Jackson Hole Landing

Greg Bockelman said:
You're right. It didn't look like it bounced to me. And at that speed, there really wasn't an excess of energy to generate a bounce.
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At that speed in my Warriors, there'd be a bit of a float. :wink2:
 
Greg Bockelman said:
I am not following. Speed brake extending? IMO you can't see enough of the wing to tell.

Other than that, I don't know what you mean.
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Here are the comparison shots: first one is from the video and the second one is a NW 757. As you can see in the second photo, the spoilers on the 757 extend pretty far out on the wing. Sure looks like they are not deployed to me.

What is interesting is that while the NTSB mentions that the exact position of the spoliers themselves was not recorded by the FDR, they make no mention of witness statements. There were definitely enough people on both sides of the plane looking out the windows that I am sure that the investigators have a pretty good idea of whether they were deployed or not.....they just aren't sayin'
 

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Fearless Tower said:
There were definitely enough people on both sides of the plane looking out the windows that I am sure that the investigators have a pretty good idea of whether they were deployed or not.....they just aren't sayin'
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Do you think there are many passengers who pay attention to the spoilers? Or even know what spoilers are?
 
Do the TRs require all three gear to be on the ground or just the mains? How about the auto-spoilers? Also, when the auto-spoiler are armed and they extend, does the handle move to the extended position?
 
Everskyward said:
Do you think there are many passengers who pay attention to the spoilers? Or even know what spoilers are?
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Most probably don't. And then there will be some who after the shock of the incident won't be able to remember if they were up or down. But remember, everyone survived this one. That is a fairly large witness pool- I suspect there were enough competent witnesses who were able to provide consistent accounts that would let the investigators draw the conclusion.

Plus, they don't have to really know what spoilers are. It is kind of like taking a witness to a police lineup. The investigator tracks down everyone seated at a window seat and show two photos one with the spoilers up and another with them down. 'Which one did you see?'
 
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Fearless Tower said:
What is interesting is that while the NTSB mentions that the exact position of the spoliers themselves was not recorded by the FDR, they make no mention of witness statements. There were definitely enough people on both sides of the plane looking out the windows that I am sure that the investigators have a pretty good idea of whether they were deployed or not.....they just aren't sayin'
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Eyewitnesses are the absolute worst people for remembering things. Unless someone said they were running a stopwatch in the back with a notepad and writing times down, AND had training in B-757 systems, I doubt they'll put much credibility on anything anyone on board said.
 
Everskyward said:
Do the TRs require all three gear to be on the ground or just the mains? How about the auto-spoilers? Also, when the auto-spoiler are armed and they extend, does the handle move to the extended position?
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Just the mains and the handle moves.
 
Fearless Tower said:
Most probably don't. And then there will be some who after the shock of the incident won't be able to remember if they were up or down. But remember, everyone survived this one. That is a fairly large witness pool- I suspect there were enough competent witnesses who were able to provide consistent accounts that would let the investigators draw the conclusion.
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How many people actually pay close attention to things that are happening on the wing during landing? I don't when I'm a passenger and I know what spoilers are. Remember that at the time, they didn't know the airplane was going to run off the runway.
 
Greg Bockelman said:
Just the mains and the handle moves.
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I was curious if the nose also had to be on the ground for the TRs to deploy. If it did, then it wouldn't take a bounce for the switches to go back into air mode. The CE-680 needs all three gear on the ground to deploy the TRs.

If the speedbrake handle stayed in the armed position then it would seem to indicate that they didn't extend but who knows.
 
Everskyward said:
How many people actually pay close attention to things that are happening on the wing during landing? I don't when I'm a passenger and I know what spoilers are. Remember that at the time, they didn't know the airplane was going to run off the runway.
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Some do and some don't. You obviously don't. I on the other hand have always been fascinated by the way things work - I always request the window seat and observe flap extension/retraction, spoilers..etc. My point is that not everyone is like you and not everyone is like me. BUT, with as many witnesses as there were on that flight, I am betting that there is bound to be enough people who did observe it.

Again, think police lineup. You don't have to be paying close attention. Most crime witnesses didn't know something was about to go down. If what you were saying is true, law enforcement would have abandoned the lineup a long time ago. The advantage in this case is you have a very large pool of witnesses to interview.
 
