Near miss with 5 airliners waiting for T/O on taxiway "C" in SFO!
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, AC 759 was vectored for a visual approach to 28R the second time around. A visual approach is not the same as an ILS (although I'm sure some folks on this thread would argue otherwise). They were given a heading of 310 to join the final and cleared for a visual approach behind an AA 777 who was on the FMS Bridge Visual Approach 28R. It's on the tape at liveatc.net
The old 30 minute CVR's used to have a union-mandated bulk erase button. And inevitably somehow this bulk erase button would often seem to 'accidentally' get pushed after an incident. As the NTSB put it in a famous 1979 upset investigation:
We believe the captain's erasure of the CVR is a factor we cannot ignore and cannot sanction. Although we recognize that habits can cause actions not desired or intended by the actor, we have difficulty accepting the fact that the captain's putative habit of routinely erasing the CVR after each flight was not restrainable after a flight in which disaster was only narrowly averted.
Our skepticism persists even though the CVR would not have contained any contemporaneous information about the events that immediately preceded the loss of control because we believe it probable that the 25 minutes or more of recording which preceded the landing at Detroit could have provided clues about causal factors and might have served to refresh the flightcrew's memories about the whole matter.
Our skepticism persists even though the CVR would not have contained any contemporaneous information about the events that immediately preceded the loss of control because we believe it probable that the 25 minutes or more of recording which preceded the landing at Detroit could have provided clues about causal factors and might have served to refresh the flightcrew's memories about the whole matter.
Last edited by Airbubba; 7th Aug 2017 at 02:55.
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The old 30 minute CVR's used to have a union-mandated bulk erase button.
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Routine deletion of CVR moves things more and more toward an automatic downlink of CVR if not in flight (and yes the bandwidth is enough) then it could be automated as soon as the aircraft plugged in at the gate for every flight. The 'system' could delete CVR data if there is no requirement for the data after 28 days, in the same way as most ATM recordings.
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When did they call the FAA supervisor? What was discussed?
Has this guy been identified & interviewed? From previous posts I've gleaned that the '28R Bridge approach' is used when 28L is in use so as to provide increased separation during the initial approach. Is that correct, or is it purely noise abate reasons? If the former is true, and 28L was closed, why give a more difficult visual approach at night than a simple straight forward ILS?
It has been agreed that this incident started many miles and minutes before; in the cruise, when the NOTAMS had not been reviewed and not included in the brief, apparently. There is much talk about the confusion created by what kind of approach was given. Possible. There is speculation about tiredness/fatigue, but then it was countered by the natural kick-in of stimulation by a challenging visual approach. Been there done that many times: it is correct. (We do not yet know at what point the A/P was a disconnected). What ever the approach given & flown it still remains that the route was to bring you onto a visual finals that is defined by lots of well known and often experienced lights. IMHO the type of 'Bridge' approach is a red herring. Green lights DO NOT = runway. Never and nowhere in the world. The confusion over the landing area started inside 4nm. The root cause lies well before that, but after the FMC brought them on to a visual finals 2 sets of eyes & brains managed to become confused.
I'd love to hear the CVR from 10nm out. "can you see the runway? yeah it's over there. Oh yep, go it." a few nm later. "do we land over the lights or on the right? Er, left is closed, I think, so over to the right." "You sure? I think so." etc. etc. all the way down to 100'.
GREEN lights DO NOT equal runway. Saying there are lights? on the runway, are we cleared to land is just astonishing. Lights on the runway or not, GREEN lights do not equal a landing area. And 2 pilots. Where was PM looking. Who was PM, LHS/RHS, and when were they under manual control?
Has this guy been identified & interviewed? From previous posts I've gleaned that the '28R Bridge approach' is used when 28L is in use so as to provide increased separation during the initial approach. Is that correct, or is it purely noise abate reasons? If the former is true, and 28L was closed, why give a more difficult visual approach at night than a simple straight forward ILS?
