AA Crash Jamaica
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It has been established the the aircraft landed with Autobrakes 3.
An earlier question has not, to my knowledge, been answered - What was the flap setting on landing?
Follow up question...what is the difference in ref speed 30 vs. 40? And if anyone has an AOM or airport analysis, are there different landing charts for 30 vs 40 flap?
Thanks in advance.
An earlier question has not, to my knowledge, been answered - What was the flap setting on landing?
Follow up question...what is the difference in ref speed 30 vs. 40? And if anyone has an AOM or airport analysis, are there different landing charts for 30 vs 40 flap?
Thanks in advance.
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Bit of waffle going on here chaps me thinks! Autobrake 3 will give approx 2000psi, Autobrake Max approx 3000 indicated until the residual pressure drops. Why on gods earth would you want Max Autobrake, or the equivalent on " normal" landing. If there is danger of leaving the paved then yes, but otherwise.. come on guys, we dont want the pax arriving at the bridge before the airplane!
Shore Guy
We know the aircraft landed with a VREF of 148 kts
I am assuming this was the Flap 30 ref speed.
If it was then Flap 40 would have been in the region of 141 kts.
Experts, please feel free to correct me if I am wrong.
We know the aircraft landed with a VREF of 148 kts
I am assuming this was the Flap 30 ref speed.
If it was then Flap 40 would have been in the region of 141 kts.
Experts, please feel free to correct me if I am wrong.
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I read that the pilot disengaged auto brakes after landing to use manual braking.
There are so many visual cues and mis cues that could throw someone off in judging the landing and rollout.
I am not a fan of auto anything...but I will say auto brakes , if left to do their job , are a good idea.
tailwind, wet, not edwards AFB (15k runways), not grooved, night...use it all, and don't cancel reverse...what's an engine surge compared to a crack up.
There are so many visual cues and mis cues that could throw someone off in judging the landing and rollout.
I am not a fan of auto anything...but I will say auto brakes , if left to do their job , are a good idea.
tailwind, wet, not edwards AFB (15k runways), not grooved, night...use it all, and don't cancel reverse...what's an engine surge compared to a crack up.
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411A,
I was trying to get a feel for training in different airlines and operating environments.
It is my understanding that most US carriers do not train for circling approaches and certainly not when it is below 1000/3??? I have also heard that "No Circling" is a restriction on some type ratings.????
BS
Why, you might ask?
It is my understanding that most US carriers do not train for circling approaches and certainly not when it is below 1000/3??? I have also heard that "No Circling" is a restriction on some type ratings.????
BS
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411 - "The subject aircraft was equipped with a HUD (as I recall), and if properly used, should greatly aid in the visibility department.
Comments from those that have used a HUD in the 737 might be interesting, in this regard."
The HUD has it's limitations. To think that it's the greatest thing since sliced bread was invented is silly.
Field of view issues. Lighting intensity issues, jumpiness of Flight Path Vector in turbulence, etc, etc.
Comments from those that have used a HUD in the 737 might be interesting, in this regard."
The HUD has it's limitations. To think that it's the greatest thing since sliced bread was invented is silly.
Field of view issues. Lighting intensity issues, jumpiness of Flight Path Vector in turbulence, etc, etc.
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It is my understanding that most US carriers do not train for circling approaches and certainly not when it is below 1000/3??? I have also heard that "No Circling" is a restriction on some type ratings.????
Depends on the individual airline.
We circle regularly, so therefore require pilots that are proficient in this maneuver.
I'ts not that difficult, just needs practise.
PENKO, fireflybob;
&
Also as most of us would know, the two systems, [reverse thrust & brakes] are different retardation devices which are effective in different speed/landing regimes, reverse being most effective at higher speeds.
There's a more subtle point here though - asking the question about brakes would not apply to the use of reverse. IOW, just because one doesn't use 3000psi on the brakes as a routine action does not mean it is reasonable to say that one shouldn't use full reverse.
The question of flap setting and stability on the approach has been around a while as well, most notably on the A320 and A321, (which have since been addressed by Airbus in terms of damping the aileron response to stick inputs).
Onthe landing flap selection, we dont' know what the crew assessed or decided was the tailwind component they expected to experience. It is likely with a long runway and experience in the approach weather and perhaps with the specific airport, the expectation of a "difficult" approach/landing may have been comparatively low and the selection of landing flap may have been governed accordingly.
