Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

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luchtzak
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Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by luchtzak »

Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco, according to media the biggest air disaster ever avoided!

https://www.aviation24.be/airlines/air-can ... francisco/

Grootste vliegramp ooit nipt vermeden: http://www.nieuwsblad.be/cnt/dmf20170711_02967525

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sn26567
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by sn26567 »

luchtzak wrote: 12 Jul 2017, 10:54 Grootste vliegramp ooit nipt vermeden: http://www.nieuwsblad.be/cnt/dmf20170711_02967525
Typical tabloid journalism exaggeration 😣

Serious journalism:
Un avion d'Air Canada frôle la catastrophe http://www.lalibre.be/s/art/5965a3e1cd706e263ec1eae8
André
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by Passenger »

Factual report:

http://avherald.com/h?article=4ab79f58&opt=0

(edited - I have deleted my previous remark after reading the comments on the above AvHerald report)
Last edited by Passenger on 12 Jul 2017, 15:21, edited 1 time in total.

DIBO
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by DIBO »

Not so sure about the "journalism exaggeration":
- 2x B789, one A343 and a B739 at or near the holding point, means potentially a lot of people and fuel rather close together
- nighttime approach
- AC A320 going down to 100ft (rounded to the nearest hundred), dead center over the taxiway
- three tails sticking up in the air at 55 ft, the fourth a bit lower
- Tower confirming that nobody was on the runway (the first time)

What if the AC A320 delayed the go-around for 5 more seconds :o

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sn26567
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by sn26567 »

Don't you think that, even without an instruction from the tower to go around, the pilots would have seen on time that they were coming onto a taxiway (blue & green lights) and not a runway (white lights), and would thus have reacted accordingly?
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by Passenger »

One paragraph from the report on AvHerald.com:

"...On Jul 11th 2017 the Canadian TSB reported the crew of C-FKCK asked ATC to confirm landing clearance as they were seeing lights when the aircraft was 0.6nm before the runway threshold. The controller was coordinating with another facility when a flight crew of another airliner taxiing on taxiway C queried ATC where AC-759 was going and stated it appeared the aircraft was lined up with taxiway C. AC-759 had already overflown taxiway C by about 0.25nm when ATC instructed the aircraft to go around. 4 aircraft were on taxiway C at the time of the occurrence. It is estimated that AC-759 overflew the first two aircraft by 100 feet, the third by about 200 feet and the last by 300 feet. The closest lateral proximity between AC-759 and one of the aircraft on taxiway C was 29 feet..."

Repeat : it is estimated that AC-759 overflew the first two aircraft by 100 feet, the third by about 200 feet and the last by 300 feet.

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KriVa
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by KriVa »

sn26567 wrote: 12 Jul 2017, 17:23 Don't you think that, even without an instruction from the tower to go around, the pilots would have seen on time that they were coming onto a taxiway (blue & green lights) and not a runway (white lights), and would thus have reacted accordingly?
You would think so, but expectation bias and confirmation bias are very powerful things, not to be underestimated in this kind of events.
Basically, the pilot(s) would have expected to be on final for a runway. Subconsciously, they would block out a lot of signals which dispute that idea, and look for signals confirming that idea.
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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by Acid-drop »

So modern planes dont have a system to auto align ?
How would they do when its foggy ? ILS ?
They have it but they dont use it ?
My messages reflect my personal opinion which may be different than yours. I beleive a forum is made to create a debate so I encourage people to express themselves, the way they want, with the ideas they want. I expect the same understanding in return.

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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by luchtzak »

Passenger wrote: 12 Jul 2017, 19:20Repeat : it is estimated that AC-759 overflew the first two aircraft by 100 feet, the third by about 200 feet and the last by 300 feet.
It was close!

convair
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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by convair »

Frightening! Could have turned out to be a disaster!

This incident raises a lot of questions. To those asked by member Acid-drop hereabove, I want to add:

Is it normal that the pilot of a plane on the ground has to warn the ATC that an approaching plane is on the wrong track? Doesn't the ATC have radars on which they should monitor the planes' movements?
Don't runways send signals indicating the right direction to approaching planes at all times?
Aren't the pilots (there are 2 of them!!!) supposed to double-check every parameter?

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KriVa
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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by KriVa »

As with most accidents/incidents/close calls, this will more than likely be the result of several holes in the cheese lining up.
I think everybody can agree this shouldn't have happened, the objective for investigators now is to figure out how and why it happened, and to prevent it from happening again.
Yes, most planes are capable of receiving an ILS signal, but that doesn't mean that, in this case, they were flying an ILS approach, or even had the ILS signal tuned/visible.
The visual approach is the most common approach type flown in the US, in Europe, a lot more ILS approaches are used. (That doesn't mean the ILS system isn't there, it just means the aircraft isn't using it) for all we know, the ILS system may not have been transmitting.
Sure, ATC has a radar, but in this case the aircraft was "on final" for a parallel taxiway, hence they were flying an offset track, unlickely to be noticed by ATC on radar because the offset is so small, relative to the size of the airspace they're looking at. Parallax also probably plays a role here. The pilots in the aircraft sitting on the taxiway see the aircraft coming straight towards them. I'm not familiar with the layout of the aerodrome, but chances are high the control tower is not in the axis of that taxiway. Hence, ATCOs would be looking at the approach path not straight on, but askew. This makes it rather hard to judge whether the aircraft is exactly straight on the runway, or a few tens of meters offset left or right.
Should pilots double check everything? Well, yes, mostly. However, like I said, expectation and confirmation bias are powerful things.
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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by Acid-drop »

The visual approach is the most common approach type flown in the US, in Europe, a lot more ILS approaches are used. (That doesn't mean the ILS system isn't there, it just means the aircraft isn't using it) for all we know, the ILS system may not have been transmitting.
I don't see any reason to not use it 100% of the time (ok, maybe one : pilots will become even lazier and will forget how to fly)
I trust computers much more than humans personally ....
My messages reflect my personal opinion which may be different than yours. I beleive a forum is made to create a debate so I encourage people to express themselves, the way they want, with the ideas they want. I expect the same understanding in return.

