American Airlines jet goes off runway in Jackson Hole, Wyoming
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perceptions of deceleration
I wonder how much the pilot perception of deceleration might play in this...if the runway is snow covered, one can't see the markings (I've always felt that runways should have the white markings outlined in red or yellow or orange).
I am also a fan of airspeed callouts during rollout...and indeed our company has 100 knot calls and 60 knot callouts during rollout.
I wonder how much the pilot perception of deceleration might play in this...if the runway is snow covered, one can't see the markings (I've always felt that runways should have the white markings outlined in red or yellow or orange).
I am also a fan of airspeed callouts during rollout...and indeed our company has 100 knot calls and 60 knot callouts during rollout.
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Much has been made of the reversers not deploying until very late in the landing roll.
Because they are not required and their performance is not included in any normal performance data, I have never seen a chart of the effectiveness of a reverse thrust installation.
I believe all AA 757's have RR engines. Their reversers are relatively ineffective compared to other installations. And the idle thrust setting produces very little thrust (air or ground flight idle).
By comparison, the Pratt powered 757's have extremely powerful reversers. They also produce a substantial amount of idle thrust.
My point.....I think at the end of the day, the lack of spoilers and either a low or no autobrake setting may be the culprit. Yes, non-deploying reversers may have occupied the crew from verifying spoiler deployment. But I do not believe the lack of reversers until late on the rollout on this aircraft will be a major factor due to their relative lack of effectiveness.
Because they are not required and their performance is not included in any normal performance data, I have never seen a chart of the effectiveness of a reverse thrust installation.
I believe all AA 757's have RR engines. Their reversers are relatively ineffective compared to other installations. And the idle thrust setting produces very little thrust (air or ground flight idle).
By comparison, the Pratt powered 757's have extremely powerful reversers. They also produce a substantial amount of idle thrust.
My point.....I think at the end of the day, the lack of spoilers and either a low or no autobrake setting may be the culprit. Yes, non-deploying reversers may have occupied the crew from verifying spoiler deployment. But I do not believe the lack of reversers until late on the rollout on this aircraft will be a major factor due to their relative lack of effectiveness.
Per Ardua ad Astraeus
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Well, I hope we all managed to interpret my 'has anyone ever seen' in its intended sense! It is indeed a bonus that we have been able to 'see' this event.
Misd - it would be useful if you could tell us what the finding was, and since you could not 'see' what happened to the sleeve, what the symptoms were? EG any REV malfunction lights in the cockpit, restricted levers, other 'symptoms' etc etc?
Misd - it would be useful if you could tell us what the finding was, and since you could not 'see' what happened to the sleeve, what the symptoms were? EG any REV malfunction lights in the cockpit, restricted levers, other 'symptoms' etc etc?
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Misd - it would be useful if you could tell us what the finding was
AA, in the dark...except for their transport of the DFDR to Tulsa.
One wonders...what do AA have to hide:?
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Recall of what the details were? 25+ yrs, maybe 5000 flights so I have no recall on the details. The 4 tire replacement was not on the 757. I do remember that becaues of the tire replacement. Similar event, no thrust reversers, no auto spoilers, don't recall if auto brakes worked. Manual brakes did. 
Four tires later we left.
I've had reversers not deploy on several different a/c types. It happens. Not often, but it happens. Recollection on Airbus and 757 were no reverse lever movement.
Shoreguy-there are performance charts that show the value of reversers during landing. Roughly 1500' reduction in landing roll for 'Fair' and almost 5000' for 'Poor' was quoted on another MB. Varies by a/c.
757 w/P&W has awesome reverse thrust. No data on if the RR 757 reverser thrust is "poor". It seems to be similar to 727/737/767 reverser thrust. So maybe the RR's reverse thrust is 'poor', instead maybe they seem poor because the P&W 757 engines are outstanding.
411A - Thanks for underlining your personal issues.
Four tires later we left. I've had reversers not deploy on several different a/c types. It happens. Not often, but it happens. Recollection on Airbus and 757 were no reverse lever movement.
