9 ms·

Because the pilot is almost never looking at a map on final approach. He is looking out the window, and in the dawn/dusk light, or with a setting sun in the ba

Because the pilot is almost never looking at a map on final approach. He is looking out the window, and in the dawn/dusk light, or with a setting sun in the background or inclement weather etc., a taxiway can look exactly like a runway. Don't forget that almost all taxiways run parallel to the runway, for about the same length. (NB: I used to be a commercial pilot.) In most airports I flew into, the surface material for the taxiways was different from the runway, so sometimes the taxiway could end up looking brighter and more prevalent than the runway under certain lighting conditions. Yep, I have had moments of confusion when on long finals into an unfamiliar airport. Never to the point of actually ending up landing on the taxiway, but the confusion is a thing that pilots have to contend with.

willidiots 9y ago
Seems like a design flaw. Do any taxiways have markings etc. to make them more distinguishable?
- cyberferret 9y ago
  They do. They have different lighting systems/colours etc. to differentiate them. Taxiways generally have green lights along the centerline to guide aircraft rolling on the ground, but runways usually have white (bright) lights along the edges. There are times when even THAT causes confusion, because sometimes the taxiway centreline lights can look like the edge lights of the runway - especially if the light is refracting off a wet windscreen. So, in the end the problem is generally avoidable, but if you are on finals at a really busy airport after a gruelling 20 hours trans oceanic flight, at night, in the rain, and the tower is trying to hurry you up to expedite traffic, you can make mistakes.
  - kobeya 9y ago
    Seems like a very good argument for autopilot landings.
    - tjohns 9y ago
      And yet, when the Asiana accident happened the complaint was that the pilots were relying on automation too much and didn't know how to properly hand-fly the airplane anymore. Not all runways are equipped for ILS landings. Sometimes the ILS equipment gets taken out of service for maintenance. And even autoland has its limitations.
    - ubernostrum 9y ago
      You might enjoy this classic video: https://www.youtube.com/watch?v=pN41LvuSz10 https://www.youtube.com/watch?v=pN41LvuSz10 Just be sure to make a note of the video title so you can find it again -- copies of it tend to get taken down, since American Airlines got in some trouble after other parts of this training course were blamed for the crash of AA flight 587: https://en.wikipedia.org/wiki/American_Airlines_Flight_587 https://en.wikipedia.org/wiki/American_Airlines_Flight_587
      - jrockway 9y ago
        > American Airlines got in some trouble after other parts of this training course were blamed for the crash of AA flight 587 More specifically, the pilots manipulated the rudder on that airplane so aggressively that it sheared off in flight. They were trained to react aggressively in the "Advanced Aircraft Maneuvering Program", which this video is a part of. (There are also related videos that I'm going through now that are more relevant to this particular incident; https://www.youtube.com/watch?v=WfNBmZy1Yuc https://www.youtube.com/watch?v=WfNBmZy1Yuc, etc.) BTW, if AA is indeed DMCA-ing these videos, that's pretty interesting. Copyright was designed to incentivize the progress of science and the arts -- not to make large corporations look less bad after they unintentionally kill a few hundred people. Oops.
        jrockway 9y ago
        Ah, here's the wake turbulence one: https://www.youtube.com/watch?v=FxXwqAm1a-Y https://www.youtube.com/watch?v=FxXwqAm1a-Y
  - BinaryIdiot 9y ago
    Perhaps this is a dumb question but is there any reason why the taxiway doesn't have HUGE red Xs going down it and the runway with HUGE green arrow going down? Sorta like what they do on bridges where the lanes can shift to allow more cares to travel in one direction but more obvious? They could even angle them so the planes on the ground see them differently or not at all.
    - cyberferret 9y ago