It has been agreed that this incident started many miles and minutes before; in the cruise, when the NOTAMS had not been reviewed and not included in the brief, apparently. There is much talk about the confusion created by what kind of approach was given. Possible. There is speculation about tiredness/fatigue, but then it was countered by the natural kick-in of stimulation by a challenging visual approach. Been there done that many times: it is correct. (We do not yet know at what point the A/P was a disconnected). What ever the approach given & flown it still remains that the route was to bring you onto a visual finals that is defined by lots of well known and often experienced lights. IMHO the type of 'Bridge' approach is a red herring. Green lights DO NOT = runway. Never and nowhere in the world. The confusion over the landing area started inside 4nm. The root cause lies well before that, but after the FMC brought them on to a visual finals 2 sets of eyes & brains managed to become confused.
I'd love to hear the CVR from 10nm out. "can you see the runway? yeah it's over there. Oh yep, go it." a few nm later. "do we land over the lights or on the right? Er, left is closed, I think, so over to the right." "You sure? I think so." etc. etc. all the way down to 100'.
GREEN lights DO NOT equal runway. Saying there are lights? on the runway, are we cleared to land is just astonishing. Lights on the runway or not, GREEN lights do not equal a landing area. And 2 pilots. Where was PM looking. Who was PM, LHS/RHS, and when were they under manual control?
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The old 30 minute CVR's used to have a union-mandated bulk erase button. And inevitably somehow this bulk erase button would often seem to 'accidentally' get pushed after an incident. As the NTSB put it in a famous 1979 upset investigation:
https://www.ntsb.gov/investigations/...ts/AAR8108.pdf
https://www.ntsb.gov/investigations/...ts/AAR8108.pdf
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RAT you really need to do a visual perception course to see how easy it is for _your_ cognition to deceive you. Aircraft landing on taxiways is not uncommon despite all the green center lines and blue edge lights - and the pilots often high hours professionals, were all convinced they were landing on the runway. It would be better to work out why these cognitive misperceptions occur rather than question the capability of the crews involved.
Also the idea that suddenly being stimulated is a way to avoid cognitive issues has been shown to be wrong since 1908 in Human Factors research. Two psychologists Yerkes and Dodson developed a theory that has been continually shown to be true since then that both little stimulation and high stimulation can lead to errors in attention, It is often called the inverted U theory as performance is best at a median level of stress/stimulation.
From Yerkes Dodson Law - AviationKnowledge
(my underline)
There are many more references on inverted U and Yerkes Dodson if you do an internet search. Being at the wrong part of the circadian cycle and fatigue will exacerbate these effects.
Also the idea that suddenly being stimulated is a way to avoid cognitive issues has been shown to be wrong since 1908 in Human Factors research. Two psychologists Yerkes and Dodson developed a theory that has been continually shown to be true since then that both little stimulation and high stimulation can lead to errors in attention, It is often called the inverted U theory as performance is best at a median level of stress/stimulation.
From Yerkes Dodson Law - AviationKnowledge
When arousal is high the quality of performance is expected to decline with load shedding, and tunnel vision symptomatic of attention narrowing. An experience Wickens and Hollands (2000, p. 484) describe as “stress produced perceptual tunnelling” directly resulting in a reduction in the standard of performance.
There are many more references on inverted U and Yerkes Dodson if you do an internet search. Being at the wrong part of the circadian cycle and fatigue will exacerbate these effects.
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Missed by 4 feet?
