A check list is that, a list to check things, not to do things (other than check, of course).

For example, lowering the landing gear and checking three green before landing is a memory procedure. Checking the status of the landing gear during the before landing checklist is a checklist item, which is not done from memory. But calling the landinig checklist is in itself a memory procedure. If the pilots forget to do it then no written checklist will help.

There are a lot of "abnormal" things that are done by memory too because thei require the normal manipulation of the cockpit controls. And yet, just like the normal proceudres, they are not considered "a memory item".

For example, there is no "airspeed went below Vref" "memory item" as such.

I guess that manual spoiler deflection is just in this category: When you land you want the spoilers to deploy and you monitor that. If they dont, you still want them deployed so you grab the spoilers handle that is there for something, move it back as you always do when you want to manually extend the spoilers (be it in flight or ground), and put it in the ground detent that is there for something too.

What is usually called "memory item" is a specific procedure that the pilto should do in one specific case. For example, sudden loss of cabin pressure reads something like "masks: put - O2: max - crew communication: check". If the procedure was simply "to increase the cabin pressure with the cabin pressure knob that is usually used by to piltos to control the cabin pressure", I bet it would not be considered a "memory item". Or the unreliable airspeed memory item calls for a specific thurst and pitch, not just "use common pilot knowledge to keep it in a cruise condition".

Of course, the border between what is a "memory item" and what is just a proceudr done from memory is not a perfectly defined thin line.

[Fear_of_Flying]

Originally Posted by Gabriel

This issue has been mentioned a few times in the last few threads, and confessing that I know nothing about this accident other than this CVR transcript, I would like to give my view on this issue.

Unlike Airbus, Boeing has a fulll feedback control system, so when the automation does something, the cockpit controls move as the pilot would move them. If the AP pulls up, the control column moves back, if the AT increases thrust, the throttle levers move forward, and if the spoilers self deploy during landing, the spoilers lever moves to the the ground spoilers detent.

The sound of the spoilers deploying can not be heard from the cockpit, and if it cuold, I bet it would not be a click. The "the click of the spoilers deploying" is in fact the click of the spoiler levers clicking into the ground detent. Once the spoiler levers are there, there is really nothing else the pilot can do to "manually deploy" the spoilers. So here is a scenario (warning: I don't know the Boing systems that well so take what follows with a grain of salt):

The airplane touches down. The plane goes to ground mode which, since the ground spoilers were armed, triggers the automatic spoilers extension.

But for whatever reason, while the spoilers lever does moves and reaches the ground detent, the spoiles don't actually deploy.

The pilot listen the spoiler lever sound (the click) and visually checks that it's in the ground detent, and calls "spoilers deployed". Now, there is a spoilers indicartor that actually sense the position of the spoilers regardless of the position of the lever, and that is what should be used to check the status of the spoiler. Doing what I propose that the pilot did would be like checking the flaps with the flaps levers instead of the flaps indicator. And I must say that this is (wrongly) done sometimes, because the pilots know that there is a flaps disagree warning that alerts of difference between the commanded position of the flaps lever and the actual position of the flaps "so if I look at the flaps lever and there is no flaps disagree warning, then the flaps are where the lever is" (that is a human factor error called primmary-backup inversion: the warning is a backup for the pilot failing to detect the problem with the indicator which is the primary means, but if the pilot usually relies on the warning then the warning becomes the primary and the pilot detection the back-up). I would not be surprised if this is what happened here, and yes, the pilots would be to blame for that: Not for not deploying the spoilers manually (after all the spoilers levers were already where the pilot would have to put it for the manual extention), not for not monitoring the spoilers deployment, but for doing it incorrectly and falling in the primmary-backup inversion trap.

Finally, if this scenario happens to be real, I wonder if the failure of the spoilers to deploy even when the spoilers lever did move to the extended position has something to do with the thrust reverser levers being jammed. Since the application of thrust reverse triggers the spoiler extension even in the spoilers are not armed, maybe there is some mechanical link between the spoiler lever and the thrust reverser lever and the malfunction was peciselly around there.

