13 ms·

Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

124 points by CaliforniaKarl 8y ago

CaliforniaKarl 8y ago
As per https://www.ntsb.gov/news/press-releases/Pages/NR20180925b.aspx https://www.ntsb.gov/news/press-releases/Pages/NR20180925b.a...: >The full report will be available on the NTSB website in several weeks.
nutcracker46 8y ago
The report identifies good preventive measures. Autotuning the ILS would be handy, as would an aural alert for lateral deviation, perhaps announcing, "Localizer, Localizer." The crew may have caught the closure of 28L and planned better with a review of NOTAMS before top of descent and including them in the approach briefing. When I'm up there, and sleepy, I ask for a coffee and pull out the NOTAMS for one last look before we pull up the approach in the computer, manually set up the radios, and do the briefing. On final approach, more precise ground based monitoring would be nice to have in case things are fubar in the plane.
- Pyxl101 8y ago
  How difficult is it to see what's happening on the ground at night from a plane? I've never been in a cockpit at night. I'd have to hope that taxiways are marked in some explicit way to make it clear that they're not runways, like with an X or some pattern of lights that's not on runways; or have all runways marked with an obvious pattern that indicates "land here" (so if you don't see that, you know you're not landing on a runway). Don't the runways have their names labeled in lights near the entrances? (Or is that only paint?) I guess I'm surprised that it took so long for the pilots to see that there were other planes where they were landing. Is it routine to keep binoculars in a cockpit? Could they have seen what was on the ground sooner if they'd looked through binoculars briefly (after noticing unexpected lights?)
  - aeternus 8y ago
    The numbers are not labeled in lights. Although this pic is blurry, this is SFO with both runways open: https://i.redd.it/hguxuyztxzdz.jpg https://i.redd.it/hguxuyztxzdz.jpg The night of the accident, the left runway was closed and lights were turned off.. and they were expecting two runways and to land on the one on the right. There's still no excuse for this happening with two ATP-rated pilots that have done this type of landing thousands of times, but you can kinda see how it is possible at least. This also isn't unheard-of. For example, Harrison Ford had a similar issue where he landed his private plane on a taxiway at an airport with parallel runways.
    - tajen 8y ago
      But Harrison Ford’s senility (absent gaze, low liveliness) couldn’t even be hidden in his last Indiana Jones even though the camera crew can retake as many times necessary, I just wonder how he was still allowed to pilot.
  - captain_perl 8y ago
    Large airports have fancy lighting schemes and are pretty obvious in good weather. Small airports or bad weather at night are a different story - I would not fly into a new airport the first time in those conditions. Think 10x - 100x the risk. Binoculars might be ok for the non-flying pilot to use, as long as he doesn't drop them on the floor and bind any rudder pedals.
- mortenjorck 8y ago
  The recommendations look like important steps, especially the concept of a system that alerts pilots to runway surface non-alignment. I have to wonder, though, does it always take a close call like this (or worse) to bring up such a proposal? Does the NTSB also study otherwise safe flights to identify risks in pilot, tower, or ground crew human factors and make proactive recommendations?
  - hueving 8y ago
    >does it always take a close call like this (or worse) to bring up such a proposal? At this point yes. There is a saying that "FAA regulations are written in blood" as a result. It seems conservative on the surface but at this point the current system is incredibly safe and making changes without clear huge upsides isn't worth the risk of unintended consequences. Pilot attention is at a premium during landing. The computer shouting "localizer" at you during an approach because you're misaligned might be the straw that breaks the cognitive burden's back while you're trying to deal with another crisis.
  - lbriner 8y ago
    Also, what Air France 447 showed us was that excessive automation becomes a problem when it is assumed to always work. The recommendations about more systems are all very well but there are 1000s of international airports who are either not going to have these systems or sometimes they won't work. What is critical is that pilots follow their checklists and that 1 action would have prevented this happening despite the fact that the other systems could have warned about it. Making NOTAMs and the like more clear just seems like good design. They should certainly be able to prioritise information or only show what is relevant for a particular flight/aircraft/location/approach so you only have to read 3 things instead of 50.
- augustz 8y ago
  Just for SFO you have 84 NOTAMs. !SFO 06/079 SFO OBST RIG (ASN 2017-AWP-3368-NRA) 373740N1222224W (0.5NM NE SFO) 41FT (34FT AGL) FLAGGED AND LGTD 1806201400-1811010100 This is a flagged and lighted obstruction half a mile way that is 34 feet above ground level. Now put in a full route and takeoff airport and maybe if you have had some stops during the day. The NOTAM seems a bit long. Then if are overseas and have to deal with the BS political notams. Check out greece and turkey notams. ...THE REF (B) TURKISH NOTAM A3009/16 LTAAYNYX (111139 EUECYIYN JUL 2016) HAS NO GROUND, CANNOT PRODUCE ANY INTERNATIONALLY LEGAL EFFECT WITHIN ATHINAI FIR/ HELLAS UIR AND IS CONSIDERED NULL AND VOID. I'm curious how many pilots fully read all NOTAMs, locate them geographically to understand where they are etc etc on every flight.
  - outworlder 8y ago
    Indeed. 'Notices' can be almost anything. I was doing simulated flights over the continental US recently. Even small airports may have a lot of NOTAMs. Some are important (for instance, warning about objects close to some parts of the runway, or issues with a runway, or even animals or birds), but many others are completely useless. Noise abatement restrictions ironically add a lot of NOTAM 'noise'. There should be a separate category for these, as these are not safety related.
  - powercf 8y ago
    Outputting that in lower case could be a small step to making them easier to parse, and therefore more likely to be read. I find the text you posted tiring even to look at. THE REF (B) TURKISH NOTAM A3009/16 LTAAYNYX (111139 EUECYIYN JUL 2016) HAS NO GROUND, CANNOT PRODUCE ANY INTERNATIONALLY LEGAL EFFECT WITHIN ATHINAI FIR/ HELLAS UIR AND IS CONSIDERED NULL AND VOID. vs The ref (B) Turkish NOTAM A3009/16 LTAAYNYX (111139 Euecyiyn Jul 2016) has no ground, cannot produce any internationally legal effect within Athinai FIR/Hellas UIR and is considered null and void.