Air Canada Flight Misses By Four Feet
By Geoff Rapoport
https://www.avweb.com/eletter/archiv...t=email#229456
New flight recorder data says Air Canada flight 759 (ACA759), an Airbus A320, descended as low as 59 feet above ground level and the 55-foot tall 787 on Taxiway C before beginning to climb out on its go-around—coming potentially as close as four feet from a collision. At four minutes to midnight on July 7, ACA759, which had been cleared to land on Runway 28R at San Francisco International, instead lined up on Taxiway C, on which three aircraft were holding for takeoff. After prompting by one of the pilots of United Flight 1 (UA1), the first in line for takeoff on Taxiway C, who was well positioned to see that ACA759 was not headed toward a runway, the tower controller instructed ACA759 to go around. After advancing the thrust levers at 85 feet above ground level, the aircraft continued to sink to a minimum altitude of 59 feet, before overflying at least two more aircraft. Altitude figures in the NTSB report are likely based on the A320’s radar altimeter, according to an A320 pilot who spoke with AVweb about the incident. The extent to which the accuracy of the radar altimeter may have been influenced by extremely close proximity to aircraft underneath has not yet been reported by the NTSB.
According to initial interviews with the flight crew, both pilots appear to have been confused by the absence of lighting on Runway 28L, which had been closed for construction. Its lights were turned off at the time of the incident, and a 20.5-foot wide flashing X had been placed near the threshold. The Air Canada pilots reporting believing that Runway 28R was actually 28L and they therefore believed that Taxiway C was Runway 28R. According to the NTSB, the pilots “did not recall seeing aircraft on Taxiway C but that something did not look right to them.” At 0.7 miles from the runway, the Airbus crew had asked the tower to confirm there were no aircraft on 28R and that they were cleared to land. The NTSB only learned of the incident two days after the fact, at which point the cockpit voice recorder had been overwritten by subsequent flights.
Air Canada Flight Misses By Four Feet
By Geoff Rapoport
https://www.avweb.com/eletter/archiv...t=email#229456
New flight recorder data says Air Canada flight 759 (ACA759), an Airbus A320, descended as low as 59 feet above ground level and the 55-foot tall 787 on Taxiway C before beginning to climb out on its go-around—coming potentially as close as four feet from a collision. At four minutes to midnight on July 7, ACA759, which had been cleared to land on Runway 28R at San Francisco International, instead lined up on Taxiway C, on which three aircraft were holding for takeoff. After prompting by one of the pilots of United Flight 1 (UA1), the first in line for takeoff on Taxiway C, who was well positioned to see that ACA759 was not headed toward a runway, the tower controller instructed ACA759 to go around. After advancing the thrust levers at 85 feet above ground level, the aircraft continued to sink to a minimum altitude of 59 feet, before overflying at least two more aircraft. Altitude figures in the NTSB report are likely based on the A320’s radar altimeter, according to an A320 pilot who spoke with AVweb about the incident. The extent to which the accuracy of the radar altimeter may have been influenced by extremely close proximity to aircraft underneath has not yet been reported by the NTSB.
According to initial interviews with the flight crew, both pilots appear to have been confused by the absence of lighting on Runway 28L, which had been closed for construction. Its lights were turned off at the time of the incident, and a 20.5-foot wide flashing X had been placed near the threshold. The Air Canada pilots reporting believing that Runway 28R was actually 28L and they therefore believed that Taxiway C was Runway 28R. According to the NTSB, the pilots “did not recall seeing aircraft on Taxiway C but that something did not look right to them.” At 0.7 miles from the runway, the Airbus crew had asked the tower to confirm there were no aircraft on 28R and that they were cleared to land. The NTSB only learned of the incident two days after the fact, at which point the cockpit voice recorder had been overwritten by subsequent flights.
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uh
At some point, the relentlessness with which you pursue this single line of argument becomes comparable to the relentlessness with which the incident crew lined up on the taxiway.
Nothing more or less than a human frailty.
Since we were in caves, progress has been marked by two endeavours
1. Making it easier for the human to do what they do
2. Removing the human from having to do anything at all
Any argument that doesn't balance these is flying in the face of logic.
Any argument that doesn't give primacy to the second answer is flyng in the face of history.
RAT you really need to do a visual perception course to see how easy it is for _your_ cognition to deceive you. Aircraft landing on taxiways is not uncommon despite all the green center lines and blue edge lights - and the pilots often high hours professionals, were all convinced they were landing on the runway. It would be better to work out why these cognitive misperceptions occur rather than question the capability of the crews involved .