In this way a single malfunction could explain a lot of things: That the spoilers levers did move to the ground position, that the pilot confirmed the spoilers deployment, that the pilot did not manually extend the spoilers, that nevertheless the spoilers did not deploy, and that the thrust reverser levers were jammed. That would be much more satisfactory than needing to explain different independent human and mechanical failures

Just a thought... maybe too good to be true.

Well, your explanation is more elegant than looking for simultaneous malfunctions. However, I'm not sure which of the malfunctions has been absolutely confirmed at this point.

Could icing explain these coinciding problems in any way?

By the way, here are a couple of sources to my earlier comments:

trib.com/news/national/pilots-struggled-with-brakes-in-wyo-runway-mishap/article_3b445365-6984-5e9b-8905-331a91b2f2b0.html

American did not immediately respond to an inquiry about the current stratus of the pilots.

The pilots did acknowledge in interviews with investigators that they didn't try to manually engage the plane's speed brakes _ essentially wing panels that pop up _ as American's procedures require under the circumstances.

From the report (http://www.avweb.com/pdf/jacksonhole...transcript.pdf)

As part of the Safety Board’s accident investigation process, the flight crew was invited to review the CVR transcript and suggest corrections or additions. The first officer declined the invitation. The captain accepted the invitation and reviewed part of the transcript on March 14, 2011.
The captain’s only addition was that when the transcript identifies, “[sound of multiple mechanical clicks and thumps]” at 11:37:44.8, the captain believed one of the clicks recorded was the sound of spoiler handle automatic actuation.

[Evan]

Originally Posted by Gabriel

Re: memory items.

I don't know about Boeing, but the 7 primary memory items for Airbus are:

1) Windshear/ windshear ahead: "Windshear, TOGA" 3.02.80 p19
2) TCAS: "Traffic, I have control" 3.02.34 p12 and p17
3) EGPWS: "Pull up, TOGA" 3.02.34 p15
4) Loss of braking "Loss of braking" 3.02.32 p11
5) Immediate actions of EMER DESCENT "Emergency Descent" 3.02.80 p7
6) Immediate actions of UNRELIABLE SPEED INDICATION/ ADR CHECK PROC "Unreliable speed" 3.02.34 p20
7) CREW INCAPACITATION 3.02.80 p9

Note that "loss of braking" does not refer to thrust reverser failure. Thrust reverser failure in the checklist only indicates "crew awareness".

Yes, a lot of things are performed from memory, but the term "memory items" refers to a short list of very critical situations that require immediate crew response where there is no time to refer to checklist procedures. These situations require instinctive training to provide a means of stabilizing the situation long enough to work the problem at hand. As MCM points out, this list must be kept short to make it realistic for pilots to absorb into memory.

There are others that certain operators add to this. But I think this is the basic starting place. Also note that stall warning and stall recovery are not on the list...

[Fear_of_Flying]

Originally Posted by Gabriel

Re: memory items.

There are lots of memory procedures. Basically, all normal procedures are done by memory. And before someone mentions checklist, let me explain this a bit:

A procedure is a sequence of actions required. A check list is that, a list to check things, not to do things (other than check, of course).

For example, lowering the landing gear and checking three green before landing is a memory procedure. Checking the status of the landing gear during the before landing checklist is a checklist item, which is not done from memory. But calling the landinig checklist is in itself a memory procedure. If the pilots forget to do it then no written checklist will help.

There are a lot of "abnormal" things that are done by memory too because thei require the normal manipulation of the cockpit controls. And yet, just like the normal proceudres, they are not considered "a memory item".

For example, there is no "airspeed went below Vref" "memory item" as such.

I guess that manual spoiler deflection is just in this category: When you land you want the spoilers to deploy and you monitor that. If they dont, you still want them deployed so you grab the spoilers handle that is there for something, move it back as you always do when you want to manually extend the spoilers (be it in flight or ground), and put it in the ground detent that is there for something too.

