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Human consciousness tries to form a coherent model that integrates current sensory perception with knowledge. During an approach at night, scarce sensory input is interpolated to form a full model by the brain. The report uses the term "expectation bias" for this phenomenon. This drive for coherence runs below consciousness and we only notice when the coherence falls apart: When our sensory input cannot be reconciled anymore with the current model. We blink, shift our head, and our model rebuilds anew.

What happened here is that the pilots were locked into a wrong model: In an environment with very little light there is no visual source to compare taxiway lighting against. If we know from experience that a light is white, our brain will use this to calibrate. Without this ever becoming a conscious thought. Color correction happens automatically for us and we don't feel it. This process can easily lead to nominally weird things like blue lights being percieved as white.

Fatigue and stress would contribute to ward off looming decoherence such as "why are the lights on 28L redder than on 28R?" When under pressure, we go with the strongest signal. And that signal may very well come from our knowledge, not our perception.

This process can easily lead to nominally weird things like blue lights being percieved as white.

https://en.wikipedia.org/wiki/The_dress

I've never experience blue taxiway lights being confused as white/runway lighting, even in the very common case of uncontrolled airport where they frequently do leave taxiway lighting on, and runway lighting off, and use pilot controlled lighting to enable the runway lights on demand.

I'd expect at SFO, like any other major airport I have flown into, does have both runway and taxiway lighting enabled as pilots are on final approach. So they do have a reference: the white runway lights versus blue taxiway lights, which on final approach are in the same field of view. And even on the lowest intensity setting, runway lights are brighter than taxiway lights.

Something about this particular situation definitely is off. I don't know if there's something operationally different about SFO's lighting. Or if the pilots really were that fatigued, and this is a seriously underestimated factor.

They expected to see two lit runways. They saw two lit lanes and their tired and distracted brain did the rest.

Obviously it's a rare occurrence otherwise airport lighting would have been adjusted to avoid the mistake.

I don't understand it either.

Here in Seattle, SeaTac airport has a parallel taxiway (Taxiway Tango) with a long history of being mistaken for a runway. The list of things tried so far to resolve the issue is interesting:

https://www.bizjournals.com/seattle/news/2015/12/31/tango-ta...

The very first thing I thought of upon reading your comment "The list of things tried so far to resolve the issue..." was "What about a big lighted 'x'?" then I clicked the link.

I'd like to know why they removed it.

Exactly my question. It's 9000+ feet long. Put a lighted red X on it every 1000 feet. Or, maybe Xes aren't the answer, but there must be some technique to produce a startling visual warning.

It's probably a situation like Chesterton's fence. There are probably good reasons for not having the Xes. At least I hope so, I hope it's not just "that costs money and then we have to maintain it". The money can't be an issue. How much would 500 or 1000 deaths cost? How expensive are all the other proposals which have been mentioned? Those aren't cheap either.

Indeed, the article does not give any reason for its removal, other than the fact that it was removed. My guess is that it was in disrepair and/or they deemed it ineffective since there were landings in the years preceding the removal.

make them jagged? (I'm half serious, if they are that much dangerous, then sorry for the people taxiing). They could also be made falsely jagged at night with the lighting system.

Who is to say that you won't now have planes coming down on a surface which constantly changes conditions, going from tarmac to grass and back again?

a google search for "taxiway landing" shows that this has happened quite a few times - with full passenger loads in some cases.

Watch this A380 landing at SFO, and watch the pilot's reaction when he's told he's cleared to land visually on 28L, but to expect the ILS for 28R.

https://www.youtube.com/watch?v=ENe89j89tBA

What's up with that?

I watched way more of that than I should have. It was way more interesting than I thought it would be.

I would love to be an airline captain.

PilotsEyeTV is a really really neat thing. They sell entire box sets of whole flights. It's pretty cool that the European airlines allow this amount of camera work in the cockpit:

http://pilotseye.tv/en/flightroutes/

If you really want to see something captivating, watch this clip of a Swiss A340 crew handling an overheating engine in-flight. It's incredibly well done.

https://www.youtube.com/watch?v=rEf35NtlBLg

Wow, that Swiss A340 video was amazing. The pilots were just so chill. "Let's have some chocolate for the landing" LOL

Yeah, it kind of makes up for all the Romansh flying back and forth in that cockpit. =)

Reminds me how those "Simulator" games are so popular in Germany!

I'll hand it to the Germans. When they get into a hobby, they really get into it.

I give up--why shouldn't airplane strobes be on while they're on the ground?

Harms night vision adaptation of other pilots.

My SOP is beacon (red, top and bottom) on with aircraft battery bus on, strobes on only when on an open runway, landing lights on when cleared for takeoff (or lined-up and waiting in position for takeoff). That seems to be a fairly common SOP for aircraft with separate control of beacon vs strobe.

It communicates a small amount of additional information, but more relevantly, it doesn't leave you sitting next to another airplane with blinding strobes on, killing your night vision adaptation. (Cirrus drives me crazy with their single switch anti-collision lights which light the strobes and beacon together.)

Here's the FAA (recommended, but not regulatory) guidance on the topic: (See "Use of Aircraft Lights") http://www.faraim.org/aim/aim-4-03-14-209.html

I guess that sounds good, though it might sound less good after a mass casualty collision.

Wonder if we couldn't have "ground strobes" visible only to viewers looking downward at a significant angle.

No, because when there's fog, the strobe gets reflected within the cloud everywhere. This is SFO after all.

In the case of fog or other low clouds though, airplanes are overwhelmingly likely to be following a localizer or GPS/RNAV approach, making this type of incident much less likely.

Hmm. So why not use that technique _all_ of the time?

Well, AC759 should have been doing so, even on the visual approach to 28R. On this particular approach (in contrast to literally every other approach in the FMS's database), a manual tuning step was required and skipped.-[0]

If there were another approach that required manual tuning and it was not a visual approach, the crew would detect they didn't have a localizer/equivalent to follow and would identify the missed step, because that's the only way they could navigate to the airport/runway.

It's a specific combination of visual approach and the only approach that required manual tuning (and not having another aircraft to follow visually) that setup this possible outcome. Then, the crew visually acquires the wrong bit of pavement and there's no safety mechanism inside the airplane remaining unless/until the pilots see that they're lined up wrong or get a go-around call from ATC/another aircrew.

[0] - Quote from the NTSB report: The FMS Bridge visual approach to runway 28R was the only approach in Air Canada’s Airbus A320 database that required manual tuning for a navigational aid, so the manual tuning of the ILS frequency was not a usual procedure for the flight crew.

They ruin other pilots' and crewmembers night vision.

Sokoloff's post just before mine is more articulate on this. I learned the same: strobes on when cleared for takeoff.