    - oh_sigh 8y ago
      How much experience do you have reading all-caps text? It isn't necessarily a burden to people who are used to it, which all airline pilots are.
- donavanm 8y ago
  As others pointed out there are fundamental problems with the system and usability of NOTAMs. Its a little absurd that theyre always used to blame the operator (“should have read the NOTAM”) when a flight briefing might have 10s or 100s applicable ones and a VAST number are junk. It reeks of retrospective blame seeking. That said there is some traction around this. And some interesting alternative takes (https://opsfox.net https://opsfox.net), which have their own problems.
- MarkMc 8y ago
  "Localizer, localizer" seems too obscure - "Landing on taxiway" is much clearer. It's interesting to listen to the radio chatter for this near-miss [1]. The air traffic controller misses a few chances to notice that something isn't right but when the pilot on the taxiway says in plain English, "Where's this guy going? He's on the taxiway" the problem immidately becomes obvious. [1] https://youtu.be/ZW-ETmZU0u8 https://youtu.be/ZW-ETmZU0u8
gok 8y ago
It's kind of baffling to me that there's a system for detecting collisions with other airplanes in the sky (TCAS) and a system for detecting collisions with the ground (EGPWS) but not system for detecting collisions with other airplanes on the ground. This easily could have killed a thousand people.
- hangonhn 8y ago
  Different problems, no? Trying to pick out an airplane against the ground is different from detecting an object in the air, which doesn't generally reflect radio back, and detecting the ground, which does reflect. The problem you're describing requires you to differentiate between two things that both reflect signals back to you. It's obviously do-able since the military does it all the time for targeting. However, I doubt it's cheap and there might be cheaper ways to do it that don't leverage the two systems you've mentioned.
  - eesmith 8y ago
    TCAS uses active transponders, not radar reflection. https://en.wikipedia.org/wiki/Traffic_collision_avoidance_system#System_description https://en.wikipedia.org/wiki/Traffic_collision_avoidance_sy...
  - gok 8y ago
    TCAS works via the transponders of other aircraft, which they actively transmit.
- metanoia 8y ago
  SFO has ground radar systems (ASDE-X/ASSC) [1] which allows ground and tower controllers to see potential conflicts on taxiways and runways. Pure speculation, but I don't think that these systems' conflict logic take into account an aircraft trying to land on a taxiway. [1] https://en.wikipedia.org/wiki/Airport_Surface_Surveillance_Capability https://en.wikipedia.org/wiki/Airport_Surface_Surveillance_C...
  - gok 8y ago
cmurf 8y ago
I'm not operationally familiar with SFO. But based on experience at other airports, a taxiway at night can be a sea of black at even 100' above the ground. I would probably see airplane navigation lights at some point, but would I bet my life on it? No. So this incident has to be taken seriously. However, I'm still not clear from this reporting how the crew mistook blue taxiway lighting for white runway lighting. This isn't supposed to be subtle, and I haven't ever experienced it to be subtle. Edit: OK there is a partial explanation here that appears as though at the time they committed to taxiway C as runway 28R, the visual cue they relied on was airplane lighting looking like it was runway lighting. Airplane taxi and takeoff/landing lights are white, navigational lights are green or red. Strobes usually aren't on while on the ground or at least probably shouldn't be. It's an interesting dilemma. And fatigue is a significant contributing factor as well.
- oasisbob 8y ago
  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-taxiway-a-history-of-mistaken-landings-and.html https://www.bizjournals.com/seattle/news/2015/12/31/tango-ta...
  - wmblaettler 8y ago
    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.
    - jonah 8y ago
      I'd like to know why they removed it.
      - PhantomGremlin 8y ago
        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.
organman91 8y ago
As a private pilot, small planes going down occasionally are just a fact of life. But this incident scares me. There were four planes lined up on the taxiway the Air Canada narrowly missed. The worst aviation accident ever was a collision of two 747s resulting in 583 deaths: https://en.wikipedia.org/wiki/Tenerife_airport_disaster https://en.wikipedia.org/wiki/Tenerife_airport_disaster - this could have doubled that number.
- village-idiot 8y ago
  Would also double the record for number of vehicles involved in an incident too, I believe
- oh_sigh 8y ago
  Is it plausible that that AC759 could have taken out all 4 other planes? I don't really have a sense of the distances planes are spaced out on taxiways at major airports.
  - DocTomoe 8y ago
    Spacing between planes on a taxiway is a lot shorter than you would imagine. Depending on type, a 25-50 meters apart is common. Keep in mind that these four planes were preparing for take-off, meaning that they were fully fuelled...
  - Arn_Thor 8y ago
    The KLM which had barely reached minimum takeoff speed and started to take off still flew 150 meters after it had plowed through the upper half of the PanAm and lost an engine and the main wheels. There's a lot of momentum in a moving plane, and they're stacked very close when holding on the taxiway
aeternus 8y ago
I'm surprised that remote video cameras aren't used by tower controllers. The perspective of the control tower makes it difficult to catch issues like this, but a simple video camera aligned with the center-line of each runway would allow controllers to more easily verify that planes are lined up as well as other possible issues like gear down & locked, etc.
- zkms 8y ago
  > I'm surprised that remote video cameras aren't used by tower controllers. I'm surprised that forward-looking infrared cameras aren't more commonly used in civilian aircraft, especially given the availability of staring arrays with decent resolution/framerate that don't require cooling. Even without the requisite certification for use as a for-realsies landing aid, it's nevertheless a useful tool to get situational awareness in inclement weather / at night.
  - outworlder 8y ago
    They are more commonly found aboard 'experimental' aircraft because of the certification issues you pointed out.
    - DuskStar 8y ago