What is usually called "memory item" is a specific procedure that the pilto should do in one specific case. For example, sudden loss of cabin pressure reads something like "masks: put - O2: max - crew communication: check". If the procedure was simply "to increase the cabin pressure with the cabin pressure knob that is usually used by to piltos to control the cabin pressure", I bet it would not be considered a "memory item". Or the unreliable airspeed memory item calls for a specific thurst and pitch, not just "use common pilot knowledge to keep it in a cruise condition".

Of course, the border between what is a "memory item" and what is just a proceudr done from memory is not a perfectly defined thin line.

Yes, I agree that the distinction between a "memory item" and a "memorized procedure" is blurry indeed. I don't know what weight one has over the other. Certainly there seems to be little room for interpretation in American Airlines procedure for manually applying spoilers in the event of loss of braking power, and on the other hand we know that memory items don't always get followed.

Maybe though, there are instances when it is safer to abort a landing rather than try to correct the braking problem. Maybe that's all it takes to prevent something from becoming a memory item, if there is even one exception to the rule.

[Fear_of_Flying]

Originally Posted by Evan

I don't know about Boeing, but the 7 primary memory items for Airbus are:

1) Windshear/ windshear ahead: "Windshear, TOGA" 3.02.80 p19
2) TCAS: "Traffic, I have control" 3.02.34 p12 and p17
3) EGPWS: "Pull up, TOGA" 3.02.34 p15
4) Loss of braking "Loss of braking" 3.02.32 p11
5) Immediate actions of EMER DESCENT "Emergency Descent" 3.02.80 p7
6) Immediate actions of UNRELIABLE SPEED INDICATION/ ADR CHECK PROC "Unreliable speed" 3.02.34 p20
7) CREW INCAPACITATION 3.02.80 p9

Note that "loss of braking" does not refer to thrust reverser failure. Thrust reverser failure in the checklist only indicates "crew awareness".

Yes, a lot of things are performed from memory, but the term "memory items" refers to a short list of very critical situations that require immediate crew response where there is no time to refer to checklist procedures. These situations require instinctive training to provide a means of stabilizing the situation long enough to work the problem at hand. As MCM points out, this list must be kept short to make it realistic for pilots to absorb into memory.

There are others that certain operators add to this. But I think this is the basic starting place. Also note that stall warning and stall recovery are not on the list...

And what are the memory items for crew incapacitation, I wonder? I assume this is referring to one crew member only?

[Evan]

Originally Posted by Fear_of_Flying

And what are the memory items for crew incapacitation, I wonder? I assume this is referring to one crew member only?

Correct... Give yourself a gold star for that one.

[Fear_of_Flying]

Originally Posted by Evan

Correct... Give yourself a gold star for that one.

It was just a lucky guess, really.

Fortunately, I found a thread on PPrune where someone - a pilot no less - thoroughly explained what the procedure is for crew incapacitation.

So tell me, are you still of the opinion that reverser malfunction "should be trained as a memory item in the future", or is that idea still a work in progress?

[MCM]

G'day Gabriel...

Just need to clarify for you the operation of the speedbrake system on the 757.

You are correct that the speedbrake lever moves when they deploy. When we're talking about being on the ground, there are three positions for the handle to move to - There is Down, Armed, and Up.

The spoiler lever doesn't "click" into up as such... it kinda makes a whirring noise, then a clicky noise as it hits the stop. The speedbrake noise is quite unique. There is a noticeable click when the spoiler goes into the down detent.

The airplane touches down. The plane goes to ground mode which, since the ground spoilers were armed, triggers the automatic spoilers extension.

Correct.

Now, there is a spoilers indicartor that actually sense the position of the spoilers regardless of the position of the lever, and that is what should be used to check the status of the spoiler.

There is such an indicator, however it is not available for display during landing. The indicator is very small, and is displayed on the lower EICAS screen which is blank for landing. The lever position is taken as being the position of the spoilers. The "deployed" check is that the lever is in the up position.