Shoreguy-there are performance charts that show the value of reversers during landing. Roughly 1500' reduction in landing roll for 'Fair' and almost 5000' for 'Poor' was quoted on another MB. Varies by a/c.
757 w/P&W has awesome reverse thrust. No data on if the RR 757 reverser thrust is "poor". It seems to be similar to 727/737/767 reverser thrust. So maybe the RR's reverse thrust is 'poor', instead maybe they seem poor because the P&W 757 engines are outstanding.
411A - Thanks for underlining your personal issues.
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Yep, what he said. The MDW airport is one slippery rascal this time of year.
SWA usually makes the high speed on 31C, and most A/C call the BRAG. I'd always call for BRA for the full length. ATC would reply..."uh, I'll check.
The last 1000 feet of 31C were usually BRAP. Sooo...I'd come out of reverse (737-800NG) expecting to keep on slowing down. I only did that once. When the -800s were new on the property, we noted the rather high ref speeds as compared to the 72'. Only, the 72' didn't have winglets.
SWA used to make fun of us for using the full length during landings during winter ops.
MDW isn't "The Hole", but it was a good trainer for "Hole" ops.
SWA usually makes the high speed on 31C, and most A/C call the BRAG. I'd always call for BRA for the full length. ATC would reply..."uh, I'll check.
The last 1000 feet of 31C were usually BRAP. Sooo...I'd come out of reverse (737-800NG) expecting to keep on slowing down. I only did that once. When the -800s were new on the property, we noted the rather high ref speeds as compared to the 72'. Only, the 72' didn't have winglets.
SWA used to make fun of us for using the full length during landings during winter ops.
MDW isn't "The Hole", but it was a good trainer for "Hole" ops.
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Some ballpark figures to give perspective. Not all of the corrections have been applied.
RR 757 Breaking Action Good @86T. Basic 1240m, add 30m/1000' altitude, add 80m for No T/R.
Breaking Action Poor @86T Basic 2040m, add 70m/1000 altitude, add 1245m for No T/R.
So under normal conditions lack of immediate T/R is no big deal, on a snowy runway its an underpant changing situation altogether!
RR 757 Breaking Action Good @86T. Basic 1240m, add 30m/1000' altitude, add 80m for No T/R.
Breaking Action Poor @86T Basic 2040m, add 70m/1000 altitude, add 1245m for No T/R.
So under normal conditions lack of immediate T/R is no big deal, on a snowy runway its an underpant changing situation altogether!
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The reversers finally begin deploying at 4000 ft and are fully open by 5000 ft but begin to achieve thrust at 5500 ft, but by then the speed is near 80 knots.
Wow, from the long SWA1248 report (mods mine) :
.
Wow, from the long SWA1248 report (mods mine) :
o- ... using SWA routine/planned deceleration procedures to decelerate, showed that the airplane would likely have stopped about 1,351 feet beyond the end of the runway....
o- Under the same conditions and if the pilots had used Boeing’s reverse thrust procedures (...), simulations showed that the airplane would likely have stopped about 531 feet beyond the end of the runway.
o- However, simulations in which maximum reverse thrust was selected 2 seconds after touchdown and maintained until the airplane came to a complete stop (...) showed that the airplane could have stopped about 271 feet before the departure end of the runway.
o- Under the same conditions and if the pilots had used Boeing’s reverse thrust procedures (...), simulations showed that the airplane would likely have stopped about 531 feet beyond the end of the runway.
o- However, simulations in which maximum reverse thrust was selected 2 seconds after touchdown and maintained until the airplane came to a complete stop (...) showed that the airplane could have stopped about 271 feet before the departure end of the runway.
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The art and science of stopping a plane is often overlooked during routine flight operations. Sadly, routine can quickly become non routine.
Most of my flying has been at critical length airports and every landing/takeoff was a max effort.
It is a discipline that is mandatory...and the first time you ''get away with something'' better teach you a lesson!
I wonder if American has a 100 knot callout on landing roll followed by a 60 knot call?
anyone out there know?
7
Most of my flying has been at critical length airports and every landing/takeoff was a max effort.