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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by Apuneger »

Acid-drop wrote: 13 Jul 2017, 14:06 I don't see any reason to not use it 100% of the time (ok, maybe one : pilots will become even lazier and will forget how to fly)
I trust computers much more than humans personally ....
Unfortunately, computers can fail too. That's why pilots should have sufficient basic piloting skills at all times, to be able to have full control over their aircraft.

I've been fortunate enough to have quite a few jumpseat rides on different Belgian airlines. It's nice to see that on many occasions (weather, traffic situation, time of the day,...) pilots already disarmed the autopilot during the initial approach phase, and flew the aircraft manually towards the runway.

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Re: Air Canada aircraft almost landed on taxiway with 4 planes at San Francisco

Post by Homo Aeroportus »

KriVa wrote: 12 Jul 2017, 22:02
sn26567 wrote: 12 Jul 2017, 17:23 Don't you think that, even without an instruction from the tower to go around, the pilots would have seen on time that they were coming onto a taxiway (blue & green lights) and not a runway (white lights), and would thus have reacted accordingly?
You would think so, but expectation bias and confirmation bias are very powerful things, not to be underestimated in this kind of events.
Basically, the pilot(s) would have expected to be on final for a runway. Subconsciously, they would block out a lot of signals which dispute that idea, and look for signals confirming that idea.

Fully agree with the confirmation bias but at night it seems rather unlikely. The TWY blue edge lights are almost not visible from a great distance (and often now replaced by reflective markers) and the green TWY centreline lights (if installed and energized) will be barely more visible. Confusion with a (near) parallel highway has occurred before but with a TWY I doubt as it must have been a dark area, next to a brightly lit one ...

If we look at misinterpretation of signals, the fact is indeed that the crew was on the "back side of the clock". This is a 5-hour flight from YYZ so landing at midnight equals 03:00 body time, typically the lowest time of the day.
Remains that the runway lights must have been On, bright white edge lights and possibly additional centreline and TDZ. Also there is a full 3000-ft approach lighting system on 28R (don't know if it was On though, but no Notam saying it was u/s either).

So if the approach was visual as it probably was, I don't understand how you can miss the runway alignment (they were on course for at least 5 NM).
On the other hand if they made an ILS approach, interferences (e.g. vehicle/aircraft within the ILS sensitive/critical area) may ruin your day, although it is usually the glide slope signal that is distorted.

It will be for sure an interesting reading when NTSB produce their report.

Google Earth showing Left to Right :
RWY 28L (inop due WIP and Notamed), RWY 28R and TWY Charlie close to the Bay and where the sitting ducks were lined up.
Screenshot 2017-07-13 21.52.09.png

H.A.

Hue

Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by Hue »

Let's not forget some essential safety elements saved the day. All traffic was on the same radio frequency speaking the same language and the combined situational awareness triggered corrective action.
The pilot on short final spoke up when saw some lights incompatible with his landing clearance, raising everyones attention. The pilot on the taxiway warned the others they were off course. The Tower controller immediately issued go around instruction when he became aware of the danger. The Air Canada pilots remained calm and executed the missed approach manoeuvre.
It was a close call that learns us some valuable lessons and raises awareness about potential risks. This event could happen elsewhere. Hopefully with equal or better outcome.

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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by Bracebrace »

I don't consider this dangerous, neither a blame for the pilots aligning with taxiway C. They questioned, got stupid replies from local pilots, and did a go-around.

American airports rely heavily on human interactions, including pilots having to fly visual approaches. Controllers will "force" aircraft into visual approaches because it makes their life easier but it creates a lot of hazards. I'm done with their "visual with" questions, I prefer to avoid the visual clearance being thrown at me. I am too unfamiliar with the airports to do pure visuals. Visual pictures on large American airports can be very misleading. Active runways for these Visuals can be very poorly lit compared to the surroundings. But controllers don't realise it, and pilots are too much "ego" to say they can't handle a visual approach (been there, done that).

Worst case I had was in Chicago in the middle of the night: works in progress on the left runway, so left runway closed. Cleared for the visual on the right runway. Had the ILS tuned as a backup and noticed drifting left. Followed the instruments to "see" the active runway at about 400ft. For the works they had lit all (yes all, PAPI's, ALS,...) lights on the closed runway full bright, the active runway had only very dim centreline and edge lights. The bright lights on the left runway made it impossible to see the active runway lights untill very close. For the record, from 3 miles out, you cannot spot the headlights of a car on a heavily lit runway... that was the day I closed the books on visual approaches in major USA airports.

Those canadian pilots were not going to land on the taxiway, they got confused somewhere and had the good reaction to question. American airports have to start thinking twice about all their visual clearances.

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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by sn26567 »

Bracebrace wrote: 18 Jul 2017, 21:02 American airports rely heavily on human interactions, including pilots having to fly visual approaches.
Interesting comment, bracebrace. I understand how you chose your nickname after that American experience ;)
André
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Re: Air Canada aircraft almost landed on taxiway with 4 planes on it at San Francisco

Post by Sonho1985 »

luchtzak wrote: 02 Aug 2017, 23:57 Image
Wow, I didn't realize that the AC aircraft was that low already.
I think the passengers on board of the waiting planes did not notice a lot, but some of the flight deck crews probably crapped their pants.


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