Everskyward said:
Do the TRs require all three gear to be on the ground or just the mains? How about the auto-spoilers? Also, when the auto-spoiler are armed and they extend, does the handle move to the extended position?
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Not sure about all that, but... the latest... they DO need to be wired up correctly!

http://online.wsj.com/article/SB10001424052748703889204576078531893643542.html?ru=MKTW&mod=MKTW said:
In an update of its preliminary findings released Wednesday, the safety board disclosed that the runway incident followed problems experienced by two separate systems designed to help decelerate the jetliner.

Panels on top of the wings, known as spoilers, failed to automatically pop up and help slow the aircraft, according to investigators. The safety board said that a portion of the linkage to an electrical switch needed to automatically activate the spoilers on the ground "was improperly installed" during earlier maintenance procedures. Investigators didn't indicate when mechanics made the alleged mistake.

Contrary to American's checklists and safety procedures, the cockpit crew apparently failed to try to manually deploy the spoilers in Jackson Hole, according to people familiar with the details.

<snip>

One angle the safety board is pursuing is whether the earlier maintenance error—potentially binding or restricting the operation of various controls in the cockpit—could have caused the delayed response from the reversers.

To help answer that question, these people said, the FAA has told American to inspect a portion of its Boeing 757 fleet for similar maintenance lapses.
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Fearless Tower said:
BUT, with as many witnesses as there were on that flight, I am betting that there is bound to be enough people who did observe it.
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There may have been many people on board but how many of those people had a good view of the speedbrakes? They would've had to have been sitting in a window seat far enough aft to see them but not too far aft.
 
Everskyward said:
There may have been many people on board but how many of those people had a good view of the speedbrakes? They would've had to have been sitting in a window seat far enough aft to see them but not too far aft.
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There's alot of window seats on a 75.
 
Fearless Tower said:
There's alot of window seats on a 75.
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Ok, you're convinced people would have been looking. I'm convinced more people are like me and are startled when the wheels touch because they are engrossed in a book, a puzzle or looking at the insides of their eyelids.
 
After a discussion about this with a friend typed in the 75/76 and 77...

He reminded me that landing distances are calculated with braking only, that spoilers and reversers augment the braking, and wondered if the auto-brake system was not armed or not functioning.

Auto-brakes are routinely used on the 75, and both common types of systems have six settings. Off, 1, 2, 3, 4, and MAX. There's also RTO, for rejected take-offs which is equivalent to MAX and is triggered by a reduction of throttle setting when armed.

In older 75s, the settings are a brake pressure. The brakes (in conjuction with anti-skid) come on and stay on at a particular pressure as soon as the aircraft squat switches show the aircraft on the ground.


In newer 75s, the setting is tied to GPS speed and is a deceleration amount. The brakes come on, and the system shoots for a minimum deceleration speed for each setting. If spoilers and reversers end up adding deceleration, the brakes ease off to save wear and tear on the braking system, as well as to avoid a "hot brake" scenario. If you never get the spoilers up or the buckets out, the aircraft will continue braking at the requested level.

To drive the point home that the aircraft can stop with brakes alone, he shared the story of a friend of his' flight in a 777 that had a complete seizure of one engine, which ripped half the engine out and tossed it out the back of the engine. This happened so close to V1 that the FO (PNF) on the CVR said, "Vee..." and a voice from the jumpseat said "Engine failure!"

FO retarded the throttles which activated RTO braking and threw the crew against their shoulder harnesses so hard, the Captain later said, "I would have eaten the yoke if it weren't for the shoulder harness."

FO said "Whoa" as the initial deceleration hit. After the aircraft stopped, the Captain joked with the FO... "Whoa, is not an approved call-out."

The aircraft stopped on the rejected takeoff from V1 with 2000' of runway to spare.

Everything I'm hearing and reading is leading me to believe the crew misjudged the runway conditions and didn't want to plaster FAs, PAX, and other objects to the forward bulkheads with auto-brakes selected to MAX, or had done the calculations and decided that a lower setting should be used than what was actually required.

When the spoilers and/or buckets didn't do what they expected, it became a problem that the auto-brakes weren't doing their thing and/or someone was already standing on the brake pedals and anti-skid was finding the challenge too high.