Nothing more or less than a human frailty.
Since we were in caves, progress has been marked by two endeavours
1. Making it easier for the human to do what they do
2. Removing the human from having to do anything at all
Any argument that doesn't balance these is flying in the face of logic.
Any argument that doesn't give primacy to the second answer is flyng in the face of history.
Last edited by pilot9249; 7th Aug 2017 at 23:50.
but then it was countered by the natural kick-in of stimulation by a challenging visual approach.
It is all a matter of degrees.
If you had been awake for 200 hours would your processing rate be slow? Yes.
If you had been awake for 100 hours would your processing rate be slow? Yes.
If you had been awake for 50 hours would your processing rate be slow? Yes
If you had been awake for 25 hours..........
If you had been awake for 12.5 hours........
When does the answer become No Rat?
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So what are the official reasons in Air Canada's ops manual for saving a CVR recording. If not available, what about at your airline?
More info: Transport Canada AC No. 700-013: Procedures and Training for the Preservation of Aircraft Recorded Data
Air operators are requested to review their training programs to ensure all flight crew members and ground personnel receive adequate training with regard to the proper procedures to safeguard on-board recorded data following an occurrence. In order to meet the above stated requirements of the CARs and the CASS, the following training should be provided to the flight crew members and ground personnel during initial and recurrent training sessions:
- Initial and annual recurrent training that addresses the importance of preserving information held on a CVR and/or FDR;
- Initial and annual recurrent training that addresses the proper procedures for disabling a CVR/FDR following an incident or accident;
- Awareness of the consequences of incorrectly disabling a CVR and/or FDR following an incident or accident; and
- The Air Operators training program should contain a provision that ensures all flight crew members and ground personnel are trained regarding any specific aircraft differences or procedures concerning the disabling of a CVR and/or FDR.
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uh
At some point, the relentlessness with which you pursue this single line of argument becomes comparable to the relentlessness with which the incident crew lined up on the taxiway.
Nothing more or less than a human frailty.
Since we were in caves, progress has been marked by two endeavours
1. Making it easier for the human to do what they do
2. Removing the human from having to do anything at all
Any argument that doesn't balance these is flying in the face of logic.
Any argument that doesn't give primacy to the second answer is flyng in the face of history.
At some point, the relentlessness with which you pursue this single line of argument becomes comparable to the relentlessness with which the incident crew lined up on the taxiway.
Nothing more or less than a human frailty.
Since we were in caves, progress has been marked by two endeavours
1. Making it easier for the human to do what they do
2. Removing the human from having to do anything at all
Any argument that doesn't balance these is flying in the face of logic.
Any argument that doesn't give primacy to the second answer is flyng in the face of history.
The way flight safety works is not to crucify each crew with the hope of 'encourager les autres'; it is to examine each incident and try to find why these landings (and in some cases take offs) on taxiways takes place. Then attempt to prevent that happening. Human factors research shows that attentional (aka cognitive) tunneling is one reason, that is then supported by confirmation bias. The same research shows that once an individual has been shown what can happen in their heads then they are less likely to have the same tunneling. Note that is less likely not impossible.
Trying to pretend that it is just that particular crew will. inevitably, only lead to another crew perhaps actually landing on a taxiway with several widebodies queued on it. Identifying what the reason was for misidentification and finding a method of mitigating it is far more productive; and is the way flight safety has been improved in the past.
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*sigh*
What breathless nonsense. In visual conditions there's no way anyone's landing on an occupied strip of pavement, night or not. ATC may have ordered a go-around but that doesn't mean the AC crew hadn't already noticed their error. If the aircraft on C were waiting to take off they would have been at the threshold end and clearly visible.
It certainly wasn't anything close to a disaster. An embarrassing, recoverable error if true, at most.
What breathless nonsense. In visual conditions there's no way anyone's landing on an occupied strip of pavement, night or not. ATC may have ordered a go-around but that doesn't mean the AC crew hadn't already noticed their error. If the aircraft on C were waiting to take off they would have been at the threshold end and clearly visible.