      Red 'X's on a runway usually denote an inactive or out of service runway. They ARE actually quite different in terms of lighting, width etc. and 99.9% of the time there is no issue telling them apart. Runways also have extra approach lights etc. at night to really make it clear where you should be pointing the nose. (NB: Check out the video posted elsewhere in this thread of the cockpit view of a 747 landing at SFO at night. It is pretty clear which is the runway and which is the taxiway). However, it is those 0.01% of the times where the weather is bad, or you are landing into the sun or the traffic is really congested and you are trying to talk on the radio at the same time etc. where mistakes can be made. In this particular scenario in the OP, I am assuming that having 4 heavy aircraft lined up on the runway pointing at the landing plane, then 4 sets of bright landing and navigation lights on the taxiway could have looked like runway lighting, and disoriented the Canada Air pilot? Just outside speculation here, but stranger things have happened. It's like the case of the Air New Zealand CD-10 crash into Mt. Erebus in clear weather. Non pilots were incredulous that a plane could fly into the side of a mountain in clear daylight weather, but the visual trickery played by bright snow on a slope actually fooled ALL pilots on board that they were flying down a valley instead of into an upward slope. [0] (A badly programmed navigation computer didn't help at all.) [0] - https://en.wikipedia.org/wiki/Air_New_Zealand_Flight_901 https://en.wikipedia.org/wiki/Air_New_Zealand_Flight_901
      - hindsightbias 9y ago
        The a/c on the taxiway will not have their landing lights on while pointed downwind. They turn them on when theyre cleared to enter the runway.
  - kakwa_ 9y ago
    Just a very naive question, would not it be possible for the taxiway lights to only be visible from the ground?
    - cyberferret 9y ago
      A good concept in theory, but bear in mind that the cockpit of a 747 or A380 is something like 2 or 3 stories above the ground, in terms of height. To be able to see a taxiway light 50m in front of the plane, the light will have to be angled up to an extent that a plane 500 feet in the air a mile away will also be able to see it. Not putting down your idea at all - anything workable that will improve flight operations should be considered. Trivia: Speaking of lighting assistance, Did you know one of the best inventions out of Australia is the T-VASIS landing system [0] that is in use at nearly every major airport in the world?? Oh, and we invented the DME too [1], in the aviation world... :) [0] - https://www.dst.defence.gov.au/innovation/tee-visual-approach-slope-indicator-system-t-vasis https://www.dst.defence.gov.au/innovation/tee-visual-approac... [1] - https://en.wikipedia.org/wiki/Distance_measuring_equipment https://en.wikipedia.org/wiki/Distance_measuring_equipment
      - ubernostrum 9y ago
        A good concept in theory, but bear in mind that the cockpit of a 747 or A380 is something like 2 or 3 stories above the ground, in terms of height. Fun fact! The A380's flight deck isn't that high off the ground. It's exactly the same height as the A330 and A340, part of an effort to reduce differences and cut down on the amount of new things pilots would have to deal with to train on the type. This is also why the A380 has such a pronounced "forehead" -- the much lower flight-deck height (compared to a 747) means there's a lot of plane above that. (and bonus fun fact: the 747's flight deck is way up top not for visibility, but because Boeing anticipated supersonic planes would take over the passenger market; the 747's high flight deck was meant to accommodate converting the plane to cargo use, so that the whole nose could swing open for loading and unloading)
      - tialaramex 9y ago
        Australia is also responsible for "black box" flight recorders, which are one of those things where it's really hard to appreciate in hindsight why we didn't mandate them much sooner.
  - justin66 9y ago
    From the sound of things, this particular disaster hasn't happened before, even though it's conceptually easy to imagine how it could. Is that because it's easy for the controllers on the ground to wave somebody off if they're going the wrong way, or is it really because we're just lucky?
willidiots 9y ago
Seems like a design flaw. Do any taxiways have markings etc. to make them more distinguishable?
wfunction 9y ago
Thank you! That raises the question, (a) why is there no kind of warning system for when you're about to land on the wrong runway (there's a GPS system in the aircraft that knows where you're going, right?) and (b) why is the pilot (or at least co-pilot) never looking at a map on final approach? Is it really that dangerous for anyone to take a quick glance?
- cyberferret 9y ago
