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-   -   Near miss with 5 airliners waiting for T/O on taxiway "C" in SFO! (https://www.pprune.org/rumours-news/596900-near-miss-5-airliners-waiting-t-o-taxiway-c-sfo.html)

Airbubba 7th August 2017 00:23


Originally Posted by WHBM (Post 9853892)
So how was it that when they came round again for their second approach they could be cleared for the ILS without issue.

More nonsense :=, 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


Originally Posted by DIBO (Post 9853628)
Well, they were requested to contact an FAA supervisor, and even given the phone no., before switching off. When did they call the FAA supervisor? What was discussed?

It sounded to me like AC 759 called ground on 121.8 while everyone else had been switched to tower freq on 120.5. Sounded like AC 759 said 'What is the phone number where we could reach you? The captain's going to give you a call.' The controller said 'sure' and gave the phone number over the air. It will indeed be interesting to hear what was discussed since ATC phone lines are usually recorded from what I've seen in NTSB reports. Or, were they doing midnight maintenance on the phone recorder and the tape is regrettably not available? ;)

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.
https://www.ntsb.gov/investigations/...ts/AAR8108.pdf

peekay4 7th August 2017 00:41


The old 30 minute CVR's used to have a union-mandated bulk erase button.
The rules are a bit different in Canada... erasing the CVR is a big no-no and on most Canadian aircraft the bulk erase function is disabled.

Ian W 7th August 2017 01:10

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.

RAT 5 7th August 2017 11:06

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?

aterpster 7th August 2017 12:24


Originally Posted by Airbubba (Post 9854171)
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

From what I can determine FAR 91.609 (g) wasn't enacted until 10 years later. And, how would it apply to Air Canada? Are they bound by Part 91 when operating in the U.S.? Seems they would be, but I don't know.

Ian W 7th August 2017 12:26

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

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.
(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.

Sea Eggs 7th August 2017 15:38

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.

pilot9249 7th August 2017 23:22

uh

Originally Posted by Ian W (Post 9854685)
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 .

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.

JammedStab 8th August 2017 01:00

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?

framer 8th August 2017 01:11


but then it was countered by the natural kick-in of stimulation by a challenging visual approach.
A brain that is processing information at a reduced rate because it has been awake for many hours doesn't suddenly become able to process information faster because you're excited. You may start processing faster than you were ten minutes ago, but it is still slower than you would process if you were well rested.
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?

peekay4 8th August 2017 01:43


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?
I've been made aware that since 2010, Canadian pilots and ground personnel must review rules and procedures re: FDR/CVR deactivation on equipped aircraft -- at least annually -- as part of their recurrent training. And the Commercial Air Service Standard (CASS) requires inclusion of the deactivation procedures in the Operations Manual.

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:
  1. Initial and annual recurrent training that addresses the importance of preserving information held on a CVR and/or FDR;
  2. Initial and annual recurrent training that addresses the proper procedures for disabling a CVR/FDR following an incident or accident;
  3. Awareness of the consequences of incorrectly disabling a CVR and/or FDR following an incident or accident; and
  4. 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.


Ian W 8th August 2017 05:28


Originally Posted by sptraveller (Post 9855248)
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.

The difference between your claim and mine is that professional crews repeatedly land on taxiways. It is not uncommon. What these incidents have in common is that each crew were convinced they were landing on the runway they were cleared to land on.

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.

787PIC 8th August 2017 06:18


Originally Posted by nolimitholdem (Post 9826855)
*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.

When I started this thread the above was the first response to my comment.
I would like to remind the Gentleman, "What is 4 Feet between friends?":cool:

WHBM 8th August 2017 10:41


Originally Posted by Airbubba (Post 9854171)
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

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.


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.
Seems just the same, along with the NOTAM that 28 approach lighting was unserviceable, as the two Gatwick taxiway landing incidents, which I hope the enquiry examines closely for common factors. Bear in mind that one of the two Gatwick incident crews were actually based there.

ElectroVlasic 8th August 2017 12:25


Originally Posted by _Phoenix (Post 9828024)
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! :D

However, had the holes in the swiss cheese lined up differently and there were two heros reporting the problem at the same time (shades of Tenerife) the transmission would have been garbled and perhaps not understood.

Near miss, says I.

PaxBritannica 8th August 2017 12:33

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.

.Scott 8th August 2017 12:57

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.

aterpster 8th August 2017 13:18


Originally Posted by WHBM (Post 9855709)
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.

You're not an airline pilot, are you.

cappt 8th August 2017 15:00


Originally Posted by .Scott (Post 9855863)
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.

My opinion based on 17K hours of experience. From a distance (6-8 miles out) the dimmed whites and bright greens look similar. Not like the sim picture above from short final with all the runway lights on high. This is also the distance where pilots flying a visual have already identified the runway and in their mind have shifted focus from runway identification to landing the A/C on the runway, I.E. airspeed, descent, final configuration. Throw in some circadian rhythm effects and tiredness and the holes begin to line up.
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.

EEngr 8th August 2017 15:12


From a distance (6-8 miles out) the dimmed whites and bright greens look similar.
And color vision at low light intensity suffers as well. Lighting/marking systems need to be based on patterns more than colors particularly at night.


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