      And high-performance infrared cameras are also probably one of those things that end up on arms control lists. (Since it's not just useful for spotting planes on your "runway", but also for spotting tanks or people on your hill requesting an ordnance delivery)
      - bigiain 8y ago
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SaberTail 8y ago
If anyone would like to listen to the ATC radio: https://www.youtube.com/watch?v=ZW-ETmZU0u8 https://www.youtube.com/watch?v=ZW-ETmZU0u8
- 8_hours_ago 8y ago
  I was just about to post that link! VASAviation has a really good youtube channel with ATC radio recordings and high quality visualizations of all kinds of interesting events: https://www.youtube.com/user/victor981994 https://www.youtube.com/user/victor981994
  - sokoloff 8y ago
    https://www.youtube.com/watch?time_continue=57&v=oF7FR7TjnME https://www.youtube.com/watch?time_continue=57&v=oF7FR7TjnME has an overview shot, showing just how low AC759 got to the airplanes on Taxiway C. (Look at the top of the frame.)
- SOLAR_FIELDS 8y ago
  I love hearing ATC radio. I think the guy who did the classic SR71 story about upstaging everyone on some California flyby noted this pretty well - even in the times of near peril pilots and ATC will be the cool-as-steel that keep everyone calm.
  - outworlder 8y ago
    Another interesting one is the guy that was suffering from hypoxia. "Unable... to control... altitude" "Unable... to control... airspeed" "Unable... to control... heading" "Other than that, everything A-OK!" Guy landed safely after ATC realized it was hypoxia and ordered the flight to descend. EDIT: link https://fearoflanding.com/accidents/accident-reports/hypoxia-on-kalitta-66/ https://fearoflanding.com/accidents/accident-reports/hypoxia...
    - cjbprime 8y ago
      Another close call: https://youtu.be/ag1-7qnkjv0 https://youtu.be/ag1-7qnkjv0 ("Pinch Hitting a King Air") And the recent case of Captain Maggie: https://youtu.be/B229-KLudTo https://youtu.be/B229-KLudTo
tialaramex 8y ago
CVR overwrite is bad news here. The crew knew this was a serious problem when it happened, there's no way they should have allowed the CVR, crucial evidence of exactly what happened, to be overwritten. Perhaps the full report will have more detail on this, as it stands I have to believe somebody made the decision to overwrite this because they thought it'd be better if it didn't exist. Whether that's the crew, their bosses or other staff, somebody managed to go from "serious incident, preserve evidence" to "maximum ass covering" and that person or persons are an obstacle to effective investigation and thus to safe air travel.
- walrus01 8y ago
  If I understand CVR tech correctly, it's running and constantly overwriting the storage in a loop whenever the plane is powered up. A lot of airplanes are 10, 15, 20 years old. CVR are based on some pretty old late 1980s technology, it's not like a modern flash based storage system with effectively infinite capacity for stereo 44KHz audio (64, 128GB, etc). There's maybe 1 or 2 hours of recording time, max.
- sokoloff 8y ago
  Subject aircraft, C-FKCK, is a 1991 A320, which is only required to have a 30 minute CVR loop. (I don't know which exact CVR it was equipped with, of course.) By the time the aircraft goes around, is resequenced, completes the second approach, lands, taxis in, and shuts down, much of the initial approach setup conversation may have already been overwritten anyway. I wouldn't jump to the assumption that there was malicious intent in the fact that the CVR was overwritten. (I also wouldn't want the crew to stop the CVR recording only to have a second, more serious incident on the same flight that would then go unrecorded.)
- cpitVoxRec 8y ago
  They actually do clearly state in this PDF that a degree of fault lies in the crew being compromised by fatigue. Operating for 19 hours straight definitely places an individual in an area where one can be fighting to pay strict attention, even when it really counts. There's also plenty of communication with Air Traffic Control in the tower, and not a whole lot of gaps to introduce significant mystery, so it's pretty unlikely that there would be anything earth shattering on the cockpit voice recorder.
tetrep 8y ago
> Cockpit voice recorder (CVR) information was not available for this incident because the data were overwritten before senior Air Canada officials became aware of the severity of this incident. How long are recordings normally kept? I would assume at least a few days for mundane flights (storage is cheap, isn't it?) but any sort of incident similar to this I would assume they keep recordings for much longer, if only for internal purposes.
- Havoc 8y ago
  The tower recordings are posted above. >(storage is cheap, isn't it?) Not on ancient planes where everything needs a billion certifications from all sorts of regulatory bodies.
  - avar 8y ago
    There's other issues at play. Pilots hate the idea of more monitoring of the cockpit, and have been vocal in trying to prevent e.g. a video recording of the cockpit being part of the "black box", even though it would have helped to shed light on a lot of aviation incidents[1]. 1. https://www.wired.com/2014/07/malaysia-370-cockpit-camera/ https://www.wired.com/2014/07/malaysia-370-cockpit-camera/
  - mikeash 8y ago
    It also needs to survive a couple of years at the bottom of the ocean or a similarly extreme environment and still be readable afterwards.
- sokoloff 8y ago
  It's a loop recorder. When that aircraft was certified, only a 30 minute loop was required. If that aircraft was newly certified, it would now require a 2 hour loop.
  - geofft 8y ago
    Can they not sync the recording elsewhere once they land and every passenger has a high-bandwidth internet connection the second the wheels are on the ground? (Is it too hard to certify that a system that connects to the internet is safe?)
abaillargeon 8y ago
I've been anticipating the release of this report this since I heard about the incident. I work on an avionics product that's designed to prevent this exact scenario. We use the aircraft's position along with a database of runways and taxiways to determine if the aircraft is approaching the runway the pilot intends. If we determine the aircraft is landing, we issue a visual and aural alert to the pilot ("TAXIWAY LANDING" or "NOT A RUNWAY").
- outworlder 8y ago
  What is the chance of false positives (or negatives) due to out of date databases?
  - abaillargeon 8y ago