Originally Posted by PENKO
Fireflybob, captplaystation, just curious. Do you use the full 3000 PSI braking power on every landing? And why not?
Originally Posted by fireflybob
Everything landing needs to be careful assessed in terms of flap setting, autobrake level, reverse thrust etc.
There's a more subtle point here though - asking the question about brakes would not apply to the use of reverse. IOW, just because one doesn't use 3000psi on the brakes as a routine action does not mean it is reasonable to say that one shouldn't use full reverse.
The question of flap setting and stability on the approach has been around a while as well, most notably on the A320 and A321, (which have since been addressed by Airbus in terms of damping the aileron response to stick inputs).
Onthe landing flap selection, we dont' know what the crew assessed or decided was the tailwind component they expected to experience. It is likely with a long runway and experience in the approach weather and perhaps with the specific airport, the expectation of a "difficult" approach/landing may have been comparatively low and the selection of landing flap may have been governed accordingly.
Last edited by PJ2; 10th Jan 2010 at 15:48.
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no written Preliminary -- only a Press Rpt about VERBAL brief
Question posed, by "Shore Guy":
Later, we might be offered better data. For now, suspect that the "Vref" cited was erroneous (but maybe the touchdown spd of 148KIAS was accurate).
"... An earlier question has not, to my knowledge, been answered - What was the flap setting on landing?"
My guess is that the PRESS reporter made a few errs in transcribing a VERBAL briefing offered by the investigating authority. The NTSB are bystanders, observers, and participants -- but the NTSB offered NO printed Preliminary Rpt. Similarly, the manufacturer carefully repeated statements carried in the press report (not their reading of the FDR).Later, we might be offered better data. For now, suspect that the "Vref" cited was erroneous (but maybe the touchdown spd of 148KIAS was accurate).
Last edited by IGh; 10th Jan 2010 at 17:35.
fireflybob, thanks for your answer and of course you have a very valid point. However I still work on the assumption that we are not total idiots up front. We know full reverse is available. And hopefully we're smart enough to consider its use when there is the slightest hint of its necessity. The funny thing is, we are afraid of being dumbed down by automatics and SOP's, but when a choice IS offered, some of us bark from the highest tree. It seems sometimes that the same guys that say that 5 knots too fast at 500' is no big deal will say that they always pull full reverse. Then again, they might need it 
But again, you do have a point of course, I'm not disputing that.
But again, you do have a point of course, I'm not disputing that.
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It doesn't matter how much reverse you use, if you land half way down the runway at these speeds you need an arresting wire! One could argue that as reverse is not part of the "stopping peformance" we don't need any.. Non normal stopping distance is nothing like the length they had here. High on glide, float, tail wind.. off the end with panache, there but for the grace etc!
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I was required to land on the 757 at autobrakes 4. I always overrode them once on the ground at TGU. You could make more braking action, same as max, by using manual brakes if needed.
If they landed almost half way down the runway for some reason then it probably didn't matter much how they used their brakes or reversers. If the NTSB concurs about their touchdown report of 4100 ft. guess that is how it happened.
If they landed almost half way down the runway for some reason then it probably didn't matter much how they used their brakes or reversers. If the NTSB concurs about their touchdown report of 4100 ft. guess that is how it happened.
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...NTSB concurs about their touchdown report of 4100 ft. guess that is how it happened.
And further, IF indeed this is the case, AA needs some major corrective action to be damn sure it does NOT happen again.
Landing long/deep with a jet transport airplane is NOT to be tolerated...ever.
EVER!
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Arrester Barrier would have helped !!
Jokes apart for planes touching down beyond the touchdown zone.. first 3 thousand feet or so..and on the short runways...the resultant ....
residual.. i call it left-overs of the runway...landing run is critical.. add to it rain and poor visibility.. its a perfect recipe for Hull Loss..
Guys we can not take tailwinds and rain so lightly.. we have seen a A320 over-running n' going off a few months ago.. rather at the beginning of the year 2009 with one Thrust Reverser under MEL and the aircraft had a overshooting approach and touched down late.. beyond touchdown zone, I guess..
Net Result =Hull Loss.
Please use MAX auto brakes when in slightest doubt.. you may need to explain about the harsh braking but not about the Hull Loss !!!
They also have a limit...and cant save you if you touch down down after 4000 feet on a 6000 feet wet runway with gusty tail winds...
Happy Landings..
residual.. i call it left-overs of the runway...landing run is critical.. add to it rain and poor visibility.. its a perfect recipe for Hull Loss..