It is a discipline that is mandatory...and the first time you ''get away with something'' better teach you a lesson!
I wonder if American has a 100 knot callout on landing roll followed by a 60 knot call?
anyone out there know?
7
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Sevenstroke..... Yes they have (when last I flew the 75) a 100 knot call, also an 80 knot call. Additionally, if nearing the last 3000 feet of runway and speed is over 80 knots, mandatory callout AND ACTION is/was "MAX BRAKES !!"
Recollections of inability to deploy reversers on two different occasions on AA 757's in about 10,000 hours between the 75/76 fleet. Both times just wrestled against the reverser interlocks and the reversers would not deploy. Each time, manually deployed the boards and used manual brakes, neither time a big deal.... but neither on slippery runways either. Immediately after touchdown, the PNF watches for amber REV indicating reverse sleeve translating aft, quickly followed by green REV
annunciation on EICAS display. PNF is also watching for spoiler deployment and auto-brake function.
As mentioned in thread, P&W engines have better reverse thrust steam that the Rolls engine on the AA 757. Whatever; the Rolls engine is plenty capable of significant reversing, of course the earlier and higher speed the better.
Thread drift.... AMR bought TWA, and their PW powered 757's came with the deal. They were great to taxi and initial TO roll.... you could release the brakes on the Pratts at idle and the jet would start moving...the Rolls needed an inch or so of throttle to get taxiing. The Pratts would also spool up quicker off idle. That was it then for the Pratt engined birds, 'cause they were about 37,000 lbs thrust. The Rolls engines, tho less quick to spool and less idle thrust.... well they cranked right up to just over 43,000 lbs thrust and it was buh-bye Pratt powered 75's. (all former TWA 757s are gone as far as I know)
Back to the story, I believe/hope the CVR/DFDR is gonna reveal the crew diligently briefed and configured the 757 IAW AA procedures. For sure, what happened on the runway is gonna be interesting. Bottom line, nobody as much as scratched and apparently no metal bent.
The RB211 has had it's share of thrust reverser AD's over the years; the first ones I recall dealt with routing of cockpit cables and pulleys/ interference with window heat wire bundles, replacing Boeing's early production phenolic pulleys with, I think, aluminum ones. Early production 757's had no thrust reverse sync-lock and caused some teething problems as well.
Recollections of inability to deploy reversers on two different occasions on AA 757's in about 10,000 hours between the 75/76 fleet. Both times just wrestled against the reverser interlocks and the reversers would not deploy. Each time, manually deployed the boards and used manual brakes, neither time a big deal.... but neither on slippery runways either. Immediately after touchdown, the PNF watches for amber REV indicating reverse sleeve translating aft, quickly followed by green REV
annunciation on EICAS display. PNF is also watching for spoiler deployment and auto-brake function.
As mentioned in thread, P&W engines have better reverse thrust steam that the Rolls engine on the AA 757. Whatever; the Rolls engine is plenty capable of significant reversing, of course the earlier and higher speed the better.
Thread drift.... AMR bought TWA, and their PW powered 757's came with the deal. They were great to taxi and initial TO roll.... you could release the brakes on the Pratts at idle and the jet would start moving...the Rolls needed an inch or so of throttle to get taxiing. The Pratts would also spool up quicker off idle. That was it then for the Pratt engined birds, 'cause they were about 37,000 lbs thrust. The Rolls engines, tho less quick to spool and less idle thrust.... well they cranked right up to just over 43,000 lbs thrust and it was buh-bye Pratt powered 75's. (all former TWA 757s are gone as far as I know)
Back to the story, I believe/hope the CVR/DFDR is gonna reveal the crew diligently briefed and configured the 757 IAW AA procedures. For sure, what happened on the runway is gonna be interesting. Bottom line, nobody as much as scratched and apparently no metal bent.
The RB211 has had it's share of thrust reverser AD's over the years; the first ones I recall dealt with routing of cockpit cables and pulleys/ interference with window heat wire bundles, replacing Boeing's early production phenolic pulleys with, I think, aluminum ones. Early production 757's had no thrust reverse sync-lock and caused some teething problems as well.