    We do get some nuisance alerts from time to time, and part of my job is to investigate them and determine the cause. I did investigate one recently, however, where the cause was a runway that was "one-way". Most runways have two ends and the pilot/ATC determines which one to take off. EDDF (Frankfurt) RWY18 is only used for takeoffs and was causing nuisance alerts due to the way we search for the runway in front of the aircraft. There's another runway (I don't remember where) where the direction in our database does not match what satellite imagery shows. I don't work in the database group but I was told that this can only be fixed by asking the airport manager to re-survey the runway. Short of that, we can't fix it even if we know it's wrong. However, It's quite rare for them to be due to a database that's out of date -- most of the time it's due to an incorrect determination that the aircraft is taking off or landing.
- ryandrake 8y ago
  Curious: what inputs feed your system? Presumably at least localizer and GPS, but anything else? What accuracy / confidence interval do you require in order to make a call?
  - abaillargeon 8y ago
    We actually don't use the localizer to check for an incorrect runway or taxiway landing because the pilot can choose to do so and we don't want to issue nuisance alerts. Runways don't move often and we've found that a GPS and two databases (runways and airport ground features) are sufficient to determine if the pilot is approaching a runway or not. We use inputs like GPS position, ground track, ground speed, altitude, and a phase-of-flight state machine that's determined for individual aircraft. This allows us to tailor the criteria for determining if the aircraft is landing for different aircraft. For some, we use throttle and landing gear position and others we use speed and altitude above the landing airport. As for accuracy, we have minimum levels of GPS figure of merit where there's enough certainty to issue alerts. I don't remember the number off the top of my head, but in the US WAAS has made GPS quite accurate.
bahmboo 8y ago
Gotta hand it to the NTSB - they are thorough. This is just the abstract.
- glup 8y ago
  Also that they cite fatigue / circadian low as one of the core causes. I thought they might avoid it because of the potential cost implications for the airline industry.
  - scrumper 8y ago
    Worth noting that the Canadian regulations are looser than USA in that respect - the Air Canada pilots were in compliance with home regs, but would have been in breach of FAA regs. Other point is that the NTSB isn't generally particularly shy about calling out the need for expensive changes (one example being their recommendation for fuel tank inerting systems after TWA 800). They have no power to mandate their recommendations be implemented after all: that's the job of the FAA.
    - jackpirate 8y ago
      Why does a plane in US airspace not follow FAA regs?
      - scrumper 8y ago
        Well, it does pretty much, just not that bit (14 CFR 117). In this Air Canada case it's governed by 14 CFR part 129, which covers operations by foreign air carriers in the USA. https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol3/xml/CFR-2011-title14-vol3-part129.xml#seqnum129.15 https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol3/xml/CFR-... EDIT - removed erroneous reference to 14 CFR 121.480-> which applies to cargo ops.
  - rconti 8y ago
    Yup - copied this to buffer for a comment: > The flight crew’s work schedule for the incident flight complied with the applicable Canadian flight time limitations and rest requirements; however, the flight and duty time and rest requirements for the captain (a company reserve pilot) would not have complied with US flight time limitations and rest requirements (14 CFR Part 117).
mmaunder 8y ago
This is what is called a 'cascade of failures' in aviation - and the term is used elsewhere. Multiple failures resulting in a catastrophic failure. In your own life and goings about, it's sometimes interesting to do a failure analysis and you'll often find you experienced a cascade. It's really unfortunate that the cockpit voice recorder was overwritten. I'm guessing they're using very old technology where storage space is at a premium. They're still using the flashing X on closed runways - e.g. at SEATAC right now. The lights looked incandescent a couple nights ago while passing the X. So not very bright or visible. This accident would probably have been one of the worst in history. Multiple passenger planes on the taxiway taken out by a passenger jet.
debt 8y ago
"The cues available to the flight crew to indicate that the airplane was aligned with a taxiway did not overcome the crew’s belief, as a result of expectation bias, that the taxiway was the intended landing runway." Damn. It didn't matter that the whole world was telling him it was a taxiway because he was so sure it was a runway.
Waterluvian 8y ago
Speaking with a fair level of ignorance, how hard would it be for some onboard computer to be freaking out that a landing attempt is being made way off course of a known runway? Going to guess this is one of those things where, yes, we have all the requisite technology, but practical implementation is the hard part.
- captain_perl 8y ago
  Automatically monitoring an ILS approach is not that difficult from the cockpit if the frequency can be sent via ADS-B. Beyond that it gets really hard because visual and circling approaches can be in any heading, as well as large cross-winds. In this deviation, the pilots literally got lost. Kind of tough to do much about that.
- abaillargeon 8y ago
  I get excited seeing stories about aviation on HN because it's something I work on every day. I've written a few comments above but I'm developer on the system you described (and more) being used in aircraft today. With a GPS and onboard databases of runways and taxiways, we can determine if a pilot is attempting to take off or land on a taxiway. The key is preventing nuisance alerts when the pilot is just flying around and happens to be aligned with a runway. The "11 secret herbs and spices" depend on the aircraft but are usually speed and configuration (ie landing gear) based. Approaches are fairly predictable and we can use that to sequence through a state machine that tells us the pilot intends to land. Here's a video of the system on a G1000 (meant for smaller planes) skip to 0:45ish https://www.youtube.com/watch?v=V2bswm0w4cY https://www.youtube.com/watch?v=V2bswm0w4cY
  - Waterluvian 8y ago
    Thank you for sharing. Really cool to see just how much real-time GIS there is in aviation these days.
oh_sigh 8y ago
Are there any reports from passengers on the taxiway planes? I'd have to imagine an A320 flying 60' over your roof would cause a fairly large disturbance.