  Yes, autolanding, or if the pilot was using ILS (Instrument Landing System), then this problem would almost never happen, as they would be aware there was a problem. However, most pilots eschew automation especially on short finals, and prefer the 'hand fly' the aircraft in so that they can maintain complete control over the aircraft. Not a bad thing, and pilots want to actually fly the plane at crucial times. When hand flying on final approach, your eyes and senses are 75% outside the aircraft. All you are worried about is your airspeed, your rate of descent and whether the runway is remaining visible at all times. Your eyes are darting from your primary instruments in front of you to the runway outside, and your arms and legs are busy working the throttles, control stick and rudder pedals. Maps and charts are well stowed away at this point. In fact, once you enter the main airport traffic pattern, they are put away as all the details should be memorised by then. At best, the pilot will have the approach plate on his/her control column. But this just gives the instrument approach paths and radio frequencies etc. and not really a detailed topography of the runways/taxiways. Ironically, AFTER the plane is on the ground, the non commanding pilot will usually pull out the airport plate which details all the taxiways and routes to gates etc., especially if they are unfamiliar with the airport and have to find their way around.
  - wfunction 9y ago
    Fantastic explanation, and the question on my mind the entire time is "but why??"! Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? Like I'm imagining there should be something on the plane that shows them their trajectory and the runway information. If there is, why isn't it telling them when they're going the wrong way? If there isn't, why not? Is the technology simply behind, or is there a safety reason or something?
dheera 9y ago
Why can't they make taxiways more obvious (e.g. paint them bright red)? Seems like it would be a small cost for a lot of insurance against an accident.
- idlewords 9y ago
  Runways are already very visually distinctive. An active runway at night is a river of light that you'd think would be unmistakable, and yet these incidents happen. https://scaredflightless.files.wordpress.com/2012/09/approach-lights.jpg https://scaredflightless.files.wordpress.com/2012/09/approac...
- vacri 9y ago
  With the setting sun just right, you wouldn't see the red, just reflected sunlight. There's no guaranteed solution for all cases, and aerospace visuals are some of the most heavily studied of any industry.
- rrmm 9y ago
  See the Tests and Research section of the following NTSB report on a Delta incident where a plane landed on a taxiway at KATL. Note Also that the lights had been recently updated with LEDs from incandescents. Basically, the taxiway centerline was brighter than the runway centerlines and the colors of the lights were only apparent at 500ft. https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation/brief2.aspx?ev_id=20091020X05636&ntsbno=OPS10IA001&akey=1 https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation...
nazri1 9y ago
Side question: do you think one day commercial pilots aren't necessary anymore, i.e. totally unmanned commercial airlines? If so, how far away in the future are they?
- briandear 9y ago
  There has been some talk of remote piloting (like drones,) but personally, I want whoever is flying the plane to have some skin in the game. Unmanned - fully autopilot aircraft are certainly possible and I sure Boeing probably has a Skunkworks looking into it, but I’ve seen enough source code over the years that I would have a hard time trusting an autonomous airplane unless they had escape pods. Autonomous airplanes seen to be solving a problem that doesn’t seem critical to solve – given the statistically exceptional safety record of commercial air travel. Pilot error is a very rare cause of airliner crashes. I think electric airplanes powered by Mr. Fusion mini nuclear reactors would be the future I’d like to see!
  - gruez 9y ago
    >Pilot error is a very rare cause of airliner crashes. Is that overall, or as a percentage of all airliner crashes? Because another commenter stated that human error is responsible for most of the crashes. https://news.ycombinator.com/item?id=14741726 https://news.ycombinator.com/item?id=14741726
deleted 9y ago
[deleted]
thekevan 9y ago
It seems like an easy problem to solve. Line the taxiway with red/blue/green or whatever color is appropriate lights.