I haven't seen anything in the NTSB preliminaries yet about the auto-brake system, settings, or testimony of the crew about the use of heavy braking, which unless the runway was significantly below the reported traction, should have been sufficient to stop the aircraft without the spoilers or reversers.

Fascinating case, but I bet they hang this one on the crew unless someone went out and measured the runway traction right after the over-run (which is often standard procedure at many airports - the ops truck rolls out).
 
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denverpilot said:
Auto-brakes are routinely used on the 75, and both common types of systems have six settings. Off, 1, 2, 3, 4, and MAX. There's also RTO, for rejected take-offs which is equivalent to MAX and is triggered by a reduction of throttle setting when armed.
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Actually, RTO is GREATER than Max. A favorite oral question is, "Is Max braking the max available?" The answer is no, because RTO is greater than Max.

FO retarded the throttles
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That is the Captain's job where I work.

Everything I'm hearing and reading is leading me to believe the crew misjudged the runway conditions and didn't want to plaster FAs, PAX, and other objects to the forward bulkheads with auto-brakes selected to MAX, or had done the calculations and decided that a lower setting should be used than what was actually required.
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I don't know what you are reading and hearing, but I am reserving judgment for now.

When the spoilers and/or buckets didn't do what they expected, it became a problem that the auto-brakes weren't doing their thing and/or someone was already standing on the brake pedals and anti-skid was finding the challenge too high.
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Hmm. I don't even know where to begin on that one. If someone was already standing on the brakes, the autobrakes are out of the loop. And I am not sure what you mean by the antiskid was finding the challenge too high.

Fascinating case, but I bet they hang this one on the crew unless someone went out and measured the runway traction right after the over-run (which is often standard procedure at many airports - the ops truck rolls out).
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Well, given the propensity of everyone to try to hang the crew, you are probably right, but I won't take that view yet. Let's see what the NTSB has to say about the systems before we pass judgment.

As a postscript, about the only thing I can fault the crew for at this time is not jumping on the brakes sooner, if they saw issues developing. That, of course, is if they weren't already on the brakes. If that is the case, I can't see anything to hang the crew on, based solely on the information I have seen to this point.
 
A GA accident in Palm Beach a few years ago involved some of the same systems. The Gulfstream-V's WOW switches (weight-on-wheels) had been disabled by use of "popsicle sticks" that prevented them from closing on the ground and allowed the MX techs to "fool the airplane into thinking it was on the ground" while it was jacked for systems checks.

The techs forgot to remove the sticks and the crew didn't catch the problem on prfeflight. After takeoff the gear wouldn't retract, so rather thn work the checklist to identify the problem, the crew elected to return to the airport. Plane was lightly loaded, so the pilot reduced power to idle well before (planned) touchdown. Plane thought it was on the ground and immediately deployed spoilers, resulting in hard landing that drove gear through wings. They said the plane would never fly again.
 
wabower said:
A GA accident in Palm Beach a few years ago involved some of the same systems. The Gulfstream-V's WOW switches (weight-on-wheels) had been disabled by use of "popsicle sticks" that prevented them from closing on the ground and allowed the MX techs to "fool the airplane into thinking it was on the ground" while it was jacked for systems checks.

The techs forgot to remove the sticks and the crew didn't catch the problem on prfeflight. After takeoff the gear wouldn't retract, so rather thn work the checklist to identify the problem, the crew elected to return to the airport. Plane was lightly loaded, so the pilot reduced power to idle well before (planned) touchdown. Plane thought it was on the ground and immediately deployed spoilers, resulting in hard landing that drove gear through wings. They said the plane would never fly again.
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Sounds very much like what I call, a "Career-Limiting Moment." Good reminder of the Chain of Causation.

---

On the original topic: From what I read thus far (granted, I am not an expert, but I have reasonable reasoning skills and know how to assess evidence), no way no how we can assign blame yet.
 
The ghost in the machine!

Anytime you are dependent upon automatic systems, the WILL be failures - right HAL?

denny-o
 
Greg Bockelman said:
Actually, RTO is GREATER than Max. A favorite oral question is, "Is Max braking the max available?" The answer is no, because RTO is greater than Max.
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Can pilot applied braking exceed the RTO autobrake level? Or would those be about the same?
 