As per https://www.ntsb.gov/news/press-releases/Pages/NR20180925b.aspx https://www.ntsb.gov/news/press-releases/Pages/NR20180925b.a...: >The full report will be available on the NTSB website in several weeks.

nutcracker46 8y ago

The report identifies good preventive measures. Autotuning the ILS would be handy, as would an aural alert for lateral deviation, perhaps announcing, "Localizer, Localizer." The crew may have caught the closure of 28L and planned better with a review of NOTAMS before top of descent and including them in the approach briefing. When I'm up there, and sleepy, I ask for a coffee and pull out the NOTAMS for one last look before we pull up the approach in the computer, manually set up the radios, and do the briefing. On final approach, more precise ground based monitoring would be nice to have in case things are fubar in the plane.

Pyxl101 8y ago
How difficult is it to see what's happening on the ground at night from a plane? I've never been in a cockpit at night. I'd have to hope that taxiways are marked in some explicit way to make it clear that they're not runways, like with an X or some pattern of lights that's not on runways; or have all runways marked with an obvious pattern that indicates "land here" (so if you don't see that, you know you're not landing on a runway). Don't the runways have their names labeled in lights near the entrances? (Or is that only paint?) I guess I'm surprised that it took so long for the pilots to see that there were other planes where they were landing. Is it routine to keep binoculars in a cockpit? Could they have seen what was on the ground sooner if they'd looked through binoculars briefly (after noticing unexpected lights?)
- aeternus 8y ago
  The numbers are not labeled in lights. Although this pic is blurry, this is SFO with both runways open: https://i.redd.it/hguxuyztxzdz.jpg https://i.redd.it/hguxuyztxzdz.jpg The night of the accident, the left runway was closed and lights were turned off.. and they were expecting two runways and to land on the one on the right. There's still no excuse for this happening with two ATP-rated pilots that have done this type of landing thousands of times, but you can kinda see how it is possible at least. This also isn't unheard-of. For example, Harrison Ford had a similar issue where he landed his private plane on a taxiway at an airport with parallel runways.
  - tajen 8y ago
    But Harrison Ford’s senility (absent gaze, low liveliness) couldn’t even be hidden in his last Indiana Jones even though the camera crew can retake as many times necessary, I just wonder how he was still allowed to pilot.
- captain_perl 8y ago
  Large airports have fancy lighting schemes and are pretty obvious in good weather. Small airports or bad weather at night are a different story - I would not fly into a new airport the first time in those conditions. Think 10x - 100x the risk. Binoculars might be ok for the non-flying pilot to use, as long as he doesn't drop them on the floor and bind any rudder pedals.
mortenjorck 8y ago
The recommendations look like important steps, especially the concept of a system that alerts pilots to runway surface non-alignment. I have to wonder, though, does it always take a close call like this (or worse) to bring up such a proposal? Does the NTSB also study otherwise safe flights to identify risks in pilot, tower, or ground crew human factors and make proactive recommendations?
- hueving 8y ago
  >does it always take a close call like this (or worse) to bring up such a proposal? At this point yes. There is a saying that "FAA regulations are written in blood" as a result. It seems conservative on the surface but at this point the current system is incredibly safe and making changes without clear huge upsides isn't worth the risk of unintended consequences. Pilot attention is at a premium during landing. The computer shouting "localizer" at you during an approach because you're misaligned might be the straw that breaks the cognitive burden's back while you're trying to deal with another crisis.
- lbriner 8y ago
  Also, what Air France 447 showed us was that excessive automation becomes a problem when it is assumed to always work. The recommendations about more systems are all very well but there are 1000s of international airports who are either not going to have these systems or sometimes they won't work. What is critical is that pilots follow their checklists and that 1 action would have prevented this happening despite the fact that the other systems could have warned about it. Making NOTAMs and the like more clear just seems like good design. They should certainly be able to prioritise information or only show what is relevant for a particular flight/aircraft/location/approach so you only have to read 3 things instead of 50.
augustz 8y ago
Just for SFO you have 84 NOTAMs. !SFO 06/079 SFO OBST RIG (ASN 2017-AWP-3368-NRA) 373740N1222224W (0.5NM NE SFO) 41FT (34FT AGL) FLAGGED AND LGTD 1806201400-1811010100 This is a flagged and lighted obstruction half a mile way that is 34 feet above ground level. Now put in a full route and takeoff airport and maybe if you have had some stops during the day. The NOTAM seems a bit long. Then if are overseas and have to deal with the BS political notams. Check out greece and turkey notams. ...THE REF (B) TURKISH NOTAM A3009/16 LTAAYNYX (111139 EUECYIYN JUL 2016) HAS NO GROUND, CANNOT PRODUCE ANY INTERNATIONALLY LEGAL EFFECT WITHIN ATHINAI FIR/ HELLAS UIR AND IS CONSIDERED NULL AND VOID. I'm curious how many pilots fully read all NOTAMs, locate them geographically to understand where they are etc etc on every flight.
- outworlder 8y ago
  Indeed. 'Notices' can be almost anything. I was doing simulated flights over the continental US recently. Even small airports may have a lot of NOTAMs. Some are important (for instance, warning about objects close to some parts of the runway, or issues with a runway, or even animals or birds), but many others are completely useless. Noise abatement restrictions ironically add a lot of NOTAM 'noise'. There should be a separate category for these, as these are not safety related.
- powercf 8y ago
  Outputting that in lower case could be a small step to making them easier to parse, and therefore more likely to be read. I find the text you posted tiring even to look at. THE REF (B) TURKISH NOTAM A3009/16 LTAAYNYX (111139 EUECYIYN JUL 2016) HAS NO GROUND, CANNOT PRODUCE ANY INTERNATIONALLY LEGAL EFFECT WITHIN ATHINAI FIR/ HELLAS UIR AND IS CONSIDERED NULL AND VOID. vs The ref (B) Turkish NOTAM A3009/16 LTAAYNYX (111139 Euecyiyn Jul 2016) has no ground, cannot produce any internationally legal effect within Athinai FIR/Hellas UIR and is considered null and void.
  - oh_sigh 8y ago
    How much experience do you have reading all-caps text? It isn't necessarily a burden to people who are used to it, which all airline pilots are.
donavanm 8y ago
As others pointed out there are fundamental problems with the system and usability of NOTAMs. Its a little absurd that theyre always used to blame the operator (“should have read the NOTAM”) when a flight briefing might have 10s or 100s applicable ones and a VAST number are junk. It reeks of retrospective blame seeking. That said there is some traction around this. And some interesting alternative takes (https://opsfox.net https://opsfox.net), which have their own problems.
MarkMc 8y ago
"Localizer, localizer" seems too obscure - "Landing on taxiway" is much clearer. It's interesting to listen to the radio chatter for this near-miss [1]. The air traffic controller misses a few chances to notice that something isn't right but when the pilot on the taxiway says in plain English, "Where's this guy going? He's on the taxiway" the problem immidately becomes obvious. [1] https://youtu.be/ZW-ETmZU0u8 https://youtu.be/ZW-ETmZU0u8