willidiots 9y ago

Seems like a design flaw. Do any taxiways have markings etc. to make them more distinguishable?

cyberferret 9y ago
They do. They have different lighting systems/colours etc. to differentiate them. Taxiways generally have green lights along the centerline to guide aircraft rolling on the ground, but runways usually have white (bright) lights along the edges. There are times when even THAT causes confusion, because sometimes the taxiway centreline lights can look like the edge lights of the runway - especially if the light is refracting off a wet windscreen. So, in the end the problem is generally avoidable, but if you are on finals at a really busy airport after a gruelling 20 hours trans oceanic flight, at night, in the rain, and the tower is trying to hurry you up to expedite traffic, you can make mistakes.
- kobeya 9y ago
  Seems like a very good argument for autopilot landings.
  - tjohns 9y ago
    And yet, when the Asiana accident happened the complaint was that the pilots were relying on automation too much and didn't know how to properly hand-fly the airplane anymore. Not all runways are equipped for ILS landings. Sometimes the ILS equipment gets taken out of service for maintenance. And even autoland has its limitations.
  - ubernostrum 9y ago
    You might enjoy this classic video: https://www.youtube.com/watch?v=pN41LvuSz10 https://www.youtube.com/watch?v=pN41LvuSz10 Just be sure to make a note of the video title so you can find it again -- copies of it tend to get taken down, since American Airlines got in some trouble after other parts of this training course were blamed for the crash of AA flight 587: https://en.wikipedia.org/wiki/American_Airlines_Flight_587 https://en.wikipedia.org/wiki/American_Airlines_Flight_587
    - jrockway 9y ago
      > American Airlines got in some trouble after other parts of this training course were blamed for the crash of AA flight 587 More specifically, the pilots manipulated the rudder on that airplane so aggressively that it sheared off in flight. They were trained to react aggressively in the "Advanced Aircraft Maneuvering Program", which this video is a part of. (There are also related videos that I'm going through now that are more relevant to this particular incident; https://www.youtube.com/watch?v=WfNBmZy1Yuc https://www.youtube.com/watch?v=WfNBmZy1Yuc, etc.) BTW, if AA is indeed DMCA-ing these videos, that's pretty interesting. Copyright was designed to incentivize the progress of science and the arts -- not to make large corporations look less bad after they unintentionally kill a few hundred people. Oops.
      - jrockway 9y ago
        Ah, here's the wake turbulence one: https://www.youtube.com/watch?v=FxXwqAm1a-Y https://www.youtube.com/watch?v=FxXwqAm1a-Y
- BinaryIdiot 9y ago
  Perhaps this is a dumb question but is there any reason why the taxiway doesn't have HUGE red Xs going down it and the runway with HUGE green arrow going down? Sorta like what they do on bridges where the lanes can shift to allow more cares to travel in one direction but more obvious? They could even angle them so the planes on the ground see them differently or not at all.
  - cyberferret 9y ago
    Red 'X's on a runway usually denote an inactive or out of service runway. They ARE actually quite different in terms of lighting, width etc. and 99.9% of the time there is no issue telling them apart. Runways also have extra approach lights etc. at night to really make it clear where you should be pointing the nose. (NB: Check out the video posted elsewhere in this thread of the cockpit view of a 747 landing at SFO at night. It is pretty clear which is the runway and which is the taxiway). However, it is those 0.01% of the times where the weather is bad, or you are landing into the sun or the traffic is really congested and you are trying to talk on the radio at the same time etc. where mistakes can be made. In this particular scenario in the OP, I am assuming that having 4 heavy aircraft lined up on the runway pointing at the landing plane, then 4 sets of bright landing and navigation lights on the taxiway could have looked like runway lighting, and disoriented the Canada Air pilot? Just outside speculation here, but stranger things have happened. It's like the case of the Air New Zealand CD-10 crash into Mt. Erebus in clear weather. Non pilots were incredulous that a plane could fly into the side of a mountain in clear daylight weather, but the visual trickery played by bright snow on a slope actually fooled ALL pilots on board that they were flying down a valley instead of into an upward slope. [0] (A badly programmed navigation computer didn't help at all.) [0] - https://en.wikipedia.org/wiki/Air_New_Zealand_Flight_901 https://en.wikipedia.org/wiki/Air_New_Zealand_Flight_901
    - hindsightbias 9y ago
      The a/c on the taxiway will not have their landing lights on while pointed downwind. They turn them on when theyre cleared to enter the runway.
- kakwa_ 9y ago
  Just a very naive question, would not it be possible for the taxiway lights to only be visible from the ground?
  - cyberferret 9y ago
    A good concept in theory, but bear in mind that the cockpit of a 747 or A380 is something like 2 or 3 stories above the ground, in terms of height. To be able to see a taxiway light 50m in front of the plane, the light will have to be angled up to an extent that a plane 500 feet in the air a mile away will also be able to see it. Not putting down your idea at all - anything workable that will improve flight operations should be considered. Trivia: Speaking of lighting assistance, Did you know one of the best inventions out of Australia is the T-VASIS landing system [0] that is in use at nearly every major airport in the world?? Oh, and we invented the DME too [1], in the aviation world... :) [0] - https://www.dst.defence.gov.au/innovation/tee-visual-approach-slope-indicator-system-t-vasis https://www.dst.defence.gov.au/innovation/tee-visual-approac... [1] - https://en.wikipedia.org/wiki/Distance_measuring_equipment https://en.wikipedia.org/wiki/Distance_measuring_equipment
    - ubernostrum 9y ago
      A good concept in theory, but bear in mind that the cockpit of a 747 or A380 is something like 2 or 3 stories above the ground, in terms of height. Fun fact! The A380's flight deck isn't that high off the ground. It's exactly the same height as the A330 and A340, part of an effort to reduce differences and cut down on the amount of new things pilots would have to deal with to train on the type. This is also why the A380 has such a pronounced "forehead" -- the much lower flight-deck height (compared to a 747) means there's a lot of plane above that. (and bonus fun fact: the 747's flight deck is way up top not for visibility, but because Boeing anticipated supersonic planes would take over the passenger market; the 747's high flight deck was meant to accommodate converting the plane to cargo use, so that the whole nose could swing open for loading and unloading)
    - tialaramex 9y ago
      Australia is also responsible for "black box" flight recorders, which are one of those things where it's really hard to appreciate in hindsight why we didn't mandate them much sooner.
- justin66 9y ago
  From the sound of things, this particular disaster hasn't happened before, even though it's conceptually easy to imagine how it could. Is that because it's easy for the controllers on the ground to wave somebody off if they're going the wrong way, or is it really because we're just lucky?