In the planes I fly, the pilot flying activates the spoilers by flipping a switch of all things, deploys the TRs by pulling a couple of handles and applies the brakes by pushing a couple of pedals with his feet. Gee, what a concept.
 
Greg Bockelman said:
Actually, RTO is GREATER than Max. A favorite oral question is, "Is Max braking the max available?" The answer is no, because RTO is greater than Max.



That is the Captain's job where I work.



I don't know what you are reading and hearing, but I am reserving judgment for now.



Hmm. I don't even know where to begin on that one. If someone was already standing on the brakes, the autobrakes are out of the loop. And I am not sure what you mean by the antiskid was finding the challenge too high.



Well, given the propensity of everyone to try to hang the crew, you are probably right, but I won't take that view yet. Let's see what the NTSB has to say about the systems before we pass judgment.

As a postscript, about the only thing I can fault the crew for at this time is not jumping on the brakes sooner, if they saw issues developing. That, of course, is if they weren't already on the brakes. If that is the case, I can't see anything to hang the crew on, based solely on the information I have seen to this point.
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Let me play the devils advocate here......

The airport is a MAJOR part of our economy in Jackson. A week before the slideoff this appeared in the local newspaper.

http://www.jhnewsandguide.com/article.php?art_id=6815

You can read between the lines but, airport officials were NOT happy with the airlines.

Now,,, add to this Christmas week is a very important time to cram as many tourists through the airport to boost revenue to all the local businesses.. and remember the old saying " follow the money.

The braking action vehicle is a yellow Saab with MU reporting equipment in it. Does it just read out numbers and they are written down and relayed to the tower? Does it have any data archiving capacity to back up the readings? But ................... What if they "fudged" the numbers to allow for more flights to make it in and it lead to this incident ?

Time will tell.

but as Mari said..... Reported MU #'s sometimes don't reflect the actual braking action.

Jackson Hole is a unique airport with a very short runway for this elevation, throw in the constant weather factor and you have a recipe for trouble. The airport plowing crew does an OUTSTANDING job given the odds thrown at them daily and they deserve due credit.

Ps. I want to say again.... If not for the perfect landing the pilots did by 'planting' it in the first few hundred feet of runway instead of landing 1/4 to 1/3 down the runway like alot of the other commercial carriers do to give the passengers a smooth landing ,and then steering it between the runway end lighting stands and a irrigation ditch as they went off the end and plowed through the snow the outcome for this 'overrun' would have turned into the lead story on all the evening news channels. That, guys and gals is why they get paid the big bucks. Cheers to the American Airlines crew that pulled that one off.:thumbsup::thumbsup::thumbsup::cool2:
 
Lance F said:
Can pilot applied braking exceed the RTO autobrake level? Or would those be about the same?
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They would be the same. RTO is the maximum braking available and probably exceeds what a pilot would do when he THINKS he is doing maximum manual braking.
 
Lance F said:
In the planes I fly, the pilot flying activates the spoilers by flipping a switch of all things, deploys the TRs by pulling a couple of handles and applies the brakes by pushing a couple of pedals with his feet. Gee, what a concept.
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Haha, I have flown mostly manual airplanes too. The exception was the autospoilers on the Lear 55. We always armed them but since most of my time was in the 35 where there was no "auto" I flipped the switch manually too. I could see myself forgetting to do it in the 35 because I was used to the automatic feature in the 55. That said, in all the jets I have flown the non-flying pilot calls out something like, "speedbrakes out" (or spoilers, depending on what it has), then "two armed, two deployed" for the TRs. AFAIK we haven't heard what the CVR showed the crew saying in this instance.
 
N801BH said:
Let me play the devils advocate here......

The airport is a MAJOR part of our economy in Jackson. A week before the slideoff this appeared in the local newspaper.

http://www.jhnewsandguide.com/article.php?art_id=6815

You can read between the lines but, airport officials were NOT happy with the airlines.
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It seems like it wasn't just the officials who weren't happy.

Eyewitnesses reported one woman who threw her jacket and told her husband she was never coming back to Jackson Hole. Another lady screamed on the phone that an airline agent was “stupid.”

Haywood McDonald, a 17-year-old passenger flying to Fayetteville, N.C., said he was frustrated that he had to wait for eight hours without any explanation from the airlines.