[MCM]

FoF,

As to aborting a landing, it is generally accepted (and stated by Boeing) that once reversers are selected (or attempted to be selected) a landing must be made. This is due to the fact that if one reverser were to not stow, safe flight is, well, compromised.

[Evan]

Originally Posted by Fear_of_Flying

It was just a lucky guess, really.

Fortunately, I found a thread on PPrune where someone - a pilot no less - thoroughly explained what the procedure is for crew incapacitation.

So tell me, are you still of the opinion that reverser malfunction "should be trained as a memory item in the future", or is that idea still a work in progress?

I think maybe reverser failure should be added to the existing "loss of braking" procedure, with an action to manually extend the spoilers in case they haven't deployed automatically. Maybe you rename it "braking anomaly" to cover any case of deficient braking. But if the problem is in the control levers themselves, I'm not sure what difference it would make.

As in:

IF BRAKING INEFFECTIVE
- SPEED BRAKE..........UP
- REV..........MAX
- BRAKE PEDALS..........RELEASE
- etc.

EDIT: I'm quoting Airbus memory items of course. AFAIK, the the Boeing 757 has 10-12 memory items, and "loss of braking" is not one of them. I think the above should be added as a Boeing memory item because it is a critical situation where there is no time to reference a checklist.

[MCM]

Evan,

It is already part of the landing procedure to check speedbrake deployment, and if it is not deployed, to manually do so.

You don't need a specific non-normal memory procedure to cover this.

[Gabriel]

MCM, only now I catch what you were trying to say. If the airplane momentarily went into ground mode and shortly after, due to some malfunction, reverted to air mode, that would explain a lot of things an it is a simpler explanation than my mechanical jam that affected both the spoilers and reversers: The ground spoilers would re-stow and the reverse levers would not go into reverse. That said, the spoilers could have still been deployed manually, if not to the ground extended position, at least to the max flight position.

[Evan]

Originally Posted by MCM

Evan,

It is already part of the landing procedure to check speedbrake deployment, and if it is not deployed, to manually do so.

You don't need a specific non-normal memory procedure to cover this.

So the procedure to actually verify that the lever is in the UP position? Yes, I realize that the ground spoilers in ARMED deploy on main gear tilt without the reversers, but to verify that they have deployed, you have to verify that the lever is in the UP position, isn't that correct? Moving the reverser levers is the only other way to manually deploy them, and if you can't move the reverser levers, the first thing you should do is verify that the speed brake lever is in the UP position... That was my thinking, based upon human factors.

[Evan]

Originally Posted by Gabriel

MCM, only now I catch what you were trying to say. If the airplane momentarily went into ground mode and shortly after, due to some malfunction, reverted to air mode, that would explain a lot of things an it is a simpler explanation than my mechanical jam that affected both the spoilers and reversers: The ground spoilers would re-stow and the reverse levers would not go into reverse. That said, the spoilers could have still been deployed manually, if not to the ground extended position, at least to the max flight position.

AFAIK the reversion to 'air mode' lasted only a half second.

[MCM]

Evan,

Correct that the PNF should verify that the speedbrake is in the Up position.

I think that this was likely missed initially. I do wonder if the deploying "noise" occurred, which can act as a bit of a false trigger to a pilot that it has deployed. You shouldn't need to go back to check and deploy the speedbrakes if the reversers are stuck - they should already be verified as being up.

It does sound like there was an intermittent malfucntion with the speedbrake system - what impact that played we'll wait and see.
Gabriel,

They know that the aircraft did go into ground mode for 1 second, before going to air mode, and then back to ground mode. This does not have to be due to a malfunction, and in this case it doesn't sound like it was. This sequence can occur if the aircraft is landed very lightly and it 'skips', or if it lands firmly and bounces.

[Gabriel]

Ok, but then the reversers should have been available as soon as the plane went back into ground mode for the second time (the spoilers would remain stowed though).

By the way, I thought that the spoilers would remain deployed during a bounce. I'm almost sure that I was in bonced landings a few times and the spoilers did just that. IIRC they were a DC-9 or MD-80 in one instance and a 737 in the other instance.