willidiots 9y ago

Seems like a design flaw. Do any taxiways have markings etc. to make them more distinguishable?

wfunction 9y ago

Thank you! That raises the question, (a) why is there no kind of warning system for when you're about to land on the wrong runway (there's a GPS system in the aircraft that knows where you're going, right?) and (b) why is the pilot (or at least co-pilot) never looking at a map on final approach? Is it really that dangerous for anyone to take a quick glance?

cyberferret 9y ago
Yes, autolanding, or if the pilot was using ILS (Instrument Landing System), then this problem would almost never happen, as they would be aware there was a problem. However, most pilots eschew automation especially on short finals, and prefer the 'hand fly' the aircraft in so that they can maintain complete control over the aircraft. Not a bad thing, and pilots want to actually fly the plane at crucial times. When hand flying on final approach, your eyes and senses are 75% outside the aircraft. All you are worried about is your airspeed, your rate of descent and whether the runway is remaining visible at all times. Your eyes are darting from your primary instruments in front of you to the runway outside, and your arms and legs are busy working the throttles, control stick and rudder pedals. Maps and charts are well stowed away at this point. In fact, once you enter the main airport traffic pattern, they are put away as all the details should be memorised by then. At best, the pilot will have the approach plate on his/her control column. But this just gives the instrument approach paths and radio frequencies etc. and not really a detailed topography of the runways/taxiways. Ironically, AFTER the plane is on the ground, the non commanding pilot will usually pull out the airport plate which details all the taxiways and routes to gates etc., especially if they are unfamiliar with the airport and have to find their way around.
- wfunction 9y ago
  Fantastic explanation, and the question on my mind the entire time is "but why??"! Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? Like I'm imagining there should be something on the plane that shows them their trajectory and the runway information. If there is, why isn't it telling them when they're going the wrong way? If there isn't, why not? Is the technology simply behind, or is there a safety reason or something?

dheera 9y ago

Why can't they make taxiways more obvious (e.g. paint them bright red)? Seems like it would be a small cost for a lot of insurance against an accident.

idlewords 9y ago
Runways are already very visually distinctive. An active runway at night is a river of light that you'd think would be unmistakable, and yet these incidents happen. https://scaredflightless.files.wordpress.com/2012/09/approach-lights.jpg https://scaredflightless.files.wordpress.com/2012/09/approac...
vacri 9y ago
With the setting sun just right, you wouldn't see the red, just reflected sunlight. There's no guaranteed solution for all cases, and aerospace visuals are some of the most heavily studied of any industry.
rrmm 9y ago
See the Tests and Research section of the following NTSB report on a Delta incident where a plane landed on a taxiway at KATL. Note Also that the lights had been recently updated with LEDs from incandescents. Basically, the taxiway centerline was brighter than the runway centerlines and the colors of the lights were only apparent at 500ft. https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation/brief2.aspx?ev_id=20091020X05636&ntsbno=OPS10IA001&akey=1 https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation...

nazri1 9y ago

Side question: do you think one day commercial pilots aren't necessary anymore, i.e. totally unmanned commercial airlines? If so, how far away in the future are they?

briandear 9y ago
There has been some talk of remote piloting (like drones,) but personally, I want whoever is flying the plane to have some skin in the game. Unmanned - fully autopilot aircraft are certainly possible and I sure Boeing probably has a Skunkworks looking into it, but I’ve seen enough source code over the years that I would have a hard time trusting an autonomous airplane unless they had escape pods. Autonomous airplanes seen to be solving a problem that doesn’t seem critical to solve – given the statistically exceptional safety record of commercial air travel. Pilot error is a very rare cause of airliner crashes. I think electric airplanes powered by Mr. Fusion mini nuclear reactors would be the future I’d like to see!
- gruez 9y ago
  >Pilot error is a very rare cause of airliner crashes. Is that overall, or as a percentage of all airliner crashes? Because another commenter stated that human error is responsible for most of the crashes. https://news.ycombinator.com/item?id=14741726 https://news.ycombinator.com/item?id=14741726

deleted 9y ago

[deleted]

thekevan 9y ago

It seems like an easy problem to solve. Line the taxiway with red/blue/green or whatever color is appropriate lights.