gok 8y ago

It's kind of baffling to me that there's a system for detecting collisions with other airplanes in the sky (TCAS) and a system for detecting collisions with the ground (EGPWS) but not system for detecting collisions with other airplanes on the ground. This easily could have killed a thousand people.

hangonhn 8y ago
Different problems, no? Trying to pick out an airplane against the ground is different from detecting an object in the air, which doesn't generally reflect radio back, and detecting the ground, which does reflect. The problem you're describing requires you to differentiate between two things that both reflect signals back to you. It's obviously do-able since the military does it all the time for targeting. However, I doubt it's cheap and there might be cheaper ways to do it that don't leverage the two systems you've mentioned.
- eesmith 8y ago
  TCAS uses active transponders, not radar reflection. https://en.wikipedia.org/wiki/Traffic_collision_avoidance_system#System_description https://en.wikipedia.org/wiki/Traffic_collision_avoidance_sy...
- gok 8y ago
  TCAS works via the transponders of other aircraft, which they actively transmit.
metanoia 8y ago
SFO has ground radar systems (ASDE-X/ASSC) [1] which allows ground and tower controllers to see potential conflicts on taxiways and runways. Pure speculation, but I don't think that these systems' conflict logic take into account an aircraft trying to land on a taxiway. [1] https://en.wikipedia.org/wiki/Airport_Surface_Surveillance_Capability https://en.wikipedia.org/wiki/Airport_Surface_Surveillance_C...
- gok 8y ago

cmurf 8y ago

I'm not operationally familiar with SFO. But based on experience at other airports, a taxiway at night can be a sea of black at even 100' above the ground. I would probably see airplane navigation lights at some point, but would I bet my life on it? No. So this incident has to be taken seriously. However, I'm still not clear from this reporting how the crew mistook blue taxiway lighting for white runway lighting. This isn't supposed to be subtle, and I haven't ever experienced it to be subtle. Edit: OK there is a partial explanation here that appears as though at the time they committed to taxiway C as runway 28R, the visual cue they relied on was airplane lighting looking like it was runway lighting. Airplane taxi and takeoff/landing lights are white, navigational lights are green or red. Strobes usually aren't on while on the ground or at least probably shouldn't be. It's an interesting dilemma. And fatigue is a significant contributing factor as well.

oasisbob 8y ago
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-taxiway-a-history-of-mistaken-landings-and.html https://www.bizjournals.com/seattle/news/2015/12/31/tango-ta...
- wmblaettler 8y ago
  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.
  - jonah 8y ago
    I'd like to know why they removed it.
    - PhantomGremlin 8y ago
      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.

organman91 8y ago

As a private pilot, small planes going down occasionally are just a fact of life. But this incident scares me. There were four planes lined up on the taxiway the Air Canada narrowly missed. The worst aviation accident ever was a collision of two 747s resulting in 583 deaths: https://en.wikipedia.org/wiki/Tenerife_airport_disaster https://en.wikipedia.org/wiki/Tenerife_airport_disaster - this could have doubled that number.

village-idiot 8y ago
Would also double the record for number of vehicles involved in an incident too, I believe
oh_sigh 8y ago
Is it plausible that that AC759 could have taken out all 4 other planes? I don't really have a sense of the distances planes are spaced out on taxiways at major airports.
- DocTomoe 8y ago
  Spacing between planes on a taxiway is a lot shorter than you would imagine. Depending on type, a 25-50 meters apart is common. Keep in mind that these four planes were preparing for take-off, meaning that they were fully fuelled...
- Arn_Thor 8y ago
  The KLM which had barely reached minimum takeoff speed and started to take off still flew 150 meters after it had plowed through the upper half of the PanAm and lost an engine and the main wheels. There's a lot of momentum in a moving plane, and they're stacked very close when holding on the taxiway

aeternus 8y ago

I'm surprised that remote video cameras aren't used by tower controllers. The perspective of the control tower makes it difficult to catch issues like this, but a simple video camera aligned with the center-line of each runway would allow controllers to more easily verify that planes are lined up as well as other possible issues like gear down & locked, etc.

zkms 8y ago
> I'm surprised that remote video cameras aren't used by tower controllers. I'm surprised that forward-looking infrared cameras aren't more commonly used in civilian aircraft, especially given the availability of staring arrays with decent resolution/framerate that don't require cooling. Even without the requisite certification for use as a for-realsies landing aid, it's nevertheless a useful tool to get situational awareness in inclement weather / at night.
- outworlder 8y ago
  They are more commonly found aboard 'experimental' aircraft because of the certification issues you pointed out.
  - DuskStar 8y ago
    And high-performance infrared cameras are also probably one of those things that end up on arms control lists. (Since it's not just useful for spotting planes on your "runway", but also for spotting tanks or people on your hill requesting an ordnance delivery)
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SaberTail 8y ago