Some took the delays in stride.

“I kinda just sat there,” said 9 year-old Marianna Schantz. “I read my book, and I talked to strangers. I like to talk.”
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I agree that the airlines could do a better job with explanations but it always amazes me that people spend their holiday at a ski area, where the object is to have SNOW, then they complain because of transportation problems. This is compounded by the fact that everyone wants to arrive and, especially, leave at the same time.

N801BH said:
Now,,, add to this Christmas week is a very important time to cram as many tourists through the airport to boost revenue to all the local businesses.. and remember the old saying " follow the money.

The braking action vehicle is a yellow Saab with MU reporting equipment in it. Does it just read out numbers and they are written down and relayed to the tower? Does it have any data archiving capacity to back up the readings? But ................... What if they "fudged" the numbers to allow for more flights to make it in and it lead to this incident ?
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I don't know that I would suspect them of fudging the numbers. I think, at least in our case, that they waited too long to take another measurement. They waited until someone (us and an airliner following us) complained about it. They ran the truck again and came up with something in the poor-nil range. Only after that did they close the runway for more plowing.
 
As the NTSB reports duly note.

Lance F said:
In the planes I fly, the pilot flying activates the spoilers by flipping a switch of all things, deploys the TRs by pulling a couple of handles and applies the brakes by pushing a couple of pedals with his feet. Gee, what a concept.
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Everskyward said:
It seems like it wasn't just the officials who weren't happy.

I don't know that I would suspect them of fudging the numbers. I think, at least in our case, that they waited too long to take another measurement. They waited until someone (us and an airliner following us) complained about it. They ran the truck again and came up with something in the poor-nil range. Only after that did they close the runway for more plowing.
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Don't ya just hate being the 'guinea' pig... :dunno::dunno:.

Unless the airliner following you was not able to go around and had to land, the 'smart and safe' thing to do would have been to send out the traction measuring vehicle to comfirm your complaint. To let an airliner have to give a second opinion is flirting with disaster. IMHO.

Kinda gives you the impression that corporate/GA pilots cannot be trusted as being able to give accurate feedback. :goofy::goofy::D
 
Greg,

Do you know if the 757 braking system incorporates Touchdown Protection or something similar? I have only flown Embraer's but both the EMB-145 and ERJ-175 had it. Here is a description from our systems manual:

TOUCHDOWN PROTECTION
Touchdown protection prevents the airplane from touching down with the main landing gear brakes applied.

It is deactivated:
• Three seconds after WOW has sensed the ground; or
• When wheel speed is above 50 kt.
 
Auburn_CFI said:
Greg,

Do you know if the 757 braking system incorporates Touchdown Protection or something similar?
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I can't speak for the 757 because I have never flown it. But in the 777 the answer is no. It is virtually impossible to "accidentally" set the parking brake in flight because it takes pressing on the brakes and pulling a lever, and if one DID manage to do that, there is a line on one if the displays that indicates the brakes are set. I can't see that warning being ignored.

But I suppose anything is possible.
 
Same problem as at KASE. The town fathers are dead set against lengthening the 7000 feet which are at nearly 8000 MSL. Jackson is 6300 feet at 6400 MSL.

The town fathers won't allow expansion but decry cancellations. I think humans are the same everywhere along the Front Range.....
 
bbchien said:
Same problem as at KASE. The town fathers are dead set against lengthening the 7000 feet which are at nearly 8000 MSL. Jackson is 6300 feet at 6400 MSL.

The town fathers won't allow expansion but decry cancellations. I think humans are the same everywhere along the Front Range.....
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Well the town fathers in Aspen must have finally seen the light. KASE will be 8000' by the end of the summer!! :thumbsup:
http://www.aspentimes.com/article/20101124/NEWS/101129935
 
Greg Bockelman said:
I can't speak for the 757 because I have never flown it. But in the 777 the answer is no. It is virtually impossible to "accidentally" set the parking brake in flight because it takes pressing on the brakes and pulling a lever, and if one DID manage to do that, there is a line on one if the displays that indicates the brakes are set. I can't see that warning being ignored.

But I suppose anything is possible.
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Gotcha. I just have to believe there was some type of serious systems degradation for whatever reason. I hope I am right! Reserving judgement until final report is released.
 
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