It certainly wasn't anything close to a disaster. An embarrassing, recoverable error if true, at most.
I would like to remind the Gentleman, "What is 4 Feet between friends?"
More nonsense, AC 759 was vectored for a visual approach to 28R the second time around ... They were given a heading of 310 to join the final and cleared for a visual approach behind an AA 777 who was on the FMS Bridge Visual Approach 28R. It's on the tape at liveatc.net
However, one then has to ask, what on earth in the SFO procedures allows an aircraft, which has had difficulties with a visual approach to a fully ILS capable runway, to be brought around and given just a visual, not an ILS-guided, approach again. I hope the FAA/NTSB really take them to task on this.
According to initial interviews with the flight crew, both pilots appear to have been confused by the absence of lighting on Runway 28L, which had been closed for construction. Its lights were turned off at the time of the incident, and a 20.5-foot wide flashing X had been placed near the threshold. The Air Canada pilots reporting believing that Runway 28R was actually 28L and they therefore believed that Taxiway C was Runway 28R.
Last edited by WHBM; 8th Aug 2017 at 10:57.
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Post #4 includes a good audio of ATC, at about 25:45:
“There's no one on 2-8 Right but you!”
“OK, Air Canada 75/Where's this guy going? He's on the taxiway!”
Fortunately, there was a guy more alert than AC flight deck and ATC, all together. He cut off the AC re-confirmation. Hundreds of souls are still with us today because of this guy. Congratulations, well done, unknown hero!
“There's no one on 2-8 Right but you!”
“OK, Air Canada 75/Where's this guy going? He's on the taxiway!”
Fortunately, there was a guy more alert than AC flight deck and ATC, all together. He cut off the AC re-confirmation. Hundreds of souls are still with us today because of this guy. Congratulations, well done, unknown hero!
Near miss, says I.
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Humble pax here who doesn't get to see out the front. Everyone has talked about the green centreline lights on the taxiway. How many of them would have been visible, with four large aircraft lined up on top? Is it possible that only fragments of green line would have been discernible?
At night, with less visual information, the brain has to extrapolate from the visual clues it has, and wrong patterns can be made. I've certainly misinterpreted the road ahead when driving at night.
At night, with less visual information, the brain has to extrapolate from the visual clues it has, and wrong patterns can be made. I've certainly misinterpreted the road ahead when driving at night.
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There was still a good amount of green line left in front of the closest aircraft on the taxiway.
Obviously, it was still possible to miss that cue. Without an actual (not simulated) photo of that approach under those conditions, it would be hard to judge how conspicuous the color was.
Obviously, it was still possible to miss that cue. Without an actual (not simulated) photo of that approach under those conditions, it would be hard to judge how conspicuous the color was.
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I gladly accept your correction to what I had seen written elsewhere.
However, one then has to ask, what on earth in the SFO procedures allows an aircraft, which has had difficulties with a visual approach to a fully ILS capable runway, to be brought around and given just a visual, not an ILS-guided, approach again. I hope the FAA/NTSB really take them to task on this.
However, one then has to ask, what on earth in the SFO procedures allows an aircraft, which has had difficulties with a visual approach to a fully ILS capable runway, to be brought around and given just a visual, not an ILS-guided, approach again. I hope the FAA/NTSB really take them to task on this.
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There was still a good amount of green line left in front of the closest aircraft on the taxiway.
Obviously, it was still possible to miss that cue. Without an actual (not simulated) photo of that approach under those conditions, it would be hard to judge how conspicuous the color was.
Obviously, it was still possible to miss that cue. Without an actual (not simulated) photo of that approach under those conditions, it would be hard to judge how conspicuous the color was.
Without mentally forcing yourself to backup and reconfirm your earlier decisions one can become focused on the task at hand and prior mistakes will go unchallenged.
From a distance (6-8 miles out) the dimmed whites and bright greens look similar.