Guys we can not take tailwinds and rain so lightly.. we have seen a A320 over-running n' going off a few months ago.. rather at the beginning of the year 2009 with one Thrust Reverser under MEL and the aircraft had a overshooting approach and touched down late.. beyond touchdown zone, I guess..
Net Result =Hull Loss.
Please use MAX auto brakes when in slightest doubt.. you may need to explain about the harsh braking but not about the Hull Loss !!!
They also have a limit...and cant save you if you touch down down after 4000 feet on a 6000 feet wet runway with gusty tail winds...
Happy Landings..
mb 787 – Please use MAX auto brakes when in slightest doubt.. you may need to explain about the harsh braking but not about the Hull Loss !!!
Does this mean using autobrakes to demand the maximum value of deceleration, i.e. RTO, or just a limited deceleration from one of the other autobrake settings?
If the latter, or possibly in both instances, then the braking system may not use all of the available braking effort in very poor conditions – wet / non grooved /rubber deposits.
See page 13 of the presentation Landing on Slippery Runways.
Also, note page 14, which suggests that using manual braking maximizes the advantage of thrust reverse on ‘slippery’ runways, i.e. the better choice is to use maximum manual brakes in marginal conditions – it provides some protection from landing error (parameters outside of the assumptions in the data).
IMHO, no pilot need explain about harsh braking; you only need to explain to the passengers about the long delay in unloading the aircraft from the overrun area.
The link reference also provides example for the 738 landing performance and compares flap 30 / 40.
Although Boeing recommends using autobrake, apparently this is in conjunction with their landing data which assumes a reasonable touchdown point and using reference speeds.
I doubt that the published data would have provided an acceptable solution for the reported conditions in this accident, but then the crew might not have been aware of that.
Does this mean using autobrakes to demand the maximum value of deceleration, i.e. RTO, or just a limited deceleration from one of the other autobrake settings?
If the latter, or possibly in both instances, then the braking system may not use all of the available braking effort in very poor conditions – wet / non grooved /rubber deposits.
See page 13 of the presentation Landing on Slippery Runways.
Also, note page 14, which suggests that using manual braking maximizes the advantage of thrust reverse on ‘slippery’ runways, i.e. the better choice is to use maximum manual brakes in marginal conditions – it provides some protection from landing error (parameters outside of the assumptions in the data).
IMHO, no pilot need explain about harsh braking; you only need to explain to the passengers about the long delay in unloading the aircraft from the overrun area.
The link reference also provides example for the 738 landing performance and compares flap 30 / 40.
Although Boeing recommends using autobrake, apparently this is in conjunction with their landing data which assumes a reasonable touchdown point and using reference speeds.
I doubt that the published data would have provided an acceptable solution for the reported conditions in this accident, but then the crew might not have been aware of that.
SkyGod
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And further, IF indeed this is the case, AA needs some major corrective action to be damn sure it does
If the only trend you can come up with is Little Rock, then the real trend is 8 million flights without over-runs between the Little Rock and Kingston accidents.
Suggest you stick to old 1011 stories and if AA or the NTSB need your advice, I am sure they will ask for it.
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So a captain is incompent or has a brain-fart/bad day (Or brake/anti-skid failure) and the whole airline needs major corrective action?
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For those that think "Autobrakes" are the saviour of everything, they are designed to give you a deceleration RATE! They take into account any reverse that might be applied, it is up to the pilot to make sure the A/C stops.
As for those suggesting max autobrake / 3000psi for EVERY landing are NOT thinking pilots, there is NO need for max on EVERY landing.
As for reverse thrust our company is quite clear, on a long dry runway into wind, then idle reverse would be okay, otherwise full reverse!
As for those suggesting max autobrake / 3000psi for EVERY landing are NOT thinking pilots, there is NO need for max on EVERY landing.
As for reverse thrust our company is quite clear, on a long dry runway into wind, then idle reverse would be okay, otherwise full reverse!
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Autobrakes set a deceleration rate depending on the setting but if braking action is poor or hydroplaning it doesn't matter what you set, the brakes can only do what the braking action is. Use all the reverse you feel you need for each landing because in certain cases the autobrakes can't help much on slick runways.
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Clearing up where perhaps none is needed...
Autobraking does not shorten stopping distances. It only serves to reduce workload, manage brake wear and heating, and has been known to produce smoother decels over some, but not all, human feet.