If anyone would like to listen to the ATC radio: https://www.youtube.com/watch?v=ZW-ETmZU0u8 https://www.youtube.com/watch?v=ZW-ETmZU0u8

8_hours_ago 8y ago
I was just about to post that link! VASAviation has a really good youtube channel with ATC radio recordings and high quality visualizations of all kinds of interesting events: https://www.youtube.com/user/victor981994 https://www.youtube.com/user/victor981994
- sokoloff 8y ago
  https://www.youtube.com/watch?time_continue=57&v=oF7FR7TjnME https://www.youtube.com/watch?time_continue=57&v=oF7FR7TjnME has an overview shot, showing just how low AC759 got to the airplanes on Taxiway C. (Look at the top of the frame.)
SOLAR_FIELDS 8y ago
I love hearing ATC radio. I think the guy who did the classic SR71 story about upstaging everyone on some California flyby noted this pretty well - even in the times of near peril pilots and ATC will be the cool-as-steel that keep everyone calm.
- outworlder 8y ago
  Another interesting one is the guy that was suffering from hypoxia. "Unable... to control... altitude" "Unable... to control... airspeed" "Unable... to control... heading" "Other than that, everything A-OK!" Guy landed safely after ATC realized it was hypoxia and ordered the flight to descend. EDIT: link https://fearoflanding.com/accidents/accident-reports/hypoxia-on-kalitta-66/ https://fearoflanding.com/accidents/accident-reports/hypoxia...
  - cjbprime 8y ago
    Another close call: https://youtu.be/ag1-7qnkjv0 https://youtu.be/ag1-7qnkjv0 ("Pinch Hitting a King Air") And the recent case of Captain Maggie: https://youtu.be/B229-KLudTo https://youtu.be/B229-KLudTo

tialaramex 8y ago

CVR overwrite is bad news here. The crew knew this was a serious problem when it happened, there's no way they should have allowed the CVR, crucial evidence of exactly what happened, to be overwritten. Perhaps the full report will have more detail on this, as it stands I have to believe somebody made the decision to overwrite this because they thought it'd be better if it didn't exist. Whether that's the crew, their bosses or other staff, somebody managed to go from "serious incident, preserve evidence" to "maximum ass covering" and that person or persons are an obstacle to effective investigation and thus to safe air travel.

walrus01 8y ago
If I understand CVR tech correctly, it's running and constantly overwriting the storage in a loop whenever the plane is powered up. A lot of airplanes are 10, 15, 20 years old. CVR are based on some pretty old late 1980s technology, it's not like a modern flash based storage system with effectively infinite capacity for stereo 44KHz audio (64, 128GB, etc). There's maybe 1 or 2 hours of recording time, max.
sokoloff 8y ago
Subject aircraft, C-FKCK, is a 1991 A320, which is only required to have a 30 minute CVR loop. (I don't know which exact CVR it was equipped with, of course.) By the time the aircraft goes around, is resequenced, completes the second approach, lands, taxis in, and shuts down, much of the initial approach setup conversation may have already been overwritten anyway. I wouldn't jump to the assumption that there was malicious intent in the fact that the CVR was overwritten. (I also wouldn't want the crew to stop the CVR recording only to have a second, more serious incident on the same flight that would then go unrecorded.)
cpitVoxRec 8y ago
They actually do clearly state in this PDF that a degree of fault lies in the crew being compromised by fatigue. Operating for 19 hours straight definitely places an individual in an area where one can be fighting to pay strict attention, even when it really counts. There's also plenty of communication with Air Traffic Control in the tower, and not a whole lot of gaps to introduce significant mystery, so it's pretty unlikely that there would be anything earth shattering on the cockpit voice recorder.

tetrep 8y ago

> Cockpit voice recorder (CVR) information was not available for this incident because the data were overwritten before senior Air Canada officials became aware of the severity of this incident. How long are recordings normally kept? I would assume at least a few days for mundane flights (storage is cheap, isn't it?) but any sort of incident similar to this I would assume they keep recordings for much longer, if only for internal purposes.

Havoc 8y ago
The tower recordings are posted above. >(storage is cheap, isn't it?) Not on ancient planes where everything needs a billion certifications from all sorts of regulatory bodies.
- avar 8y ago
  There's other issues at play. Pilots hate the idea of more monitoring of the cockpit, and have been vocal in trying to prevent e.g. a video recording of the cockpit being part of the "black box", even though it would have helped to shed light on a lot of aviation incidents[1]. 1. https://www.wired.com/2014/07/malaysia-370-cockpit-camera/ https://www.wired.com/2014/07/malaysia-370-cockpit-camera/
- mikeash 8y ago
  It also needs to survive a couple of years at the bottom of the ocean or a similarly extreme environment and still be readable afterwards.
sokoloff 8y ago
It's a loop recorder. When that aircraft was certified, only a 30 minute loop was required. If that aircraft was newly certified, it would now require a 2 hour loop.
- geofft 8y ago
  Can they not sync the recording elsewhere once they land and every passenger has a high-bandwidth internet connection the second the wheels are on the ground? (Is it too hard to certify that a system that connects to the internet is safe?)

abaillargeon 8y ago

I've been anticipating the release of this report this since I heard about the incident. I work on an avionics product that's designed to prevent this exact scenario. We use the aircraft's position along with a database of runways and taxiways to determine if the aircraft is approaching the runway the pilot intends. If we determine the aircraft is landing, we issue a visual and aural alert to the pilot ("TAXIWAY LANDING" or "NOT A RUNWAY").