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thanks sks777
I read somewhere that when any captain is the non flying pilot (monitoring pilot) he often doesn't comply with all the callouts as well as when the copilot is the nfp.
Now , I sure don't know what happened in that cockpit, but I wonder if there was a recognition of braking problems/stopping problems.
I also wonder if runway markings were difficult to see with snow on them.
I read somewhere that when any captain is the non flying pilot (monitoring pilot) he often doesn't comply with all the callouts as well as when the copilot is the nfp.
Now , I sure don't know what happened in that cockpit, but I wonder if there was a recognition of braking problems/stopping problems.
I also wonder if runway markings were difficult to see with snow on them.
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My 757 landing incident at AA's most critical aiport, Tegucigalpa, Honduras was a non event. One reverser didn't deploy but it didn't matter. We taxied in and got it fixed. You don't need thrust reversers for 99% of your landings to be legal. They probably didn't need reverse thrust on this landing either to be legal. Why the left reverser didn't deploy is not that important, it wasn't required. That 20 seconds skating down the runway off the end is the question. 757's have manual brakes so unless they had a total brake failure they should have stopped with no reverse. Something is missing here.We will know with the CVR.
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thanks B44
we have lots of ways of stopping...I wish we could hear the CVR, but I am sure we won't.
Oh well, I'm sure American won't be the next airline to go off the end...they lucked out on this one.
we have lots of ways of stopping...I wish we could hear the CVR, but I am sure we won't.
Oh well, I'm sure American won't be the next airline to go off the end...they lucked out on this one.
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Bubbers44...
I no longer have my KJAC airport pages, but I recall that flying into JAC for wet or icy conditions, that functioning thrust reversers were required for dispatch.
I don't recall tho, if they were required at JAC for known dry conditions, but suspect they were/are required there.
I no longer have my KJAC airport pages, but I recall that flying into JAC for wet or icy conditions, that functioning thrust reversers were required for dispatch.
I don't recall tho, if they were required at JAC for known dry conditions, but suspect they were/are required there.
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I believe the Capt was quoted as having said that he pulled the CVR CB right after they got the airpane stopped and shut down so as to preserve the voice data.
On another subject. I have flown both PW and RR powered B757's and I'm not aware of any reuction in reverse power on the RR aircraft, nor is Boeing, so you might want to call the performance engineers up in Renton and let them know about this issue.
On another subject. I have flown both PW and RR powered B757's and I'm not aware of any reuction in reverse power on the RR aircraft, nor is Boeing, so you might want to call the performance engineers up in Renton and let them know about this issue.
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To use the full runway, at a constant deceleration, they would have had to
decelerate at 1.66 m/s/s, which they never achieved at any instant.
This resembles the SWA1248 accident more and more; but luckily without any dead.
.
decelerate at 1.66 m/s/s, which they never achieved at any instant.
This resembles the SWA1248 accident more and more; but luckily without any dead.
.
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alpha2Z
I think they did achieve a better decel rate than that ..... in about 600 some feet of deep snow.
they would have had to
decelerate at 1.66 m/s/s, which they never achieved at any instant.
decelerate at 1.66 m/s/s, which they never achieved at any instant.
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isn't it funny how the copilot uses his left hand (usually the weaker) to operate the throttles and reverse levers
there are some differences between this and the southwest...worse visibility for southwest, a quartering tailwind
but both had mountains...those in chicago of course were man made ;0
we really don't practice stopping airplanes enough and what to do if stopping devices don't work properly.
memory items:
reverser failure checklist
brake failure checklist
spoiler failure checklist
how many of you have practiced those? (none of course)
there are some differences between this and the southwest...worse visibility for southwest, a quartering tailwind
but both had mountains...those in chicago of course were man made ;0
we really don't practice stopping airplanes enough and what to do if stopping devices don't work properly.
memory items:
reverser failure checklist
brake failure checklist
spoiler failure checklist
how many of you have practiced those? (none of course)