outworlder 8y ago
What is the chance of false positives (or negatives) due to out of date databases?
- abaillargeon 8y ago
  We do get some nuisance alerts from time to time, and part of my job is to investigate them and determine the cause. I did investigate one recently, however, where the cause was a runway that was "one-way". Most runways have two ends and the pilot/ATC determines which one to take off. EDDF (Frankfurt) RWY18 is only used for takeoffs and was causing nuisance alerts due to the way we search for the runway in front of the aircraft. There's another runway (I don't remember where) where the direction in our database does not match what satellite imagery shows. I don't work in the database group but I was told that this can only be fixed by asking the airport manager to re-survey the runway. Short of that, we can't fix it even if we know it's wrong. However, It's quite rare for them to be due to a database that's out of date -- most of the time it's due to an incorrect determination that the aircraft is taking off or landing.
ryandrake 8y ago
Curious: what inputs feed your system? Presumably at least localizer and GPS, but anything else? What accuracy / confidence interval do you require in order to make a call?
- abaillargeon 8y ago
  We actually don't use the localizer to check for an incorrect runway or taxiway landing because the pilot can choose to do so and we don't want to issue nuisance alerts. Runways don't move often and we've found that a GPS and two databases (runways and airport ground features) are sufficient to determine if the pilot is approaching a runway or not. We use inputs like GPS position, ground track, ground speed, altitude, and a phase-of-flight state machine that's determined for individual aircraft. This allows us to tailor the criteria for determining if the aircraft is landing for different aircraft. For some, we use throttle and landing gear position and others we use speed and altitude above the landing airport. As for accuracy, we have minimum levels of GPS figure of merit where there's enough certainty to issue alerts. I don't remember the number off the top of my head, but in the US WAAS has made GPS quite accurate.

bahmboo 8y ago

Gotta hand it to the NTSB - they are thorough. This is just the abstract.

glup 8y ago
Also that they cite fatigue / circadian low as one of the core causes. I thought they might avoid it because of the potential cost implications for the airline industry.
- scrumper 8y ago
  Worth noting that the Canadian regulations are looser than USA in that respect - the Air Canada pilots were in compliance with home regs, but would have been in breach of FAA regs. Other point is that the NTSB isn't generally particularly shy about calling out the need for expensive changes (one example being their recommendation for fuel tank inerting systems after TWA 800). They have no power to mandate their recommendations be implemented after all: that's the job of the FAA.
  - jackpirate 8y ago
    Why does a plane in US airspace not follow FAA regs?
    - scrumper 8y ago
      Well, it does pretty much, just not that bit (14 CFR 117). In this Air Canada case it's governed by 14 CFR part 129, which covers operations by foreign air carriers in the USA. https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol3/xml/CFR-2011-title14-vol3-part129.xml#seqnum129.15 https://www.gpo.gov/fdsys/pkg/CFR-2011-title14-vol3/xml/CFR-... EDIT - removed erroneous reference to 14 CFR 121.480-> which applies to cargo ops.
- rconti 8y ago
  Yup - copied this to buffer for a comment: > The flight crew’s work schedule for the incident flight complied with the applicable Canadian flight time limitations and rest requirements; however, the flight and duty time and rest requirements for the captain (a company reserve pilot) would not have complied with US flight time limitations and rest requirements (14 CFR Part 117).

mmaunder 8y ago

This is what is called a 'cascade of failures' in aviation - and the term is used elsewhere. Multiple failures resulting in a catastrophic failure. In your own life and goings about, it's sometimes interesting to do a failure analysis and you'll often find you experienced a cascade. It's really unfortunate that the cockpit voice recorder was overwritten. I'm guessing they're using very old technology where storage space is at a premium. They're still using the flashing X on closed runways - e.g. at SEATAC right now. The lights looked incandescent a couple nights ago while passing the X. So not very bright or visible. This accident would probably have been one of the worst in history. Multiple passenger planes on the taxiway taken out by a passenger jet.

debt 8y ago

"The cues available to the flight crew to indicate that the airplane was aligned with a taxiway did not overcome the crew’s belief, as a result of expectation bias, that the taxiway was the intended landing runway." Damn. It didn't matter that the whole world was telling him it was a taxiway because he was so sure it was a runway.

Waterluvian 8y ago

Speaking with a fair level of ignorance, how hard would it be for some onboard computer to be freaking out that a landing attempt is being made way off course of a known runway? Going to guess this is one of those things where, yes, we have all the requisite technology, but practical implementation is the hard part.

captain_perl 8y ago
Automatically monitoring an ILS approach is not that difficult from the cockpit if the frequency can be sent via ADS-B. Beyond that it gets really hard because visual and circling approaches can be in any heading, as well as large cross-winds. In this deviation, the pilots literally got lost. Kind of tough to do much about that.
abaillargeon 8y ago
I get excited seeing stories about aviation on HN because it's something I work on every day. I've written a few comments above but I'm developer on the system you described (and more) being used in aircraft today. With a GPS and onboard databases of runways and taxiways, we can determine if a pilot is attempting to take off or land on a taxiway. The key is preventing nuisance alerts when the pilot is just flying around and happens to be aligned with a runway. The "11 secret herbs and spices" depend on the aircraft but are usually speed and configuration (ie landing gear) based. Approaches are fairly predictable and we can use that to sequence through a state machine that tells us the pilot intends to land. Here's a video of the system on a G1000 (meant for smaller planes) skip to 0:45ish https://www.youtube.com/watch?v=V2bswm0w4cY https://www.youtube.com/watch?v=V2bswm0w4cY
- Waterluvian 8y ago
  Thank you for sharing. Really cool to see just how much real-time GIS there is in aviation these days.

oh_sigh 8y ago

Are there any reports from passengers on the taxiway planes? I'd have to imagine an A320 flying 60' over your roof would cause a fairly large disturbance.